Incidence, Comorbidity, and Mortality of Primary Congenital Glaucoma in Korea from 2001 to 2015: A Nationwide Populationbased Study

Purpose@#To report incidence rates of primary congenital glaucoma in Korea and evaluate comorbidity and mortality from 2001 to 2015. @*Methods@#This study is a nationwide and retrospective population-based study. We used claims data from the Korean National Health Insurance Service database between 2001 and 2015. Data for all patients diagnosed with primary congenital glaucoma were retrieved using the Korean Electronic Data Interchange and Korean Standard Classification of Diseases-6 codes. @*Results@#The number of patients with primary congenital glaucoma between 2001 and 2015 was 776, of which 437 were male (56.31%) and 339 were female (43.69%). The annual prevalence demonstrated a general decreasing trend since 2011, but this was not significant. Over the total survey period, the incidence rate was 11.0 per 100,000 births, with 12.0 cases among males and 10.0 among females. The incidence according to age was 518 (68.78%) patients at age 0, 112 (13.66%) at 1year, 70 (8.39%) at 2 years, and 76 (9.17%) at 3 years. Of the 776 patients diagnosed with primary congenital glaucoma in the study population, 27 died. The observed mortality per 100,000 people is about 10 times higher than that of the general infant and child population under the age of 4 years. Visual impairment was the most common accompanying disability, followed by brain lesion. @*Conclusions@#Our study’s estimates of the nationwide population-based incidence of primary congenital glaucoma in a Korean population will expand our understanding of the disease and allow healthcare systems to plan for primary congenital glaucoma.

Prevalence of Exudative Age-related Macular Degeneration and Projections of the Cost of Ranibizumab in Korea

PURPOSE: To analyze the incidence and prevalence of exudative age-related macular degeneration (AMD) and to predict the future AMD populations and health expenditures of intravitreal ranibizumab injection. METHODS: From 2010 to 2014, the National Health Insurance claims data were used to estimate the incidence and prevalence change of exudative AMD, according to demographic characteristics (year, sex, residence, and age). Based on the above results and changes in future population distribution, we estimated the AMD population by 2030. Considering the cost of Intravitreal ranibizumab injection from 2010 to 2014, we predicted the future health expenditure for AMD. RESULTS: The incidence and prevalence of exudative AMD increased from 14.04 and 295.11 per 100,000 populations in 2010 to 14.25 and 580.71 in 2014, respectively. The prevalence rate was higher in men and showed a large increase over 70 years of age. The ranibizumab was prescribed 13 times per person in average, and the amount consumed increased as the number of insurance coverage increased from 2013. Future AMD populations are predicted to reach 557,007 in 2030 from 146,871 in 2014. As a result, the cost of intravitreal ranibizumab injection is expected to increase from 83.6 billion won in 2014 to 171.7 billion won in 2030. CONCLUSIONS: The increase in medical expenses for AMD is expected due to social aging. Therefore, we need policies to secure medical resources and expand insurance indications.

Effect Analyses of a Health Information Exchange in Ophthalmology: Evidence from a Pilot Program

PURPOSE: To estimate the impact of a health information exchange (HIE) pilot project on ophthalmology department care. METHODS: Study sites included 4 ophthalmic clinics in three regions participating in the HIE pilot project (group A), and 12 clinics with similar distances and numbers of patient referrals as group A but who were not participating in the HIE pilot project (group B). The mean wait time, total medical costs, and ophthalmic examinations of referral patients were analyzed. RESULTS: The mean wait times were 8.4 ± 8.0 days in group A, which included 83 patients, and 11.7 ± 15.4 days in group B, which included 417 patients. The wait time was significantly shorter in group A (p = 0.005). Sensitivity analyses also indicated shorter wait times in group A. In 247 patients in group B who were referred to tertiary referral hospitals automatically through the conventional clinical cooperation center with group A, the wait times were 8.4 ± 8.0 and 7.7 ± 8.8 days, respectively, and the total cost of medical care was 260.6 ± 271.4 and 257.0 ± 251.7 thousand Won, respectively. No differences in these factors were found between the groups (p = 0.503, 0.913, respectively). There were no significant differences in participation in the HIE pilot project regarding ophthalmic examinations conducted within 2 weeks since patient referral (p > 0.050 for all). CONCLUSIONS: The HIE is advantageous because it results in shorter wait times to see an ophthalmologist, due to the automatic referral method based on medical records. However, there are no benefits in reducing total costs of medical care or the number of clinical examinations.

