A 12-year nationwide cohort study on the association between central retinal artery occlusion and cancer.

PURPOSE: This study aims to investigate the association between incident central retinal artery occlusion (CRAO) and the subsequent development of cancer. METHODS: We included incident CRAO patients from the 2002-2013 National Health Insurance Service database in South Korea. For the patient cohort, we included patients diagnosed with CRAO from the database, and excluded patients having CRAO or any cancer history during the first 2-year washout period (2002-2003). Then, we defined their 1:4 propensity-score matched non-CRAO subjects as controls, all of whom also had no history of cancer during the washout period. Time-varying covariate Cox regression models were conducted to determine the association of CRAO with cancer. Kaplan-Meier curves with log-rank test were also analyzed. RESULTS: A total of 9712 patients with CRAO and 38,848 controls were included in the study. CRAO was associated with an increased risk of subsequent cancer (hazard ratio = 1.27; 95% confidence interval, 1.19-1.35). The incidence rate of overall cancer during the study period was 29.12 per 1000 person-years in the CRAO group and 22.77 per 1000 person-years in the control group. Incidence probability of overall cancer was significantly higher among CRAO patients than controls (P < 0.001, log-rank test). CONCLUSION: The risk of cancer occurrence was increased in patients with CRAO. The results supported that CRAO could be attributed to one of the consequences of arterial thrombosis in cancer patients.

Antihypertensive Use and the Risk of Cataract in Patients with Hypertension: A Nationwide Case-control Study.

PURPOSE: This study aims to investigate the association between antihypertensive use and the risk of cataract in a matched case-control study. METHODS: We analysed the Korean National Health Insurance Service-Health Screening Cohort database from 2002 to 2013. We defined 'cases' as patients prescribed antihypertensives and underwent their first eye cataract surgery between 2010 and 2013. 'Controls' were patients prescribed antihypertensives and no history of cataract surgery or diagnosis between 2002 and 2013. Four controls were matched to each case by several variables. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated for cataract risk using a conditional logistic regression model after adjustment. RESULTS: The analyses comprised 12,166 cases and 48,664 controls. The adjusted ORs for cataracts were 1.18 (95% CI: 1.12-1.24) in thiazide diuretics, 1.12 (95% CI: 1.07-1.18) in beta-blockers, 0.94 (95% CI: 0.90-1.00) in calcium channel blockers, 1.22 (95% CI: 1.14-1.30) in angiotensin-converting enzyme (ACE) inhibitors, and 0.97 (95% CI: 0.91-1.03) in angiotensin II receptor blockers compared to 'non-use' of each antihypertensive. CONCLUSION: In a nationwide case-control study, the use of thiazide diuretics, beta-blockers, or ACE inhibitors do not represent minimal clinical important difference in the risk of cataract and the use of calcium channel blockers or angiotensin II receptor blockers is not associated with an increased risk of cataracts compared to non-use of each antihypertensive. Given the benefits of treating hypertension, such as the reduction in further complications, we suggest there is no need to change current clinical practice for antihypertensives.

Cardiovascular risk in patients receiving ranibizumab for exudative age-related macular degeneration: a nationwide self-controlled case-series study.

