Evaluation of Ab externo subretinal bands removal during pars plana vitrectomy for rhegmatogenous retinal detachment complicated by proliferative vitreoretinopathy

BACKGROUND: To compare the safety and efficacy of Ab-externo subretinal bands removal in comparison with the classical Ab-interno approach during pars plana vitrectomy for primary rhegmatogenous retinal detachment. METHODS: Subjects aged 28-62 years with primary RRD complicated by proliferative vitreoretinopathy (PVR) with subretinal bands interfering with retinal flattening were treated by pars plana vitrectomy (PPV) and silicone oil injection. Subretinal bands were removed using the classical AB interno approach through one or more retinotomies in ten patients (group A) and using AB externo approach in twenty cases (group B). Post-operative follow-up visits occurred at 1 day, 1 week, 1 month, and 3 months, after surgery. The main outcomes were assessment of subretinal bands removal efficacy, documentation of complications, anatomical reattachment rate, and postoperative best-corrected visual acuity (BCVA). RESULTS: There was no statistically significant difference between both groups regarding patients' age, gender, lens status, and the onset of retinal detachment. Seventy percent of both groups presented with inferior retinal detachment while ten percent presented with temporal detachments and twenty percent had a total retinal detachment. Both groups had a statistically significant improvement in postoperative visual acuity in comparison with preoperative visual acuity (P = 0.005 for group A and P = < 0.001 for group B). There was no statistically significant difference between both groups regarding preoperative (P = 0.928) and postoperative (P = 0.185) visual acuity. A higher incidence of complications was reported in group A (40%) in comparison with group B (30%) but this difference was not statistically significant (P = 0.69). More Epimacular membranes were seen postoperatively in group A (30%) in comparison with group B (20%) but again this difference was not statistically significant (P = 0.657). Subretinal hemorrhage was seen in ten percent of cases in both groups. Intraocular pressure was measured in every follow-up of all patients in both groups, no statistically significant difference was found between both groups. CONCLUSIONS: Both techniques are effective and safe to remove subretinal bands with similar outcomes.