Differences among Ophthalmology Patients Referred to Tertiary Medical Centers according to Referral Hospital

PURPOSE: This study aimed to investigate the diagnosis and severity of patients who were referred to tertiary medical centers according to the type and function of the referral hospitals. METHODS: First-visit patients referred from July 2015 to June 2016 were retrospectively reviewed with regard to referral hospital, final diagnosis, treatment necessity, and medical fees for the six months after their first hospital visit. Based on these data, differences in type and function of medical institution were examined. RESULTS: In a comparison of hospitals according to their number of beds, clinics, hospitals and, tertiary hospitals had no differences in the ratio of patients who needed treatment (p = 0.075) and their medical fees over six months (p = 0.372). When hospitals were classified by functional capability in terms of doctors' medical specialty, increasing ratios of patients requiring medical treatment (p < 0.001) and medical fees for six months (p < 0.001) were found in the order of non-eye specialists, eye specialists, and eye specialists in trainee hospital. CONCLUSIONS: Efficient healthcare delivery systems should classify medical institutions by functionality capability based on medical specialties rather than hospital size according to the number of beds.

Trends of Pars Plana Vitrectomy Rates in South Korea: A Nationwide Cohort Study

PURPOSE: To assess the trends in pars plana vitrectomy surgery rates and factors affecting rate change between 2002 and 2013 in South Korea. METHODS: Data from National Health Insurance Service-National Sample Cohort 2002–2013, which represents 1,025,340 samples with a sampling rate of 2.2% from the total eligible Korean population, was analyzed. RESULTS: A total of 3,816 vitrectomy procedures were performed (male, 2,010; female, 1,806) from 2002 to 2013. Annual rates of vitrectomy increased from 15.1 (in 2002) to 49.4 (in 2013) per 100,000 individuals, and this trend was prominent in those aged 60 years or older. As for the anesthetic method, vitrectomy under local anesthesia increased more prominently than vitrectomy under general anesthesia. The most common diagnoses associated with vitrectomy were diabetic retinopathy, retinal detachment, epiretinal membrane, and macular hole. CONCLUSIONS: The average annual rate of vitrectomy surgery was 31.5 per 100,000 between 2002 and 2013, and the rate has steadily increased.

Diagnostic Availability of Ultra-Wide-field Fundus Imaging in Korean Patient with Retinal Break

PURPOSE: To evaluate the availability of ultra-wide-field fundus photography compared to fundus examination after pupil dilatation in Korean patients with retinal break. METHODS: For this retrospective case review of consecutive 160 patients, 230 lesions with retinal breaks were recruited. The ultra-wide-field images were taken after fundus examination with pupil dilatation performed by a retinal specialist. We analyzed ultra-wide-field images according to patient characteristics and separated area. We divided lesions into anterior and posterior areas, and each area was separated into 4 quadrants (superior, inferior, temporal, and nasal). RESULTS: The sensitivity of ultra-wide-field imaging for detecting retinal break was 72% (95% confidence interval [CI] 65-79%), and the specificity was 94% (95% CI 90-98%). The sensitivity of detection of posterior retina was 89% (95% CI 85-93%), and that of anterior retina was 72% (95% CI 66-78%); this difference was significant (p = 0.007). There was a significant statistical difference at the inferior quadrant between anterior and posterior retina, but not at superior, temporal, or nasal quadrants. The sensitivity of detection in the inferior quadrant in the anterior retina was 43% (95% CI 29-57%). CONCLUSIONS: Ultra-wide-field fundus photography can detect retinal break, but there is limitation in anterior retinal lesions, especially the inferior area. Therefore, ultra-wide-field fundus photography cannot be an alternative method instead of fundus examination with pupil dilatation.