AIMS: To identify the association between ranibizumab and risk of stroke and acute myocardial infarction (AMI) in patients with exudative age-related macular degeneration (AMD). METHODS: We identified patients aged ≥45 years who received ranibizumab for exudative AMD from the Korean National Health Insurance database. Of these, we selected patients suffering stroke or AMI for the self-controlled case series. We estimated incidence rate ratios (IRR) for stroke or AMI by comparing incidence rates of ranibizumab-exposed periods to that of baseline using conditional Poisson regression. The risks of haemorrhagic and ischaemic strokes were also calculated separately. RESULTS: Among 33 134 patients receiving ranibizumab, 2397 patients had stroke or AMI. The risk of stroke (IRR=0.83, 95% CI 0.75 to 0.91) was not increased during the overall exposed period; however, there was a marginally elevated risk in ≥57 days exposed period (IRR=1.14, 95% CI 1.001 to 1.31). When analysing by the types of stroke, no increased risks of haemorrhagic (IRR=1.01, 95% CI 0.80 to 1.26) and ischaemic stroke (IRR=0.78, 95% CI 0.71 to 0.86) were observed during the exposed period, although the risks of ischaemic and haemorrhagic stroke were slightly elevated during ≥57 days exposed period. We could not find an association between ranibizumab and AMI. CONCLUSIONS: Ranibizumab intravitreal injections did not increase the overall risk of stroke or AMI. Although the cardiovascular risk in patient receiving ranibizumab seems to be low, continuous monthly use of ranibizumab for high-risk patients should be judged carefully.

Increased risk of cancer in patients with retinal vein occlusion: a 12-year nationwide cohort study.

AIMS: To investigate the association between incident retinal vein occlusion (RVO) and the subsequent development of cancer. METHODS: In this nationwide population-based retrospective study using 2002-2013 National Health Insurance Service database which covers the entire South Korean population, 186 701 incident RVO patients and their 1:1 propensity-score matched controls were included. We defined the fixed cohort from January 1st, 2004 to December 31st, 2013; the cohort included patients who suffered incident RVO after entering the cohort and their matched controls, and excluded patients having any cancer history before entering the cohort. The association of RVO and cancer was assessed by time-varying covariate Cox regression models; Model 1 included RVO as a time-varying covariate, Model 2 included Model 1 plus demographic information and Model 3 included Model 2 and comorbidities. RESULTS: RVO was associated with an increased risk of subsequent cancer (HR=1.29; 95% CI, 1.26-1.31 in Model 1), which was consistent in Models 2 and 3. The incidence rate of overall cancer during the study period was 25.55 (95% CI, 25.19-25.91) per 1000 person-years in the RVO group and 18.62 (95% CI, 18.46-18.79) per 1000 person-years in the control group. In the subgroup analysis, haematological malignancies showed the highest association with RVO (HR=1.65; 95% CI, 1.49-1.83). CONCLUSION: Patients with RVO have an increased risk of subsequent cancer development even after adjusting for demographic factors and comorbidities. Further study is warranted to elucidate these associations to provide proper recommendations for RVO patients regarding the cancer screening.

Effects of Hypertension, Diabetes, and Smoking on Age and Sex Prediction from Retinal Fundus Images.

