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Abstract

Objective
To examine the extent to which visual function in Beckman age-related macular degeneration (AMD) disease stages differ from age similar peers with no AMD and using reference limits derived from those with no AMD, test the hypothesis that people with intermediate AMD (iAMD) have heterogenous visual function deficits.

Design
Cross-sectional analyses of a range of baseline visual function measures from the MACUSTAR study; an international, multi-center (n=20), non-interventional clinical trial.
Participants
585 participants with iAMD (67% female, mean [standard deviation] age 72 [7] years) were recruited alongside 56 with no AMD (59% female, 68 [6]), 34 with early AMD (79% female, 72 [6]) and 43 with late AMD (49% female, 75 [6]).

Methods
Participants performed best-corrected visual acuity (BCVA), low luminance visual acuity (LLVA), Moorfields acuity test (MAT), Pelli-Robson contrast sensitivity (PR-CS), Small Print Standardized International Reading Speed Test (SPS), mesopic and scotopic Average Threshold (MesAT and ScoAT; Macular Integrity Assessment, iCare,) and Rod Intercept Time (RIT; AdaptDx, Lumithera).

Main Outcome Measures
Relationship between each visual function measure and disease classification was examined by linear regression adjusted for age, sex and phakic status. No AMD data were used to estimate normal reference limits for each visual function test. iAMD scores were dichotomised against reference limits and proportion worse than each limit calculated.

Results
Relative to no AMD, SPS was significantly worse in early AMD (p = 0.001), all measures except SPS were significantly reduced in iAMD (p<0.02) and all measures were markedly reduced in late AMD (p<0.0001). 31% of iAMD participants breached reference limits for PR-CS, 29% for RIT, 24% for LLVA, 23% for MAT, 21% for BCVA, 20% for MesAT, 18% for ScoAT and 13% for SPS. 69.6% and 42.7% of iAMD participants breached ≥1 and ≥2 reference limits respectively, whereas 33.6% and 5.7% would be expected by chance.

Conclusions
A large proportion of people with structurally defined iAMD exhibit heterogenous visual function deficits outside normal reference limits. This observation may be relevant for the design and inclusion criteria of future interventional trials.

Publication Type:	Article
Publisher Keywords:	age-related macular degeneration, visual function, visual dysfunction
Subjects:	R Medicine > RE Ophthalmology
Departments:	School of Health & Medical Sciences School of Health & Medical Sciences > Optometry & Visual Sciences
SWORD Depositor:	Symplectic Administrator

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