Other congenital corneal opacities

See Chapter 10 for discussion of congenital hereditary stromal dystrophy (CHSD) and congenital hereditary endothelial dystrophy (CHED).

Congenital Corneal Opacities in Hereditary Syndromes and Chromosomal

Aberrations

Mucopolysaccharidoses (MPS) and mucolipidoses are disorders caused by abnormal carbohydrate metabolism. Corneal clouding and haziness may be present in early life in varying degrees in many of these entities, including Scheie syndrome (MPS I S) and Hurler syndrome (MPS I H). A more detailed discussion of these conditions appears in Chapter 11.

Secondary Abnormalities Affecting the Fetal Cornea

Intrauterine Keratitis: Bacterial and Syphilitic

Maternally transmitted congenital infections can cause ocular damage in several different ways:

through direct action of the infecting agent, which damages tissue through a teratogenic effect resulting in malformation

through a delayed reactivation of the agent after birth, with inflammation that damages developed tissue

A posterior corneal defect called von Hippel internal corneal ulcer may follow intrauterine inflammation. Often, signs of inflammation may still be present after birth, including corneal infiltrates and vascularization, keratic precipitates, and uveitis. Iris adhesions are extensive and may arise from areas apart from the collarette; the lens is usually involved.

Congenitally acquired syphilis infections caused by the Treponema pallidum spirochete can lead to fetal death or premature delivery. A variety of systemic manifestations have been described. Interstitial keratitis can develop in the first decade of life in children with untreated congenital syphilis. It presents as a rapidly progressive corneal edema followed by abnormal vascularization in the deep stroma adjacent to Descemet membrane. The cornea may assume a salmon pink color because of intense vascularization, giving rise to the term salmon patch. Over several weeks to months, blood flow through these vessels gradually ceases, leaving empty “ghost” vessels in the corneal stroma. (See Chapter 7 for a more complete discussion of interstitial keratitis.)

Congenital Corneal Keloid

Corneal keloids are relatively rare lesions, most commonly described following corneal perforation or trauma. Congenital corneal keloids, often bilateral, have been described in Lowe disease (oculocerebrorenal syndrome) and the ACL syndrome (acromegaly, cutis gyrata, cornea leukoma syndrome). They can be seen in association with cataracts, aniridia, and glaucoma and may represent a developmental anomaly with failure of normal differentiation of corneal tissue. Histologic examination reveals thick collagen bundles haphazardly arranged, with focal areas of myofibroblastic proliferation. Autosomal dominant inheritance has been observed in the ACL

syndrome. Acquired corneal keloid is discussed in Chapter 12.

Congenital Corneal Anesthesia

Congenital corneal anesthesia is a rare condition that is often misdiagnosed as herpes simplex virus keratitis, recurrent corneal erosion, and dry eye. Most cases are bilateral and present with painless corneal opacities and sterile epithelial ulcerations during infancy and childhood. Rosenberg classified the disorder into 3 distinct groups: group I is associated with isolated trigeminal anesthesia, probably due to primary hypoplasia of the hindbrain; group II is associated with mesenchymal anomalies, which include Goldenhar syndrome, Möbius syndrome, and familial dysautonomia (FD; also known as Riley-Day syndrome); group III is associated with focal brainstem signs without evidence of mesenchymal dysplasia.

A thorough systemic examination, including neuroradiologic studies, should be performed to rule out associated systemic conditions. In family linkage studies, FD, also referred to as hereditary sensory and autonomic neuropathy type III, is an autosomal recessive disorder that maps to chromosome 9q31-q33.

Treatment should include frequent topical lubrication, punctal occlusion, nighttime eyelid splinting, lateral tarsorrhaphy, amniotic membrane transplantation, scleral contact lenses and, in recalcitrant cases, conjunctival flap to stabilize the ocular surface.

Mathen MM, Vishnu S, Prajna NV, Vijayalakshmi P, Srinivasan M. Congenital corneal anesthesia: a series of four case reports. Cornea. 2001;20(2):194–196.

Verpoorten N, De Jonghe P, Timmerman V. Disease mechanisms in hereditary sensory and autonomic neuropathies. Neurobiol Dis. 2006;21(2):247–255.

Congenital Glaucoma

Primary congenital glaucoma is evident either at birth or within the first few years of life. It is believed to be caused by dysplasia of the anterior chamber angle without other ocular or systemic abnormalities. Characteristic findings in the newborn include the triad of epiphora, photophobia, and blepharospasm. External eye examination may reveal buphthalmos, with corneal enlargement greater than 12 mm in diameter during the first year of life. (The normal horizontal corneal diameter is 9.5– 10.5 in full-term infants.) Corneal edema is present in 25% of affected infants at birth and in more than 60% by the sixth month. It may range from mild haze to dense opacification in the corneal stroma because of elevated intraocular pressure. Tears in Descemet membrane called Haab striae may occur acutely as a result of corneal stretching. They are typically oriented horizontally or concentric to the limbus. For additional discussion, see BCSC Section 6, Pediatric Ophthalmology and Strabismus, and Section 10, Glaucoma.

Birth Trauma

Progressive corneal edema developing during the first few postnatal days, accompanied by vertical or oblique posterior striae, may be caused by birth trauma (Fig 9-10). Ruptures occur in the Descemet membrane and the endothelium. Healing usually takes place but leaves a hypertrophic ridge of Descemet membrane. The edema may or may not clear; if it does clear, the cornea can again become edematous at any time later in life. High astigmatism and amblyopia may be associated. Congenital glaucoma can present with similar findings and should be considered in the differential diagnosis.

Figure 9-10 Vertical ruptures of Descemet membrane secondary to traumatic delivery. (Courtesy of Vincent P. deLuise, MD.)

Arcus Juvenilis

Arcus juvenilis, a deposition of lipid in the peripheral corneal stroma, occasionally occurs as a congenital anomaly. Usually the condition involves only a sector of the peripheral cornea and is not associated with abnormalities of serum lipid.