Retinal fundus images are used to detect organ damage from vascular diseases (e.g. diabetes mellitus and hypertension) and screen ocular diseases. We aimed to assess convolutional neural network (CNN) models that predict age and sex from retinal fundus images in normal participants and in participants with underlying systemic vascular-altered status. In addition, we also tried to investigate clues regarding differences between normal ageing and vascular pathologic changes using the CNN models. In this study, we developed CNN age and sex prediction models using 219,302 fundus images from normal participants without hypertension, diabetes mellitus (DM), and any smoking history. The trained models were assessed in four test-sets with 24,366 images from normal participants, 40,659 images from hypertension participants, 14,189 images from DM participants, and 113,510 images from smokers. The CNN model accurately predicted age in normal participants; the correlation between predicted age and chronologic age was R2 = 0.92, and the mean absolute error (MAE) was 3.06 years. MAEs in test-sets with hypertension (3.46 years), DM (3.55 years), and smoking (2.65 years) were similar to that of normal participants; however, R2 values were relatively low (hypertension, R2 = 0.74; DM, R2 = 0.75; smoking, R2 = 0.86). In subgroups with participants over 60 years, the MAEs increased to above 4.0 years and the accuracies declined for all test-sets. Fundus-predicted sex demonstrated acceptable accuracy (area under curve > 0.96) in all test-sets. Retinal fundus images from participants with underlying vascular-altered conditions (hypertension, DM, or smoking) indicated similar MAEs and low coefficients of determination (R2) between the predicted age and chronologic age, thus suggesting that the ageing process and pathologic vascular changes exhibit different features. Our models demonstrate the most improved performance yet and provided clues to the relationship and difference between ageing and pathologic changes from underlying systemic vascular conditions. In the process of fundus change, systemic vascular diseases are thought to have a different effect from ageing. Research in context. Evidence before this study. The human retina and optic disc continuously change with ageing, and they share physiologic or pathologic characteristics with brain and systemic vascular status. As retinal fundus images provide high-resolution in-vivo images of retinal vessels and parenchyma without any invasive procedure, it has been used to screen ocular diseases and has attracted significant attention as a predictive biomarker for cerebral and systemic vascular diseases. Recently, deep neural networks have revolutionised the field of medical image analysis including retinal fundus images and shown reliable results in predicting age, sex, and presence of cardiovascular diseases. Added value of this study. This is the first study demonstrating how a convolutional neural network (CNN) trained using retinal fundus images from normal participants measures the age of participants with underlying vascular conditions such as hypertension, diabetes mellitus (DM), or history of smoking using a large database, SBRIA, which contains 412,026 retinal fundus images from 155,449 participants. Our results indicated that the model accurately predicted age in normal participants, while correlations (coefficient of determination, R2) in test-sets with hypertension, DM, and smoking were relatively low. Additionally, a subgroup analysis indicated that mean absolute errors (MAEs) increased and accuracies declined significantly in subgroups with participants over 60 years of age in both normal participants and participants with vascular-altered conditions. These results suggest that pathologic retinal vascular changes occurring in systemic vascular diseases are different form the changes in spontaneous ageing process, and the ageing process observed in retinal fundus images may saturate at age about 60 years. Implications of all available evidence. Based on this study and previous reports, the CNN could accurately and reliably predict age and sex using retinal fundus images. The fact that retinal changes caused by ageing and systemic vascular diseases occur differently motivates one to understand the retina deeper. Deep learning-based fundus image reading may be a more useful and beneficial tool for screening and diagnosing systemic and ocular diseases after further development.

Incremental economic burden associated with exudative age-related macular degeneration: a population-based study.

BACKGROUND: The exudative age-related macular degeneration (AMD) causes considerable healthcare costs for patients and healthcare system, which are expected to grow as the population ages. The objective of this study was to assess the incremental economic burden of exudative AMD by comparing total healthcare costs between the exudative AMD group and non-AMD group to understand economic burden related to exudative AMD. METHODS: This retrospective cohort study used the National Health Insurance Service database including the entire Korean population. Exudative AMD group included individuals with at least one claim for ranibizumab and one claim using the registration code for exudative AMD (V201). Non-AMD group was defined as individuals without any claims regarding the diagnostic code of H35.3 or ranibizumab. The exudative AMD group and non-AMD group were matched using a propensity-score model. Incremental healthcare resource utilization and healthcare costs were measured during a one-year follow-up by employing econometric models: ordinary least squares (OLS) with log transformation and heteroscedastic retransformation; and generalized linear model (GLM) with a log link function and gamma distribution. RESULTS: A total of 7119 exudative AMD patients were matched to 7119 non-AMD patients. The number of outpatient visits was higher in the exudative AMD group (P-value < 0.0001), while the length of hospitalization was shorter in exudative AMD group (P-value < 0.0001). Exudative AMD patients had total costs 2.13 times (95%CI, 2.08-2.17) greater than non-AMD group using OLS, and total costs 4.06 times (95%CI, 3.82-4.31) greater than non-AMD group using GLM. Annual incremental total costs were estimated as $5519 (OLS) and $3699 (GLM). CONCLUSIONS: Exudative AMD was associated with significantly increased healthcare costs compared to the non-AMD group. Attention is needed to manage the socioeconomic burden of exudative AMD.

