Frequency of amount and axis of astigmatism in subjects of Rawalpindi, Pakistan

Objective: To assess the frequency of amount and axis of astigmatism with respect to age and gender. Methods: The prospective, observational study was carried out from September 2009 to January 2010 at Armed Forces Institute of Ophthalmology, Rawalpindi. Patients from 5-70 years of age were included from both genders with no previous history of eye abnormality, surgery or eye pathology. An auto refractor-keratometre was used for measurement. Descriptive statistics were used to analyse data on SPSS 15. Results: Among the total 288 patients, with-the-rule astigmatism (n=21; 55%) had greater frequency in the 26-35 years sub-group. In terms of gender, 88 (48%); against-the-rule in 81 (44%); and oblique astigmatism in 14 (7.6%). In females, with-the-rule astigmatism was found in 52 (50%); against-the-rule in 36 (34.2%); and oblique in 17 (16%). The frequency of astigmatism 0.25 ranged from 0.8% (n=1) to 74% (n=28) across all age groups. The amount of astigmatism which was noted to be the most common and prominent in the sample was 1D. Conclusion: The amount and axis of astigmatism varied within the age sub-groups and within the gender.