title: Racial differences in central corneal thickness and refraction among refractive surgery candidates.
abstract: OBJECTIVE
  To examine the preoperative central corneal thickness and refractive status of Caucasians, Hispanics, Asians, and African Americans in a refractive surgery patient population.
  
  
  METHODS
  In a retrospective case series, a total of 803 consecutive eyes, which had no history of anterior segment surgery, underwent central corneal thickness and refraction measurement as part of a preoperative evaluation for refractive surgery from December 1999 to October 2002. Preoperative central corneal thickness was measured by a DGH-550 ultrasonic pachymeter, and spherical equivalence was determined by manifest refraction.
  
  
  RESULTS
  This study included Caucasian (34.4%), Hispanic (34.5%), Asian (20.7%), African American (8.9%), and other (1.5%) patients. A one-way analysis of variance (ANOVA) revealed no significant differences in the central corneal thickness measurements among Asians, Hispanics, and Caucasians. However, mean central corneal thickness was 14 microm thinner in African Americans compared to Caucasians, and was significantly different at the 95% confidence interval. A one-way ANOVA revealed a significant difference in the preoperative spherical equivalence among the four groups (F=4.91; df=3; P<.05) but no significant differences were noted in the preoperative astigmatism among any of the four groups (F=1.08; df=3; P>.05). A significant difference was noted in age in the four preoperative groups.
  
  
  CONCLUSIONS
  Among the refractive population, African Americans were found to have thinner central corneal thickness than Caucasians. Asians were significantly (P<.05) more myopic compared to Caucasians, Hispanics, and African Americans. No difference was noted in the preoperative astigmatism among any of the four groups. Asians sought refractive surgery at a younger age whereas Caucasians sought it at an older age.
authors.affiliation: Department of Ophthalmology, University of Southern California-Los Angeles County Hospital, USA. Christopher.Yo@kp.org
authors.forename: Christopher
authors.initials: C
authors.lastname: Yo
authors.forename: Reginald G
authors.initials: RG
authors.lastname: Ariyasu
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D000704:Analysis of Variance; D044466:Asian People; D003315:Cornea / Q000473:pathology*; D048988:Corneal Surgery, Laser; D019781:Corneal Topography; D006630:Hispanic or Latino; D006801:Humans; D008875:Middle Aged; D011300:Preoperative Care; D012030:Refractive Errors / Q000208:ethnology* / Q000473:pathology; D054140:Refractive Surgical Procedures; D012189:Retrospective Studies; D012307:Risk Factors; D044465:White People