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Chapter 219 – Congenital Glaucoma

Chapter 219 – Congenital Glaucoma

 

JAMES D. BRANDT

 

 

 

 

 

DEFINITION

• Glaucoma that arises in children under 2 years of age.

• Primary infantile glaucoma—the result of isolated abnormal development of the anterior chamber angle structures.

• Secondary infantile glaucoma—associated with a variety of ocular and systemic syndromes and with surgical aphakia.

 

KEY FEATURES

• Elevated intraocular pressure.

• Glaucomatous optic atrophy.

• Ocular enlargement (buphthalmos).

 

ASSOCIATED FEATURES

• Corneal edema.

• Haab’s striae.

• Photophobia.

• Tearing.

• Amblyopia.

 

 

 

INTRODUCTION

In this chapter, an overview of the various forms of glaucoma that occur in infants and young children is given. Many clinicians group these varied disorders under the somewhat generic heading of congenital glaucoma. Primary infantile glaucoma, also commonly referred to as congenital glaucoma, represents a specific developmental defect of the anterior chamber angle structures and is exceedingly rare. Nonetheless, most ophthalmologists will encounter the wide variety of secondary forms of glaucoma seen in this age group. In this chapter, the reader is provided with a basic understanding of how the various forms of glaucoma can manifest in infants and young children, along with their differential diagnosis and the options available for management.

EPIDEMIOLOGY AND PATHOGENESIS

The incidence of primary infantile glaucoma often is quoted as between 1:10,000 and 1:15,000 live births in the heterogeneous population of the United States.[1] [2] In other countries, the published series range from a low of 1:22,000 in Northern Ireland[3] to a high of 1:2500 in Saudi Arabia[4] and 1:1250 among gypsies in Romania.[5] Primary infantile glaucoma is bilateral in up to 80% in larger case series [6] ; in North America and Europe it is more common in boys,[7] whereas in Japan it is more common in girls.[8]

The varied incidence among different populations suggests a strong genetic component to the disease. In fact, most (about 90%) of new cases of primary infantile glaucoma appear to be sporadic. However, in the remaining 10% there appears to be a strong familial component; penetrance of the defect varies in the range of 40–100%. The recent characterization of genes linked to primary infantile glaucoma in a large cohort of affected families suggests that over the next few years genetic screening may become possible for selected mutations. [9] [10] [11] Taken as a group, the secondary glaucomas of childhood are far more common than primary infantile glaucoma. Perhaps the most common of these are the glaucomas associated with cataract extraction in infancy. Lens opacities are noted in 0.44% of all live births.[12] The incidence of glaucoma in children who have undergone lens extraction ranges from as low as 8%[13] to as high as 41% if follow-up is extended to middle childhood.[14] These figures suggest that glaucoma in aphakic children is more common than is recognized generally.

The exact cause and pathophysiology that underlies primary infantile glaucoma remains unknown. In an attempt to explain why the operation he developed—goniotomy—was so successful in cases of infantile glaucoma, Barkan[15] postulated that a thin, imperforate membrane covered the anterior chamber angle structures and impeded aqueous humor outflow. This so-called Barkan’s membrane, as the structure became known, has not been confirmed on light or electron microscopy, despite numerous attempts to do so. Some observers have described a compaction of trabecular meshwork that might appear clinically as a continuous membrane.[16] That the anterior chamber “cleavage” disorders,[17] despite their broad spectrum, often are associated with infantile glaucoma suggests that the principal defect in primary infantile glaucoma is a failure of one or more steps in the normal development of the anterior chamber angle. As the genes associated with primary infantile glaucoma are characterized further and the physiological or developmental role of the proteins they encode become better understood, the molecular, cellular, and embryological pathophysiology of this rare disorder will become clear. [10]

Among the secondary glaucomas of childhood, the underlying pathophysiology is as varied as that in adults. Occurrence at or shortly after birth indicates a profound developmental abnormality of the anterior chamber angle, whereas manifestation later in life usually suggests a different process. For example, patients who have aniridia who have obvious glaucoma at birth or early childhood have visibly abnormal anterior chamber angle structures; when glaucoma becomes apparent later in life in patients who have aniridia, the previously functional trabecular meshwork is occluded by an anterior migration and rotation of the rudimentary iris stump.[18] In patients who suffer Sturge–Weber syndrome (SWS) or its variants, appearance at birth is associated with a gonioscopic appearance that cannot be differentiated from that of primary infantile glaucoma ( Fig. 219-1 ), whereas later occurrence is thought to be related to elevated episcleral venous pressure.