Prevalence and Risk Factors for Undercorrected Refractive Errors among South Korean: KNHANES 2008-2012

PURPOSE: To assess the prevalence and risk factors of undercorrected refractive error in South Korea. METHODS: We analyzed 36,162 participants for estimating prevalence using the Korean National Health and Nutrition Examination Survey (KNHANES, 2008-2012). Undercorrected refractive error was defined as an improvement of at least 2 lines in best corrected visual acuity compared with the presenting visual acuity in the right eye. Proportion of undercorrected refractive error by occupation was presented, and associated sociodemographic factors were evaluated by multivariable logistic regression. RESULTS: The prevalence of undercorrected refractive error among all participants and among adults was 8.5% (n/N, 6,954/36,162) and 18.8% (n/N, 3,980/19,884), respectively. The proportion of undercorrected refractive error was higher among those with did not wear spectacles or contact lenses (23.1%) than among spectacle or contact lens wearers (8.1%). The proportion of participants who gained more than four or more lines of best corrected visual acuity was 7.2% (n = 2,606) for the all age group. In terms of occupation, farming, fishing, and forestry occupations (22.8%, 570/2,499) and laborer (20.2%, 497/2,457) were more likely to have undercorrected refractive error. Age groups of 10s, 70s, or 80s (30s as a reference group), female sex, lower income, lower education level, and living without a spouse were associated with undercorrected refractive error. CONCLUSIONS: People of older age, female sex, and lower socioeconomic status were more likely to have undercorrected refractive error. This suggests that a public-health approach is needed for preventing visual impairment via proper vision correction.

Refractive Errors in Koreans: The Korea National Health and Nutrition Examination Survey 2008-2012

PURPOSE: Our study provides epidemiologic data on the prevalence of refractive errors in all age group ≥5 years in Korea. METHODS: In 2008 to 2012, a total of 33,355 participants aged ≥5 years underwent ophthalmologic examinations. Using the right eye, myopia was defined as a spherical equivalent (SE) less than -0.5 or -1.0 diopters (D) in subjects aged 19 years and older or as an SE less than -0.75 or -1.25 D in subjects aged 5 to 18 years according to non-cycloplegic refraction. Other refractive errors were defined as follows: high myopia as an SE less than -6.0 D; hyperopia as an SE larger than +0.5 D; and astigmatism as a cylindrical error less than -1.0 D. The prevalence and risk factors of myopia were evaluated. RESULTS: Prevalence rates with a 95% confidence interval were determined for myopia (SE <-0.5 D, 51.9% [51.2 to 52.7]; SE <-1.0 D, 39.6% [38.8 to 40.3]), high myopia (5.0% [4.7 to 5.3]), hyperopia (13.4% [12.9 to 13.9]), and astigmatism (31.2% [30.5 to 32.0]). The prevalence of myopia demonstrated a nonlinear distribution with the highest peak between the ages of 19 and 29 years. The prevalence of hyperopia decreased with age in subjects aged 39 years or younger and then increased with age in subjects aged 40 years or older. The prevalence of astigmatism gradually increased with age. Education was associated with all refractive errors; myopia was more prevalent and hyperopia and astigmatism were less prevalent in the highly educated groups. CONCLUSIONS: In young generations, the prevalence of myopia in Korea was much higher compared to the white or black populations in Western countries and is consistent with the high prevalence found in most other Asian countries. The overall prevalence of hyperopia was much lower compared to that of the white Western population. Age and education level were significant predictive factors associated with all kinds of refractive errors.

Visual Acuity and Falls in South Korea: Korean National Health and Nutrition Examination Survey 2008-2012

