Central corneal pachymetry in Yemeni patients undergoing refractive surgery

OBJECTIVE: To assess the preoperative central corneal thickness (CCT) of myopic and/or astigmatism patients presenting for refractive surgery in a tertiary hospital in Yemen.

METHODS: In this hospital-based cross-sectional study, 2,304 subjects aged 18-50 years with myopia and myopic astigmatism who presented to the refractive surgery unit were recruited. Data for the current study was collected from our electronic pool of patients presenting to the refractive surgery clinics in Yemen Magrabi Hospital, Sana’a, Yemen, between January 2006 and December 2008. The inclusion criteria were absence of corneal or anterior segment disease, glaucoma, and any ocular surgery. Central corneal thickness was assessed by ultrasound pachymetry. Data from the right eye only was analyzed.

RESULTS: All patients were Yemeni citizens, where the majority (1248; 54.2%) were women with a mean (+/-SD) age of 26.74 (+/-6.1), range 18-50 years. The mean (+/-SD) CCT was 521.7 (+/-31.62), range 432-643 um. The measured CCT was independent of gender (p=0.567) and did not differ between both eyes (p=0.371). Corneal thickness increased with age, correlated to vision (p=0.027), keratometric readings (K1 , K2) (p<0.001 for both), and increased with the increase in severity of myopia (p=0.026).

CONCLUSION: Yemeni patients have thinner CCT compared to other populations. Refractive surgeons should be careful in choosing the suitable procedures. The available cornea for ablation in Laser-Assisted in situ Keratomileusis (LASIK) is very limited. Possible alternative treatments; namely photorefractive keratectomy (PRK) and phakic intraocular lens implantation options should be discussed with patients prior to surgery.