Abstract
Purpose: :
To test the hypothesis that hyporeflective spaces have different optical reflectivities according to the pathology of the eye. OCT optical density ratio (ODR) values of subretinal fluid (SRF) in eyes with rhegmatogenous retinal detachment (RRD) and retinoschisis (RS) were compared with values of neovascular age-related macular degeneration (nAMD), diabetic macular edema (DME), central serous chorioretinopathy (CSC), and pseudophakic cystoid macular edema (PCME).
Methods: :
SD OCT (Spectralis), was used to evaluate subretinal fluid in eyes with RRD (n=18), RS (n=10), nAMD (n=17), DME (n=7), CSC (n=17) and PCME (n=4). Images were generated using horizontal scans within subretinal fluid areas. Raw scan data were exported and used to calculate light reflectivity profiles using image J software. Reflectivity data were acquired by projecting two identical rectangular boxes onto the subretinal spaces and the corresponding vitreous. Light reflectivity in the vitreous and subretinal spaces for the various pathologies were measured. ODRs were calculated by dividing the mean pixel intensity of the SRF by the mean pixel intensity of the vitreous
Results: :
Measured ODR values: RRD (0.67:0.19), RS (O.7:0.16), nAMD (1.47:0.73), DME (1.48:0.51), CSC (1.43:0.48), and PCME (1.36:0.52). Post-hoc Tukey B yielded significant differences in ODR values between nAMD/DME/CSC/PCME and RRD/RS (p<0.05). Confounders (age, image quality, vertical distance between measurements) were accounted for by multiple linear regression (adjusted R2=0.507; p<0.001) without affecting the significance of the difference.
Conclusions: :
Although OCT reveals neither origin nor composition of the subretinal spaces, the lower reflectivity of the SRF in RRD/RS compared to nAMD/CSC/DME/PCME may be due to the presence of proteins (e.g., albumin) and acute-phase serum reactants in the fluid. These pathologies are caused by a breakdown of the blood-retinal barrier, unlike SRF found in RRD/RS which has no exudative or inflammatory components. ODR profile analysis may be an adjunctive tool to differentiate between uncertain retinal pathologies in subretinal fluid.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retinal detachment • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)