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mercredi 4 septembre 2019

Management of infantile glaucoma





 Classification

In the visual literature the term "infantile glaucoma" used a broad and heterogeneous spectrum of glaucoma in childhood. Glaucoma manifested in children younger than 3 years usually causes a visible bulge of the world (Figure 7-1), leading to the historical term "eye inflammation" (bull's eye). In order to achieve accurate diagnoses and divide this huge entity of the disease, many authors have proposed childhood glaucoma classifications according to age, anterior part morphology, and the presence of further ocular or systemic abnormalities (Table 7.1). Tommy [54] provided a very useful overview of these classifications. However, the terms "infantile glaucoma", "congenital glaucoma" and "developmental glaucoma" are frequently used in the literature as synonyms without regard

Management of parasitic glaucoma Thomas S. Detelin, Gunter K.

essence. Child abuse teams are usually multidisciplinary and may include nurses, pediatricians who abuse children, social workers, psychologists and other professionals. However, if the ophthalmologist thinks they have justified doubts and the child abuse experts do not agree, the ophthalmologist will still be responsible for reporting. Although anyone working with children in any professional capacity is an authorized reporter, anyone, even an ordinary neighbor who provides anonymous reports, can initiate a report. Unfortunately, doctors are the most credible reporters when a case is evaluated by child protection agencies, but doctors are also the least persistent in reporting behaviors. Some doctors cite many excuses that lead to their failure to report, including the fear that they will be called to testify in court, they will lose patients (and income), have an uncertain diagnosis, the parents will go to prison, or the child will be removed from the family, or The family will take action (physical or legal) against them, otherwise the regime will not. Work well on behalf of the child. In fact, in less than 1% of cases the ophthalmologist will be asked to go to court, where many cases are settled or do not involve criminal charges, and when the case is brought to court, the ophthalmologist is often not called to testify because Other child abuse experts may be able to testify on eye results on behalf of an ophthalmologist. There is no obligation that the doctor is right in doubt. In most countries, doctors are successfully protected from prosecution for incorrect reporting unless they report malicious intent. Reporting does not necessarily mean that the parents will go to prison or the child will be separated. The primary concern of most child protection agencies is to maintain family unity whenever possible, as long as the child is safe. When separation must occur, all attempts will be made to rehabilitate the perpetrator from a parent so that the family can be reunited. I am not aware of any case of physical harm to the doctor to report. Although the system is not ideal, and some children are returned to unsafe or abused environments in the nursery, the only way to improve the system is to continue using it.
When physicians do report abuse, there is evidence that over-reporting occurs for visible minorities and those from low socioeconomic groups, and under-reporting occurs with Caucasians and families from higher income groups [9,12].In fact,child abuse occurs in every racial group, country, religious group and socioeconomic group [33].It is recommended that physicians be open with families when they are reporting and avoid accusations.Rather,it can be suggested that someone may have injured the child and that the parents and ophthalmologist must work as a team to be sure whether this did or did not occur and ensure that if the child has been abused, that it will not occur again.Very few parents will not be willing to openly agree with such a stance.Even if it is patently obvious that the child was abused and the most likely perpetrator is in the room,the ophthalmologist must come to grips with their own emotions and realize that to help the child they must work together with the family, taking a similar approach without confrontation. Although physical discipline of children is accepted in many communities (and not endorsed by this author), perpetrators of abuse rarely injure children (with the exception of sexual abuse, see below) purposely and specifically with the intent to harm to a degree that will need medical attention. In the 10% that purposely cause significantly bodily harm,psychiatric disease is usually a factor. Most perpetrators regret their actions and will accept help.However,they rely on the reporter’s initiative to be identified so that their child can be protected.
14.1.3 Testifying
The ophthalmologist may occasionally be called to court as either a fact witness or an expert witness. In the former, the witness is being asked only to report what they witnessed,which in the case of an ophthalmologist would be limited to observations made during the eye examination and any other communications related to the care of the patient. The ophthalmologist will likely be asked to detail the nature of the eye examination and the findings. If called as an
220 Chapter 14 Nonaccidental Injury.The Pediatric Ophthalmologist’s Role
expert witness, whether or not the ophthalmologist has examined the child, the ophthalmologist will then be asked to give opinions regarding the interpretation of the physical findings, perhaps extending into areas such as pathophysiology, mechanisms of injury, differential diagnosis,and prognosis. Much has been written to help the physician prepare for their role as an expert witness and there has been much concern about irresponsible expert testimony [3,19].In general,it serves the ophthalmologist well to remember a few basic principles 1. Testify for the facts and your interpretation of the facts rather than what the prosecution or the defense wants you to say. 2. Remember that you are not on trial, even when it seems that an attorney is trying to challenge and discredit you. 3. Do not testify in areas that you are not truly expert. 4. Say you do not know when you do not know. 5. Remember that you are there to educate the court,not to prove a point.
Although testifying is not enjoyed by many physicians, it is a professional role that in the context of abuse is part of the physician’s duty as an advocate for the abused child.
14.2 Physical Abuse
Any physical injury to the eye could be caused by abuse. The key to making a diagnosis of physical abuse lies in recognizing patterns of injury that are not consistent with a given history from the caretakers. Likewise, certain ophthalmic findings indicate trauma (e.g.,avulsion of the vitreous base, commotio retinae, ruptured globe) and in the absence of a history of trauma,should raise a suspicion ofabuse.Other concerning red flags include a history which is changed each time it is offered,a history ofmultiple or recurrent injuries without adequate explanation, and high-risk social situations such as a parent who presents inebriated or exhibiting violent tendencies towards the child in the waiting room (e.g.,“If you don’t shut up I will
beat you with this belt”). Physical abuse may occur as part of what the perpetrator perceived as acceptable discipline. In most jurisdictions, even those which allow for spanking,any visible injury as a result of discipline is considered indicative that the perpetrator has lost control and entered the realm of abusive behavior.It is important that the ophthalmologist conduct a complete body examination (or refer to another physician specifically for this purpose) when abusive eye injury is suspected as there may be other signs of abuse elsewhere (Fig.14.1).
14.2.1 Blunt Trauma
The multitudes ofinjuries that can be caused by blunt trauma are well beyond the scope of this chapter. However, a few deserve special mention. Periorbital ecchymosis is a not uncommon result of blunt trauma. However, the presence of bilateral involvement does not prove abuse. A blunt injury (accidental or nonaccidental) to the forehead can result in bilateral periocular ecchymosis.Bilateral ecchymosis can also result from systemic disease such as neuroblastoma.
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Fig.14.1. Lacerations and ecchymosis in the pattern of a looped chord which was used to abusively beat this child.These injuries could not be accidental
Abuse should never be reported on the basis of bruising or bleeding alone unless appropriate history and testing has been conducted to rule out coagulopathy.A basic panel should include at least a complete blood count with differential and platelet count, prothrombin time, partial thromboplastin time,and perhaps tests to rule out factor deficiencies or INR and von Willebrand disease.Bruising of the skin is difficult to date and particularly unreliable when located in the loose periocular and eyelid skin, which can allow for excessive accumulation of blood, thus changing color-related dating patterns. It is probably best not to attempt dating of periocular ecchymosis. This author has now observed eight cases in which a child’s eye was injured “accidentally” during a beating with a belt directed at other parts of the body. All sustained hyphema, one also had commotio of the macula,one required enucleation, and another resulted in a permanently legally blind eye. In each case, the diagnosis was made by history obtained from the parent or the child.Indeed,children may be interviewed directly by the physician. It may be helpful when suspicion arises to ask the child if they would like to speak to the ophthalmologist alone or to make an encouraging statement such as “I sometimes see children who have injuries like this because someone has hurt them. I can help make it so that they don’t get hurt like this again.Might someone have hurt you?”Despite the parent’s remorse and lack of intent to injure the eye,these cases do require reporting to child protective services to help the parent learn alternative means of discipline and prevent another episode where control is lost resulting in such serious injury.
