Purpose: To investigate the frequency of residual cortex and the effectiveness of removal of residual cortex in the fovea during vitrectomy for primary rhegmatogenous retinal detachment repair.
Methods: We retrospectively reviewed the charts and the operative videos of the 80 patients (80 eyes) who underwent vitrectomy for repair and who were observed for more than 6 months. After triamcinolone acetonide injection, we observed residual cortex on the surface of the retina. Residual cortex was removed with a diamond-dusted scraper. After surgery, we watched for the occurrence of epiretinal membrane (ERM) for at least 6 months. We graded ERM according to the postoperative visual acuity (thin membranes that did not affect vision vs. thick membranes that reduced vision).
Results: Of the 80 eyes, 60 eyes (75%) showed macular residual cortex, which we removed with a scraper, and 20 eyes (25%) did not have visible cortical remnants. Postoperative ERM occurred in 30% of eyes (24/80). The rate of postoperative ERM was 35% (21/60) in eyes with residual cortex and 15% (3/20) in eyes without residual cortex (P = 0.091). In the 60 eyes with residual cortex during vitrectomy, a thin membrane occurred in 18 eyes (30%) and a thick membrane occurred in 3 eyes (5%). In the 20 eyes without residual cortex, however, a thin membrane occurred in 3 eyes (15%) and no thick membrane was found.
Conclusion: Eyes with residual cortex have a higher rate of ERM than eyes with no residual cortex after vitrectomy for primary repair. It is uncertain whether removing the cortex reduces the rate of postoperative ERM. The residual cortex may have already started the pathogenesis of ERM, or surgical trauma may have played a role.