Simple Vision Function Tests that Distinguish Eyes with Early to Intermediate Age-related Macular Degeneration

ABSTRACT

Purpose

To present and compare baseline vision findings in eyes with early age-related macular degeneration (E-AMD), intermediate AMD (I-AMD), and age-similar participants with normal aging changes to the retina (No-AMD).

Methods

Two hundred and thirty-seven eyes of 125 individuals (66.4% female, mean age 75.3 years) were tested monocularly using several simple, rapid psychophysical tests: high contrast visual acuity, low contrast visual acuity at reduced luminance, contrast sensitivity, shape discrimination hyperacuity, colour vision, reading rate, and glare recovery. Retinal status was determined using colour fundus photographs that were graded according to the Beckman Initiative for Macular Research Classification Committee scale. Logistic regression analyses with generalized estimating equations were used to assess the association between each vision variable and AMD category, while taking into account the correlation between the two eyes.

Results

Three vision measures (contrast sensitivity [CS], shape discrimination hyperacuity [SDH], and colour discrimination [DesatCCS]) were significantly and independently associated with intermediate AMD. Relative Risk Ratios (RRR), 95% Confidence Intervals (in parentheses), beta coefficients, and significance (p) for the I-AMD vs. No-AMD model are: CS: RRR = 6.5 (1.91–22.0), beta = 1.87, p < .01; SDH: RRR = 2.34 (1.24–4.44), beta = 0.85, p < .001; DesatCCS: RRR = 1.43 (1.22–1.68), beta = 0.36, p < .001. Performance on these measures was significantly poorer for participants with I-AMD vs. No-AMD.

Conclusions

Simple screening tests distinguish eyes with intermediate AMD from eyes with less severe AMD or normal aging changes. This suggests that these vision measures may be significant predictors of which participants will go on to develop advanced AMD.

Acknowledgments

Funded by NIH EY023320 (to LAL) and by the Smith-Kettlewell Eye Research Institute. We also wish to thank all our study participants, West Coast Retinal Medical Group, Pacific Eye Associates, Rosa Rodriguez, Zelda Bosch, Meagan Mendoza, and Tiffany Giamanco for recruitment and scheduling; Vital Art and Science for software support; Kenneth Huie for technical assistance.

Conflicts of interest

None of the authors have any proprietary interests or conflicts of interest related to this submission.

Additional information

Funding

Supported by The National Eye Institute of the National Institutes of Health, USA. Grant # EY023320.