Summary for the Clinician ∑ Dating of periocular ecchymosis is imprecise and should be avoided ∑ Accidental forehead injury (with ecchymosis),coagulopathy and neuroblastoma are part of the differential diagnosis of unilateral or bilateral periorbital ecchymosis ∑ Unintended eye injury that occurs during discipline is a measure of the caretaker’s loss of control and should be reported as suspected physical abuse
14.2.2 Shaken Baby Syndrome
Shaken baby syndrome (SBS) is a form of child physical abuse in which a perpetrator subjects a child to repeated acceleration-deceleration forces with or without impact ofthe head.Alternate terminology has been suggested,including shaken impact syndrome,abusive head trauma, and inflicted neurotrauma. Herein, the term SBS will be used,understanding that the classic “shaking,” for example when a perpetrator grasps a child by the thorax, is but one way in which abuse can cause the findings.But regardless of the terminology used, the syndrome findings are well recognized and share in common the presence ofcharacteristic central nervous system injury, fractures, and/or retinal hemorrhages. Some physicians and biomechanists,most of whom are not clinically active in caring for abused children,have argued that it is impossible for a human being to shake a child hard enough to cause serious injury or death [7]. Unfortunately, such arguments fail to recognize that much lower levels of force are needed to incite the cascade of events that lead to cell injury and death than those that would be calculated to actually injure or kill the cell outright. There is overwhelming evidence that this syndrome is real,including the confessions of perpetrators [29], experiments with animal [24] and mechanical [5] models, the absence ofsimilar physical findings following witnessed accidental injury [16], and the failure of alternative proposed pathophysiologic mechanisms to explain the observed findings [26].The syndrome is well recognized by virtually every major professional organization, including the American Academy of Ophthalmology and the American Association of Pediatric Ophthalmology and Strabismus, and is described throughout the world. Excellent reviews are available [25]. The infant head is relatively big and poorly supported by weak cervical musculature.Acceleration–deceleration forces may lead to cervical and neck injury.There is relatively more room for the immature incompletely myelinated infant brain to move within the cranial vault.It
222 Chapter 14 Nonaccidental Injury.The Pediatric Ophthalmologist’s Role
for these reason, and the progressive inability for adults to apply sufficient force to bigger children, that SBS occurs most frequently in the 1styear oflife and decreases steadily in frequency over the next 3–4years.Characteristic brain injuries include subdural hemorrhage, subarachnoid hemorrhage, brain contusion, and secondary cerebral edema with evidence of shearing injury to the parenchyma, including diffuse axonal injury on histology. The edema may be so severe as to result in auto-infarction of major cerebral blood vessels, including the distribution to the occipital lobes. The most common cause of visual loss and blindness following SBS is cortical visual impairment.Of the two-thirds of patients who survive, approximately one-half have permanent physical sequelae, which not uncommonly include vision deficits.Neuroimaging should be conducted in all cases where SBS is considered. Fractures may occur either from the perpetrator grasping the rib cage,resulting in characteristic and often multiple posterior or posterolateral rib fractures,or the extremities,resulting in typical chip fractures to the metaphyses and/or periosteal stripping with subperiosteal hemorrhage. Evidence of blunt head trauma, which significantly increases the magnitude of acceleration-deceleration force [6], may result in fracture of the skull.Skull fractures that are comminuted, depressed, or crossing sutures in the absence of a history of severe accidental injury are particularly worrisome and should raise a suspicion of abuse.In SBS,fractures are less common than eye and brain injury,and are not required for diagnosis. The retinal hemorrhages that characterize SBS are perhaps the most common reason that ophthalmologists will become involved with abused children. This topic is reviewed elsewhere in great detail [15,16,31].It is essential to remember that not all retinal hemorrhages are the same and although characteristic patterns may help to diagnose abuse,a small number of intraretinal hemorrhages confined to the posterior pole is a nonspecific picture that can be seen in many disorders (Fig.14.2). Approximately two-thirds of children with retinal hemorrhage as a result of SBS will show too numerous to count retinal hemorrhages, including
preretinal, superficial nerve fiber layer, intraretinal dot/blot hemorrhage, and subretinal hemorrhage extending to the ora serrata [17–19] (Fig.14.3). With the exception of hemorrhages following normal birth, this is a picture that is rarely seen in any other clinical entity.Although one isolated case report has suggested that such a finding can be seen as a result of crush injury to the head [14],we were unable to demonstrate such findings in our own clinical and pathologic case series.Ofcourse,crush injury to the head
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Fig.14.2. Mild nonspecific pattern of preretinal and intraretinal hemorrhages confined to the posterior pole and peripapillary area
Fig.14.3. Transpupillary view of retina showing retinal hemorrhage in posterior pole and peripherally approaching ora serrata (arrows) with relative sparing of the equatorial retina.This 3 years old child was a victim of shaken baby syndrome in which the father gave a detailed account of shaking the child
has a characteristic clinical presentation that is rarely of concern when considering SBS. Birth hemorrhage should be considered in the differential diagnosis for flame hemorrhage in the 1stweek of life and dot/blot hemorrhage up to 4–6weeks of age (with the exception of intrafoveal hemorrhage,which may last longer). One form of hemorrhage seems to be particularly specific for SBS: traumatic macular retinoschisis. Although only present in up to one-third of patients [20], this characteristic finding is caused by traction applied to the macula by the tightly adherent vitreous as it is submitted to violent acceleration-deceleration forces.This entity has been confirmed by electroretinogram,ultrasound and histology [8,16]. The latter often demonstrates the vitreous still attached to a retinal fold at the edge of the schisis cavity.Clinically,the schisis may be demarcated by a curvilinear fold,hemorrhagic line,or white line of depigmented retinal pigmented epithelium (Fig.14.4). Most often the blood, which may fill the cavity in part or totally, is under the internal limiting membrane, although deeper cavities can also be seen. This may cause the ophthalmologist to confuse schisis with subhyaloid or preretinal blood.As paramacular folds in children have not previously been reported in any other entity except perhaps crush injury to the head [13],this finding has particular diagnostic significance. Blood may break through the cavity wall into the over
lying subhyaloid or vitreous space (Fig.14.4). Therefore, if the macula cannot be adequately viewed,it is wise to re-examine the child every 1–2 weeks until the underlying retina becomes visible to identify if schisis is present.Although many other entities may be associated with retinal hemorrhage, the presence of extensive hemorrhagic retinopathy,especially when macular retinoschisis is present, must raise strong suspicion that abusive head injury has occurred through a repetitive acceleration-deceleration mechanism. Vitreoretinal traction and perhaps acceleration-deceleration injury to the orbital structures [16] appear to be the main mechanism by which retinal hemorrhage is generated in SBS [20]. Even with major accidental head injury such as motor vehicle accidents,retinal hemorrhage is uncommon, lending credence that there is something unique about the forces applied in inflicted neurotrauma [16, 32]. One author has suggested that short falls can very rarely result in significant retinal hemorrhage [23],but the study suffers from many flaws that make the reported case series difficult to interpret [17]. Other proposed mechanisms such as increased intracranial pressure, intracranial hemorrhage (Terson syndrome),and increased intrathoracic pressure (Purtscher retinopathy), seem to play little if any role [16, 20, 27]. The chest compressions of cardiopulmonary retinopathy rarely if ever cause retinal hemorrhage, and when they do,like most nonabusive causes of retinal hemorrhage other than birth, the findings would be confined to a small number of hemorrhages in the posterior pole [16]. The role of other factors such as mild coagulopathy secondary to brain injury,anemia,hypoxia,and autonomic dysregulation are worth further research but independently (i.e.,in the absence of abusive head injury) do not cause severe hemorrhagic retinopathy.That retinal hemorrhages can occur with little or no apparent brain injury or hemorrhage on neuroimaging may support the isolated role of vitreoretinal traction, but some of these patients will exhibit intracranial pathology with alternative neuroimaging strategies or postmortem [21,22]. When faced with an infant who has retinal hemorrhages, the examining ophthalmologist
224 Chapter 14 Nonaccidental Injury.The Pediatric Ophthalmologist’s Role
Fig.14.4. Circinate elevated macular fold associated with traumatic retinoschisis in a shaken baby syndrome victim. The internal limiting membrane centrally has settled back against the retina
must begin by carefully documenting the findings. Detailed and well-labeled drawings are adequate, especially when accompanied by description of the number, type, pattern and extent of the retinal hemorrhages.Clinical photography is ideal but not required and even when obtained, may demonstrate artifacts brought on by the challenges of the moving eye, poorly dilated pupil, particular photographic technique and other technical factors. Postmortem photography, both gross and histologic,is also helpful.As we begin to realize the importance of orbital pathology, it is recommended that the orbital contents and globe be removed en bloc using a combined intracranial and transconjunctival approach and then fixated for 72h followed by serial sections [16].In the absence of other explanatory findings,if abuse is considered, skeletal radiographic examination, neuroimaging, blood studies and other tests where appropriate to rule out systemic disorders [16], consultation with a child abuse pediatrician and ultimately, reporting to child protective services are required.
