Physical Activity Is Associated With Macular Thickness: A Multi-Cohort Observational Study.

Purpose: To assess the association between physical activity and spectral-domain optical coherence tomography (SD-OCT)-measured rates of macular thinning in an adult population with primary open-angle glaucoma. Methods: The correlation between accelerometer-measured physical activity and rates of macular ganglion cell-inner plexiform layer (GCIPL) thinning was measured in 735 eyes from 388 participants of the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study. The association between accelerometer-measured physical activity and cross-sectional SD-OCT macular thickness was then assessed in 8862 eyes from 6152 participants available for analysis in the UK Biobank who had SD-OCT, ophthalmic, comorbidity, and demographic data. Results: Greater physical activity was associated with slower rates of macular GCIPL thinning in the PROGRESSA study (beta = 0.07 µm/y/SD; 95% confidence interval [CI], 0.03-0.13; P = 0.003) after adjustment for ophthalmic, demographic and systemic predictors of macular thinning. This association persisted in subanalyses of participants characterized as glaucoma suspects (beta = 0.09 µm/y/SD; 95% CI, 0.03-0.15; P = 0.005). Participants in the upper tertile (greater than 10,524 steps/d) exhibited a 0.22-µm/y slower rate of macular GCIPL thinning than participants in the lower tertile (fewer than 6925 steps/d): -0.40 ± 0.46 µm/y versus -0.62 ± 0.55 µm/y (P = 0.003). Both time spent doing moderate/vigorous activity and mean daily active calories were positively correlated with rate of macular GCIPL thinning (moderate/vigorous activity: beta = 0.06 µm/y/SD; 95% CI, 0.01-0.105; P = 0.018; active calories: beta = 0.06 µm/y/SD; 95% CI, 0.006-0.114; P = 0.032). Analysis among 8862 eyes from the UK Biobank revealed a positive association between physical activity and cross-sectional total macular thickness (beta = 0.8 µm/SD; 95% CI, 0.47-1.14; P < 0.001). Conclusions: These results highlight the potential neuroprotective benefits of exercise on the human retina.

Association Between Body Mass Index and Primary Open Angle Glaucoma in Three Cohorts.

PURPOSE: To evaluate the relationship between body mass index (BMI) and glaucoma progression. DESIGN: Multicohort observational study. METHODS: This study combined a retrospective longitudinal analysis of suspect and early manifest primary open angle glaucoma cases from the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study with 2 replication cohorts from the UK Biobank and the Canadian Longitudinal Study of Ageing (CLSA). In the PROGRESSA study, multivariate analysis correlated BMI with longitudinal visual field progression in 471 participants. The BMI was then associated with glaucoma diagnosis and cross-sectional vertical cup-disc ratio (VCDR) measurements in the UK Biobank, and finally prospectively associated with longitudinal change in VCDR in the CLSA study. RESULTS: In the PROGRESSA study, a lower BMI conferred a faster rate of visual field progression (mean duration of monitoring (5.28 ± 1.80 years (10.6 ± 3.59 visits) (ß 0.04 dB/year/SD95% CI [0.005, 0.069]; P = .013). In the UK Biobank, a 1 standard deviation lower BMI was associated with a worse cross-sectional VCDR (ß -0.048/SD 95% CI [-0.056, 0.96]; P < .001) and a 10% greater likelihood of glaucoma diagnosis, as per specialist grading of retinal fundus imaging (OR 0.90 95% CI [0.84, 0.98]; P = .011). Similarly, a lower BMI was associated with a greater risk of glaucoma diagnosis as per International Classification of Disease data (OR 0.94/SD; 95% CI [0.91, 0.98]; P = .002). Body mass index was also positively correlated with intraocular pressure (ß 0.11/SD; 95% CI [0.06, 0.15]; P < .001). Finally, a lower BMI was then associated with greater VCDR change in the CLSA (ß -0.007/SD; 95% CI [-0.01, -0.001]; P = .023). CONCLUSIONS: Body mass index correlated with longitudinal and cross-sectional glaucomatous outcomes. This supports previous work illustrating a correlation between BMI and glaucoma.