Abstract
Purpose :
To determine whether scores on the Low Luminance Questionnaire (LLQ) are significantly associated with objective measures of visual function in early and intermediate dry age-related macular degeneration.
Methods :
Cross-sectional study of subjects with early dry AMD (AREDS stage 2, N=33) and intermediate AMD (AREDS stage 3, N=47) along with 21 age-matched normal controls. Subjects underwent a dilated fundus examination and were interviewed using the LLQ. Psychophysical tests were performed, including best-corrected visual acuity (BCVA), mesopic microperimetry with eye tracking (MAIA, CenterVue), dark adaptometry (AdaptDx), low luminance visual acuity (LLVA) (standard using a log 2.0 neutral density filter and a computerized method) and cone contrast test (CCT) (Innova Systemc Inc). Low Luminance Deficit (LLD) was defined as the difference in the number of letters read under standard versus low luminance conditions (LLD=BCVA-LLVA). Linear regression was used to assess the relationship between scores on LLQ and visual function tests.
Results :
Subjects with intermediate AMD had significantly lower LLQ scores than participants with early AMD or controls (76.5 vs. 86.4 vs. 97.0, p=0.009, p=0.0004, respectively). LLQ Composite score was associated with standard LLVA (p=0.032), Computerized LLVA1 (measured at 1.3 cd/m2) and LLVA2 (at 0.5 cd/m2, p<0.001), LLD2 (p=0.036), and rod intercept (p=0.03), but only computerized LLVA1 and LLVA2 remained significant after adjusting for AMD versus control status. Among dry AMD subjects, LLQ composite scores were significantly associated with computerized LLVA1 and LLVA2 (p=0.009, p=0.014, respectively) as well as LLD1 and LLD2 (p=0.045, p=0.044, respectively). The association between LLQ composite scores and computerized LLVA1 was independent of AMD severity (p=0.025). Several LLQ subscales were significantly related to computerized LLVA in dry AMD patients, including driving, external lighting, emotional distress, and dim lighting (p<0.05).
Conclusions :
Low luminance questionnaire scores are significantly associated with objective functional measures such as LLVA, LLD, and rod intercept. Among subjects with early and intermediate dry AMD, both LLVA and LLD were significantly related to LLQ scores, suggesting that LLQ is a robust patient-centered functional measure of early visual impairment in early and intermediate AMD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.