Central Corneal Thickness in an Adult Non-Glaucomatous Ethnic Population in Nigeria

Abstract

Purpose: To determine the mean central corneal thickness (CCT) of healthy adult Nigerians from the Igbo ethnic population in southeastern Nigeria which has the highest prevalence of glaucoma and to evaluate the relationship if any between mean CCT and patients’ demographics.Methods: A cross sectional study conducted at an eye screening center in Enugu Southeastern Nigeria. Subjects with healthy eyes from the Igbo ethnic population were recruited. Central corneal thickness was measured with ultrasound pachymetry (Sonomed PacScan plus, model 300AP+) on eligible subjects. Topical anesthetic was instilled and 3 measurements of corneal thickness were taken. The average thickness for each eye was calculated and the relationship between mean CCT, age and gender were studied.Results: 706 eyes of 353 participants were examined. 52.7% of the subjects were females while 47.3% were males. The mean age of participants was 50.29 ± 16.58 years. The mean central corneal thickness (CCT) for RE was 527.68 ± 36.88μm (95% CI: 523.83 –531.55μm) and 527.45 ± 38.01μm for LE (95% CI: 523.47 – 531.43μm). There was a decrease in CCT values with increasing age (p= 0.016, p= 0.05 for RE and left eyes respectively). Males had a significantly higher CCT compared to females for both right and left eyes (p=0.004, p=0.007).Conclusion: Central corneal thickness values in the Igbo ethnic population of Southeast Nigeria, an ethnic group with the reported highest prevalence of glaucoma in Nigeria from our study is thinner than those reported from other regions both within Nigeria as well as some Sub-Saharan populations, Caucasians, Asians, and Hispanics but it is however comparable with values reported among Cameroonians and African Americans. CCT among Nigerian Igbos, seems to decrease with age and appears thicker in males compared with females.

Ocular Phenotypic Features of Adult-Onset Primary Open Angle Glaucoma in A Tertiary Hospital in Southern Nigeria

“…Studies suggest that subjects of African descent African have thinner corneas than Caucasians and harbor a higher incidence and prevalence of glaucoma [20][21][22][23]. CCT affects the accuracy of intraocular pressure (IOP) measurement by applanation tonometry,thicker cornea requires greater force to flatten and, conversely, a thinner cornea is more easily flattened, thus a thinner cornea may give rise to a falsely lower IOP than the actual value [24]. In this study, the mean ± 36.88μm [24].…”

“…CCT affects the accuracy of intraocular pressure (IOP) measurement by applanation tonometry,thicker cornea requires greater force to flatten and, conversely, a thinner cornea is more easily flattened, thus a thinner cornea may give rise to a falsely lower IOP than the actual value [24]. In this study, the mean ± 36.88μm [24].…”