Summary for the Clinician ∑ Abusive head injury with an accelerationdeceleration component (Shaken baby syndrome) can result in potentially lethal brain injury,fractures,and retinal hemorrhage ∑ Children under 4years old,and especially those less than 1year old,are particularly susceptible ∑ The ophthalmologist must carefully characterize the types,distribution pattern,and number of retinal hemorrhages,as this will aid in differential diagnosis ∑ Whereas a few preretinal and intraretinal hemorrhages in the posterior pole are nonspecific,they may be due to inflicted neurotrauma ∑ Extensive hemorrhagic retinopathy with too numerous to count hemorrhages at all levels and extending to the ora serrata are rarely caused by systemic or ocular disease other than abuse ∑ Macular retinoschisis is a lesion highly suggestive of abusive head injury with acceleration-deceleration components
∑ The differential diagnosis of retinal hemorrhage can be refined based on the age of the child and the pattern of retinal hemorrhage ∑ Vitreoretinal traction plays a major role in the generation of eye injuries in Shaken baby syndrome ∑ Retinal hemorrhage can not be dated
14.2.3 Munchausen Syndrome by Proxy (Factitious Illness by Proxy)
This uncommon and somewhat bizarre form of abuse involves the falsification or manipulation ofmedical data or physical findings such that the child has the appearance ofhaving a medical disorder that is actually created by the perpetrator, usually the mother.For greater review ofthis entity,the reader is referred elsewhere [28].Often, the mother may have secondary gains as a result of the attention the child’s illness draws from a well-meaning medical team, that will often engage in numerous diagnostic interventions,even surgery,to solve the medical dilemma.These interventions may lead to prolongation of the time before the disorder is recognized and even iatrogenic injury. Reported ophthalmic manifestations include subconjunctival hemorrhages from covert suffocation, pupillary abnormalities or nystagmus from covert poisoning,recurrent periorbital cellulitis as a result of covert injections around the eye of foreign substances, corneal scarring secondary to covert instillation of noxious chemicals,and pupillary abnormalities due to indirect application of drops or even inhaler sprays (e.g., atropine) [15]. Ophthalmologists should expect Munchausen syndrome by proxy when they are faced with a child,usually preverbal,whose ocular illness does not fit into a known diagnosis,responds inconsistently to treatment, and has been presented by the parent to multiple ophthalmologists at different centers.The perpetrator will often appear as the “ideal” parent, often offering to help the nurses in the care ofthe child during inpatient stays and befriending hospital staff.The perpetrator may have a history ofworking in the health care field or having medical experience as a patient, perhaps even for Munchausen syndrome.
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Summary for the Clinician ∑ Munchausen syndrome by proxy is a disorder in which the caretaker,usually the mother,causes the child to appear to have an illness by the manipulation of samples from the patient,falsification of the history, or covert injury to the child ∑ Munchausen syndrome by proxy should be suspected when the eye condition does not make physiologic sense,responds inconsistently to treatment,and/or has been the subject of repeated visits to different physicians without satisfactory resolution. There may be a characteristic (although not necessarily required for diagnosis) profile to the family and victim
14.3 Sexual Abuse
Sexual abuse ofa child is very different from the violent isolated acts of adult rape.Rather,children become victims to chronic secretive abuse which may range from inappropriate touching to anal or vaginal penetration. Rarely, children may be victims of child pornography.Both victim and perpetrator may be either male or female although most commonly the victim is female and the perpetrator male.The perpetrator of child sexual abuse is often known to the child and in a position ofauthority which might be exploited through the use of threats to the child to maintain secrecy.Very young children may not even realize that the behavior of this trusted adult is abnormal. Over 90% of child abuse victims will show no physical evidence of the abuse.It may be years before sexual abuse is discovered or disclosed. Although uncommon, sexual abuse may present as sexually transmitted ocular disease. Gonorrhea or chlamydial conjunctivitis,human papilloma virus of the conjunctiva,pubic lice of the eyelashes,periocular infection with molluscum or herpes simplex, or ocular involvement with HIV or syphilis may all occur in sexually abused children.However,there is evidence that some infections, such as gonorrhea [18], may be transmitted to the eye nonsexually. This is
contrary to the well-documented exclusivity of sexual transmission for gonorrhea to the oropharynx, vagina, rectum and male urethra. There may be unique factors about the externalized conjunctival mucosa that allow for this nonsexual transmission to occur. Infections such as molluscum and herpes simplex are so frequently transmitted nonsexually that consideration ofsexual abuse seems almost misdirected in the absence of other concerning findings. Nonsexual transmission of syphilis to children does not occur. But like virtually all sexually transmitted diseases, infection via the birth canal is an important consideration and some infections, particularly Chlamydia, may have very long latent periods.Consultation with child abuse and infectious disease specialists may be helpful.In teenagers,one must also consider the possibility of consensual sexual activity with peers as the source ofinfection.At the very least, sexually transmitted diseases with ocular manifestations should lead the ophthalmologist to place sexual abuse in the differential diagnosis, and communicate this concern to the child’s primary care physician or a child abuse pediatrician,to consider further evaluation. There is also important literature to suggest that covert sexual abuse, and perhaps other forms of abuse, may lead to functional visual loss in children [4,30].Although it would not be appropriate to question every child with functional visual loss regarding possible covert abuse,it is recommended that the evaluation of functional symptoms include consideration of possible stressors in the child’s life.
Summary for the Clinician ∑ Sexual abuse of a child is a chronic covert act that may escape detection or report by the child for years and is most often not associated with physical injury to the victim ∑ Ocular manifestations of sexually transmitted disease may be a sign of sexual abuse ∑ The ophthalmologist must consider the possibility of nonsexual transmission of sexually transmitted diseases to the conjunctiva,but when there is a suspicion of sexual abuse,the ophthalmologist should refer to expert professionals
226 Chapter 14 Nonaccidental Injury.The Pediatric Ophthalmologist’s Role
∑ Infection via the birth canal,and, in teenagers,via voluntary sexual activity, must be considered ∑ Functional visual loss and other symptoms may be a sign of covert abuse
14.4 Neglect and Noncompliance
Although this form ofchild abuse is perhaps the most common, it is also the most difficult to identify and manage. Although neglect may manifest as a more dramatic physical failure to thrive (psychosocial growth retardation), the ophthalmologist is more often confronted with parents and other caregivers who fail to attend scheduled appointments or adhere to prescribed treatment regimens such as occlusion therapy for amblyopia. Apparent noncompliance may result from confounding factors that significantly impair a parent’s ability to comply: poverty leading to an inability to afford care,access to care (transportation, insurance coverage), lack of child care for siblings, inability to leave work, misunderstanding of the instructions or the seriousness of the eye disease,and others.When concerned about possible abusive neglect and noncompliance, the ophthalmologist should first explore such factors, perhaps with the help ofa social worker or other support personnel.Absent such factors,the ophthalmologist can enter into written contracts with patients, documented in the chart and signed by the patient and a witness, that indicate the physician’s expectations and the consequences (e.g., reporting to child protective services) should the behavior continue.This will empower the report once it is made, as otherwise, the agency receiving the report may blame misunderstanding and miscommunication rather than neglectful behavior.
