Longitudinal Optical Density Measurements of Subretinal Fluid Pockets After Surgical Repair of Rhegmatogenous Retinal Detachment

Abstract

 

Purpose

 

Prior observations have demonstrated persistent subretinal fluid (SRF) on optical coherence tomography (OCT) imaging of rhegmatogenous retinal detachments (RRD) following surgical repair not evident on clinical exam or fluorescein angiography. The purpose of this study was to investigate the reflectivity and optical density (OD) characteristics of the residual SRF in eyes following surgical repair of macula-off RRD.

 

Methods

 

In this retrospective case series, serial spectral domain OCT was used to measure the OD of residual SRF and SRF height in 9 patients with macula-off RRD repaired with scleral buckling (SB, n = 7) or vitrectomy with or without SB (n = 2). Major inclusion criteria included (1) high quality OCT scans at two or more time points through the fovea and (2) sufficient SRF for OCT sampling without including tissue edges. Demographic, clinical, and OCT imaging data were collected on all patients. Optical density ratio (ODR) and SRF height measurements were obtained using a manual image segmentation method with ImageJ (NIH). ODR was defined as the ratio of the reflectivity of the SRF compartment compared to the reflectivity of an equivalent area of overlying vitreous. Correlations were assessed for significance via both univariate and multivariate regression analyses (Microsoft Excel).

 

Results

 

Overall, ODR measurements were found to increase with time after surgery, and this was found to be statistically significant (p = 0.001, R² = 0.331). SRF height measurements revealed an overall decreasing trend in all patients (100%). There was also a significant correlation between ODR and log of SRF height (p = < 0.001, R² = 0.485). In multivariate analysis, neither ODR nor SRF height was found to be a statistically significant predictor of visual acuity. No difference was observed in subgroup analyses comparing eyes that underwent vitrectomy versus SB.

 

Conclusions

 

Changes in residual SRF reflectivity and ODR following retinal detachment repair may be representative of changes in the composition of the SRF over time. This is in agreement with previous biochemical studies. OCT analysis of residual SRF may serve as a non-invasive method of assessing SRF composition and clinical behavior in vivo.

 

Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 550 imaging/image analysis: clinical • 697 retinal detachment