GENDER AND AGE RELATED VARIATION IN CORNEA POWER

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

A retrospective study.

The eye clinic of the Niger Delta University Teaching Hospital.

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.

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

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.

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.