Summary for the Clinician ∑ The ophthalmologist must ensure that explanatory factors (e.g.,poverty) for noncompliance are identified and addressed ∑ Written contracts with parents/guardians can be helpful in managing non compliance
14.5 Emotional Abuse
Often it is the faces and affect of abused children that tell us the adverse emotional consequences of their abuse.Other times a physician may actually witness emotionally abusive interactions in the waiting room or examination room. Like all forms of abuse, it is sometimes difficult to draw a line between acceptable but harsh parental verbal discipline and emotional abuse, but clearly comments such as “You did not deserve to be born,” “You are a good for nothing/stupid/evil child,” and other forms of threat and intimidation cross the line into the realm of abuse. When such behavior is witnessed first hand,office staff should notify the ophthalmologist who can then approach the parent in a nonconfrontational, nonaccusatory way saying something like “Your child seems to be particularly challenging today”or “You seem to be feeling very angry with your child.” The patient’s entry into the examination room should be prioritized and the observed behaviors addressed in a fashion that explores the parental feelings rather than condemns them for their actions.Enlisting the support of social work or nursing services can be very helpful. Reporting to child protective services is indicated if emotional abuse is observed or suspected.
Summary for the Clinician ∑ Potentially abusive behavior by a child’s caretaker that is observed by an ophthalmologist or their staff must be addressed
14.6 Conclusion
Every ophthalmologist who cares for children will be confronted with the challenges of child abuse.Every ophthalmologist is a mandated reporter.Yet we must carefully consider alternative explanations for the physical findings, and not rush to the conclusion that a child has been abused.Consideration of a broad differential diagnosis must also be balanced with the immediate protection needs ofthe child.Abuse should be
14.6 Conclusion 227
reported when there is reasonable suspicion.One need not achieve complete medical certainty.By using an open and sensitive partnership with parents,they are more likely to understand the ophthalmologist’s intentions and obligations to act on behalf of the child.The ophthalmologist must honor the responsibility to advocate for their
∑ Treatment patterns and prognosis of infantile glaucomas are very heterogeneous depending on the underlying pathomechanism of glaucoma ∑ Glaucoma surgery is the primary option in treatment of infantile glaucoma except when the prognosis for the child’s life or that of the eye is very poor or when multiple previous glaucoma surgeries have achieved only limited success ∑ Several restrictions for medical treatment in infantile glaucoma need to be considered. Brimonidine can cause severe systemic side-effects in children younger than 8years ∑ First-line interventions in primary congenital glaucoma are trabeculotomy or trabeculectomy or a combination of both. In cases with a sufficiently clear cornea and good gonioscopic view,goniotomy is also a first-line option ∑ Second-line interventions in congenital glaucoma are tube implants,which lead to a high rate of reintervention ∑ In refractory cases or complex malformations with high intra- and postoperative risks,cyclodestructive methods may be an alternative,achieving moderate success in long-term IOP control ∑ The inflammatory and aphakic glaucomas represent a special group with limited results from any form of surgery.The prognosis of infantile glaucoma surgery in chronic uveitis associated with autoimmune diseases may be influenced by systemic immunomodulative therapy Core Messages
Fig.7.1. Eleven-month-old boy with primary congenital glaucoma showing enlarged horizontal corneal diameter and slight corneal cloudiness in the left eye
exact age.When comparing the outcome of different treatment patterns,it is now mandatory to accurately differentiate the age distribution and the subdiagnoses of the patient group treated.
7.2 Diagnostic Aspects
7.2.1 Clinical Background
Glaucoma in childhood is a relatively rare disease with an incidence of 1 in 10,000 live births [15],which requires special knowledge in management owing to the very heterogeneous pathomechanisms and prognosis of the subgroups. There are some reports of a self-limiting congenital glaucoma [27], but also many papers focusing on the refractory congenital glaucomas, especially if associated with other ocular malformations,such as chronic uveitis,aniridia or Peters anomaly [2,3,15,30].Consequently,it is crucial to differentiate between individual prognoses before determining therapy. As the characteristic symptoms of blepharospasm, photophobia, and epiphora in congenital glaucoma are reported with very high frequency by parents,the individual anamnesis is an important and reliable clinical parameter. The early onset of these suspicious symptoms seems helpful in congenital glaucoma as manifest clinical symptoms are mostly seen during the first 3months of life [15,17].
Sometimes,in very young children,megalocornea, chronic conjunctivitis, and lacrimal stenosis can imitate the classical features of congenital glaucoma.In order to avoid the risk of treating a nonglaucomatous eye for glaucoma,the exact diagnosis of congenital glaucoma often needs to be confirmed by an examination under general anesthesia as cooperation in the young child may be lacking.If possible,examination for congenital glaucoma should include tonometry,skiascopy,biomicroscopy of the an
96 Chapter 7 Management of Infantile Glaucoma
Table7.1. Classifications of the glaucomas in childhood
Age Congenital glaucoma Manifestation at birth or thereafter Infantile glaucoma Manifestation between 1st and 4th year Juvenile glaucoma Manifestation after the 4th year
Associated pathologies Primary glaucoma Isolated dysgenesis of the TM Secondary glaucomas Associated ocular or systemic pathology
Morphology Trabeculodysgenesis (e.g.,primary congenital glaucoma) of the anterior segment Iridotrabeculodysgenesis (e.g.,Riegers syndrome) Iridocorneotrabeculodysgenesis (e.g.,Peter’s anomaly)
Table7.2. Work-up of clinical examination in congenital/infantile glaucoma
Careful individual anamnesis Skiascopy (Myopia? Anisometropia?) Biomicroscopy of the anterior and posterior segment (Haab striae? Distension of the superior limbal region? Glaucomatous excavation?) Measurement of the horizontal corneal diameters Hand-held tonometry Gonioscopy (Iris insertion? Synechiae?) A-scan sonography (Deviation from age-related growth?) B-scan sonography (Retinoblastoma?) Ultrasound biomicroscopy (completely opaque cornea)
terior and posterior segment, gonioscopy, and sonographic measurement of the axial length (Table7.2).Under certain circumstances or with increasing age, visual field testing, laser scanning optic disc morphometry, or ultrasound biomicroscopy may be possible and helpful.
7.2.2 Tonometry
It is important to consider that normal intraocular pressure (IOP) in children ranges from 9–12mmHg under general anesthesia. IOP measurements of 16–18mm Hg under general anesthesia already require cautious interpretation.Intraocular pressure measurement in children under general anesthesia should not be performed in the initial phase but during deep anesthesia,in order to avoid the massive fluctuations occurring in the initial phase of general anesthesia [26]. Several studies have demonstrated that intraocular pressure is lowered under general anesthesia, especially halothane anesthesia [4].Chloral hydrate or ketamine sedation seems to avoid a considerable decrease of IOP, but also requires meticulous monitoring and supervision during and after a child’s sedation [28,54]. Tonometry in general anesthesia has to be performed using hand-held devices, e.g., the Schiötz, Perkins, or Tonopen tonometer. Any form oftonometry in the awake child is relatively unreliable owing to unpredictable factors such as pressure of the eye lids or increased episcleral pressure in the crying child.Tonometry in the young child is usually performed with devices designed for adult patients, thus introducing the risk of systematic measurement errors. Experimental and clinical studies have shown that pathological conditions ofthe sclera and cornea can lead to considerable tonometric measurement errors.In buphthalmic eyes with corneal scars and opacifications, significantly higher values are obtained with indentation tonometry than with applanation tonometry. As the diameter of the cornea and axial length of the eye are increased in children with congenital glaucoma, the central cornea is significantly thinner in these children than those with
nonglaucomatous eyes.[29] This may also contribute to a considerable underestimation of the actual intraocular pressure in buphthalmic eyes.
7.2.3 Optic Disc Evaluation
Glaucomatous optic disc cupping is seen in the majority of children with infantile glaucoma,as far as limited corneal clarity allows visualization of the optic disc. The degree of optic disc excavation depends on the size ofthe optic disc, the pressure level,and the duration ofincreased intraocular pressure. A reversal of optic disc cupping after pressure-reducing surgery can be observed at an early stage of primary congenital glaucoma. This phenomenon ofan “improved”cup disc ratio occurs if intraocular pressure is successfully reduced, especially during the 1styear of life. Between the 2nd and 5thyears of life, unchanged cupping is more frequent following successful glaucoma surgery [57].In older children,optic disc cupping is considered to be the safest parameter to indicate the stage of glaucomatous damage. Little information is available on the clinical potential of optic disc morphometry by laser scanning tomography in children with congenital glaucoma. Compliance in children of 4 or 5years is often already sufficiently good to perform laser scanning tomography of the optic
7.2 Diagnostic Aspects 97
Fig.7.2. Macroexcavation in a large optic disc (>4mm2).This healthy 6-year-old boy was suspected ofhaving childhood glaucoma.Follow-up revealed no change of the macroexcavation
disc and this is extremely helpful to rule out or to clearly quantify a macroexcavation in a very large optic disc (Fig.7.2) and to avoid unnecessary treatment.
