Conversion factors for fovea on / off detachments
Reviewed by Jonathan Chan

This is a retrospective study of medical records in a single unit over a 14 year period from January 2001 – December 2014, of patients who converted from fovea-on to fovea-off rhegmatogenous retinal detachment (RRD). Ten cases were identified while awaiting surgery; this represented 1.1% of RRDs (n=930) at presentation. Nine out of 10 were superotemporal (STRRDs) extending to the vascular arcade and all had STRRDs breaks in the detached area, which had a more significant rate than other RRDs (100% vs. 63%, p=0.02). There were 2.4 breaks per eye, similar to other RRDs. Six out of 10 patients converted to a fovea-off RRDs within a few hours and the remainder by the following day. Eight out of 10 patients retained or improved their preoperative visual acuity. Two patients lost a line of acuity on the Snellen chart. The authors concluded that same day surgery for this group of patients may not significantly affect the visual outcome and would not prevent about half of the conversions to fovea-off. STRRDs extending to near the arcades are most at risk and might warrant early surgery or posturing to limit spread of the RRDs in the preoperative period. 

Rate and risk factors for the conversion of fovea-on to fovea-off rhegmatogenous retinal detachment (RRD) while awaiting surgery.
Kontos A, Williamson TH.
BRITISH JOURNAL OF OPHTHALMOLOGY
2017;101:1011-5.