Tracy B. Høeg

Danish Rural Eye Study: the association of preschool vision screening with the prevalence of amblyopia

To determine the prevalence of amblyopia in Denmark before and after the initiation of the Danish national preschool vision screening programme.

Danish Rural Eye Study: Epidemiology of Adult Visual Impairment

ABSTRACT Purpose: To examine the frequency and causes of visual impairment (VI) in a select population of Danish adults. Methods: A total of 3843 adults aged 20–94 years from the Danish General Suburban Population Study (GESUS) were included in the population-based, cross-sectional ophthalmological study, Danish Rural Eye Study (DRES). All DRES participants received a comprehensive general health examination preceding their eye examination, including measurement of best-corrected visual acuity (BCVA) for each eye, bilateral 45° retinal fundus photographs and further ophthalmological examination where indicated. Results: Overall, 3826 of 3843 participants (99.6%) had bilateral visual acuity measurements. The overall frequency of VI (BCVA <20/40 in the better-seeing eye) was 0.4% (95% confidence interval, CI, 0.2–0.7%; n = 15) among all DRES participants, 0.6% (95% CI 0.3–1.0%; n = 15) among participants >50 years and 3.7% (95% CI 2.1–6.5%; n = 11) in participants >80 years. The primary causes of VI in the better-seeing eye were age-related macular degeneration (AMD) in 46.7% (7/15) and cataract in 26.7% (4/15). A total of 43.3% (n = 115) of participants >80 years were pseudophakic in one or both eyes. The frequency of diabetes (HbA1c ≥48 mmol/mol or self-reported diagnosis) was 5.9% (n = 227), including 1.3% (n = 51) newly diagnosed in the GESUS. Of participants determined to have VI due to exudative AMD, 50% had received anti-vascular endothelial growth factor (VEGF) treatment. Conclusion: We report a relatively low frequency of VI among Danish adults over 59 years of age compared with that observed 10–15 years ago, which is both consistent with other recent Scandinavian studies and reflective of our relatively healthy and mobile population sample.

An investigation of ultramarathon-associated visual impairment.

OBJECTIVE The purpose of this study was to investigate the characteristics under which ultramarathon-associated visual impairment occurs and to seek to identify its physiological basis and risk factors. METHODS Through an online questionnaire, distributed worldwide, we obtained information from 173 self-identified ultramarathon runners who had experienced visual impairment during an ultramarathon. We attempted to characterize this vision impairment-its symptoms, duration, and the conditions under which it occurs. Select characteristics were compared with a reference group of 412 registrants of the 161-km Western States Endurance Run. RESULTS Ultramarathon-associated visual impairment was typically characterized as painless clouding of vision that resolved either during (13.5%) or after racing within a median of 3.5 hours (range 0 to 48 hours) upon cessation of running. The mean (±SD) distance at which vision impairment occurred was 73±40 km, and the 161-km distance was the most frequent race distance (46.8%) in which visual impairment occurred. Visual impairment was often recurrent, with respondents reporting having it develop during a median of 2 races. Respondents with a history of refractive surgery had more episodes than those without such history (median 3.5 vs 2 episodes, P=.010). Compared with the reference group, runners with visual impairment were nearly twice as likely (23.7% vs 12.1%, P<.001) to have had refractive surgery. CONCLUSIONS Ultramarathon-associated visual impairment typically presents as a painless clouding of vision that is self-limited but tends to recur in certain runners. Risk appears higher among those with a history of refractive surgery, which is relevant for ultramarathon runners who are considering, or who have a history of, refractive surgery.

An evaluation of fundus photography and fundus autofluorescence in the diagnosis of cuticular drusen

Purpose To examine non-mydriatic fundus photography (FP) and fundus autofluorescence (FAF) as alternative non-invasive imaging modalities to fluorescein angiography (FA) in the detection of cuticular drusen (CD). Methods Among 2953 adults from the Danish Rural Eye Study (DRES) with gradable FP, three study groups were selected: (1) All those with suspected CD without age-related macular degeneration (AMD) on FP, (2) all those with suspected CD with AMD on FP and (3) a randomly selected group with early AMD. Groups 1, 2 and 3 underwent FA and FAF and group 4 underwent FAF only as part of DRES CD substudy. Main outcome measures included percentage of correct positive and correct negative diagnoses, Cohens κ and prevalence-adjusted and bias-adjusted κ (PABAK) coefficients of test and grader reliability. Results CD was correctly identified on FP 88.9% of the time and correctly identified as not being present 83.3% of the time. CD was correctly identified on FAF 62.0% of the time and correctly identified as not being present 100.0% of the time. Compared with FA, FP has a PABAK of 0.75 (0.60 to 1.5) and FAF a PABAK of 0.44 (0.23 to 0.95). Conclusions FP is a promising, non-invasive substitute for FA in the diagnosis of CD. FAF was less reliable than FP to detect CD.

THE ASSOCIATION BETWEEN CUTICULAR DRUSEN AND KIDNEY FUNCTION: A Population-Based Case-Control Study.

Purpose: To determine the association between cuticular drusen (CD) and kidney function. Design: observational case-control study. Methods: Setting: Population-based. Patients or Study Population: 53 participants with (CD) and 53 age- and sex-matched controls, selected from the Danish Rural Eye Study. Cuticular drusen participants were diagnosed using fluorescein angiography and controls were excluded if the patients were suspected of having CD on fundus photography or did not have an available estimated glomerular filtration rate. Main Outcome Measures: creatinine and estimated glomerular filtration rate. Results: The mean estimated glomerular filtration rate of those with CD was 73.3 mL·min·1.73 m−2 (95% confidence interval [CI]: 70.0–76.6) and 73.4 mL·minute−1·1.73 m−2 (95% CI: 69.5–77.3) in controls. The difference was not significant (P: 0.970). The mean creatinine among those with CD was 72.8 &mgr;mol/L (69.3–76.4) and 73.5 &mgr;mol/L (95% CI: 69.3–77.6) among controls. The difference was not significant (P = 0.820). Conclusion: The authors did not find an association between a (CD) diagnosis and decreased kidney function at a population level.