Specular microscopic study of cornea in infectious and non-infectious uveitis in rural population of south India

Background: Intermediate uveitis is a form of uveitis localized to the vitreous and peripheral retina. Primary sites of inflammation include the vitreous of which other such entities as pars planitis, posterior cyclitis, and hyalitis are encompassed. Intermediate uveitis may either be an isolated eye disease. Involvement of the corneal endothelium during uveitis has not been extensively studied even though it might participate in or constitute a target of ocular inflammation. Formation of keratic precipitates (KP) is a characteristic finding in several forms of uveitis. Aim: The aim of this prospective study was to examine the vicinity of keratic precipitates in infectious and non-infectious uveitis by specular microscopy. Materials and methods: Patients with infectious and non-infectious uveitis in any activity level and presence of keratic precipitates were enrolled. A noncontact specular microscope was used to capture endothelial images in the vicinity of keratic precipitates. The automated morphometric analysis was done for cell size, cell density and cells coefficient of variation. Statistical comparisons were made between the infectious and non-infectious groups. Results: Totally 50 patients were enrolled in this study, 30 (64%) eyes presented infectious uveitis, 20 (36%) non-infectious uveitis and 1 (3%) eye were excluded due to the impossibility to obtain a specular image. The mean cell density estimated was 2,628 ± 204 cells/mm2 in the infectious group and 2,622 ± 357 cells/mm2 in the non-infectious group. The mean cellular area in the infectious and non-infectious group was respectively 385 ± 31 µm2 and 390 ± 60 µm2. The coefficient of variation (%) of the cellular area in the vicinity of keratic precipitates was 26.36 ±3.44 in infectious and 27.69 ± 4.61 in the non-infectious group. The differences between the groups were not statistically significant (P<0.005 / Mann-Whitney test) for the three morphologic variables. Conclusion: The clinical applicability of specular microscopy in patients with uveitis can be a useful tool to evaluate the corneal endothelium in the presence of keratic precipitates, however, the handicap of the specular image formation might not be discarded in some cases. The differences found were not clinically meaningful between the infectious and non-infectious groups, however the uveitis in various degrees of intraocular inflammation