Age-related psychophysical changes and low vision

Abstract

When considering the burden of visual impairment on aging individuals and society at large, it is important to bear in mind that vision changes are a natural aspect of aging. In this article, we consider vision changes that are part of normal aging, the prevalence of abnormal vision changes caused by disorders of the visual system, and the anticipated incidence and impact of visual impairment as the US population ages. We then discuss the services available to reduce the impact of vision loss, and the extent to which those services can and should be improved, not only to be better prepared for the anticipated increase in low vision over the coming decades, but also to increase the awareness of interactions between visual impairment and comorbidities that are common among the elderly. Finally, we consider how to promote improved quality, availability, and acceptance of low vision care to lessen the impact of visual impairment on individuals, and its burden on society.

Keywords: health care delivery; normal aging; visual impairment.

Figure 1

Age dependence of the average threshold for 10 visual function measures, in log units relative to the normal adult value. Glare recovery was the time required to read 0.2 log units above threshold on the SKILL card, following a 1-minute glare exposure; color vision was the Adams desaturated D-15 score. For details see the report of Haegerstrom-Portnoy et al. HCVA, high contrast VA; LCVA, low contrast VA (low contrast Bailey-Lovie chart); LCLLVA, low contrast/low luminance VA (SKILL card); LCGVA, low contrast VA under glare conditions; CS, Pelli-Robson contrast sensitivity; Stereo, stereo plates (4 levels); AVF, Smith Kettlewell attentional visual field ratio.

Figure 2

Drawn line graph: age distribution of the patients enrolled for low vision rehabilitation at 28 centers participating in the Low LoVRNet study. Symbols: age distribution of the US population over age 20, in the years 2000 (Census data) and 2030 (projected), illustrating the expected doubling of demand for low vision services by 2030, compared to the beginning of the century.

Figure 3

Causes of VI among 675 participants in the LoVRNet study (based on Table 1 in the study of Vitale et al.), ordered according to the affected stage along the visual pathway.