Topographic, Biomechanical, in Vivo Confocal Microscopic and Ocular Surface Tests Evaluation of Corneal Changes and...

To assess corneal tomographic and biomechanical changes and the presence of dry eye and in vivo confocal microscopic(IVCM) changes in patients with systemic sclerosis(SSc).

This study with a prospective design included 52 eyes of 26 patients with SSc and 56 eyes of 28 healthy participants. Corneal tomography (Sirius dual imaging) provided keratometric data, corneal and anterior chamber parameters, and aberration values for all participants. An ocular response analyzer (Reichert Ophthalmic Instruments) was used to measure corneal biomechanics, while IVCM (Confoscan 4.0) assessed corneal subbasal nerve plexus, endothelium, and epithelium morphology. Presence of dry eye was examined using the tear break-up time(BUT) and ocular surface disease index(OSDI).

The mean follow-up period for the patients with SSc was 84 ± 84 (6-360 months) months. In the SSc group, tomographic measurements revealed significantly lower mean central corneal thickness, corneal volume, anterior chamber angle, and anterior chamber depth, alongside higher anterior elevation, trefoil, and spherical aberrations(p < 0.05 for all). There were no significant differences between the groups in terms of mean corneal biomechanical parameters (p > 0.05 for all). The IVCM measurements in the SSc group showed lower corneal subbasal nerve fiber length and density, nerve branch density, endothelial cell hexagonality, and intermediate epithelial cell count (p < 0.05 for all) when compared to the healthy subjects. The mean TBUT was lower, and the OSDI score was higher in the SSc group (p < 0.001 for both).

This study demonstrated some changes in subbasal nerve plexus and endothelial cell morphology in patients with SSc along with decreased corneal thickness, volume, anterior chamber angle and depth, and increased higher order aberrations. Subjective and objective dry eye tests further showed dry eye in SSc patients.