Angle closure may be caused by forward pressure from a process that occurs in the vitreous cavity, as in persistent hyperplastic primary vitreous, retinopathy of prematurity, or retinoblastoma. Synechial angle closure, caused by chronic inflammation or neovascularization, is seen in a variety of situations. Primary angle closure that results from iris bombé generally is not seen in children, except in cases of spherophakia, but when the pupil becomes secluded by an inflammatory or neovascular

 

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Figure 219-1 Angle appearance in Klippel–Trenaunay–Weber syndrome. Koeppe lens visualization of the anterior chamber angle of the right eye of the patient shown in Figure 219-7 . Note the striking similarity of the angle appearance to that of primary infantile glaucoma (see Fig. 219-6 ).

membrane, iris bombé and subsequent angle closure may occur.

Secondary open-angle glaucomas also occur in young children. Both corticosteroid-induced and chronic uveitic glaucomas are described clearly.[19] Open-angle glaucoma may develop long after blunt trauma to the eye has occurred[20] and also may follow the spontaneous bleeding of juvenile xanthogranuloma.[21]

It is difficult to classify the underlying cause of glaucoma that frequently follows pediatric cataract extraction. Walton[22] examined 65 children, most of whom developed glaucoma 2 or more years after lensectomy. Preoperative gonioscopy revealed no consistent angle defect, but postoperative gonioscopy revealed a near-constant (96%) filtration-angle deformity he characterized as blockage of the posterior trabecular meshwork with pigment and synechiae.[22] Many clinicians familiar with this scenario believe that retained lens material is one risk factor for glaucoma that follows pediatric cataract extraction; another may be the presence of a small cornea. Parks et al. [23] described a secondary glaucoma risk of 15% in their cohort of 174 eyes; only 2.9% of eyes that had normal corneal diameters developed glaucoma, whereas 32% of eyes that had corneal diameters smaller than 10?mm developed the disease. The presence of both a cataract and a small cornea almost certainly indicates a problem during ocular development; perhaps cataract surgery unmasks a marginally functional and maldeveloped anterior chamber angle that causes later glaucoma.

OCULAR MANIFESTATIONS

The typical infant with congenital glaucoma is referred to an ophthalmologist initially because of clinically apparent corneal edema ( Fig. 219-2 ). The corneal edema may be subtle, especially in bilateral cases, or profound, with an enlarged corneal diameter and globe, breaks in Descemet’s membrane (Haab’s striae), and sometimes even acute hydrops ( Fig. 219-3 ). Often in these cases, the commonly described triad of epiphora, blepharospasm, and photophobia has been present for some time but is dismissed until the more alarming corneal edema becomes apparent. The epiphora of congenital glaucoma often is misattributed to congenital nasolacrimal duct obstruction, which is found in 5–6% of unselected newborns.

The hallmark of all forms of glaucoma in infants and young children is ocular enlargement, which occurs because the immature and growing collagen that constitutes the cornea and sclera in the young eye still responds to increased intraocular pressure (IOP) by stretching. All parts of the globe may stretch in response to the elevated IOP until 3–4 years of age, and glaucoma-related axial myopia may be seen until the early teenage years. Clinically, ocular enlargement is most evident as an increase in

 

 

Figure 219-2 Clinical appearance of primary infantile glaucoma. This 8-month-old boy had an acute (3-day) history of corneal edema in the left eye. Note the enlarged corneas in both eyes and the epiphora. Intraocular pressure at examination under anesthetic was >35?mmHg (>4.7?kPa) in the right eye. Trabeculotomy ab externo was carried out bilaterally.

