Persistent subfoveolar fluid following retinal detachment surgery: an SD-OCT guided study on the incidence, aetiological associations, and natural history.

Abstract

To investigate the incidence and natural history of persistent subfoveolar fluid (PSF) following surgery for macular off rhegmatogenous retinal detachment and the effect of PSF on photoreceptor structure and final visual acuity. Retrospective study of 61 cases with post-operative optical coherence tomography (OCT) performed within 12 weeks of surgery. Based on aetiology, cases were categorized into tractional retinal tears (TRT) group or atrophic round holes and dialyses (RHD) group to investigate the incidence and duration of PSF. A Kaplan-Meier graph was plotted to compare survival time of subfoveolar fluid for both groups. Following secondary reclassification of cases into those with and without PSF, the effect of PSF on final visual acuity and photoreceptor structure was investigated with Mann-Whitney U-test used for comparison. Spearman's correlation testing was used to probe associations between time to recorded resolution of PSF with final visual acuity and photoreceptor structure. Incidence of PSF was greater in the RHD group and persisted for longer compared with TRT group. No detectable adverse effect of PSF on final visual acuity was seen however an individual case of severe photoreceptor atrophy was observed. No significant correlation was found between the time to recorded resolution of PSF and the final visual acuity or to photoreceptor grading scores. A difference in incidence of PSF was detected between the aetiological groups. PSF was ubiquitous and slow to resolve in the RHD group. Most cases of PSF resolve without adverse sequelae; however, progressive photoreceptor atrophy and sub-optimal visual outcome may result in a minority.