Rate and risk factors for the conversion of fovea-on to fovea-off rhegmatogenous retinal detachment while awaiting surgery

Background/aims Progression of a fovea-on to a fovea-off rhegmatogenous retinal detachment (RRD) while awaiting surgery is rare. Methods A retrospective review of patient records to identify patients in whom a fovea-on retinal detachment at presentation was found to be fovea off at surgery. Results We identified 10 cases over 14 years which converted from fovea-on to fovea-off RRD while awaiting surgery. This represented 1.1% of RRDs that were fovea on at presentation (n=930). Nine out of 10 patients had superotemporal RRDs extending to at least the vascular arcade at presentation and all had superotemporal breaks within detached retina, which was significantly higher than the rate for other retinal detachments (100% vs 63%, p=0.02). There were 2.4 breaks per eye, similar to other retinal detachments. Six of the 10 patients converted to a fovea-off retinal detachment within a few hours and the rest by the following day. Visual outcomes were good, with eight patients maintaining their presenting visual acuity and two losing one Snellen line. Conclusions Offering same-day surgery to high-risk fovea-on RRDs may not significantly influence visual outcomes and would only prevent about half of the conversions to fovea off. Superotemporal retinal detachments extending to near the arcades are most at risk and might warrant posturing to limit spread of the detachment in the preoperative period.