Immunocytochemical characterization of macular hole opercula

Objective: To immunocytochemically characterize the neural and glial elemen ts of idiopathic full-thickness macular hole (FTMH) opercula excised during vitrectomy, and to correlate them with the outcome of surgery. Methods: Opercula were collected from eyes undergoing vitrectomy for stage 3 FTMH and processed for transmission electron microscopy, light epifluores cence, and laser scanning confocal microscopy. Glia were identified using a nti-glial fibrillary acid protein (GFAP), antivimentin, and anti-cellular r etinaldehyde binding protein antibodies. Anti-phosphodiesterase gamma and a ntirhodopsin were used for cone and rod photoreceptors, and anticytokeratin was used for retinal pigment epithelium. The findings were correlated with the clinical data before and after surgery. For statistical analysis, data were combined with those of a previous study by the authors of 18 opercula . Results: Opercula from 12 consecutive eyes of 12 patients were studied. In all opercula, GFAP, vimentin, and cellular retinaldehyde binding protein-po sitive glia were present. Six (50%) of 12 opercula contained more than 5 ph otoreceptors with somata and internal photoreceptor fibres, but lacking out er segments, demonstrating strong immunoreactivity to anti-phosphodiesteras e gamma without antirhodopsin reactivity consistent with cones. Further, 2 (17%) of 12 opercula showed few cones (1-5 cones), and 4 (33%) of 12 contai ned only glia. Clinicopathologic correlation of the 30 opercula from the 2 studies showed that eyes with opercula containing more than 5 photoreceptor s were associated with a worse anatomical closure rate after initial surger y, compared with those with fewer than 5 photoreceptors (P=.004). Once clos ure had been achieved with reoperation, median postoperative vision was sim ilar in both groups (20/40 and 20/60, respectively). Conclusions: A spectrum of opercula occur in FTMH ranging from those contai ning only glia to those containing numerous cones. The extent of foveal neu roretinal tissue loss may affect the outcome of surgery.