Choroidal thickness and myopia in relation to physical activity - the CHAMPS Eye Study.

PURPOSE: To describe the relationship between choroidal thickness (CT) and myopia in relation to physical activity (PA) in a population-based child cohort. METHODS: In a prospective study of 307 children from the CHAMPS Study Denmark, we used objective data from GT3X accelerometer worn at four periods between 2009 and 2015 to determine the amount and intensity of PA. Intensity was estimated as counts/minutes, and cut-off points were defined at four intensity levels. Eye examinations were performed in 2015 and included autorefraction in cycloplegia, axial length (AL) by biometric and fovea-centred enhanced depth imaging optical coherence tomography. By a semi-automated method, we measured the CT at 17 targets per eye representing anatomically different locations (subfoveal, 1 and 3 millimetre in each direction of fovea). RESULTS: Mean age at the eye examination was 15.4 ± 0.7 years. The mean AL was 23.5 ± 0.9 mm, and the mean subfoveal CT was 369 ± 87 µm. Choroidal thickness (CT) was 331 ± 68 µm for the overall macula, 355 ± 78 µm for the 1-mm zone and 304 ± 60 µm for the 3-mm zone. All CT measurements were thinner in myopic eyes (p < 0.0001) and in boys (p < 0.05). We found no association between total PA and the CT by either mixed model analysis (p = 0.074) or linear regression by any intensity levels (p = 0.22, p = 0.15 and p = 0.43). CONCLUSION: Among adolescents aged 14-17 years, there was no association between objective PA exposures and the CT, AL or refractive error.

Physical activity and myopia in Danish children-The CHAMPS Eye Study.

PURPOSE: To determine associations between physical activity (PA) and myopia in Danish school children and investigate the prevalence of myopia. METHODS: This is a prospective study with longitudinal data on PA in a Danish child cohort. Physical activity (PA) was measured objectively by repeated ActiGraph accelerometer measurement four times with different intervals (1-2.5 years) at the mean ages 9.7, 11.0, 12.9 and 15.4 years. Mean intensity of PA was estimated as counts/minutes, and time spent in sedentary, light, moderate and vigorous PA was summed using defined cut-off points. The ophthalmologic examination was conducted at the mean age of 15.4 ± 0.7 years and included cycloplegic autorefraction and biometry. RESULTS: A total of 307 children participated in the Childhood Health, Activity, and Motor Performance School (CHAMPS) Eye Study. The cycloplegic spherical equivalent (SE) was 0.30 ± 1.46 dioptres. The prevalence of myopia was 17.9% (SE ≤-0.5 dioptres). Mean axial length (AL) was 23.5 ± 0.9 mm. For all participants, the overall mean daily distribution of PA was 67.2% in sedentary, 25.6% in light, 4.4% in moderate and 2.9% in vigorous PA. Age- and sex-adjusted linear regression showed no association between PA and SE or AL. In a prospective slope analysis, there was no association between accumulated PA during the 7 years and AL or SE. CONCLUSION: The prevalence of myopia among Danish children was 17.9%. By logistic regression and slope analysis, we found no association between PA and myopia, in this first of its kind study based on objective and repeated PA data.

Noninvasive Retinal Markers in Diabetic Retinopathy: Advancing from Bench towards Bedside.

The retinal vascular system is the only part of the human body available for direct, in vivo inspection. Noninvasive retinal markers are important to identity patients in risk of sight-threatening diabetic retinopathy. Studies have correlated structural features like retinal vascular caliber and fractals with micro- and macrovascular dysfunction in diabetes. Likewise, the retinal metabolism can be evaluated by retinal oximetry, and higher retinal venular oxygen saturation has been demonstrated in patients with diabetic retinopathy. So far, most studies have been cross-sectional, but these can only disclose associations and are not able to separate cause from effect or to establish the predictive value of retinal vascular dysfunction with respect to long-term complications. Likewise, retinal markers have not been investigated as markers of treatment outcome in patients with proliferative diabetic retinopathy and diabetic macular edema. The Department of Ophthalmology at Odense University Hospital, Denmark, has a strong tradition of studying the retinal microvasculature in diabetic retinopathy. In the present paper, we demonstrate the importance of the retinal vasculature not only as predictors of long-term microvasculopathy but also as markers of treatment outcome in sight-threatening diabetic retinopathy in well-established population-based cohorts of patients with diabetes.

Physical activity in relation to development and progression of myopia - a systematic review.

On a global scale, myopia is one of the most common causes of visual impairment. Given the increasing prevalence of myopia, it is vital to understand the pathogenesis and to identify potential interventions. Some studies have described physical activity as a potential correlation for myopia. The objective of this study was to make a systematic review regarding the correlation between physical activity and myopia. A total of 263 papers were identified in a systematic database search of PubMed/Medline and Embase. Five steps of screening removed studies of a low evidence quality and animal studies. Studies included had refractive error and physical activity (as measured by questionnaires, accelerometers and cycle ergometers) as separate, well-defined outcomes. Nine studies (six cross-sectional, two cohorts and one case-control study) with a total of 17 634 subjects were included. Six studies demonstrated a reverse association between physical activity and myopia. Three studies supported this, but also attributed the results to time spent outdoors and not physical activity per se. One cross-sectional study found no relation. We could not identify trends among the papers regarding the type of studies, population sizes, ethnicity or age of study subjects. A consistent relationship between more physical activity and less myopia was observed. No evidence of physical activity as an independent risk factor for myopia was seen. Evidence suggests that time outdoors remain the most important factor. Future studies should include objective measurements of physical activity to determine a potential independent effect. Distinction between physical activity and outdoor exposure remains important.

Localized changes in retinal vessel caliber after focal/grid laser treatment in patients with diabetic macular edema: a measure of treatment response?

PURPOSE: To compare retinal vessel caliber changes at the macula region and surrounding the optic disk after focal/grid laser treatment for diabetic macular edema. METHODS: The study included 69 eyes from 46 patients treated with focal/grid laser for diabetic macular edema. Retinal photographs were taken <6 months before and 2 months and 12 months after focal/grid photocoagulation treatment. The diameters of retinal vessels around macula and the optic disk were measured separately before and after treatment. Optic disk and macular diameters were summarized into central retinal arteriolar and venular equivalent and macular retinal arteriolar and venular equivalent. RESULTS: Median age and duration of diabetes was 60 years and 13 years. There was a statistically significant decrease in diameter of the macular arterioles (macular retinal arteriolar equivalent 73.5 vs. 72.0 µm, P = 0.04) and venules (macular retinal venular equivalent 63.5 vs. 62.4 µm, P = 0.02) after treatment but no difference in central retinal arteriolar equivalent or central retinal venular equivalent before and after treatment. Retinal vascular calibers in control eyes did not change throughout the study. CONCLUSION: The diameters of macular vessels decreased after focal/grid laser treatment in most eyes. In contrast, vessel calibers at the optic disk did not change. Quantitative measurement of macular vessels may allow physicians to monitor the progress and success of diabetic macular edema treatment.