Iridian anterior segment OCT in rubella uveitis syndrome and cytomegalovirus anterior uveitis: a comparative study

To compare iris affectation in cytomegalovirus anterior uveitis (CMVAU), rubella virus-associated uveitis (RVU), and healthy contralateral eyes, using swept-source anterior segment optical coherence tomography (SS-AS-OCT).

A comparative, transversal, retrospective study examining 60 eyes from 30 patients-18 eyes (17 patients) with CMVAU, 14 eyes (13 patients) with RVU, and 28 healthy eyes-was performed. Six-millimeter cross-sectional SS-AS-OCT B-scans were obtained in each iris quadrant. Images were exported to ImageJ®. Qualitative and quantitative analyses were done: stromal thickness (ST), smooth index (SI), and optical density (OD) of pigment epithelium. Comparisons between measurements and clinical-demographic parameters were performed using SPSS®.

Qualitative analysis showed extensive damage in iris stroma but was unable to differentiate between both uveitis. RVU eyes had a lower mean ST (315.72 μm ± 42.4) compared to those with CMVAU (348.6 μm ± 46) (p = 0.047) and a lower ST in the upper (338.9 μm ± 38.52)/(386.25 μm ± 47.2) (p = 0.005) and temporal (281.5 μm ± 57.3)/(326.43 μm ± 62.3) (p = 0.016) quadrants. Mean (0.94 ± 0.02)/(0.9 ± 0.03) (p = 0.001), temporal (0.94 ± 0.02)/(0.89 ± 0.03) (p < 0.001), and nasal SI (0.094 ± 0.02)/(0.9 ± 0.04) (p = 0.005) were higher in RVU. OD was similar in both uveitis. In healthy eyes, mean ST (376.8 μm ± 39.7) was higher and mean SI was lower (0.87 ± 0.04) than in RVU (p < 0.001) and CMVAU eyes (p = 0.032). Mean OD was higher in healthy eyes (911 ± 130) than in CMVAU eyes (800 ± 200) (p = 0.037).

The quantitative analysis of the SS-AS-OCT iris images allows for the differentiation between healthy eyes and those with CMVAU and RVU, as well as between both uveitis.