7.2.4 Sonography
7.2.4.1 A-Scan
The pathological increase of the axial length leading to the typical buphthalmic configuration of the eye is an extremely frequent sign in congenital glaucoma during the 1styears of life. Beyond the 4thyear of life,the onset of glaucoma is usually not associated with buphthalmic growth of the eye owing to age-dependent changes in the sclera architecture.In contrast to tonometry, which offers only a snapshot of intraocular pressure fluctuations, the pathologically increased axial length in congenital glaucoma reflects the long-term level of intraocular pressure. Preoperative axial length and age are basic factors in the interpretation of ocular growth following glaucoma surgery in primary congenital glaucoma. Temporary cessation of ocular growth is a frequent finding after successful pressure-reducing surgery in eyes with an axial length greater than 22mm and in children aged 3months or older.
7.2.4.2 B-Scan
B-scan sonography – wherever available – should be obligatory in buphthalmic eyes with severe opacities of cornea,lens,or vitreous to rule out secondary glaucoma owing to retinoblastoma, other tumor-like lesions, or persistent primary hyperplastic vitreous.Although rare,these secondary glaucomas require different treatment strategies with their own prognosis. Follow-up examination of buphthalmic eyes with opaque optical media should also include B-scan sonography, because of the relatively high incidence of retinal detachment following any kind of antiglaucomatous surgery.
7.2.4.3 Ultrasound Biomicroscopy
Ultrasound biomicroscopy is a useful diagnostic tool in cases of complete corneal opacification hindering clear identification of anterior chamber structures. Iris adhesions to the cornea can be visualized by ultrasound biomicroscopy, allowing diagnoses such as Peters anomaly or iris tamponade following perforation [21]. Such information can be helpful in determining subsequent treatment strategies if glaucoma surgery or keratoplasty is planned.
7.2.5 Corneal Morphology
7.2.5.1 Corneal Opacifications
Much attention is focused on the cornea in the diagnosis of congenital glaucoma. There are several typical signs that can be observed such as a stretched superior limbal region (Fig.7.3), tears in the Descemet membrane,the so-called Haab striae (Fig.7.4),and corneal opacifications (Fig.7.5). Corneal opacities are frequent in infantile glaucoma, occurring in up to 75% of glaucomatous eyes [17].Corneal clouding as an isolated ocular symptom (without Haab striae and limbal stretching) in infants is a suspect sign of a genetic (congenital hereditary endothelial dystrophy,Turner or Noonan syndrome)
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Fig.7.3. Primary congenital glaucoma in 14-monthold girl showing massive distension and stretching of the superior limbus region
or metabolic (mucopolysaccharidoses, cystinosis) disease, sometimes imitating congenital glaucoma.Even where meticulous examination is not possible, such as in a crying or restless, awake child,the degree ofcorneal clarity should always be observed. Even the smallest corneal opacity can be symptomatic ofa severe ophthalmological disease such as congenital glaucoma or anterior-dysgenesis syndrome.
7.2.5.2 Corneal Diameters
Owing to the extremely stretched superior limbal region in buphthalmic eyes,it seems reasonable to measure corneal diameters horizontally rather than vertically. Enlarged corneal diameters of more than 12mm during the 1styear of life are highly indicative of buphthalmia.Average horizontal corneal diameters in the newborn
are between 9.5 and 10mm.In the 1styear oflife, corneal diameters reach 10.5–12.0mm. Corneal diameters are accepted as a diagnostic criterion of high sensitivity for congenital glaucoma. However, as a factor for monitoring the longterm progression ofglaucoma,the measurement of the corneal diameters seems inappropriate in most cases, although no larger reliable studies exist on changes in buphthalmic corneal diameter following pressure-reducing surgery. Megalocornea has been reported as a developmental,nonprogressive anomaly with corneal diameters of at least 12mm in the newborn.In contrast to congenital glaucoma,the limbal region is not stretched in megalocornea,and ruptures of the Descemet membrane with edema and opacities are also absent.However,associations between megalocornea and congenital glaucoma have been described in one family.All patterns of inheritance have been reported.
7.2.6 Visual Field Testing
Visual field testing requires a minimum ofcompliance and understanding from the patient. This kind ofexamination is therefore rarely feasible in children younger than 8years.Conventional kinetic manual perimetry has been shown to be of use in detecting localized visual field defects in children between 4 and 14years of age [16].
7.2.7 Objective Refraction
Determination of objective ocular refraction is extraordinarily important in the management ofinfantile glaucoma in order to protect against amblyopia.Reliable skiascopy is frequently hindered by corneal clouding or endothelial scars. The majority of glaucomatous eyes are myopic beyond the first months of life even when pressure-reducing surgery has been successfully performed [38].In 65–100% of patients,amblyopia due to ametropia or anisometropia threatens visual acuity in later life, even in pressurecontrolled buphthalmic eyes [15].
7.2 Diagnostic Aspects 99
Fig.7.4. Haab striae (endothelial tears) in a adult patient who had undergone glaucoma surgery for congenital glaucoma in his first year of life
Fig.7.5. Iridocorneotrabeculodysgenesis with glaucoma in a 3-year-old girl
Summary for the Clinician Typical clinical signs of congenital glaucoma occurring in the first 2years of life: ∑ History of epiphora,photophobia and blepharospasm during the first months of life ∑ Corneal opacities,tears of the Descemet membrane (Haab striae),an overstretched superior limbal region and large corneal diameters ∑ In contrast to management in adult glaucoma,several specifications have to be considered in the diagnostic work-up: ∑ Abnormally increased ocular axial length (in comparison to the normal age-correlated growth curve) is a common feature of congenital glaucoma.However,if onset of glaucoma occurs after 3years of age the typical stretching of the globe is usually absent ∑ Despite manifest congenital glaucoma the intraocular pressure may be normal under deep general anesthesia.Several sources of error may confuse intraocular pressure measurements in buphthalmic eyes ∑ Glaucomatous excavation of the optic disc is usually present,but evaluation of the optic disc is often impossible owing to corneal opacities.Glaucomatous excavation can be reversible in very young children following IOP control ∑ Visual field testing is usually impossible in children younger than 6–8years.Optic disc morphometry can be performed even in younger children from 4years of age ∑ Skiascopy,or another method of determining the objective ocular refraction,should be performed regularly,because refractive problems such as ametropia and anisometropia are very common in buphthalmic eyes and may also contribute to amblyopia
7.3 Medical Treatment
Medical treatment is usually a treatment option of second choice in young children if surgery has to be postponed for certain reasons: if life expectancy is undoubtedly limited owing to a complex syndrome or severe, life-threatening disease or, exceptionally, if multiple previous antiglaucomatous surgical interventions have achieved only limited success requiring further pressure-reducing treatment with poor surgical prognosis. Fundamental problems connected with medical treatment of children with congenital glaucoma include an understandable poor compliance on instillation ofdrops.Topical and systemic side effects can also arise, owing to the relatively high concentration of pharmaceutical agents, originally designed for adults, in the child’s body, and on long-term application of preservatives such as benzalkonium chloride. For all new medications introduced into glaucoma management over the last 15years, knowledge oflong-term side-effects (>20years) of their use in early childhood is naturally lacking. This may be of particular importance for iris pigmentation after use of latanoprost.
7.3.1 Miotics
Pilocarpine and other miotics are often used postoperatively to prevent the formation of anterior synechiae (e.g., following goniotomy, trabeculotomy,or cyclodialysis).Changing pupil size and disturbed accommodation limit the use of this agent in long-term treatment of infantile glaucoma. Another concern may be the use of strongacting miotics in highly myopic eyes, since an association has been described between miotics use and retinal detachment in highly myopic eyes with glaucoma.