Nonarteritic anterior ischemic optic neuropathy is associated with cerebral small vessel disease.

We investigated the presence of cerebral small vessel disease (SVD) in patients with nonarteritic anterior ischemic optic neuropathy (NAION) compared to control subjects without NAION to identify the association between NAION and cerebral SVD. We retrospectively reviewed the cases of 63 patients with NAION and 2749 control subjects without any neurologic and ocular diseases including NAION who underwent careful medical interviews, ophthalmic examinations, and magnetic resonance imaging (MRI) studies of the brain. We assessed and compared the degree of cerebral SVD on the MRIs. The patients with NAION presented with cerebral SVD more frequently than controls (68% versus 37%, respectively, p<0.001), which was also observed after adjusting for age, sex, comorbid conditions including hypertension, diabetes, and dyslipidemia, and smoking using the standardized mortality ratio (68% vs. 37%, p<0.001). A multivariate logistic regression analysis showed that the odds of cerebral SVD were 4.86 (95% CI, 2.10 to 11.24, p<0.001) times higher in patients with NAION than in the controls. We found that there was an association between cerebral SVD and NAION even after adjusting for age, sex, and medical histories. Clinicians should consider brain MRI scans in patients with NAION to prevent neurological impairment after cerebral SVD.

Risk of Nonarteritic Anterior Ischemic Optic Neuropathy After Cataract Surgery.

PURPOSE: To determine whether the development of nonarteritic anterior ischemic optic neuropathy (NAION) is increased after receiving cataract surgery in a large general population. DESIGN: Nationwide, population-based, retrospective cohort study. METHODS: Setting: A 12-year nationwide, population-based, retrospective cohort study including 1,025,340 beneficiaries in the 2002-2013 Korean National Health Insurance Service database. PATIENTS: We identified 40,356 patients who had undergone cataract surgery and matched non-cataract surgery controls (1:2) using estimated propensity scores in reference to age, sex, demographics, comorbidities, and co-medications. OBSERVATIONS: Kaplan-Meier curves and Cox proportional hazard models were generated to determine the risk of developing NAION in the cataract surgery group compared to the non-cataract surgery group. MAIN OUTCOME MEASURES: Effect (hazard ratio [HR]) of cataract surgery on NAION development. RESULTS: The 10-year incidence probability of NAION was 0.70% (95% confidence interval [CI], 0.55%-0.86%) in the cataract surgery group and 0.27% (95% CI, 0.25%-0.29%) in the non-cataract surgery group (P < .0001, log-rank test). The cataract surgery group had an increased risk of developing NAION compared to the non-cataract surgery group (HR = 1.80; 95% CIs, 1.46-2.21) even after adjusting for demographics, comorbidities, Charlson comorbidity index, and co-medications. CONCLUSION: Our results suggest that patients undergoing cataract surgery have an increased risk of NAION.

Five-year nationwide incidence of macular hole requiring surgery in Korea.

BACKGROUND/AIMS: To estimate the incidence and demographics of macular hole (MH) requiring surgery in Korea. METHODS: Patients who underwent surgery for MH in Korea from 2011 to 2015 with the diagnostic code for MH and the surgical code for vitrectomy were retrospectively identified using the Korean national health claims database. The average incidence rate of MH during the 5-year study period was estimated by applying the direct method of standardisation using the 2015 census data as a reference population. RESULTS: A total of 7301 patients with MH requiring surgery were identified. The average incidence of MH requiring surgery was 3.14 (95 % CI, 3.07 to 3.21) per 100 000 person-years . The incidence in women (4.29 per 100 000 person-years; 95% CI, 4.17 to 4.40) was significantly higher than that in men (2.00 per 100 000 person-years; 95% CI, 1.92 to 2.07; p<0.001). The incidence rate of MH increased exponentially with increasing age between the ages of 35 years and 69 years and was highest among patients aged 65-69 years. The female-to-male ratio for the incidence of MH was 2.15:1. CONCLUSIONS: This study represents the largest nationwide population-based investigation of the incidence of MH, using a database that covers the entire population of South Korea. MH is the disease of elderly peaked 70 years old and more common in women.

