Figure 28-11 Fundus appearance in an adolescent boy with Sturge-Weber syndrome. A, Right eye. Note the glaucomatous disc cupping and deeper red color of surrounding choroid, compared with the healthy fellow eye (B).

Glaucoma is the most common and serious ocular complication. It has been reported to occur in up to approximately 70% of patients. Causes of elevated intraocular pressure (IOP) include elevated episcleral venous pressure, hyperemia of the ciliary body with hypersecretion of aqueous, and developmental anomaly of the anterior chamber angle. Involvement of the upper eyelid skin, choroidal hemangioma, iris heterochromia, and episcleral hemangioma increase the likelihood of glaucoma. Onset of glaucoma can be at birth or later in childhood.

Management

It is essential that patients with SWS undergo a complete ophthalmic evaluation, including measurement of IOP. Sedation or general anesthesia may be necessary for uncooperative children. Patients should be monitored throughout childhood.

SWS glaucoma is difficult to treat. Initial therapy with topical drops can be effective, especially when onset occurs later. Surgery is indicated in early-onset cases and when medical treatment is inadequate. Adequate long-term pressure control can frequently be achieved, although multiple operations are typically necessary. A particular risk of glaucoma surgery in SWS is intraoperative or postoperative exudation or hemorrhage from anomalous choroidal vessels, caused by rapid ocular decompression. The surgeon must exercise special care with implanted drainage devices to prevent excessive early postoperative hypotony. Choroidal or subretinal fluid accumulation after surgery may be dramatic, but spontaneous resorption usually occurs within 1–2 weeks.

Angle surgery (goniotomy and trabeculotomy) has been used successfully in some patients with SWS. Treatment of affected skin with a pulsed-dye laser has been shown to reduce vascularity, considerably improving appearance without causing significant damage to dermal tissue.

Khaler A, Nischal KK, Espinoza M, Manoj B. Periocular port wine stain: the Great Ormond Street Hospital experience. Ophthalmology. 2011;118(11):2274–2278.

Ataxia-Telangiectasia

Ataxia-telangiectasia (AT), or Louis-Bar syndrome, is an autosomal recessive disorder that involves primarily the CNS (particularly the cerebellum), the ocular surface, the skin, and the immune system. Though rare (incidence is approximately 1 in 40,000), AT is thought to be the most common cause of progressive ataxia in early childhood. Truncal ataxia is usually noted during the second year of life, with subsequent development of dysarthria, dystonia, and choreoathetosis. Progressive deterioration of motor function leads to serious disability by age 10 years. Intellectual disability may be present along with microcephaly.

Ocular motor abnormalities are found in many patients with AT and are frequently among the earliest manifestations. Characteristically, there is poor initiation of saccades with preservation of vestibulo-ocular movements, similar to congenital ocular motor apraxia. Head thrusts are used to compensate for saccades. Strabismus and nystagmus may also be present.

Telangiectasia of the conjunctiva occurs in 91% of patients and develops between the ages of 3 and 5 years. Involvement is initially interpalpebral but away from the limbus (Fig 28-12); it eventually becomes generalized. Similar vessel changes can appear in the skin of the eyelids and other sunexposed areas.

Figure 28-12 Abnormally dilated and tortuous interpalpebral conjunctival vessels in a child with ataxia-telangiectasia, seen only in the interpalpebral fissure.

Individuals with AT show greatly increased sensitivity to the tissue-damaging adverse effects of therapeutic radiation and many chemotherapeutic agents. Defective T-cell function in patients with AT is usually associated with hypoplasia of the thymus and decreased levels of circulating immunoglobulin. Recurrent respiratory tract infections and increased susceptibility to malignancies are frequent causes of mortality.

The causative gene in AT, ATM (ataxia-telangiectasia mutated gene), is found on 11q22.3. The protein of ATM is involved in the repair of DNA and the regulation of tumor-suppressor genes. A rapid test from peripheral blood can accurately diagnose AT. AT heterozygosity is present in an estimated 1%–3% of the population. Although gene carriers are generally healthy and cannot be identified except in the context of a known AT pedigree, they are at increased risk for common forms of malignancy and show greater-than-normal sensitivity to radiation.

There is no effective therapy for halting the progression of the ataxia. Several agents (α-lipoic acid, vitamin E, and coenzyme Q10) may slow the deterioration. Neurotoxic chemotherapeutic agents should be avoided, and radiation therapy for malignancy should be reduced to 30% of the usual dosage.

Incontinentia Pigmenti

Incontinentia pigmenti (IP), or Bloch-Sulzberger syndrome, involves the skin, brain, and eyes and shows the unusual inheritance pattern of X-linked dominance with a presumed lethal effect on the hemizygous male fetus. Nearly all affected persons are female, with mother-to-daughter transmission in familial cases. IP results from a mutation of the IKBKG gene (previously termed the NEMO gene) located on band Xq28, which is detected in 80% of affected individuals.

The skin usually appears normal at birth, but erythema and bullae develop during the first few days of life, usually on the extremities, and persist for weeks to months (Fig 28-13A). When healed, the lesions appear as clusters of small hyperpigmented macules in a characteristic “splashed-paint” distribution, most prominently on the trunk (Fig 28-13B).

Figure 28-13 Pigmented skin lesions of incontinentia pigmenti. A, Bullous lesions. B, Hyper-pigmented macules. (Courtesy of

Edward L. Raab, MD.)

Approximately one-third of patients with IP have CNS problems that include microcephaly, hydrocephalus, seizures, and varying degrees of cognitive impairment. Missing and malformed teeth are found in roughly two-thirds of cases. Less common findings include scoliosis, skull deformities, cleft palate, and dwarfism.

Ocular involvement occurs in 35%–77% of cases and tends to be unilateral or very asymmetric if bilateral, typically in the form of proliferative retinal vasculopathy that closely resembles retinopathy of prematurity. At birth, the only detectable abnormality may be incomplete peripheral retinal vascularization. Abnormal arteriovenous connections, microvascular abnormalities, and neovascular membranes develop at or near the junction of the vascular and avascular retina (Fig 28-14). Rapid progression sometimes leads to total retinal detachment and retrolental membrane formation within the first few months of life. Microphthalmos, cataract, glaucoma, optic atrophy, strabismus, and nystagmus may occur, usually secondary to end-stage retinopathy.