The impact of swept-source optical coherence tomography (SS-OCT) in the management of scleral inflammation

Abstract

Purpose : To investigate the scleral changes observed in patients with active and inactive anterior scleritis with a posterior segment swept-source optical coherence tomography device (SS-OCT, Atlantis DRI OCT-1, Topcon, Japan).

Methods : Single centre consecutive case series. SS-OCT images were acquired in patients with active anterior scleritis and followed up until remission with sequential scans. Images were quantitatively and qualitatively assessed using the caliper incorporated in the device software. Quantitative analysis included measurement of scleral thickness (conjunctiva and sclera) in the mid point between the sclerocorneal limbus and the rectus muscle insertion rim (Tillaux spiral). Three measurements were obtained and the average value was annotated for analysis. Qualitative analysis included the presence of: 1) subconjunctival hyporreflective areas, 2) scleral hyporreflective areas, 3) collagen fiber separation, 4) collagen fiber aggregation, 5) scleral destruction / scleral thinning areas.

Results : Twenty active scleritis eyes (19 patients) were included in the study. Of them, 75% had diffuse scleritis, 15% nodular scleritis, and 10% necrotizing scleritis. Mean scleral thickness was significantly higher during active phase compared to remission phase (891.5±241.7 µm vs 687.4±142.1 µm, p<001). No significant differences were observed between the inactive phase and the normal fellow eye (659.3±63.8, p=0.63). All eyes showed subconjunctival and scleral hyporreflective spaces in active phase, which resolved completely in remission (100% and 0%, respectively). Collagen fiber separation and aggregation was observed in 100% and 15% of eyes in active phase, and in only 10% and 5% of eyes following remission. In our cohort, no differences in scleral destruction / scleral thinning were observed in active and inactive phases and were just seen in necrotizing scleritis eyes.

Conclusions : Posterior segment SS-OCT can be employed to obtain direct images of the anterior sclera, allowing adequate identification of conjunctival and scleral layers that might render useful in the assessment of the inflammatory status in scleritis. The longer wave-lenght of the laser source permits accurate definition of fluid in the deep layers of conjunctiva and sclera that might not be evident to clinical examination. These findings may have implications for the treatment of scleritis.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.