High-resolution optical coherence tomography demonstration of membranes spanning optic disc pits and colobomas

To demonstrate the features of optic disc pits and colobomas revealed by high-resolution optical coherence tomography (OCT) and their association with the development of maculopathy.

Subjects with disc pits or colobomas and no other ocular history underwent full ophthalmic examinations including logMAR visual acuity and contrast sensitivity. Fundus photographs and high-resolution OCT images were obtained.

Seven patients were identified with optic disc pits or colobomas aged 25 to 63 years. Five patients had a unilateral optic disc pit, one had a unilateral disc coloboma, and another had bilateral disc colobomas. Apart from one eye with a grossly anomalous disc, vision was logMAR 0.4 or better in all eyes. In three of five eyes without maculopathy, a complete membrane could be identified traversing the optic disc cup that was absent or deficient in the three eyes with maculopathy. One patient with optic disc pit and marked schisis-like separation of the retinal layers throughout the macula was asymptomatic with logMAR visual acuity of 0.0 and normal achromatic contrast sensitivity.

In this small series of patients with optic disc pits or colobomas, it was possible to identify a membrane spanning the optic disc cup, and it is speculated that this may protect against the development of maculopathy. Schisis-like separation of retinal layers can be associated with normal visual function.