 

 

Figure 219-3 Acute corneal hydrops in a neonate. The baby girl whose eye is shown here had acute hydrops at birth, an extreme Descemet’s tear, and corneal decompensation associated with infantile glaucoma. The child has an older sister who had an identical clinical picture 2 years previously. They are the children of consanguineous gypsy parents from Romania and may demonstrate examples of the highly penetrant, inherited form of infantile glaucoma described in this population by Gencik.[5]

corneal diameter. A variety of published series provide some guidelines as to normal measures of corneal diameter[24] [25] ; in general, the horizontal corneal diameter in the normal neonate is in the range 10.0–10.5?mm and increases 0.5–1.0?mm during the first year of life. In an infant in whom glaucoma is suspected, a horizontal corneal diameter greater than 12?mm indicates a high index of suspicion for the disease.

As the cornea stretches and distends, Descemet’s membrane and the overlying corneal endothelium may fracture and rip, which results in breaks in these structures that are evident clinically as profound corneal edema (see Fig. 219-2 ) and, in severe cases, acute hydrops (see Fig. 219-3 ). As the endothelial cells migrate over the breaks and lay down new basement membrane, ridges develop along the separated edges of Descemet’s membrane, which results in the formation of the double striae first recognized by Haab in 1899 [26] ( Fig. 219-4 ).

In children over 2 years of age, corneal enlargement usually is not the predominant sign that glaucoma is present. In these children, decreased visual acuity or strabismus noted at the pediatrician’s office or progressive unilateral myopia noted in an optometrist’s office prompts a referral and the correct diagnosis.

The hallmark of all forms of glaucoma, and the principal cause of irreversible visual loss, is damage to the optic nerve. Early descriptions of infantile glaucoma stated that optic nerve cupping occurred late in the disease process. It is now apparent not only that cupping may occur rapidly in infants, but also that with surgical management and normalization of IOP, this cupping

 

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Figure 219-4 Haab’s striae. A red reflex view of the right eye of the infant shown in Figure 219-2 , at 5 years of age. Haab’s striae are seen just adjacent to the visual axis. The child has a best-corrected visual acuity of 20/50 (6/15) in the right eye and 20/20 (6/6) in the left eye despite aggressive amblyopia management.

 

 

 

 

Figure 219-5 Choroidal hemangiomas associated with Sturge–Weber syndrome. A, An extensive choroidal hemangioma in the posterior pole of a 10-year-old boy who has Sturge–Weber syndrome before uncomplicated trabeculectomy. B, The same hemangioma after uncomplicated trabeculectomy. Preoperative intraocular pressures were 30–40?mmHg (4.0–5.3?kPa); note the dramatic reversal of optic disc cupping. The presence of choroidal hemangiomas increases the risk of intraoperative choroidal expansion and hemorrhage when the eye is entered and the intraocular pressure is reduced.

is reversible.[27] Indeed, reversibility of optic nerve cupping is one of the hallmarks of successful management of glaucoma in infants and young children ( Fig. 219-5 ). The resilience of the infant optic nerve should be taken into account by the surgeon who contemplates incisional surgery based only on borderline anterior segment findings; if the optic nerve appears normal, a repeat EUA in a few weeks may spare the child an unnecessary intraocular procedure.

DIAGNOSIS AND ANCILLARY TESTING

The diagnosis of glaucoma in infants is clinical. In most cases, particularly when the disease occurs unilaterally or asymmetrically, the diagnosis is made in the office using a penlight (see Figs. 219-2 and 219-3 ). With some practice, IOP can be measured in the office in a conscious, swaddled infant using a Tono-Pen or handheld Goldmann tonometer. Usually, the IOP in infants with normal eyes is in the range of 11–14?mmHg (1.5–1.9?kPa) using these devices. The office measurement of an IOP greater than 20?mmHg (2.7?kPa) in a calm, resting infant is suspicious for glaucoma when other signs and symptoms suggest the disease, as is an asymmetry of more than 5?mmHg (6.7?kPa) in suspected unilateral or asymmetrical cases. Measurements of IOP undertaken while a child cries and resists efforts to hold the eye open are usually invalid, because the Valsalva maneuver and lid squeezing can result in an IOP of 30–40?mmHg (4.0–5.3?kPa), even in normal eyes.