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7.3.2 Beta-Blockers
Topical beta-blockers are the best documented antiglaucomatous agents with regard to efficacy and side effects.Owing to systemic resorption, topical timolol can cause bradycardia, arterial hypotension and pulmonary problems in children,especially when drops are instilled bilaterally with no interval between applications to the two eyes. These side effects will undoubtedly occur more often in very young children than in older patients.
7.3.3 Carbonic Anhydrase Inhibitors
Systemic acetazolamide may cause severe systemic side effects including metabolic acidosis, renal problems,and hepatic necrosis.Owing to its chemical structure, acetazolamide should not be given in cases with a sulfonamide allergy. Under controlled circumstances,acetazolamide is sometimes used for short periods,preferably in older children. Topical carbonic anhydrase inhibitors, such as dorzolamide and brinzolamide,are less likely to cause side effects than oral acetazolamide,but seem to be less effective in pressure reduction [45].Little is known about the disturbance of endothelial function in buphthalmic eyes with extensive Haab striae on treatment with topical carbonic anhydrase inhibitors.
7.3.4 Prostaglandins
The use of latanoprost in pediatric glaucoma has been described [23]. Mean IOP reduction after addition of latanoprost in 48 pediatric patients was relatively small.Pressure-reducing efficacy,especially in young patients with infantile glaucoma,seems to be more limited than in older patients with juvenile glaucoma. The special use oflatanoprost as an additional antiglaucomatous medication has been studied in children with port wine stain-related pe
diatric glaucoma.Nearly halfofthe patients had controlled IOP at 1year follow-up [44]. Little is known,however,about the long-term changes in iris pigmentation and the clinical importance of this for children.As in adults,the application of latanoprost in uveitic glaucoma should be avoided. Latanoprost was suspected of having caused heavy sweat secretion over the entire body 1–2h after local administration in a child with aniridia [51].
7.3.5 Alpha-2 Agonists
Brimonidine is a topical alpha-2 agonist that is widely used as a hypotensive drug in adults.In a retrospective analysis six out of 22 children between the ages of 0 and 14years had to stop local administration of brimonidine 0.2%.Reasons for terminating treatment were fainting attacks in two children, tiredness in another two, and local irritations in a further two patients [10].A considerable proportion of young children suffer from systemic side effects following brimonidine 0.2% drops [9,22],leading to the recommendation not to use this medication in young children. Severe systemic problems such as bradycardia and hypothermia have been described following topical application not only of brimonidine but also of apraclonidine in children.
7.4 Surgical Therapy
Owing to the rarity of congenital glaucoma and the unusual tissue consistency of buphthalmic sclera and cornea, any glaucoma surgery in buphthalmia (Table7.3) requires special equipment,knowledge,skill,and experience. Prospective randomized clinical studies of surgical strategies in congenital glaucoma are extremely rare.The reasons for this could be the low incidence of the disease or the uncertainty of randomization, to which many parents will not consent.Thus,most data are taken from retrospective studies in large tertiary glaucoma centers, reflecting the surgical experience and
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preferences of some very highly skilled glaucoma surgeons but also regional differences between patient groups with regard to ethnic origin,type of glaucoma,and patient compliance. Another well-known problem is the discrepancy between success criteria used in different studies,which can range from the simple statement “no further re-surgery required”to attainment of certain intraocular pressure measurements after a given period or satisfactory values for a combination of clinical parameters such as clinical symptomatology, corneal clearness, intraocular pressure, A-scan sonography, and optic disc morphology.
7.4.1 Goniotomy
The technique of goniotomy was introduced clinically by Barkan in the early 1940s.Goniotomy involves incision ofthe thickened trabecular beams and disconnection of the abnormally forward insertion of the iris. However, a clear cornea and highly specialized surgical experience are required for this delicate surgery.Especially in the intraoperatively flattened anterior chamber of newborns with leaking corneal incisions,maneuvers with the goniotomy knife carry certain risks, even when high-viscosity viscoelastics are used. Success rates of 60–90% have been reported following goniotomy in childhood glaucoma [15,41,46,49].However,re-goniotomies have to
be performed in up to one-third of patients.In order to perform this kind of surgery in eyes with a cloudy cornea, endoscopic approaches have been described [33].To guarantee a stable anterior chamber, endoscopic goniotomy has also been performed using an anterior chamber maintainer.With this technique,a 240°goniotomy can be performed with no major complications [7]. Retrospective studies in juvenile uveitis patients around 10years of age have also revealed relatively good results for conventional goniotomy in experienced hands. The overall success rate after goniotomies (54 in 40 eyes) was 72% with a postoperative IOP of 14–16mmHg. Kaplan-Meier survival probabilities were 0.81at 5years and 0.71at 10years. The most frequent complication was hyphema in 80% of the goniotomies.Prognosis for the outcome was better in eyes with fewer anterior synechiae,in phakic eyes, in eyes without prior surgery, and in patients younger than 10years [30]. If the surgeon has sufficient experience with this technique and clinical results are comparable to ab-externo approaches in his hands,it is reasonable to perform goniotomy or similar pressure-reducing ab-interno surgery (e.g.,endoscopically guided goniotomy) as a primary intervention, because the conjunctiva will not be damaged and thus future surgery is not prejudiced.
7.4.2 Trabeculotomy
As with goniotomy, success rates of around 70–90% have been reported within a period of 2–9years following trabeculotomy [14,15,31,41]. However,one-third of the eyes operated on required a second or tertiary trabeculotomy.This ab-externo method is not dependent on the visibility of the chamber angle structures through an often cloudy cornea. However, abnormal anatomy of the limbus in congenital glaucoma makes it difficult to clearly identify the lumen of Schlemm’s canal that should be cannulated by a trabeculotome. In these cases, trabeculotomy might be changed into a trabeculectomy by excising a small block of scleral tissue as for
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Table7.3. Surgical treatment options in congenital and infantile glaucoma
Primary congenital glaucoma Goniotomy Trabeculotomy Combined trabeculotomy-trabeculectomy Trabeculectomy Refractory congenital glaucomas Glaucoma implants (Ahmed valve, Baerveldt and Molteno implant) Laser cyclophotocoagulation (cyclocryocoagulation) Adjunctive antimetabolites in filtration surgery Cyclodialysis
routine trabeculectomy.This externalization of trabeculotomy is also performed as a planned procedure in developmental glaucoma (see Sect.7.4.3). A 360° trabeculotomy has been proposed by threading a polypropylene suture into Schlemm’s canal for the whole circumference and tearing the meshwork with the suture.The pressure-reducing potential of this procedure has been demonstrated in a retrospective study of 24 eyes,achieving success rates of more than 90% [40]. However, massive ocular hypotony has also been described in a small series following 360°suture trabeculotomy [25].
7.4.3 Trabeculotomy Combined with Trabeculectomy
Trabeculectomy has been combined with trabeculotomy as a primary intervention achieving comparable or better success rates to trabeculotomy alone. In the difficult group of very young patients undergoing glaucoma surgery within the 1stmonth of life, an Indian retrospective study revealed success rates of 89% after 1year and 72% after 3years for the combined trabeculotomy–trabeculectomy approach. No essential intra- and postoperative complications were seen in any patient though anesthesia-related problems occurred in two patients [37]. Elder [20],who exclusively studied Palestinian patients younger than 1year,showed better results for combined trabeculotomy–trabeculectomy procedures (93.5%) after 2years than for trabeculectomy (72%), although the incidence of corneal haze in the trabeculectomy group was obviously higher (82% vs 56%), whereas other preoperative parameters (e.g., age, intraocular pressure, corneal diameters) were similar in the two groups.The author explained the superior outcome of the combined procedure by establishing two different new ways of facility improvement (through the trabecular meshwork and through the sclera). Slightly worse results for combined trabeculotomy–trabeculectomy (72% success rates) were noted for primary congenital glaucoma in
a retrospective study in Saudi Arabian patients. In this study,outcome was much worse for eyes with associated ocular malformations (45% success rate) although mitomycin C was additively used in 87% of the eyes [43].
