Changes in Central Corneal Thickness and Endothelial Cell Count after Lasik

Purpose: To compare the pre and postoperative endothelial cell counts and central corneal thickness in patients undergoing laser in situ keratomileusis (LASIK) for the treatment of myopia.

Study Design: Prospective study.

Place and Duration: This hospital based study was carried out at the LASIK Centre in the Postgraduate Department of Ophthalmology, Government Medical College, Srinagar for a period of one and a half year (from April 2014 to October 2015).

Materials and Methods: A series of 53 patients (100 eyes) with myopia between -1 and -8.25D and upto -2.75D of myopic astigmatism were included in the study. These patients underwent LASIK using Carl Zeiss Meditec AG’s MEL 80 (Germany) laser. Central corneal thickness and endothelial cell counts were measured before and 1 day, 1 week, 1 month and 3 months after LASIK using non contact specular microscopy. Age and refractive error were also recorded.

Results: The mean age of the patients was 26.9±4.71 years (range 19 to 36 years). The study included 30(56.6%) males and 23(43.4%) females. A total of 100 eyes were operated.47 patients underwent LASIK in both eyes while only one eye was operated in 6 patients. At the end of 3 months, the mean spherical equivalent of refraction was -0.24±0.369 compared to a preoperative mean of -4.81±2.053. The preoperative central corneal thickness ranged from 442 to 590 microns with a mean of 515.7 microns ± 36.4 and endothelial cell count ranged from 2365 to 3578 cells per mm2 with a mean of 2874.6 cells per mm2 ± 225.14. At 1 day, 1 week, 1 month and 3 months after LASIK, mean CCT was recorded as 414.5±48.5, 406.7±47.9, 411.3±48.1 and 418.3±48 respectively. No significant correlation was found between age, refractive error and mean CCT. The mean endothelial cell count was recorded as 2867.1±218.14, 2865.6±212.64, 2864.8±207.64 and 2861.3±201.48 at 1 day, 1 week, 1 month and 3 months after LASIK.

Conclusion: There was a significant decrease in central corneal thickness in the immediate postoperative period. It continued to decline till 1 week after the surgery and then increased over time in the late postoperative period. However no significant change was observed in endothelial cell counts in the postoperative period.