Examination of the optic nerve is attempted whenever possible, because obvious glaucomatous cupping confirms the diagnosis. Shaffer and Hetherington noted a cup-to-disc (C/D) ratio greater than 0.3 in 68% of 126 eyes affected by primary infantile glaucoma,[28] whereas a C/D ratio greater than 0.3 was found in less than 2.6% of newborns with normal eyes.[29] Asymmetry in the C/D ratio for the two optic nerves, especially when the asymmetry corresponds to other findings, is strongly suggestive of glaucoma.

A Koeppe infant diagnostic lens that does not have a central depression employs a lid-retention flange to prevent the infant from squeezing out the contact lens. Once the lens is in place, good visualization of the disc is possible using a direct ophthalmoscope, even with a relatively small pupil; with dilatation, fundus photography to document the appearance of the optic nerve may be possible.

With a Koeppe diagnostic infant lens in place, gonioscopy may be performed, even on a conscious infant in the office. Simultaneous gonioscopy of both eyes may be carried out to compare the angle appearance in unilateral or asymmetrical cases. The diagnosis of glaucoma is not made using gonioscopic appearance alone but is based primarily on the other signs and symptoms of the disease. However, gonioscopy may help to differentiate among the various forms of glaucoma and provide the surgeon with an idea of whether angle surgery (goniotomy or trabeculotomy) or fistulization surgery (trabeculectomy or drainage implant) should be the first intervention made. The gonioscopic appearance of the anterior chamber angle in primary infantile glaucoma is characteristic ( Fig. 219-6 ); the iris inserts anteriorly compared with the normal infant angle. The stroma of the peripheral iris is hypoplastic, unpigmented, and has a scalloped appearance.

If the diagnosis of glaucoma is confirmed or strongly suspected based on the office examination, an examination under anesthesia (EUA) and definitive surgical management is pursued within a few days. Details of EUA and of goniotomy and trabeculotomy are provided in Chapter 238 .

As noted previously, some forms of primary infantile glaucoma represent heritable disorders, as do many of the secondary or systemically associated glaucomas of childhood. All children who have glaucoma and who are diagnosed at birth or during early childhood must be referred to a clinical geneticist familiar with ocular disease; in some cases a subtle syndromic diagnosis

 

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Figure 219-6 Gonioscopic appearance of the anterior chamber angle in primary infantile glaucoma. When viewed through a Koeppe diagnostic lens, the iris is seen to insert anteriorly, and the peripheral iris is hypoplastic and unpigmented and has a scalloped appearance. A sheen occurs over the angle structures (which is difficult to photograph) and gives the impression that a membrane coats the surface of the angle; however, Barkan’s membrane has not been identified histologically.

 

 

 

Differential Diagnosis of Ocular Signs and Symptoms in Congenital Glaucoma

 

CORNEAL EDEMA OR CLOUDING

Congenital hereditary endothelial dystrophy

 

Mucopolysaccharidoses I, IS, II, III

 

Cystinosis

 

Sclerocornea

 

Rubella keratitis

 

Obstetric birth trauma (“forceps injury”)

 

Chemical injury

 

 

EPIPHORA AND/OR RED EYE

Nasolacrimal duct obstruction

 

Conjunctivitis (viral, chlamydial, bacterial)

 

Corneal epithelial defect, abrasion

 

 

PHOTOPHOBIA

Conjunctivitis

 

Iritis

 

Trauma (especially hyphema)

 

 

CORNEAL ENLARGEMENT

Axial myopia

 

Megalocornea (X-linked or sporadic)

 

Microphthalmic fellow eye

 

 

 

 

may be made that has important implications for the parents’ childbearing plans. With the predicted advances in the molecular diagnosis of some forms of infantile glaucoma, it may soon be possible to offer prenatal screening for some families.

DIFFERENTIAL DIAGNOSIS

The differential diagnosis of the various signs and symptoms of glaucoma in children is given in Box 219-1 ; this list is by no means exhaustive.

