GENDER AND AGE RELATED VARIATION IN CORNEA POWER.

OBJECTIVE: To determine the mean cornea power for this population and how it varies with gender and age.

DESIGN: A retrospective study.

SETTING: The eye clinic of the Niger Delta University Teaching Hospital.

SUBJECTS: All patients referred to the Optometric unit by the duty optometrist using a Carl Zeiss 599 Auto-refractokeratometer and the findings recorded in a register designed for that purpose. These patients had previously undergone full ocular examination by the referring Ophthalmologist.

STATISTICAL ANALYSIS: Data collected were analysed using the statistical package of social scientist (SPSS) version 16.

RESULTS: Two hundred and one patients (402 eyes) were analysed in this study. They consisted of 100 males and 101 females (M/F = 1:1.01). Their ages ranged from 8 to 84 years with a mean of 42.74 years (SD ± 14.62). The mean cornea power in the entire population was found to be 43.24 D (95% Cl 43.01-43.41). The horizontal cornea meridian has a higher diopteric power than the vertical meridian (43.38 D versus 43.13). The mean cornea power in females is greater than the mean cornea power in males (43.62 D versus 42.80 D). Cornea power was found to vary with age (P = 0.003), and the relationship was found to be linear on regression analysis.

CONCLUSION: The diopteric power of the female cornea is higher than that of their male counterpart. There is evidence that suggests a reduction of the diopteric power of the cornea with aging, but further studies are needed to confirm this observation.