Choroidal structural changes in tubercular multifocal serpiginoid choroiditis

Abstract

Purpose : Recently, choroidal vascularity index (CVI) has been proposed as a novel objective proxy measure of choroidal vascular perfusion in various vitreoretinal conditions. A prospective cohort study was performed to assess the changes in CVI among patients with tubercular multifocal serpiginoid choroiditis (TB MSC).

Methods : In this prospective case-control study, 18 patients with TB MSC (mean age: 26.92 ± 3.42 years) were recruited. 30 patients (age-matched) with no known ocular disease were also recruited as healthy controls. Patients of TB MSC and healthy controls underwent enhanced-depth imaging optical coherence tomography (EDI-OCT) scans were recruited. Patient demographics, clinical features, and fundus images were analyzed. Using previously validated semi-automated algorithm of image binarization, EDI-OCT scans were segmented to derive total choroidal area, luminal area, stromal area, and CVI. These values were correlated with controls using non-parametric Mann-Whitney U test and analyzed at follow-up using Wilcoxon signed-rank test.

Results : All the patients received anti-tubercular therapy with oral corticosteroids and followed up at regular intervals. There was a statistically significant difference in the CVI between controls (66.90 ± 1.77%) and TB MSC patients (65.46 ± 2.53%; p<0.001). There was statistically significant reduction in CVI at follow-up (3 months) (63.77 ± 3.91%; p=0.05). The subfoveal choroidal thickness (CT) was higher in TB MSC compared to controls (278.90 ± 57.84 µm versus 329.33 ± 27.69 µm; p=0.001). During the healed stage, CT decreased significantly (313.44 ± 21.41 µm; p=0.001).

Conclusions : CVI provides an objective assessment of choroidal vascularity in TB MSC. During the active disease, there is relative choroidal hypoperfusion. As the lesions heal, choriocapillaris atrophy occurs with further reduction in CVI.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Calculation of CVI of a patient with TB MSC shows decrease in total choroidal area from baseline (A-C) at the follow-up visit (D).