METHODS: A cross-sectional study was conducted to evaluate the corneal cell morphology of 47 keratoconus patients and 32 healthy eyes without any ocular disease. New keratoconus patients with different disease severities and without any other ocular co-morbidity were recruited from the ophthalmology department of a public hospital in Malaysia from June 2013 to May 2014. Corneal cell morphology was evaluated using an in vivo slit-scanning confocal microscope. Qualitative and quantitative data were analysed using a grading scale and the Nidek Advanced Visual Information System software, respectively.
RESULTS: The corneal cell morphology of patients with keratoconus was significantly different from that of healthy eyes except in endothelial cell density (P = 0.072). In the keratoconus group, increased level of stromal haze, alterations such as the elongation of keratocyte nuclei and clustering of cells at the anterior stroma, and dark bands in the posterior stroma were observed with increased severity of the disease. The mean anterior and posterior stromal keratocyte densities and cell areas among the different stages of keratoconus were significantly different (P < 0.001 and P = 0.044, respectively). However, the changes observed in the endothelium were not significantly different (P > 0.05) among the three stages of keratoconus.
CONCLUSION: Confocal microscopy observation showed significant changes in corneal cell morphology in keratoconic cornea from normal healthy cornea. Analysis also showed significant changes in different severities of keratoconus. Understanding the corneal cell morphology changes in keratoconus may help in the long-term monitoring and management of keratoconus.
METHODS: Thirty nine eyes of 39 new keratoconus patients were selected and randomly fitted with two types of RGP contact lenses. Group 1 had 21 eyes with regular rigid gas-permeable (RRGP) contact lens and rest 18 eyes were in group 2 with specially designed rigid gas-permeable (SRGP) contact lens. Corneal cell morphology was evaluated using a slit scanning confocal microscope at no-lens wear and after 1y of contact lens wearing.
RESULTS: After 1y of contact lens wearing in group 1, the mean anterior and posterior stromal keratocyte density were significantly less (P=0.006 and P=0.001, respectively) compared to no-lens wear. The mean cell area of anterior and posterior stromal keratocyte were also significantly different (P=0.005 and P=0.001) from no-lens wear. The anterior and posterior stromal haze increased by 18.74% and 23.81%, respectively after 1y of contact lens wearing. Whereas in group 2, statistically significant changes were observed only in cell density & area of anterior stroma (P=0.001 and P=0.001, respectively) after 1y. While, level of anterior and posterior stromal haze increased by 16.67% and 11.11% after 1y of contact lens wearing. Polymegathism and pleomorphism also increased after 1y of contact lens wearing in both the contact lens groups.
CONCLUSION: Confocal microscopy observation shows the significant alterations in corneal cell morphology of keratoconic corneas wearing contact lenses especially in group 1. The type of contact lens must be carefully selected to minimize changes in corneal cell morphology.