Reappraisal of biomicroscopic classification of stages of development of a macular hole

Abstract

Purpose: To update the biomicroscopic classification and anatomic interpretations of the stages of development of age-related macular hole and provide explanations for the remarkable recovery of visual acuity that occurs in some patients after vitreous surgery.

Methods: Recent biomicroscopic observations of various stages of macular holes are used to postulate new anatomic explanations for these stages.

Results: Biomicroscopic observations include the following: (1) the change from a yellow spot (stage 1-A) to a yellow ring (stage 1-B) during the early stages of foveal detachment is unique to patients at risk of macular hole; (2) the prehole opacity with a small stage 2 hole may be larger than the hole diameter; and (3) the opacity resembling an operculum that accompanies macular holes is indistinguishable from a pseudo-operculum found in otherwise normal fellow eyes.

Conclusions: The change from a yellow spot (stage 1-A) to a yellow ring (stage 1-B) is caused primarily by centrifugal displacement of retinal receptors after a dehiscence at the umbo. The hole may be hidden by semiopaque contracted prefoveolar vitreous cortex bridging the yellow ring (stage 1-B occult hole). Stage 1-B occult holes become manifest (stage 2 holes) either after early separation of the contracted prefoveolar vitreous cortex from the retina surrounding a small hole or as an eccentric can-opener-like tear in the contracted prefoveolar vitreous cortex, at the edge of larger stage 2 holes. Most prehole opacities probably contain no retinal receptors (pseudo-opercula). Surgical reattachment of the retina surrounding the hole and centripetal movement of the foveolar retina induced by gliosis may restore foveal anatomy and function to near normal.