Optical coherence tomography biomarkers of posterior scleritis in different stages of the disease activity.

Abstract

Purpose: The study aimed to analyze the optical coherence tomography (OCT) characteristics in different stages of posterior scleritis (PS) and explore possible correlations between OCT features and the different stages of PS.

Methods: This is a retrospective study on clinically diagnosed cases of PS with transparent media and good OCT images at an academic tertiary eye care center in India between April 2014 and March 2019. Stage-specific prevalence, distribution, and associations of 25 predefined OCT biomarkers across the acute, resolving, and resolved stages of PS were analyzed.

Results: A total of 104 OCT plates from 31 patients were analyzed; 43, 28, and 33 were associated with active, resolving, and resolved stages of PS, respectively. Acute PS demonstrated choroidal thickening (100%), retinal pigment epithelium (RPE)-choroidal bump (97.7%), internal limiting membrane (ILM) folds (90.7%), and neurosensory detachment (NSD) (86.0%); resolving PS showed hyperreflective dot (HRD) prevalence (inner retina 92.9%, subretinal space 92.9%, and outer retina 89.3%); while resolved PS was characterized by ellipsoid zone (EZ) reflectivity (54.5%), variable external limiting membrane (ELM) reflectivity (51.5%), and epiretinal membrane (ERM) (39.4%). Median central foveal thickness (CFT) declined significantly from 737 µm in acute PS to 269 µm in resolving PS and 212 µm in resolved PS (p < 0.0001). Acute PS was strongly associated with RPE-choroidal bump [odds ratio (OR) 527.7, 95% confidence interval (CI) 54.8-5,079.4], ILM folds (OR 73.1, 95% CI 19.5-273.9), RPE thickening (OR 29.0, 95% CI 9.1-92.3), NSD (OR 14.8, 95% CI 5.0-44.0), cystoid macular edema (OR 8.3, 95% CI 3.4-20.5), and vitreous cells (OR 3.1, 95% CI 1.2-7.6). Resolving PS showed associations with HRD involving the inner retina (OR 8.39, 95% CI 1.95-36.2), outer retina (OR 7.10, 95% CI 1.94-25.9), subretinal space (OR 7.43, 95% CI 1.72-32.2), and choroid (OR 4.50, 95% CI 1.20-16.8). Resolved PS was associated with variable reflectivity of the EZ (OR 15.6, 95% CI 3.75-65.0) and ELM (OR 7.31, 95% CI 1.87-28.5), and posterior vitreous detachment (OR 2.80, 95% CI 1.29-6.11).

Conclusion: OCT characteristics analyzed in this study can aid in identifying the stage of disease activity in PS.