Abstract
Purpose: :
The Vision Data 2007 database was developed to study visual and refractive changes across the human lifespan. Here we report changes in mean ocular refraction (MOR) and total astigmatism as a function of age.
Methods: :
The Vision Data 2007 database is a retrospective database of 6397 individuals generated from all Pediatric and Primary Care Clinic patient visits at the University of Waterloo, School of Optometry between Jan 2007 and Jan 2008. It contains comprehensive information on visual symptoms, ocular and systemic health history, visual function, refractive status, accommodation, binocular vision and ocular health for persons between the age of 0 and 93 years. Each individual’s MOR was determined. MOR frequency was calculated for 1 diopter (D) intervals and MOR averages were calculated for 1 year age intervals. Likewise, astigmatism values for individuals of the same age were averaged.
Results: :
The refractive error (MOR) distribution of this population is leptokurtic and negatively skewed. The distribution peaks at +1D and the range is -16.25 to +14.88 D. For children below 1 year of age MOR was +1.79 D. Hyperopia decreases with age until 8-9 years at which MOR becomes myopic. Myopia continues to increase until the early twenties where average refraction reaches -2.77D. Following a short period of relative stability myopia begins to decline in the late 20’s and early 30’s. There is steady change in the hyperopic direction until the end of the lifespan and average MOR becomes hyperopic again between the ages of 65 & 75 years. Below age 1 year the average amount of astigmatism was 0.50D. There was a gradual but consistent increase in astigmatism throughout the lifespan. LASIK and cataract surgery reduced MOR slightly between 25-40 years and 70+ years respectively.
Keywords: clinical (human) or epidemiologic studies: natural history • refractive error development • aging