Refraction and eye size in the elderly. A review based on literature, including own results

A review is given of the literature concerning refraction and eye size in the elderly. Information being sporadic, a picture has to be pieced together from cross-sectional studies of various authors. This implies differences from study to study regarding definitions, composition of samples, and methodology in particular. In Western communities, the main refractive change after the age of 50 is towards hypermetropia, but there are only few studies dealing with eye size. The secular trend--increasing bodily dimensions for each new generation--has possibly contributed to the concept of smaller eyes with old age, where this has been reported. Otherwise an impression is gained of eye size stability in the elderly. From a mechanistic point of view this seems probable, considering that intraocular pressure is maintained--or increased--in senescence. The usual non-pathology demand can hardly be fulfilled in studies of the elderly, clear lenses being the exception. Epidemiologically, cataract series can probably be used for eye size estimates, though refractively and eye-dimensionally it is not fully known whether skewness might apply to such samples.