Corneal cloudiness may have a myriad of causes. Corneal opacity that results from hereditary dystrophies is usually symmetrical, whereas corneal edema that arises from obstetrical trauma is usually unilateral.

Corneal enlargement may result from megalocornea, which is frequently X-linked. In affected children, the anterior chamber angle, IOP, and optic nerve are all normal. Some clinicians consider megalocornea to be a forme fruste of primary infantile glaucoma[1] ; such children should be followed carefully for later signs of glaucoma. An entirely normal eye may appear enlarged relative to a microphthalmic fellow eye and, in such cases, familiarity with the age-appropriate corneal diameters and axial lengths prevents misdiagnosis.

The differential diagnosis of a red, tearing eye in a child is a lengthy procedure; infectious, malignant, or inflammatory causes rarely result in a diagnostic dilemma. Congenital nasolacrimal duct obstruction occurs in 5–6% of otherwise normal infants and coexists with infantile glaucoma with similar frequency. If epiphora persists after apparently successful management of glaucoma in an infant, the nasolacrimal system must be evaluated.

SYSTEMIC ASSOCIATIONS

A number of classifications of congenital and infantile glaucomas have been proposed; one that the author has found clinically useful is given in Table 219-1 . It is beyond the scope of this chapter to cover all of the glaucoma syndromes associated with developmental and systemic disorders—an almost encyclopedic coverage of these forms of pediatric glaucoma is given by Ritch et al.[30] Here, two of the more commonly encountered secondary glaucomas associated with ocular and systemic disorders are discussed.

Aniridia

Congenital aniridia is a heritable disease of the eye characterized by an obvious iris defect (which varies from an almost complete absence to relatively complete, albeit abnormal, irides), decreased visual acuity with nystagmus, small corneas, small discs, foveal hypoplasia, and cataract. Glaucoma occurs in 50–75% of patients who have aniridia.

Aniridia may be either sporadic or familial. The gene for aniridia has been localized to the short arm of chromosome 11; a deletion in this area results in a syndrome that comprises the ocular findings given above with, in addition, mental retardation, genital anomalies, and a greatly increased risk of Wilms’ tumor at a young age.[31] Children of parents who have aniridia are at a 50% risk of inheriting the syndrome.

Although most children who have aniridia go on to develop glaucoma, most do not do so until late in the first decade of life. This late-onset glaucoma associated with aniridia appears to be the result of a unique form of angle closure. [18] It is advisable to re-examine these patients scrupulously and treat when early angle closure and optic nerve changes have been confirmed. Chen and Walton[32] recently described goniosurgery to prevent the development of aniridic glaucoma in 55 eyes of 33 patients, reporting excellent results. Adachi and colleagues[33] report excellent results with trabeculotomy and advocate its use in aniridia. However, once severe disease is present and requires surgery, fistulization is the procedure of choice.

Sturge–Weber Syndrome and Variants

Although rare, glaucoma associated with encephalotrigeminal angiomatosis (SWS) is one of the more frequently encountered forms of glaucoma of childhood. There are several variants of SWS, which is considered to be one of the phakomatoses. Classic SWS comprises the triad of port wine facial telangiectasis (nevus flammeus) in the distribution of the trigeminal nerve that respects the vertical midline, ipsilateral glaucoma, and intracranial angiomata. In patients affected by glaucoma, both the upper and lower lids usually are involved in the facial telangiectasis ( Fig. 219-7 ). Cibis et al.[34] report that glaucoma occurs in about one third of patients who have SWS.

As noted previously, SWS-associated glaucoma that manifests early in life is likely to be the result of a developmental angle abnormality

 

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TABLE 219-1 — CLASSIFICATION OF THE CONGENITAL AND INFANTILE GLAUCOMA

PRIMARY INFANTILE GLAUCOMA (CONGENITAL GLAUCOMA, TRABECULODYSGENESIS)

SECONDARY INFANTILE GLAUCOMA

 

Associated with mesodermal neural crest dysgenesis

Iridocorneotrabeculodysgenesis

• Rieger’s anomaly or syndrome

• Axenfeld’s anomaly or syndrome

• Peters’ anomaly

• systemic hypoplastic mesodermal dysgenesis (Marfan’s syndrome)

