Assessment of the reproducibility and repeatability of a method of grading macular subretinal fluid using optical coherence tomography

AIM: To devise a quantative method for the measurement of the extent of macular subretinal fluid using optical coherence tomography (OCT), and to assess the interobserver and intraobserver agreement for this grading system. METHODS: Observational cohort series. Patients were a cohort who underwent retinal detachment surgery over an 18-month period. All patients had OCT scan at 6 weeks after surgery. The scans were graded by two independent observers experienced in OCT interpretation and each grader was masked to the others findings. Observer 1 then regraded the scans on a later day masked to his previous findings. The interobserver and intraobserver agreement was assessed using weighted Kappa (Kw) statistics. RESULTS: In all, 116 patients were analysed. Both the intraobserver and interobserver agreement was very high, with Kw being 0.9631 and 0.9070, respectively. CONCLUSIONS: The grading system for assessment of the extent of macular subretinal fluid using OCT appears to have very good reproducibility and repeatability. We propose that this grading system would be clinically useful when applied to pathologies visible on OCT scan of the macula

Spectral-domain optical coherence tomography analysis of persistent subretinal fluid after scleral buckling surgery for macula-off retinal detachment

PurposeTo determine the predictive value of markers for persistent subretinal fluid (SRF) absorption and the influence of subfoveal fluid on visual outcome after scleral buckle (SB) surgery for rhegmatogenous retinal detachment (RRD).Patients and methodsThis was a retrospective, observational study. We reviewed the medical records of 64 eyes of 64 patients who underwent SB surgery for macula-off RRD. Patients underwent clinical examination and spectral-domain optical coherence tomography before surgery, at 1 month and every 3 months postoperatively. The height and width of SRF bleb(s) were measured over time.ResultsPersistent SRF at 1 month was observed in 40 eyes (62.5%). SRF blebs were first detected 1.7±2.2 months postoperatively. In 29 cases that could be fully followed up, SRF blebs were completely absorbed 7.8±4.4 months postoperatively. Resolution of fluid was associated with an improvement of VA (P=0.003). Serial measurements of SRF bleb size showed that bleb width decreased significantly at all time points during the 12-month follow-up period (P<0.05), while significant bleb height decrease occurred from postoperative sixth month only (P<0.05). There was no correlation between VA outcomes and subfoveal bleb height or width (P>0.05). The cut-off value of the bleb width-to-height ratio level for predicting bleb absorption at 6 months was 7, with 89% sensitivity and 83% specificity.ConclusionsVisual improvement may occur with late resolution of residual subfoveal fluid. A bleb width-to-height ratio >7 indicates a higher risk of SRF to persist beyond 6 months after surger