MANAGEMENT/TREATMENT AND PROGNOSIS

Treatment of the corneal erosions due to cystine crystals was once purely supportive with frequent lubricant drops and ointments. Bandage contact lenses can be used to reduce both the frequency and pain of epithelial erosions. Over the past several years topical cysteamine drops have been used to reduce the corneal signs and symptoms of cystinosis.79 Treatment with oral cysteamine can minimize many of the systemic findings in cystinosis, but does not reduce crystal formation in the cornea.80

Infectious diseases

Corneal infections which lead to scarring and opacity can be caused by both bacterial and viral mediators. These are not seen very commonly but need to be kept in the differential diagnosis of a corneal opacity. In some patients sensation is reduced in the cornea due to either infectious keratitis or other congenital causes such as familial dysautonomia or Goldenhar–Gorlin–Goltz syndrome.83 The following section reviews the most common causes of keratitis in the pediatric population.

Tyrosinemia

ETIOLOGY

Oculocutaneous tyrosinemia (tyrosinemia type II or Richner–Hanhart syndrome) is an AR disorder, caused by a deficiency of hepatic tyrosine aminotransferase.

CLINICAL PRESENTATION

Affected patients suffer from mental retardation, a hyperkeratotic rash on the palms and soles of their feet, and dendritic corneal lesions. The ocular findings can often present before the cutaneous.81 The lesions seen on the cornea look very much like the lesions seen in herpetic keratitis, and may stain with fluorescein stain. What differentiates these lesions from those seen in HSV is bilateral involvement, lack of response to antiviral therapy, and normal corneal sensation. The corneal changes often present in the first year of life and are associated with a significant amount of pain, light sensitivity, and tearing.81

Diagnosis of tyrosinemia II is confirmed by finding elevated levels of plasma or urine tyrosine levels. Any infant diagnosed with bilateral herpetic keratitis should be screened for tyrosinemia.

MANAGEMENT/TREATMENT AND PROGNOSIS

Treatment of tyrosinemia II is through dietary restriction of tyrosine and phenylalanine. With early detection and dietary changes, both systemic and corneal signs can be improved.82

Herpes simplex virus (HSV)

ETIOLOGY

One of the most common corneal infections seen in the adult population is due to the herpes simplex virus, type I. The pediatric patients most affected by this are the neonates. In the neonate herpetic infection is relatively uncommon with estimates as low as 1 in 20,000 to as high as 1 in 3000.84 An estimated 20% of neonates will manifest ocular infection in the form of periocular dermatitis, dendritic or stromal keratitis, or chorioretinitis.

Approximately 35% of neonatal HSV infection is from HSV I, the remainder is from HSV II.85 Transmission can be transplacental, exposure during delivery, or exposure shortly after birth.86

MANAGEMENT/TREATMENT AND PROGNOSIS

Treatment for neonatal HSV relies on prompt diagnosis. Timely diagnosis is critical due to the relatively high incidence of encephalitis due to HSV, which can lead to death or permanent neurologic sequelae. Many expecting mothers are asymptomatic at the time of delivery but can still transmit the virus. Even C-section delivery does not guarantee nontransmission. The use of intravenous antiviral medication has reduced morbidity and mortality from HSV, but even with early diagnosis and proper treatment an excellent outcome is not guaranteed.87

ETIOLOGY

Congenital syphilis occurs in fetuses infected after 16 weeks of gestation. Before that time, transmission to the fetus can occur but does not lead to damage to the developing eye. Almost all children born to mothers with primary syphilis acquired after the fourth month of pregnancy will develop congenital syphilis.

CLINICAL PRESENTATION

Congenital syphilis will often lead to bilateral corneal scarring in association with intraocular inflammation. In the majority of patients corneal scarring is not seen at birth, but presents after the age of 2 years. The keratitis typically presents as peripheral inflammation in the cornea that progresses centrally. The corneal changes tend to be a later ocular sequela of congenital syphilis and signs of retinal damage are already present by the time the keratitis is noted. Corneal scarring associated with hearing loss and notched teeth due to congenital syphilis is commonly known as Hutchinson’s triad. Other common nonocular stigmata of congenital syphilis include frontal bossing of the forehead, saddle nose defect,88 and skin wrinkling radiating from the mouth.89

MANAGEMENT/TREATMENT AND PROGNOSIS

Any patient with suspected ocular changes from congenital syphilis needs to be treated by an eye care specialist. Many authorities feel that patients with ocular findings need to be treated as neurosyphilis patients. Early treatment can prevent corneal scarring. Corneal scarring may require transplantation.

ETIOLOGY

Ocular involvement in congenital rubella is caused by maternal infection with rubella in the first trimester with transplacental transmission to the fetus. Infection in the later stages of pregnancy does not result in serious ophthalmic sequelae.

Congenital infection with rubella can cause extensive damage to the eye. Cataract formation, congenital glaucoma, corneal opacity, and microphthalmia have all been

reported from congenital infection with rubella.90,91

MANAGEMENT/TREATMENT AND PROGNOSIS

In most developed countries vaccination has helped to eradicate congenital rubella. If necessary, surgery to reduce the pressure of glaucoma or to remove a congenital cataract can be done. With persistent corneal edema corneal transplantation is necessary for normal visual development. The best way to reduce visual loss due to infectious diseases such as rubella is to continue with aggressive vaccination programs, which have reduced the

incidence of vaccine-preventable disease in the US to an all-time low.92

•Introduction

•Structural lens abnormalities

Aphakia

Spherophakia (microspherophakia) Coloboma

Subluxation (ectopia lentis) Lenticonus

Persistant fetal vasculature

•Cataracts

Nuclear cataracts Lamellar cataracts Anterior polar cataracts Posterior polar cataracts Sutural cataracts

Anterior subcapsular cataracts Posterior subcapsular cataracts Cerulean (blue-dot) cataracts Complete cataracts

•Etiology of cataracts

Genetic and metabolic diseases Trauma

Medication and toxicity Maternal infection

•Diagnosis of cataracts

•Management/treatment of cataracts

Visual significance Surgery

Aphakia Pseudophakia Amblyopia

•Cataract prognosis