Change of Corneal Astigmatism with Aging in Koreans with Normal Visual Acuity

ABSTRACT

PURPOSE: To evaluate the distribution and change of corneal astigmatism with aging in persons with normal visual acuity. METHODS: We classified 504 subjects (504 eyes) showing good naked vision at least 1.0 from 3 to 83 years into 15 groups with 5 year interval and analyzed corneal astigmatism using refraction and keratometry. RESULTS: With-the-rule astigmatism (WTR) was shown in 98.5% between 3 and 25 years and progressively decreased with aging. In 61 to 65 years' group WTR was 34.1% and against-the-rule astigmatism (ATR) was 36.4%. After then ATR was more predominant. Mean corneal astigmatism was about 1 diopter under 20 years and progressively decreased to 0.5 D at 60 years with aging. CONCLUSIONS: 84.7% of persons with normal visual acuity have corneal astigmatism. WTR was predominant in the youth but progressively decreased with aging to equal balance with ATR in the mid sixties. After then corneal astigmatism would be inclined to against-the-rule. The amount of corneal astigmatism was decreased from about an 1 diopter in twenties to 0.5 diopter in sixties.