Detecting vision loss in intermediate age-related macular degeneration: A comparison of visual function tests.

The purpose of the study was to evaluate the diagnostic accuracy of visual function tests in intermediate age-related macular degeneration (iAMD). A total of 62 subjects (38 patients with iAMD and 24 controls) were included and underwent several functional assessments: Best-corrected visual acuity (BCVA), low luminance visual acuity (LLVA), visual acuity (VA) measured with the Moorfields Vanishing Optotypes Acuity Charts (MAC), contrast sensitivity with the Pelli-Robson test, reading speed using the International Reading Speed texts (IReST) and mesopic and dark-adapted microperimetry (S-MAIA, CenterVue, Padova, Italy). Groups were compared using non-parametric Wilcoxon rank sum tests and ROC analyses. Linear regression was used to control for confounding. Results showed that all visual function test performances except the IReST were significantly reduced in iAMD patients compared to controls (p < 0.05). These effects did not alter after controlling for age and sex. Best discrimination between iAMD and controls yield the combination of LLVA and contrast sensitivity as well as MAC-VA and contrast sensitivity (ROC area under the curve 0.95 and 0.93, respectively). Our results suggest that LLVA, MAC-VA, contrast sensitivity and mesopic and dark-adapted microperimetry can capture visual impairment characteristic for iAMD. Best discrimination against iAMD is achieved with a combination of two tests.

Association of Visual Function Measures with Drusen Volume in Early Stages of Age-Related Macular Degeneration.

Purpose: To assess which visual function measures are most strongly associated with overall retinal drusen volume in age-related macular degeneration (AMD). Methods: A total of 100 eyes (16 eyes with early AMD, 62 eyes with intermediate AMD, and 22 eyes from healthy controls) were recruited in this cross-sectional study. All subjects underwent several functional assessments: best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), visual acuity (VA) measured with the Moorfields Acuity Chart (MAC-VA), contrast sensitivity with the Pelli-Robson test, reading speed using the International Reading Speed texts, and mesopic and dark-adapted microperimetry. Drusen volume was automatically determined based on optical coherence tomography using an approach based on convolutional neural networks. The relationship between drusen volume and visual function was assessed with linear regressions controlling for confounders. Results: Mean drusen volume and MAC-VA differed significantly among all AMD stages and controls (P < 0.001). In univariate linear regression, LLVA, MAC-VA, contrast sensitivity, and mesopic and dark-adapted microperimetry were significantly negatively associated with the overall drusen volume (all P < 0.006). After controlling for AMD stage, age, and the presence of subretinal drusenoid deposits, MAC-VA and mesopic and dark-adapted microperimetry were still significantly associated with drusen volume (P = 0.008, P = 0.023, and P = 0.022, respectively). Conclusions: Our results suggest that MAC-VA, as well as mesopic and dark-adapted microperimetry, might indicate structural changes related to drusen volume in early stages of AMD.

Association of Vision-related Quality of Life with Visual Function in Age-Related Macular Degeneration.

The purpose of this study was to assess which visual function measures are most strongly associated with vision-related quality of life (VRQoL) in age-related macular degeneration (AMD). A cross-sectional study of subjects with early AMD (n = 10), intermediate AMD (n = 42) and late AMD (n = 38) was conducted. Subjects were interviewed with the Impact of Vision Impairment (IVI) questionnaire. Functional tests performed included best-corrected visual acuity (BCVA), low luminance visual acuity (LLVA), visual acuity measured with the Moorfields Acuity Charts (MAC), contrast sensitivity, reading speed, mesopic and dark-adapted microperimetry. The relationship between VRQoL and visual function was assessed with multiple regressions controlling for confounders. Rasch analysis demonstrated the validity of the IVI to assess VRQoL through three subscales: reading and accessing information, mobility and independence, and emotional well-being. Subjects with late AMD had significant lower IVI scores on all subscales compared with intermediate and early AMD (p < 0.011). In the overall cohort, IVI subscales were associated with BCVA, LLVA, MAC-VA and contrast sensitivity (all p < 0.001). Among the subgroup of early and intermediate AMD subjects, reading and mobility subscales were significantly associated with MAC-VA (p < 0.013). These results suggest that MAC-VA is a useful, patient-relevant measure of visual impairment in AMD.

Impact of visual impairment on physical activity in early and late age-related macular degeneration.

BACKGROUND: Modifiable risk factors for age-related macular degeneration (AMD) include smoking, nutrition and likely physical activity (PA). Levels of PA, however, are impacted by any visual impairment which makes the assessment of any association with AMD difficult. PURPOSE: To assess the impact of visual impairment under both high and low luminance conditions on levels of PA in early and late AMD. METHODS: Ninety participants with early to late AMD underwent a clinical assessment including conventional best-corrected visual acuity, low luminance visual acuity, contrast sensitivity and the Moorfields acuity test. PA was recorded using a wrist-worn accelerometer (GENEActiv, Activeinsights) on seven consecutive days. Patient characteristics were compared with the Wilcoxon rank-sum test and determinants of moderate-to-vigorous-PA (MVPA) were assessed using linear regression models. RESULTS: Mean age was 73.9 ± 8.5 years (range 50-89) and 47 subjects (52.2%) were women. Average MVPA time was longer in the early (355.1 ± 252.0 minutes/week) compared to the late AMD group (162.2 ± 134.6 minutes/week; p<0.001). Using linear regression, age [ß = -0.25; 95% confidence interval (CI): -12.9; -0.8, p = 0.028] and AMD stage (ß = -0.28; 95% CI: -230.9, -25.0; p = 0.015) but not visual impairment on any of the employed tests were associated with MVPA (minutes/week). CONCLUSIONS: We found late AMD to be associated with reduced PA. As performance on any of the visual tests was not associated with PA, this association cannot entirely be explained by functional impairment. More research is needed to further explore the association of PA and AMD as PA may be a potentially modifiable risk factor.

Retest Reliability of Mesopic and Dark-Adapted Microperimetry in Patients With Intermediate Age-Related Macular Degeneration and Age-Matched Controls.

Purpose: To determine the intrasession test-retest reliability of mesopic and dark-adapted fundus-controlled perimetry in patients with intermediate age-related macular degeneration (iAMD). Methods: We conducted a cross-sectional study with 23 iAMD patients (67.3 ± 8.2 years; range, 50-85; 78% female) and 24 healthy controls (61.3 ± 5.2 years; range, 50-71; 50% female) using a modified MAIA microperimeter. All patients underwent duplicate mesopic (achromatic stimuli, 400-800 nm) and dark-adapted (red stimuli, 627 nm) microperimetry, using a grid of 33 stimuli over 14° of the central retina. Main outcome measure was the intrasession test-retest reliability for pointwise sensitivity (PWS). Results: PWS test-retest reliability was good among mesopic and dark-adapted testing in both patients and controls (coefficient of repeatability of 4.4, 4.52, 3.96, and 4.56 dB, respectively). Mean mesopic sensitivity in patients was 2.62 dB lower than in controls (P < 0.01); mean dark-adapted sensitivity was 2.49 dB lower than in controls (P < 0.01). Conclusions: The modified MAIA device allows for reliable mesopic and dark-adapted microperimetry in iAMD patients. We found that iAMD is associated with both reduced mesopic and dark-adapted retinal sensitivity.