7.4.4 Trabeculectomy
Depending on follow-up and risk profile in the study patients,the success rates published in the literature for primary trabeculectomy alone range from 50% to over 90% in congenital glaucoma [18, 20, 24]. Burke [11] reported surgical success in 18 of 21 eyes (86%) with congenital glaucoma after a mean follow-up of nearly 4years.In the same patient group,Fulcher [24] even observed a 5-year success rate of92% after the first trabeculectomy in 13 eyes with primary congenital glaucoma, although no patients younger than 4months of life or with a corneal diameter larger than 13.5mm were treated in this study. Debnath et al.[14],who clearly described the distribution of risk factors in their Saudi Arabian study group, found a 1-year success rate of 54% for trabeculectomy.The authors concluded that their high failure rate might be influenced by an ethnic factor. Furthermore, the proportion of patients manifesting glaucoma soon after birth was relatively high in this study and obviously predisposed the group to poor results for both procedures.Trabeculectomy was rarely followed by cataract,endophthalmitis,or vitreous loss. In another retrospective study comparing the outcomes oftrabeculotomy,trabeculectomy and combined trabeculotomy–trabeculectomy, there was no significant difference between outcome for the surgical techniques after 5years. [18] Several authors do not recommend trabeculectomy as a primary procedure in congenital glaucoma,as they have attained only moderate success rates associated with severe intra- and postoperative complications such as vitreous loss,endophthalmitis,retinal detachment,scleral collapse,subluxation of the lens,and uveitis as possible risks.Shallow anterior chamber and
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hyphema are the most common postoperative complications and these usually resolve spontaneously. The rate of resurgery (1/3) after initial trabeculectomy is comparable to that after trabeculotomy or goniotomy,but prognosis is particularly poor for neonatal forms of congenital glaucoma and highly myopic eyes. Secondary trabeculectomy in primary congenital glaucoma achieves significantly worse results than primary trabeculectomy [18].
7.4.5 Use of Antifibrotic Agents
Intra- or postoperative application of topical mitomycin C or 5-fluorouracile in young children with a long life expectancy is associated with the risk oflate toxicity and potential mutagenicity of these antimetabolites, even though the filtering procedures combined with the use of mitomycin are becoming increasingly routine in antiglaucomatous surgery. Further possible deleterious complications of filtering procedures with mitomycin C are rupture of thin-walled blebs, wound leakage, late endophthalmitis, and long-standing hypotony. Owing to extreme scleral thinning in buphthalmia, the potential risk of localized retinal necrosis has also to be considered.However,in refractory cases the use of antimetabolites or other methods to prevent scarring seems unavoidable where goniosurgery and ab-externo procedures without antimetabolites have failed. The intraoperative use of mitomycin C (MMC) during trabeculectomy and its longterm effectiveness in congenital glaucoma have been investigated in several retrospective studies, with the general conclusion that there are significantly more complications associated with the use ofMMC in infantile glaucomas [38, 48]. Incidence and frequency of postoperative complications (thin avascular filtering blebs, choroidal detachment, wound leakage) following combined trabeculotomy–trabeculectomy were found to depend on the concentration of mitomycin C used (0.2mg/ml vs 0.4mg/ml) [1]. A higher concentration of mitomycin C (0.5mg/ml) administered intraoperatively for
3–4min during trabeculectomy produced a considerable rate of late bleb-related infection (17%) at an average follow-up of 28months [50].The success rate in this study was 59% after 3years for primary and secondary pediatric glaucomas. Another retrospective study investigated the outcome of trabeculectomy with and without MMC in aphakic and pseudophakic eyes in children.Neither IOP levels nor success rates after 2years differed significantly between the two groups. In the MMC group, one patient developed bleb-related endophthalmitis in both eyes underlining the relatively high risk of bleb infection after MMC administration [38].
7.4.6 Glaucoma Implants
The most frequently used glaucoma shunt implants are the Molteno, Ahmed, and Baerveldt implants [8,42].They are used following failed prior surgery,in aphakia and in different types of anterior segment anomalies. Several retrospective studies have proven the pressure-reducing potential ofdrainage devices in infantile glaucoma.The Ahmed valve was implanted in a consecutive series of 60 eyes in 44 patients (mean age,6years).More than two-thirds ofthe patients attained IOP control 2years following the procedure with reduction of pressure-lowering eye drops from 4 to 2 medications.However,complications occurred in 30 eyes (50%), leading to severe visual loss in four patients. Interestingly,uveitic glaucoma was a risk factor for tube extrusion in this study [42]. A shallow anterior chamber is a frequently seen complication (25%) in the early postoperative period following Ahmed implant surgery. Prognosis of glaucoma implant surgery seems to be partially influenced by the surgeon’s experience [19]. In a retrospective comparison between trabeculectomy with mitomycin C (MMC) and Ahmed/Baerveldt implants in children younger than 3years, postoperative complications requiring surgical revision were more common in the implant group (45.7%) than in the MMC group (12.5%), but success rates (IOP
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<23mmHg with maximum medication) were also higher in the implant group after 1 (87%) and after 6years (53%) than in the MMC group (36% and 19%) [8]. The most common postoperative intervention in the implant group was tube repositioning. In eight eyes of five patients with aniridia (mean age, 92months) a glaucoma drainage device achieved intraocular pressure reduction from 35mmHg to 15mmHg with a follow-up of 19months.The success rate after 1year was 88% in this retrospective study. One eye lost light perception owing to postoperative retinal detachment [3]. Simultaneous use of an Ahmed glaucoma valve implant and penetrating keratoplasty in refractory congenital glaucoma with corneal opacities has limited long-term efficacy. IOP control was achieved in one-third of eyes after 4years,and graft success in only 17% ofeyes [2]. Complications included conjunctival scarring, corneal graft failure, and corneal ulcerations (Streptococcus pneumoniae). Systemic immunomodulation seems to have a favorable influence on the outcome of glaucoma implant surgery in patients with uveitic glaucoma and autoimmune disease (e.g., juvenile rheumatoid arthritis) [13].
7.4.7 Nonperforating Glaucoma Surgery
Nonperforating glaucoma surgery,such as deep sclerectomy or viscocanalostomy,has been performed in infantile glaucoma as a primary and secondary intervention.The efficacy and surgical risks of this surgery are a matter of controversy.While some authors report good success rates of 75% without essential surgical side effects,others emphasize the problems and risks of these procedures in refractory congenital glaucoma leading to a further thinning of the scleral envelope [36,53]. Nonperforating glaucoma surgery has been proposed as a safe and promising approach in episcleral venous pressure glaucoma (e.g., Sturge-Weber-Krabbe syndrome), as surgical risks are minimized and late goniopuncture can produce a late and “controlled”filtration [36].
7.4.8 Cyclodialysis
Cyclodialysis was abandoned long ago owing to the unpredictability of the surgical outcome. With the increasing use of viscoelastics, cyclodialysis has become more and more attractive as an ab-interno technique,alone in refractory aphakic glaucoma or in combination with goniotomy in the developmental glaucomas [34]. If successful, the uveoscleral outflow can be greatly increased. However, longstanding ocular hypotony can result from cyclodialysis.
7.4.9 Cyclodestructive Procedures
Over the last decade, laser destruction of the ciliary body has gradually replaced cryodestruction as the cyclodestructive procedure of choice in refractory congenital glaucoma,since the ocular side effects are less severe after laser surgery.Owing to the anomalous limbal anatomy ofbuphthalmic eyes,it is feasible to perform transscleral laser coagulation ofthe ciliary body with the aid of transscleral illumination in order to determine the exact localization of the ciliary body and to identify areas of previous destruction. The most frequent method used to destroy the nonpigmented ciliary body in pediatric glaucoma is contact-diode transscleral cyclophotocoagulation (TSCPC). Most retrospective studies reveal that this laser procedure is generally applied more than once in each patient. Although IOP reduction can be achieved by TSCPC after 1year, the success rates are not always completely convincing,ranging between 27% and 79% [5,28,35] depending on the success criteria used and the number oflaser interventions. The results following contact-diode transscleral laser cyclophotocoagulation seem to be worse in congenital or juvenile glaucoma compared than in older patients with primary open-angle glaucoma [50]. Possibly, regenerative mechanisms ofthe infantile ciliary epithelium contribute to this finding.
