Congenital Optic Pit

Abstract

Optic pits occur unilaterally more than 80% of the time. The incidence of optic nerve pits is 1:11,000. The optic pit probably has a sporadic hereditary pattern, although some investigators have suggested that it may be autosomal dominant. Characteristically, the pit is located on the inferotemporal aspect of the disc and may be associated with development of serous detachment of the macula. Optic pits can be slitlike, polygonal or oblong. They can be up to one diopter in depth and .3 disc diameter in width. The latter is usually seen in patients between the ages of 20 and 40. It has been postulated that the fluid is cerebrospinal fluid that has leaked around the nerve sheaths and settled under the macula. The disc abutting the pit has peripapillary atrophy. It is through this area that some investigators believe liquefied vitreous seeps under the macula to create the nonrhegmatogenous detachments. These detachments occur up to 40% of the time. Various visual field defects can be seen, such as an enlarged blind spot, nasal steps, arcuate scotomas, paracentral scotomas, centrocecal scotomas or generalized constriction. The fluorescein angiogram will demonstrate the serous maculopathy, if present. The optic pit exhibits a hyperfluoresence that fades in the late phases.