• systemic hyperplastic mesodermal dysgenesis (Weill–Marchesani syndrome)

Iridotrabeculodysgenesis (aniridia)

Associated with phakomatoses and hamartomas

Neurofibromatosis (Von Recklinghausen’s disease)

Encephalotrigeminal angiomatosis (Sturge–Weber syndrome and variants, e.g., Klippel–Trénaunay–Weber syndrome)

Angiomatosis retinae et cerebelli

Oculodermal melanocytosis

Associated withmetabolic disease

Oculocerebrorenal syndrome (Lowe’s syndrome)

Homocystinuria

Associated withinflammatory disease

Maternal rubella syndrome (congenital rubella)

Herpes simplex iridocyclitis

Associated withmitotic disease

Juvenile xanthogranuloma (nevoxanthoendothelioma)

Retinoblastoma

Associated with othercongenital disease

Trisomy 13–15 syndrome (Patau’s syndrome)

Rubinstein–Taybi syndrome

Persistent hyperplastic primary vitreous

Congenital cataract

• in phakic eyes

• in aphakic eyes following surgery

(Modified and expanded from deLuise VP, Anderson DR. Primary infantile glaucoma (congenital glaucoma). Surv Ophthalmol. 1983;28(1):1–19; Freedman SF, Walton DS. Approach to infants and children with glaucoma. In: Epstein DL, Allingham RR, Schuman JS, eds. Chandler and Grant’s glaucoma, ed 4. Baltimore: Williams & Wilkins, 1997; and Walton DS. Primary congenital open angle glaucoma: a study of the anterior segment abnormalities. Trans Am Ophthalmol Soc. 1979;77:746–68.)

 

 

similar to that found in primary infantile glaucoma (see Fig. 219-1 ), whereas glaucoma that occurs later in life may result from elevated episcleral venous pressure. The best management of SWS-associated glaucoma is unclear; when the angle appears similar to that of primary infantile glaucoma, goniotomy or trabeculotomy are reasonable first steps[35] ; some have advocated the use of combined trabeculotomy and trabeculectomy as the best procedure.[36] When increased episcleral venous pressure is invoked as the cause of elevated IOP, a fistulization procedure (trabeculectomy or drainage implant) might be more likely to succeed. The presence of choroidal hemangiomas in many of these patients (see Fig. 219-5 ) increases the risk of choroidal expansion or hemorrhage intraoperatively; some surgeons advocate using prophylactic posterior sclerotomies prior to entering the anterior chamber.

PATHOLOGY

Because primary infantile glaucoma is rare, few of these infants die of unrelated causes, and the angle surgery does not involve the excision of a surgical specimen. Pathology descriptions of the anterior

 

 

Figure 219-7 An infant who has Klippel–Trenaunay–Weber syndrome. Note the extensive facial telangiectasis that does not respect the vertical midline. Limb and trunk involvement is characteristic (with profoundly asymmetrical limb growth in severely affected individuals). Upper and lower lids are involved, which indicates a high likelihood of glaucoma (see Fig. 219-1 ).

chamber angle in this disease are limited to a small number of specimens. Furthermore, eyes enucleated at an advanced stage because of blindness and pain may not be representative of the early disease and a trabeculectomy specimen is fixed in a nonphysiological manner, as a tissue fragment rather than as a living tissue with a hydraulic pressure across it. Nonetheless, several general observations have been made.[8] The iris inserts anteriorly (see Fig. 219-6 ), but the angle is open. The trabecular meshwork appears open and is perforate, and Schlemm’s canal usually is present and open. As noted previously, histologically, Barkan’s membrane has not been identified conclusively.

TREATMENT

The preferred management of the congenital forms of glaucoma is surgical, not medical. Medical therapy alone is rarely effective for these conditions. Surgical techniques used on the anterior chamber angle (goniotomy and trabeculotomy) enjoy a high degree of success in primary infantile glaucoma, and alternative surgical approaches (trabeculectomy and drainage implant surgery) may be highly effective in the secondary congenital and pediatric forms. Even with the newer topical agents and formulations that can be administered once a day and that may be safer (systemically) than those previously available, it remains unrealistic to expect more than short-term medication compliance in children who have a lifelong disease that may result in blindness.

