Diagnosis
Leukocoria
Discussion
Differential Diagnosis:
This is a case of leukocoria, or an abnormal white pupillary reflex, likely due to congenital cataracts. Differential diagnosis of leukocoria includes the following: retinoblastoma, congenital cataracts (from infectious [ex. intrauterine rubella infection] or congenital etiologies [ex. galactosemia, Lowe’s syndrome, familial]), retinopathy of prematurity, persistent hyperplastic primary vitreous, Coat’s disease, familial exudative vitreoretinopathy, retinal detachment, coloboma and corneal opacities.
Definition:
Congenital cataracts can form due to intrauterine infections, metabolic disorders, a malignancy, or a genetic defect. Intrauterine infections that can result in congenital cataracts include rubella (German measles, the most common infectious cause), rubeola, cytomegalovirus, herpes simplex, herpes zoster, poliomyelitis, influenza, Epstein-Barr virus, syphilis, and toxoplasmosis. Metabolic disorders that can cause congenital cataracts include galactosemia and diabetes mellitus. Systemic syndromes such as Lowe’s syndrome (oculocerebrorenal syndrome) or Alport syndrome may also be associated with congenital cataracts. The differential of leukocoria, or a white light reflex, must also include retinoblastoma, the most prominent intraocular malignancy in children.
Examination:
A complete medical history including maternal illness or drug use during pregnancy is very important. Family ocular history of congenital blindness, congenital cataracts, strabismus, or amblyopia should also be addressed. A complete eye exam including visual assessment of each eye alone and an attempt to determine the visual significance of the cataract is necessary. B-scan can be helpful to evaluate the posterior eye to rule out posterior abnormalities. A physical examination to determine signs and/or symptoms of systemic intrauterine-acquired infections is essential.
Treatment:
Cataract surgery is the treatment of choice and should be performed as soon as possible to minimize the risk of amblyopia and sensory nystagmus. Cataract extraction with primary posterior capsulectomy and anterior vitrectomy is the procedure of choice due to the high rate of capsular opacification. Most patients are left aphakic and are fitted with a contact lens shortly after surgery. Secondary intraocular lens implantation can be done later in life after the eye has matured. After cataract extraction, patients should be assessed and treated for amblyopia. Life-long follow up is important to maximize visual potential.