corneal confocal microscopic analysis in patients with keratoconus 窑 Clinical Research 窑

· AIM: To quantify corneal ultrastructure using laser scanning confocal microscopy (IVCM) in patients with keratoconus and control subjects. · METHODS: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slitlamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated. ·RESULTS: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub -basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817依306 cells/mm2 4802依508 cells/mm2, < 0 . 001 ) , anterior stromal keratocyte density (800 依111 cells/mm2 555 依115 cells/mm2, <0.001), posterior stromal keratocyte density (333依34 cells/mm2 270 依47 cells/mm2, <0.001), endothelial cell density (2875 依223 cells/mm2 2686 依265 cells/mm2, <0.001), sub -basal nerve fiber density (31.2依8.4 nerves/mm2 18.1 依9.2 nerves/mm2, <0.001), sub -basal nerve fiber length (21.4依3.4 mm/mm2 16.1依5.1 mm/mm2, <0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 third quartile 68.7) nerve branches/mm2 median 25.0 (first quartile 6.2 third quartile 45.3) nerve branches/mm2, <0.001) were observed in patients with keratoconus. ·CONCLUSION: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non invasive technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus. ·