PURPOSE: To assess the influence of visual acuity (VA) and ocular condition on falls. METHODS: We analyzed 28,899 Korean adults using cross-sectional data from the Korean National Health and Nutrition Examination Survey (2008-2012). Associations between best corrected VA based on better or worse seeing eye and ocular condition and falls were identified using multivariable logistic regression. We included sociodemographic factors and comorbidities including hypertension, diabetes, arthritis, acute myocardial infarction/angina, and stroke as independent variables. VA was divided into 1.0, 0.8, 0.5-0.63, and <0.5. RESULTS: Among 28,899 subjects, falls occurred in 511. In multivariable logistic regression analysis, low VA based on the better seeing eye was significantly associated with falls (VA 1.0 as a reference group; adjusted odds ratio [aOR] = 1.31, 95% confidence interval [CI], 1.00-1.72 in VA of 0.8; aOR = 1.86, 95% CI, 1.07-3.24 in VA of 0.5-0.63; and aOR = 1.21, 95% CI, 0.58-2.54 in VA of <0.5; p = 0.025 for trend). There was no association between VA based on the worse seeing eye and falls. Early age-related macular degeneration was associated with falls in univariable analysis (OR = 2.24) and age- and sex-adjusted analysis (aOR = 1.52), but not in multivariable analysis. In terms of age subgroups, subjects with VA of 0.5-0.63 were more likely to have experienced falls compared with subjects with VA of 1.0 (aOR = 5.83, 95% CI, 1.58-21.54) among subjects 50 years of age or younger. An increasing trend of falls with decreasing VA among subjects between 50 and 70 years of age was observed (p = 0.033 for trend). However, no such association was observed in elderly subjects ≥70 years of age. CONCLUSIONS: VA should be considered for preventing falls because lower VA is associated with increased risk of falls.

Factors Associated with Vision Screening in Children: The Korea National Health and Nutrition Examination Survey

PURPOSE: To identify the factors associated with vision screening in children. METHODS: This study included 4,827 young children 3-11 years of age who answered the question "Has [name] ever had an eye examination (vision screening) in the past year?" from The Korea National Health and Nutrition Examination Survey 2008-2012 (KNHANES). The trained interviewer asked the questions to a member of the household familiar with the study participant. The factors related to vision screening were analyzed using multivariate logistic regression. RESULTS: The rate of vision screening gradually increased with age in young children between 3 (25.8%) and 11 years of age (72.5%). Regarding the rate by region, Busan had the highest rate (63.5%), followed by Daegu (62.2%) and Seoul (59.9%). Chungnam had the lowest rate (43.2%), followed by Chonbuk (44.6%) and Chonnam (44.9%). Higher income was associated with increased screening rate with marginal statistical significance (adjusted odds ratio [aOR]=1.5 for 3rd quartile, 95% confidential interval [CI], 1.0-2.4 versus 1st quartile as a reference group). Households with 5 or more members were less likely to receive vision screening compared to households with 1 child (aOR=0.6, 95% CI, 0.4-0.8). CONCLUSIONS: The rate of vision screening differed according to age group (25.8-72.5%) and region (43.2-63.5%). Regional disparity, low household income and large number of household members were barriers for vision screening in Korean children.

Factors Associated with Cataract in Korea: A Community Health Survey 2008-2012

PURPOSE: To investigate sociodemographic factors, health behaviors, and comorbidities associated with cataracts in a large, nationally representative Korean sample. MATERIALS AND METHODS: This cross-sectional study included 715554 adults aged 40 years or older who participated in the 2008-2012 Community Health Survey. Significant risk factors were identified using multivariate logistic regression analysis for self-reported cataract, and a nomogram for analysis of cataract risk was generated. RESULTS: Roughly 11% of participants (n=88464) reported being diagnosed with cataracts by a doctor. Age was the most important independent risk factor [adjusted odds ratio (aOR)=1.11, 99% confidence interval (CI), 1.11-1.11 for each increasing year]. Significant comorbidities with descending order of effect size (aOR, 99% CI), included diabetes mellitus (1.78, 1.71-1.85), osteoporosis (1.62, 1.56-1.69), arthritis (1.54, 1.48-1.59), hepatitis B infection (1.46, 1.31-1.63), atopic dermatitis (1.50, 1.33-1.69), angina (1.46, 1.35-1.57), allergic rhinitis (1.45, 1.36-1.55), dyslipidemia (1.38, 1.31-1.45), asthma (1.35, 1.26-1.44), and hypertension (1.23, 1.19-1.28). Subjects who sleep less than 6 hours/day were more likely to have cataract than subjects who sleep more than 9 hours/day as a reference group (aOR=1.22, 99% CI, 1.11-1.34). CONCLUSION: While the most important cataract risk factor was age, the ten comorbidities mentioned above were also significant risk factors. Interestingly, longer duration of sleep was associated with a protective effect against cataract development.