Optical coherence tomography of pneumatic displacement of optic disc pit maculopathy.

Abstract

The authors have previously concluded that fluid from an optic disc pit creates an inner layer separation (ILS) of the retina. An outer layer detachment (OLD) centred on the macula is a secondary phenomenon that causes a dense central scotoma. Pneumatic displacement of the OLD effects an improvement in central vision. Pathology to confirm these conclusions is lacking. Intraretinal images obtained by optical coherence tomography (OCT), however, are confirmatory. Three patients with optic disc pit maculopathy were studied with stereoscopic photographs, visual fields, and OCT before and after intravitreal gas was injected to displace the central retinal elevation to below the inferior temporal vascular arcade. Preoperatively, OCT demonstrated an ILS that connected with the optic disc pit. External to it was an OLD that centred on the fovea and did not connect with the optic disc pit. Pneumatic displacement of the OLD was accompanied by an improvement in central vision. Long term follow up indicates that the effect of displacement may be temporary. OCT confirmed the two layer structure of optic disc pit maculopathy and that the improvement in central vision after pneumatic displacement coincides with a reattachment of the OLD in the macula. It also supports the hypothesis that the ILS, which persists, provides a conduit for the continuous flow of fluid from the pit to the displaced retinal elevation.