The surgical management of all infants affected by glaucoma begins with a detailed EUA. The ophthalmologist who undertakes the surgical management of an infant or child who has glaucoma must approach the EUA with experience in infant gonioscopy and a flexible surgical plan. Surgical flexibility is particularly crucial in the secondary forms of congenital glaucoma, for which the surgeon must be prepared to alter the surgical plan depending upon what is found intraoperatively; for example, in the infant with glaucoma associated with aphakia, a synechially closed anterior chamber angle is a relative contraindication to conventional angle surgery, so a trabeculectomy or drainage implant must be considered, instead.

In primary infantile glaucoma, either goniotomy or trabeculotomy is the procedure of choice; these are associated with success rates in various series of 90% or greater. Goniotomy requires a clear cornea for adequate observation of the anterior chamber angle; trabeculotomy may be performed if the cornea is hazy or opaque. The choice of procedure is left to the surgeon’s discretion.

Trabeculectomy has been proposed as a primary management option for glaucoma in children,[37] [38] considering the technical challenges of the rarely performed goniotomy or trabeculotomy

 

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compared with the more common trabeculectomy. However, a trabeculectomy in an infant eye is not without its own set of unique challenges. To raise a partial thickness flap in a buphthalmic eye is particularly difficult, as is the perioperative adjustment of flap tension without the use of the argon laser to lyse flap sutures. Hypotony and a flat chamber that cause a cataract in an infant may result in profound amblyopia before the visual axis is cleared. Most proponents of filtration surgery in infants and young children advocate the intraoperative application of the potent antimetabolite mitomycin C, because postoperative injection of 5-fluorouracil usually is not an option. Filtration procedures augmented with antimetabolites result in the formation of thin, acellular blebs that impart high susceptibility to late-onset bleb infection and endophthalmitis.[39] [40] The prospect of a lifetime with a 1–2% annual rate of infectious complications must be considered when the surgical approach to these difficult cases is chosen.

Another alternative to consider in cases of congenital glaucoma for which conventional angle surgery has either failed or is unlikely to succeed is the use of a drainage implant, such as a Baerveldt, Molteno, or Ahmed implant. This option is attractive, particularly for patients in whom aphakia is managed by daily wear or extended wear contact lenses, because the fistula into the eye is diverted posteriorly, away from the edge of the contact lens, and perhaps reduces the incidence of contact lens–facilitated endophthalmitis. Several series examined the results of drainage implants in the pediatric population.[41] [42] Although the short-term success of drainage implants appears less than that using antimetabolite-augmented trabeculectomy in this age group, none of the reported clinical series has followed up for as long as 10 or 20 years, by which time devastating infectious complications might be expected to have taken their toll.

When conventional glaucoma surgery has failed to control IOP, cycloablative procedures such as cyclocryotherapy[43] or laser cyclophotocoagulation[44] may lower the IOP profoundly ( Fig. 219-8 ). Cyclodestructive procedures are painful and in children usually are performed under general anesthesia. A long-acting retrobulbar block of bupivacaine 0.75% can be used to provide pain control for the first 12 hours after surgery. When the greater part of vision is lost and the goal of the procedure is pain control, the block may be combined with retrobulbar alcohol for a longer analgesic effect.

COURSE AND OUTCOMES

Glaucoma in children may be recognized anytime from birth to late childhood. The age of onset appears to have prognostic implications,[2] [8] in that a child who has buphthalmos at birth most likely has more significant developmental angle anomalies and is

 

 

Figure 219-8 Diode Laser Cyclophotocoagulation. Trans-scleral application of laser energy to the ciliary body of an eye with Peters’ anomaly following numerous glaucoma and corneal transplant procedures. In such disrupted eyes it is beneficial to identify the ciliary body by transillumination to better aim the laser.

likely to have secondary damage to the structures of the eye already. It is these children, along with those who have more profound disorganization of the anterior segment (e.g., Peters’ anomaly, sclerocornea, microcornea), who require a surgical team approach that involves penetrating keratoplasty, lensectomy, vitrectomy, and drainage implant. Despite aggressive management, most of these eyes achieve only limited, if any, vision.

