Some patients may experience ganglion cell loss post-vitrectomy. Photo: Derek N. Cunningham, OD. Click image to enlarge.

Severe loss of macular ganglion cells may occur after vitrectomy and is associated with central vision loss, according to a recent study. The diagnosis is made by having a high index of suspicion when examining OCT B-scan images and evaluating ganglion cell layer (GCL) volume. Unfortunately, the study author noted the frequency of this occurrence is currently unknown.

The study included eight referred patients who were comprehensively examined, including OCT and microperimetry.

All patients had a sudden central vision loss following vitrectomy, and many suspected the central loss was present even before the eye patch was removed on the first postoperative day. Of the patients, one had a vitrectomy with no membrane peeling while the remaining seven had membrane peeling. The mean postoperative visual acuity was 20/200. The outer retinal architecture was unremarkable in the involved eyes and did not appear to explain the poor acuity.

The mean GCL volume was 0.69μm3 in the involved eye and 1.04μm3 in the fellow eye. The global retinal nerve fiber layer (RNFL) thicknesses in the involved and fellow eyes were 81.3μm and 90μm, respectively. The GCL volume loss was not necessarily associated with RNFL thicknesses that were in the abnormal range or in optic nerve pallor. Microperimetry showed severe depression of the threshold sensitivities.

“While loss of ganglion cells and RNFL may produce what appears to be a primary optic neuropathy, the damage and its apparent causes appear to primarily involve the central macula,” the study noted.

The author did take into account the relatively small sample size. “It is possible the entity described in this report is not rare, as the eight cases in the present report were examined by a single provider in a community retinal practice,” the researcher wrote. “Perhaps with greater recognition, a greater number of cases could be obtained for more precise statistical analysis.”