We perform membrane peeling in a variety of surgical cases: during epiretinal membrane removal, for macular hole closure and in the repair of a tractional retinal detachment.
Initiating the peel without causing direct trauma is of utmost concern. Methods of initiating the peel include the pinch-and-peel maneuver (pinching the internal limiting membrane or the epiretinal membrane to elevate a flap of tissue), using a diamond-dusted eraser or using a nitinol loop (Finesse Loop). The rest of the peel is carried out by forceps sometimes exerting additional tractional forces on the retina.
A recent paper published by the Cleveland Clinic Cole Eye Institute highlighted the adverse events that can occur by initiating the peel with these methods. In this retrospective analysis of the PIONEER study, intraoperative OCT was used to visualize the ultrastructural changes that occurred on the retinal surface after initiating the peel with either forceps or a diamond-dusted membrane scraper. Video and intraoperative OCT identified 69% of alterations of the retinal macro-architecture compared with only 26% due to the diamond-dusted eraser. The study concluded that while these intraoperative differences were seen, the long-term implications of these changes are largely unknown. And this study is not alone in its findings. Small studies have described subtle alterations in the architecture of the retina, including expansion of the ellipsoid zone to retinal pigment epithelium.
Because many of these alterations are noted to be non-foveal, vision might not be the best method for determining the functional impact of these surgical maneuvers. Future studies might include an assessment of functional outcomes assess by microperimetry or evaluation of dissociated optic nerve fiber layer severity. Newer techniques such as a vacuum-based removal system have been developed, which may potentially lead to fewer intraoperative and postoperative microarchitectural changes.
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Ehlers JP, et al. Invest Ophthalmol Vis Sci. 2015;doi:10.1167/iovs.15-17526.
Disclosure: Singh reports he is a consultant to Zeiss, Novartis, Regeneron, Genentech and Alcon and receives grant support from Apellis and Graybug.