Happily, the child who has primary infantile glaucoma and who is diagnosed a few months after birth, before dense amblyopia or severe structural damage to the cornea or optic nerve has occurred, may expect a good outcome if the disease is detected and managed promptly. The results of various surgical series of goniotomy and trabeculotomy are reviewed in Chapter 238 ; in general, IOP is reduced in over 90%.

With goniotomy and trabeculotomy as the primary management for infantile glaucoma, and trabeculectomy and drainage implant surgery available for more intractable cases, the surgeon who treats the child affected by glaucoma has many effective options for the management of a disease that uniformly resulted in blindness only 50 years ago. However, the goal of glaucoma management is more than the achievement of normal IOP—it is the achievement of normal visual function. The child shown in Figures 219-2 and 219-4 illustrates this clearly. Despite timely and successful surgical intervention and aggressive amblyopia management, this child has decreased vision in one eye because of amblyopia and will enter adulthood with decreased binocularity. Nonetheless, at present this represents an excellent result and with earlier diagnosis through a better knowledge of the molecular biology of this disorder, results are likely to be even better in the coming decades.

 

 

REFERENCES

 

1. Kwitko ML. Glaucoma in infants and children. New York: Appleton-Century-Crofts; 1973:651.

 

2. Walton DS. Primary congenital open angle glaucoma: a study of the anterior segment abnormalities. Trans Am Ophthalmol Soc. 1979;77:746–68.

 

3. McGinnity FG, Page AB, Bryars JH. Primary congenital glaucoma: twenty years experience. Ir J Med Sci. 1987;156(12):364–5.

 

4. Debnath SC, Teichmann KD, Salamah K. Trabeculectomy versus trabeculotomy in congenital glaucoma. Br J Ophthalmol. 1989;73(8):608–11.

 

5. Gencik A. Epidemiology and genetics of primary congenital glaucoma in Slovakia. Description of a form of primary congenital glaucoma in gypsies with autosomal-recessive inheritance and complete penetrance. Dev Ophthalmol. 1989;16:76–115.

 

6. Moller PM. Goniotomy and congenital glaucoma. Acta Ophthalmol (Copenh). 1977;55(3):436–42.

 

7. Shaffer RN. Genetics and the congenital glaucomas. Am J Ophthalmol. 1965; 60(6):981–94.

 

8. deLuise VP, Anderson DR. Primary infantile glaucoma (congenital glaucoma). Surv Ophthalmol. 1983;28(1):1–19.

 

9. Stoilov I, Akarsu AN, Alozie I, et al. Sequence analysis and homology modeling suggest that primary congenital glaucoma on 2p21 results from mutations disrupting either the hinge region or the conserved core structures of cytochrome P4501B1. Am J Hum Genet. 1998;62(3):573–84.

 

10. Stoilov I, Akarsu AN, Sarfarazi M. Identification of three different truncating mutations in cytochrome P4501B1 (CYP1B1) as the principal cause of primary congenital glaucoma (buphthalmos) in families linked to the GLC3A locus on chromosome 2p21. Hum Mol Genet. 1997;6(4):641–7.

 

11. Sarfarazi M, Akarsu AN, Hossain A, et al. Assignment of a locus (GLC3A) for primary congenital glaucoma (buphthalmos) to 2p21 and evidence for genetic heterogeneity. Genomics. 1995;30(2):171–7.

 

12. Rudolph AM, Hoffman JIE, Rudolph CD. Rudolph’s pediatrics, 20th ed. Stamford, Conn: Appleton & Lange; 1996:xxxvi, 2337.

 

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One comment on “Chapter 219 – Congenital Glaucoma

  1. Dear Author,
    thanks for this article . very informative and everything from etiology to managment of disease in precised form.. when i want to know very badlyabout child glaucoma because one of my cousins son was diagnosed as congenital glaucoma.Thanks a lot once again..
    regards,
    Dr. Sajeera

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