Macular translocation in a patient with adult-onset foveomacular vitelliform dystrophy with light- and electron-microscopic observations on the surgically removed subfoveal tissue

Abstract

Purpose: To correlate the functional results of macular translocation (MT) in a patient suffering from an adult-onset foveomacular vitelliform dystrophy (AFVD) with the microscopic findings of the surgically removed subfoveal retinal pigment epithelium (RPE).

Methods: A 78-year-old woman with AFVD underwent MT with 360 degrees retinotomy 3-4 months after loss of reading ability. Most of the vitelliform material was lost during surgery; the subfoveal tissue was excised, fixed in aldehydes, postfixed in reduced OsO4 and embedded in epoxy resin. Semithin sections were stained with toluidine blue for light microscopy (LM) and thin sections with uranyl acetate and lead citrate for transmission electron microscopy (TEM).

Results: Postoperatively, the patient developed a retinal detachment complicated by proliferative vitreoretinopathy (PVR) requiring two additional vitreoretinal procedures before finally the silicone oil could be removed. Twenty-two months after MT the distance visual acuity was unchanged at 0.2; the near visual acuity had improved from less than 0.1 before MT to 0.4. The retina was completely attached. LM and TEM revealed serious alterations indicative of a breakdown of the outer layer of the retina.

Conclusion: Through the present single case it is not possible to determine whether MT could be a therapeutic approach in patients with AFVD. The most important cause for the limited postoperative visual improvement seems to be a primary injury of the foveal function due to the AFVD. This is supported by the extensive subfoveal degeneration and necrosis affecting not only the RPE cells but also their basement membrane and the interposed basal laminar deposits.