Abstract
Purpose:
Vitrectomy with membrane peel sometimes has poor visual outcome, usually following re-operations. To determine the role of timing between the primary procedure and re-operation in persistent/recurrent macular pucker (MP) and macular hole (MH), the final vision and histopathologic analyses of excised membranes were correlated with the time interval between operations. Tissue obtained at surgery was analyzed to seek elements of inner retina adherent to the excised membrane, which was hypothesized to be the cause of poor post-operative vision.
Methods:
Eyes with a history of prior vitreo-retinal surgery, retinal detachment, vein occlusion, wet age-related macular degeneration or diabetic retinopathy were excluded. Ten pseudophakic eyes undergoing re-operation for MH or MP were evaluated using Snellen visual acuity (VA) as an outcome measure. 25G vitrectomy was performed in all cases. Chromodissection with doubly-diluted indocyanine green dye was performed in all primary MH surgeries and in all re-operations for MH and MP. VA was correlated with immunohistochemistry for neurofilament and transmission electron microscopy of excised tissue in 6/10 cases.
Results:
VA improved by >3 lines in 6 cases and worsened by >3 lines in 3 cases. All 6/6 (100%) cases with ≥6 month interval before re-operation had VA improvement (>3 lines), while 3/4 (75%) with <6 month interval had VA worsening (>3 lines; P = 0.03). The average post-operative logMAR VA was 1.59 ± 1.07 (20/800) for <6 months inter-operation interval, with positive neurofilament staining and retinal cell debris present on the peeled membrane in 2/2 eyes. Waiting ≥6 months before re-operating resulted in logMAR VA of 0.42 ± 0.25 (20/50) (P = 0.03) and no evidence of neurofilament staining or retinal elements on the peeled membranes (0/4 eyes).
Conclusions:
If repeat vitrectomy with membrane peeling is performed too early, there may not be adequate time for Müller cells to re-form a layer of endplates over the denuded retinal nerve fiber layer, exposing it to damage during the second operation with resultant poor vision. Waiting more than 6 months before re-operating for MH or MP may allow enough time to re-form normal tissue planes, enabling a better surgical plane of dissection at re-operation, which seems to be associated with significantly less inner retinal damage and superior final vision.
Keywords: 462 clinical (human) or epidemiologic studies: outcomes/complications •
762 vitreoretinal surgery •
586 macular holes