Unique advantage of gonioscopy for viewing an anterior pyramidal cataract.

Anterior polar cataracts (APC) are a relatively rare but well-documented form of congenital cataract. Occasionally, these white disc-shaped opacities protrude towards the anterior chamber with an inverse cone-like morphology and are known as anterior pyramidal cataracts. These represent three to four per cent of all types of congenital cataracts. APCs portray a dominant mode of inheritance and generally do not progress over time. Due to their small size, APCs generally have little effect on vision and are simply monitored clinically. Photodocumentation of pyramidal cataracts has traditionally shown biomicroscopic views of the opacities. In addition to a review of APC, this report describes how a gonioscope offers a unique observational advantage in viewing an anterior pyramidal cataract.