Corneal Eccentricity in a Rural Japanese Population: The Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS).

PURPOSE: To determine normal corneal eccentricity in a rural Japanese population and to examine factors associated with eccentricity value. METHODS: This used data from the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS) project between 2009 and 2012. Residents of Minamiaizu and Tadami in Fukushima, Japan, who were aged 40 years or over, were invited for a comprehensive eye examination. For 1371 patients with no history of internal eye surgery, corneal eccentricity was measured using a Pentacam. RESULTS: Of 1371 people recruited to the study, 1215 (1215 eyes) met the inclusion criteria. The overall mean eccentricity was 0.46 (SD = 0.18; range, -0.85 to 0.88). Corneal eccentricity was significantly associated with age, spherical equivalent, pupil diameter, anterior chamber angle, anterior chamber volume, and central corneal thickness, but not with gender or body mass index. CONCLUSIONS: In this study, the normal cornea in this Japanese population was prolate. Corneal eccentricity was likely to decrease with increasing age. Also, spherical equivalent and other anterior segment parameters had an influence on corneal eccentricity. Corneal eccentricity measurements might be helpful in the diagnosis of corneal diseases and in calculations for intraocular lens implantation and corneal refractive surgery.

Prevalence and factors associated with uncorrected presbyopia in a rural population of Japan: the Locomotive Syndrome and Health Outcome in Aizu Cohort Study.

PURPOSE: To investigate the prevalence and factors associated with uncorrected presbyopia among rural community dwellers in Japan. STUDY DESIGN: A population-based cross-sectional study was conducted in 2011 among community dwellers aged 40-74 years who received specific health checkups in Minamiaizu and Tadami, Fukushima Prefecture, Japan. METHODS: Uncorrected presbyopia was considered as when the distance-corrected visual acuity in the better eye was ≥0.5 and the near-presenting visual acuity in the better eye was <0.4, regardless of distance refractive status. Multiple logistic regression analysis was employed to calculate the odds ratios (ORs) for uncorrected presbyopia and to adjust for possible confounders. RESULTS: A total of 2054 individuals participated in the specific health checkups. In the 1156 individuals (response rate: 56.28%) analyzed in the study, the mean (SD) age was 63.0 (8.7) years, the percentage of women was higher (57.87%), and the prevalence of uncorrected presbyopia was 26.38% (95% CI 23.86%-29.03%). Multivariate analysis revealed that the factors associated with uncorrected presbyopia were older age (adjusted OR: 1.054 [95% CI: 1.034-1.075]), female sex (adjusted OR: 1.388 [95% CI: 1.006-1.915]), and distance-presenting vision impairment (adjusted OR: 2.651 [95% CI: 1.697-4.143]). CONCLUSION: Approximately one-quarter of the participants in this study from a rural population of Japan did not have adequate near vision. It is recommended that a public health intervention should be enacted to correct presbyopia, especially in the older age group, women, and those with uncorrected refractive errors.

Retinal vessel diameters in a Japanese population: the Locomotive Syndrome and Health Outcome in Aizu Cohort Study.

PURPOSE: To describe the relationship between retinal vascular calibre and cardiovascular risk factors in a Japanese population. METHODS: The Locomotive Syndrome and Health Outcome in Aizu Cohort Study is a population-based, cross-sectional survey that included 2346 persons (56.1% of the eligible population) aged 40 to 74 years old. Retinal vascular calibre was measured from digital retinal photographs using a validated standardized protocol. Data on major cardiovascular risk factors were collected from all participants. RESULTS: Of the 1787 participants with available retinal vascular calibre data, the mean retinal arteriolar calibre (CRAE) was 141.6 ± 18.6 µm, the mean venular calibre (CRVE) was 209.3 ± 26.1 µm, and the mean arteriole-to-venule ratio was 0.68 ± 0.08. A smaller CRAE was associated with male sex, increasing quartiles of systolic blood pressure and diastolic blood pressure, history of hypertension, current alcohol intake and higher quartiles of serum creatinine. A larger CRAE was associated with increasing quartiles of total cholesterol. A larger CRVE was associated with current cigarette smoking. Multivariate analyses showed that a smaller CRAE was associated with male sex, elevated mean arterial blood pressure and a history of hypertension; and a larger CRVE was associated with cigarette smoking. CONCLUSIONS: The results of this study suggest that a narrowed diameter of the retinal arteriole in Japanese people is related to hypertension and sex (male) and that an enlarged retina venular diameter is related to a history of smoking. The pattern of these associations is similar to that in white populations and other Asian populations.

Prevalence of pterygium in a population in Northern Japan: the Locomotive Syndrome and Health Outcome in Aizu Cohort Study.

PURPOSE: The aim of the study was to determine the prevalence and risk factors for pterygium in a population aged 40-74 years in Fukushima Prefecture, Japan. METHODS: Of 4185 citizens of the towns of Minamiaizu-machi and Tadami-machi, 2312 (55.2%) gave consent to an ocular examination during a health examination. Pterygium was diagnosed when a radially oriented fibrovascular lesion growing over the limbus into the cornea was observed. Eyes with a history of pterygium excision were also diagnosed with pterygium. Prevalence and factors associated with pterygium were investigated. RESULTS: Of the 2312 subjects, 101 (4.4%; 95% confidence interval, 3.6-5.3%) had pterygium in at least 1 eye. The average age (±SD) of the subjects was 64.3 ± 8.0 years. Gender, age, outdoor job history and smoking history were examined as possible associated factors, but only age was found to be significantly associated with pterygium in logistic regression analysis. CONCLUSION: The prevalence of pterygium was 4.4% in the study population. This low rate may be due to the northern latitude of these towns. Age was associated with a risk of pterygium, but gender and outdoor job history were not associated with onset of pterygium in this study.

Influence of cataract surgery and blood pressure changes caused by sodium restriction on retinal vascular diameter.

PURPOSE: To investigate the impact of cataract surgery and blood pressure changes induced by one week of sodium restriction on retinal vascular diameter. METHODS: Fundus photographs of 200 patients were obtained before and one week after cataract surgery. For one week after admission, 100 patients received sodium restriction and 100 patients (ie, the control group) did not receive sodium restriction. The diameter of the retinal vessels and blood pressure were compared between the sodium restriction group and the control group. The vascular diameter was measured using an objective computer-based method. RESULTS: Neither group had a significant change in the diameter of the retinal vessels after cataract surgery. Although there was no significant change in retinal arterial and venular diameter in the sodium restriction group, one-week sodium restriction significantly reduced mean blood pressure. However, multiple linear regression analyses indicated that an increase in retinal arteriolar diameter was significantly associated with diabetes, hyperlipidemia, and alcohol intake. CONCLUSION: Cataract surgery and blood pressure reduction induced by one week of sodium restriction resulted in no significant change in retinal arteriolar diameter.