Risk of Stroke After Nonarteritic Anterior Ischemic Optic Neuropathy.

PURPOSE: To determine whether nonarteritic ischemic optic neuropathy (NAION) raises the risk of subsequent stroke in the general population. DESIGN: Population-based, retrospective cohort study. METHODS: Setting: Nationwide, population-based, retrospective cohort study. PATIENTS: Of 1 025 340 beneficiaries in the National Health Insurance Service-National Sample Cohort database (2002-2013), we included 400 952 eligible individuals in the analysis. OBSERVATIONS: To determine the effect of incident NAION on the occurrence of subsequent stroke, we used time-varying covariate Cox regression models. Model 1 included only incident NAION as a time-varying covariate. Model 2 included Model 1 and defined demographics. Model 3 included Model 2, comorbidity, co-medication, and Charlson index score. MAIN OUTCOME MEASURES: Effect (hazard ratio [HR]) of NAION on stroke development. RESULTS: Of 400 952 eligible individuals, 1125 patients developed NAION and 16 998 patients suffered from stroke. NAION was not associated with an increased risk of subsequent stroke in Model 1, with HR of 1.31 (95% confidence interval [CI], 0.89-1.92). This was consistent, after adjusting for demographics and/or confounding factors, in Model 2 (HR = 1.19, 95% CI, 0.81-1.75) and Model 3 (HR = 1.10, 95% CI, 0.75-1.62). CONCLUSIONS: Our results suggest that NAION per se is not associated with a subsequent risk of stroke in the general population.

Association of Pediatric Atopic Dermatitis and Cataract Development and Surgery.

Importance: There is a paucity of data addressing the risk of cataract development in pediatric patients with atopic dermatitis (AD). Objective: To investigate the association of AD with subsequent cataract development and cataract surgery in a Korean pediatric population. Design, Setting, and Participants: This population-based retrospective longitudinal cohort study used nationally representative data from the Korean National Health Insurance Service database from 2002 to 2013. Incident AD cases, consisting of patients younger than 20 years with AD and severe AD and were matched to 4 controls each using propensity score derived from age, sex, residential area, and household income. Main Outcomes and Measures: Incidence probabilities of cataract development and cataract surgery between the AD group and controls were compared using Kaplan-Meier methods and log-rank tests. Cox proportional hazard models were fitted for cataract and cataract surgery to determine the risk factors in the matched cohort. Results: Of 34 375 patients with incident AD (16 159 girls [47%]; mean [SD] age, 3.47 [4.96] years), there were 3734 severe AD cases (10.9%) with 137 500 matched controls. Development of cataracts was not different between the AD and control groups, (0.216% vs 0.227%; 95% CI, -0.041% to 0.063%; P = .32) or between the severe AD cohort and their controls (0.520% vs 0.276%; 95% CI, -0.073% to 0.561%; P = .06). Cataract surgery was performed more frequently in the AD cohort than in the control group (0.075% vs 0.041%; 95% CI, 0.017%-0.050%; P = .02) and in the severe AD cohort compared with their controls (0.221% vs 0.070%; 95% CI, 0.021%-0.279%; P = .03). Severe AD was associated with both development of cataract (adjusted hazard ratio, 1.94; 95% CI, 1.06-3.58, P = .03) and requirement for cataract surgery (adjusted hazard ratio, 5.48; 95% CI, 1.90-15.79, P = .002). Conclusions and Relevance: Absolute risk of cataract was rare, with or without AD, even after 10 years of observation. However, our results suggest that pediatric patients with AD have an increased risk for cataracts requiring surgery and that disease severity may increase the risk for cataract development and cataract surgery.