Abstract
Purpose: :
To investigate the aging change of retinal image contrast in eyes with transparent lenses of Japanese population.
Methods: :
Subjects comprised right eyes of 269 Japanese (mean age 39.7 years; 23 in age 20s, 118 in 30s, 95 in 40s and 33 in 50s) with no organic disease other than refractive error and with over 0logMAR best corrected visual acuity. A point spread function analyzer (PSF-1000, TOPCON) was used to measure sensitivity of retinal images under condition of best corrected refractive error, through Landolt ring simulation with 3 mm pupils. An anterior segment analysis system (EAS-1000, NIDEK) was used to measure backward light scattering intensity (LSI) and optical distance (mm) of each layer of lens (anterior capsule (A), anterior adult nucleus (B) and central inner layer (C)). Lens transparent property (LTP), an index we introduced previously (Sasaki H, et al: Ophthalmic Res. 1999), was used to estimate lens transparency. It is determined by: LTP = LSI at A + LSI at B × optical distance (mm) between A and B + LSI at C × optical distance (mm) between A and C. We also evaluated higher order aberrations (µm) with 4 mm pupils by wavefront analyzer (9000PW, TOPCON). Examinations were performed under maximal mydriasis.
Results: :
Retinal image contrast degenerated significantly with aging. The largest difference was seen with optotype 0.423logMAR which is in the intermediate frequency range. The retinal image contrast reduced by 5.4% in 10 years. That with optotype 0.423logMAR also degraded remarkably with increase of total higher order aberrations (p<0.01) and LTP (p<0.01). Multiple linear regression analysis of influencing factors showed the effects of higher order aberration and LTP were almost equal.
Conclusions: :
Retinal image contrast in eyes with transparent lenses degenerated with aging. It was clarified that this age related degradation can be attributed to increase of higher order aberrations and LTP among the Japanese subjects aged from 20s to 60s.
Keywords: contrast sensitivity • aging • retina