Anterior segment OCT imaging in cases of episcleritis and scleritis
Reviewed by Saruban Pasu

The purpose of this study was to determine whether it is feasible to obtain good-quality images with anterior segment OCT (AS-OCT) in patients with episcleral or scleral inflammation located anterior to the equator, and whether this technique is able to identify changes associated with inflammation. Eleven patients were prospectively enrolled for this study. OCT scans in the nasal and temporal quadrants were acquired using a spectral domain AS-OCT (Heidelberg Engineering, Dossenheim, Germany). The sclera mode with EDI was chosen with an OCT grid and the number of B-Scans was 11 with a pattern size of 15 x 5deg (8.3 x 2.8 mm) and the distance between B-Scans was 277 microns. The scleral thickness was measured in the affected quadrant of the sclera and compared to the contralateral unaffected quadrant of the fellow eye. Based upon slit-lamp examination and phenylephrine testing, four of the 11 patients were diagnosed with nodular scleritis, three with diffuse scleritis, two with nodular episcleritis, and three with diffuse episcleritis. The affected quadrant was more frequently the temporal (10 eyes) than the nasal one (single eye). The mean thickness of the sclera and episclera combined in episcleritis was 952 ±107 microns as compared to 764 ±15 microns in the fellow eye (p=0.158). Mean thickness in eyes with scleritis was 1006 ±58 microns as compared to 813 ±39 microns in the same quadrant of the fellow eye (p < 0.05). When combining both groups, mean thickness in the affected eye was 982 ±56 microns as compared to 790 ±23 microns in the fellow eye (p < 0.05). The episcleral layers were thickened on OCT in both scleritis and episcleritis. The deeper vascular network showed a marked dilation of vessels extending into the superficial layers of the sclera in scleritis cases. In contrast, the vessels involved in episcleritis were dilated more diffusely and more superficially and did not extend into the sclera. The report concludes by suggesting AS-OCT may be use to monitor therapeutic effects in scleral and episcleral inflammatory disease.

Imaging of the sclera in patients with scleritis and episcleritis using anterior segment optical coherence tomography.
Axmann S, Ebneter A, Zinkernagel MS.
OCULAR IMMUNOLOGY & INFLAMMATION
2016;24(1):29-34.