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The postoperative risk of phthisis seems relatively low, around 3.5% [28]. Signs of intraocular inflammation are relatively frequent, around 25%. Especially in aphakic eyes, severe vision-threatening postoperative complications including retinal and choroidal detachment have been described in children.[5]
7.4.10 Surgical Iridectomy (Laser Iridotomy)
Iridectomy is the treatment of choice in certain cases of angle-closure glaucoma. Pupillary block that should be treated by iridectomy may be present in spherophakia (e.g.,Weill-Marchesani syndrome),in uveitic glaucoma with 360° posterior synechiae, and in nanophthalmic eyes. Pupillary block mechanisms due to lens dislocation (e.g.,in Marfan’s syndrome) should be primarily treated by lens extraction rather than by iridectomy. Other reasons for angleclosure glaucoma in children may be iridociliary cysts,hyperplastic primary vitreous,and retinopathy of prematurity [47].
7.4.11 Special Aspects
7.4.11.1 Secondary Glaucoma in Pediatric Uveitis
Secondary glaucoma is observed in nearly 30% of children with chronic uveitis. Owing to the high rate of band keratopathy, the visual prognosis is still poor today for every third child.In older children with glaucoma and arthritis,the medical treatment option is effective in 30–50% of cases, thus avoiding glaucoma surgery with unpredictable prognosis. A few studies have reported good surgical results following glaucoma implant surgery combined with systemic immunomodulation in children with uveitis, but also following goniotomy and trabeculodialysis.
7.4.11.2 Aphakic Glaucoma
In contrast to primary congenital glaucoma, some standard techniques, including filtering surgery with antimetabolites [6, 38] or goniosurgery [56], reveal unsatisfactory results in aphakic glaucoma in children.Acceptable longterm results have been reported – albeit with a considerable rate of postoperative complications – for glaucoma implant surgery [12] and with temporarily limited success for cyclodiode laser treatment [32]. A recent study has raised the question of whether delayed surgery in congenital cataract might reduce the risk ofglaucoma.In this retrospective analysis,early cataract surgery during the 1stmonth of life increased the 5-year risk of secondary glaucoma (50%) compared to those eyes that underwent cataract surgery later (15%). Corrected visual acuity did not differ between eyes operated before and after 1month of age. The 5-year risk of glaucoma in at least one eye was 25% following bilateral limbal lensectomy,with anterior vitrectomy remaining at a constant level for the first 5years [55].From these data,glaucoma risk in modern surgery of congenital cataract by a limbal approach must still be considered relatively high.
7.5 Surgical Complications
7.5.1 Intraoperative Complications
Chamber angle bleeding with small hyphema occurs in two-thirds ofeyes during trabeculotomy and in a quarter ofeyes undergoing primary trabeculectomy. The blood is usually absorbed during the 1st postoperative day.A frequent intraoperative complication (>5%) of trabeculotomy is early perforation of the anterior chamber by the trabeculotomy probe. Further, relatively rare,instrumentally induced intraoperative complications of trabeculotomy are cyclodialysis with postoperative hypotony, iris damage, and lens subluxation [31]. Although trabeculectomy is widely performed by many
106 Chapter 7 Management of Infantile Glaucoma
ophthalmic surgeons, this procedure remains technically challenging in congenital glaucoma, as the limbal anatomy is usually distorted and the sclera extraordinarily thin.This can lead to inadvertent scleral perforation during preparation of the scleral flap. Another potential risk can be prolapse of the vitreous or ciliary body through the peripheral iridectomy into the trabeculectomy opening,especially in the case of a primarily dislocated lens.Typical intraoperative problems of goniotomy may be touching of the lens, with subsequent cataract formation and leaking corneal incisions. Intraoperative complications of cyclodialysis ab-interno also include massive hemorrhage.
7.5.2 Postoperative Complications
Retinal detachment in buphthalmic eyes following trabeculotomy has been reported with a frequency of 3% over a mean follow-up period of 9years [31]. This demonstrates the general susceptibility to retinal tears in the stretched and highly myopic buphthalmic eye rather than a special postoperative risk of any one surgical method.Even after goniotomy,Rice [46] reported several cases ofretinal detachment with congenital glaucoma. Long-standing postoperative hypotony may sometimes lead to retinal detachment. Prolapse of the elongated ciliary processes and iris incarceration in the trabeculectomy opening are not infrequent findings after trabeculectomy (Fig.7.6) and do not therefore necessarily reflect surgical failure.Scleral incisions performed during scleral flap dissection in trabeculectomy or deep sclerectomy increase the risk of scleral rupture in case of subsequent blunt trauma to the buphthalmic eye (Fig.7.7). Further severe postoperative complications comprise subluxation of the crystalline and cataract formation, typically following trabeculectomy, but also following trabeculotomy or goniotomy.The risk of blebitis and endophthalmitis should be borne in mind, especially after filtering surgery with mitomycin C, but also after glaucoma implant surgery if conjunctival erosion occurs.
In eyes with Peters anomaly,the risk of postoperative complications is especially high. In a retrospective study of34 eyes in 19 patients who had undergone trabeculectomy,trabeculotomy, goniotomy,Molteno shunt implantation,cyclodialysis,or cyclocryotherapy,a graft failure was observed in 26 eyes (76%), cataract in six eyes (18%), inoperable retinal detachment with phthisis in 12 eyes (35%),and phthisis alone in six (18%).Finally,there was no light perception in 12 eyes (35%),light perception alone in seven eyes (12%), and vision between 20/400 and hand motion in 12 eyes (35%) [58].
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Fig.7.7. Eight-month-old girl with primary congenital glaucoma that had a blunt trauma to the eye 2weeks following uncomplicated trabeculectomy,resulting in a broad uveal prolapse along the scleral flap
Fig.7.6. Slit-lamp photography in a 4-year-old girl 2years following primary trabeculectomy because of primary congenital glaucoma. Uveal prolapse at the edges of the scleral flap has occurred,but is covered by conjunctiva. The intraocular pressure has been normal following surgery
7.6 Prognosis
Although the main pathological feature reported in primary congenital glaucoma is trabeculodysgenesis, resulting in outflow obstruction and a rise in intraocular pressure, the starting point for pressure-reducing surgery varies from patient to patient and prognosis of any surgery seems to be largely governed by the underlying nature of dysgenesis.Any association with other ocular or systemic abnormalities evidently reduces the long-term prognosis.Early and severe manifestation ofbuphthalmia (axial length >24mm) seems to be a limiting factor for individual prognosis in trabeculotomy and trabeculectomy, but also in glaucoma implant surgery.Russell-Eggitt also reported a poor outcome for goniotomy in very young patients with congenital glaucoma, thereby confirming the importance of age for individual prognosis, whatever form of pressure-reducing surgery is used [49].The limited prognostic power of preoperative intraocular pressure can mainly be attributed to the many sources of error in tonometry in buphthalmic eyes.
7.7 Concluding Remarks
For many reasons, information on surgical treatment in congenital glaucoma is based almost exclusively on retrospective studies. Retrospective studies comparing the outcome of different strategies have to be evaluated with caution,especially if the decision to operate in a certain way follows regional and historical trends or individual preferences and experience,as is obvious in the treatment of congenital glaucoma.Furthermore,the small number of patients treated by each particular surgical strategy limits the statistical significance of most retrospective studies.
ملخص للعيادة the تعتبر جراحة تخفيف الضغط هي العلاج المفضل في الجلوكوما الخلقية ، حيث أن الخيارات الطبية ، مثل استخدام البريموندين ، محدودة بسبب الآثار الجانبية الجهازية interventions التدخلات الجراحية في الخط الأول في الجلوكوما الخلقية الأولية هي trabeculotomy ، الجمع بين trabeculotomy- trabeculectomy أو trabeculectomy ∑ إن تشخيص جميع التدخلات الجراحية يرتبط ارتباطًا وثيقًا بعمر الطفل ، وانتفاخ ما قبل الجراحة للعين ، ومزيد من أمراض العين والجهازية المصاحبة لها lications مضاعفات ما بعد الجراحة الشديدة في العيون الباطنية إعتام عدسة العين ، التهاب باطن المقلة بعد تطبيق mitomycin C ∑ Amblyopia قد يتطور نتيجة لعتامة القرنية ومشاكل الانكسار (على سبيل المثال ، قيلة الاميتريوم ، قلة النظر)

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