Prevalence and Clinical Implications of Subretinal Fluid in Retinal Diseases: A real-world cohort study
Authors: Jeff Park, Tina Felfeli, Imaan Z. Kherani, Filiberto Altomare, David R. Chow, David T. Wong.
Author Disclosure Block: J. Park: None. T. Felfeli: None. I.Z. Kherani: None. F. Altomare: None. D.R. Chow: None. D.T. Wong: None.
Purpose: To characterize the baseline prevalence of subretinal fluid (SRF), and its effects on anatomical and visual acuity (VA) outcomes in diabetic macular edema (DME) and retinal vein occlusion (RVO) eyes treated with real-world variable dosing regimen of intravitreal anti- vascular endothelial growth factor (VEGF) injections.
Study Design: Single-center, retrospective cohort study.
Methods: Treatment-naïve DME and RVO patients who were initiated on intravitreal anti-VEGF injections for macular edema between January 2016 to December 2017 were included. The DME and RVO cohorts were subclassified into SRF or non-SRF groups based on the presence of SRF on optical coherence tomography (OCT) at baseline. All patients received injections of bevacizumab, ranibizumab or aflibercept. RVO patients were treated based on a treat-and-extend regimen while DME patients were treated according to the regimen adapted from the DRCR.net Protocol T with retreatment decisions largely dependent on the individual clinician’s judgment of disease activity. Changes in visual acuity (VA) and central subfield thickness (CST) were assessed up to 24 months. Comparisons between SRF and non-SRF groups were made using the independent samples t-test and chi-square test.
Results: A total of 122 DME and 54 RVO patients were included. At baseline, SRF was present in 22% and 41% in DME and RVO, respectively. DME patients with SRF were more likely to have bilateral macular edema at baseline (odds ratio = 2.7, 95% confidence interval 1.1-6.4, P<0.05) compared to those without SRF. In the DME cohort, SRF eyes demonstrated a mean logMAR VA at 24-month of 0.41 ± 0.28 (Snellen 20/50) that was significantly higher compared to baseline (0.65 ± 0.35 [20/90], P<0.05). Furthermore, improvement in logMAR VA at 24-month was significantly greater for the SRF eyes compared to the non-SRF eyes (0.25 ± 0.29 vs. -0.08 ± 0.54, P<0.05). Percent reduction in CST was 25 ± 23 for SRF and 11 ± 20 for non-SRF at 3-month (P<0.05). In the RVO cohort, there was no association between SRF and the VA outcomes, while the percent reduction in CST was 36 ± 19 versus 18 ± 17 (P<0.05) at 1-month for SRF and non-SRF, respectively.
Conclusions: Baseline SRF is a good marker for a greater reduction in CST in both DME and RVO, but an improvement in VA associated with SRF may be only noted in DME. The presence of SRF may have significant clinical implications on patients undergoing therapy, and it may be used in clinical decision making for ophthalmologists treating DME and RVO.