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Epidemiology, onset & clinical features

Epidemiology

Though the exact prevalence remains unknown, PHPV is considered to be not a very rare disease. The condition is usually unilateral and isolated (without associated systemic findings) in normal full-term infants. A study on childhood blindness and visual loss in the United States showed that PHPV accounts for about 5 % of all cases of blindness.

Onset

PHPV is typically found in full term infants. In majority of cases, the abnormality can be noted at birth or within the first few weeks of life.

Clinical features

The most common presenting signs are leukoria (white papillary reflex due to a dense retrolenticular membrane or cataractous lens), microphthalmia and cataract, but the clinical presentation may vary.

In more than 90 % of cases PHPV is unilateral. Microphthalmos is usually moderate, cornea is clear, anterior chamber is shallow. The lens may be clear or cataractic. The cataract may range from a tiny visually insignificant opacity to a widespread vascularised plaque on the back of the lens and varying degrees of opacity throughout the lens, including total white cataract. It may worsen with age. The iris may be normal or may show small notches at the margins of the pupilla.

Characteristic traction of the ciliary processes is sometimes visible in the periphery of the dilated pupil. Small eye, white papillary reflex and iridohyaloidal vessels seen over the anterior iris surface, papillary margin and posterior iris surface are the most important diagnostic parameters.

Occasionally, extensive intravitreal hemorrhage and retinal detachment are present. Visual acuity can be nearly normal, but in most cases of posterior PHPV it is 20/200 or less at diagnosis. Strabismus may be present at birth or develop shortly after in the postnatal period.

Complications of PHPV include glaucoma, intraocular hemorrhage, retinal detachment and phthisis bulbi.

Though the disease is typically isolated, it has also been reported in combination with other syndromes: trisomy 13, Norrie disease, Walker-Warburg syndrome, incontinentia pigmenti, cerebro-oculo-dysplasia-muscular dystrophy, fetal alcohol syndrome, neurofibromatosis 2, Axenfeld-Rieger syndrome.

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