Longitudinal assessment of patients with anterior scleritis using scleral area vessel density

Abstract

Purpose : There are limited measures that can help clinicians to grade severity of scleritis in an objective and quantitative manner. We had introduced a protocol recently that describes the use of optical coherence tomography angiography (OCTA) for the measurement of scleral area vessel density (SAVD), which showed significant differences between patients with non-infectious scleritis and normal controls. The purpose of this longitudinal study is to assess prospective changes in SAVD among subjects with non-infectious anterior scleritis undergoing treatment.

Methods : Eighteen patients with non-infectious anterior scleritis were recruited in our study. Eyes with infectious scleritis, grade 4+ (necrotizing) scleritis, or with concomitant eyelid/orbital inflammatory disease were excluded. Each eye was measured at two different time points. Customized protocol using OCTA to measure SAVD in a standardized temporal scleral area was utilized. SAVD was defined as the percentage of area occupied by vessels in the imaged space and was reported as an automated result from the modified OCTA imaging. Clinical grading of anterior scleritis was assessed using scale developed by Sen (Sen et al., 2011). Longitudinal changes in SAVD and clinical grading were assessed using paired t-test and ANOVA test.

Results : Thirteen patients (72%) were female; the average age was 47.8±16.7 years. At the beginning of study, eight, six, three, and one subjects had 0.5+ (minimal/trace), 1+ (mild), 2+ (moderate), and 3+ (severe) grade of scleritis, respectively. The mean duration of follow-up was 4.5 months. There was a stepwise decrease in SAVD in patients showing 1-, 2-, or 3-step improvement in the clinical grade of scleritis (figure1). Subjects achieving ≥2-step improvement (n=12) in scleritis grade showed a greater decrease in the SAVD than those without (n=6) [7.0% vs. 0.8% reduction; p= 0.049] (figure2).

Conclusions : Change in SAVD has a direct correlation with the change in the clinical grade of anterior scleritis. Measurement of SAVD may be an objective method to quantify the degree of scleral inflammation and to aid in disease monitoring.

This is a 2020 ARVO Annual Meeting abstract.

 

Figure1: Mean change in scleral area vessel density with improvement in clinical scleritis grade

 

Figure2: Mean change in scleral area vessel density with or without 2-step improvement in scleritis grade