Postoperative Refractive Outcomes of Biometric Formulas in Phacovitrectomy with Gas Tamponade

Purpose@#To investigate the refractive accuracy of intraocular lens (IOL) power calculation for biometric formulas in phacovitrectomy. @*Methods@#This retrospective study included 357 eyes of 357 patients who underwent phacovitrectomy using four commonly available IOL power formulas: Hoffer Q (87 eyes), Holladay 1 (78 eyes), Holladay 2 (91 eyes), and SRK/T (101 eyes). The mean refractive error (ME) and the mean absolute refractive error (MAE) were calculated based on the predicted postoperative refraction error, and they were compared using analysis of variance test. Subjects were divided into high myopic eyes (axial length, ≥26 mm) and nonhigh myopic eyes (axial length, <26 mm). @*Results@#The ME and the MAE after phacovitrectomy did not show a significant difference among the four IOL power formulas (p = 0.546 and p = 0.495, respectively). There was no significant statistical difference in formulas when the eyes were grouped into high myopia and nonhigh myopia (ME: p = 0.526 and p = 0.482, respectively; MAE: p = 0.715 and p = 0.627, respectively). The ME showed myopic shift in all formulas regardless of IOL formula used. The ME showed greater myopic shift in high myopia group than nonhigh myopia group in all formulas. @*Conclusions@#Our study did not find evidence for superiority of any formula in phacovitrectomy. However, in phacovitrectomy, possible myopic shift should be considered for IOL power calculation. Especially, in phacovitrecotmy in patients with high myopia, more myopic shift should be considered when selecting IOL.

Methodology and Rationale for Ophthalmic Examinations in the Seventh and Eighth Korea National Health and Nutrition Examination Surveys (2017–2021)

This report provides a detailed description of the methodology for ophthalmic examinations according to the Korea National Health and Nutrition Examination Survey (KNHANES) VII and VIII (from 2017 to 2021). The KNHANES is a nationwide survey which has been performed since 1998 in representatives of whole Korean population. During the KNHANES VII and VIII, in addition to the ophthalmic questionnaire, intraocular pressure measurement, visual field test, auto refractometry, axial length and optical coherence tomography measurements were included. This new survey will provide not only provide normative and pathologic ophthalmic data including intraocular pressure, refractive error, axial length, visual field and precise measurement of anterior segment, macula and optic nerve with optical coherence tomography, but also a more accurate diagnosis for major adult blindness diseases, including age-related macular degeneration, diabetic retinopathy, glaucoma, and other ocular diseases, for the national Korean population.

Hyperglycemia and Hypo-HDLcholesterolemia Are Primary Risk Factors for Age-related Cataract, and a Korean-style Balanced Diet has a Negative Association, based on the Korean Genome and Epidemiology Study

Background@#The prevalence of cataracts is steadily increasing among the middle-aged and elderly worldwide. We hypothesized that adults aged > 50 years with age-related cataracts (ARCs) have an association with metabolic syndrome (MS) and its components, and MS has interactions with different dietary patterns and lifestyles that affect ARC risk. We examined the hypothesis using the Korean Genome and Epidemiology Study (KoGES; a large-scale hospital-based cohort study), which collected data between 2004–2013. @*Methods@#Participants ≥ 50 years old were classified as cases (1,972 ARC patients) and controls (38,290 healthy controls) based on a diagnosis of cataract by a physician. MS and its components were defined using WHO definitions for Asians. Dietary consumption was evaluated using a validated semi-quantitative food frequency questionnaire (SQFFQ), which contained 106 foods, and dietary patterns were analyzed by principal component analysis. After adjusting for potential covariates, logistic regression was used to investigate associations between MS and its components and between dietary patterns and a positive cataract history. @*Results@#ARC had a positive association with MS after 1.32-fold adjusting for age, sex, residence area, body mass index, and energy intake. Plasma glucose and HbA1c concentrations exhibited an increased ARC risk in the participants with MS by 1.50- and 1.92-fold and without MS by 1.35 and 1.88-fold, respectively. Serum high-density lipoprotein (HDL) concentrations were negatively associated with ARC risk only in the MS patients, but not without MS. However, blood pressure, abdominal obesity, and serum triglyceride concentrations did not associate with ARC risk regardless of MS. High intake of a Koreanbalanced diet (KBD) containing fermented food exhibited a negative association with ARC risk (OR = 0.81) only in the MS group. The fat and coffee intake had a negative association with ARC only in the non-MS group. Current- and former-smokers were positively associated with ARC risk. @*Conclusion@#Persons who have hyperglycemia and low-HDL-cholesterolemia had increased susceptibility of ARC prevalence. A KBD with a proper amount of fat (≥ 15%) is recommended, and smoking should be prohibited.

2021 Clinical Practice Guidelines for Diabetes Mellitus in Korea

The Committee of Clinical Practice Guidelines of the Korean Diabetes Association (KDA) updated the previous clinical practice guidelines for Korean adults with diabetes and prediabetes and published the seventh edition in May 2021. We performed a comprehensive systematic review of recent clinical trials and evidence that could be applicable in real-world practice and suitable for the Korean population. The guideline is provided for all healthcare providers including physicians, diabetes experts, and certified diabetes educators across the country who manage patients with diabetes or the individuals at the risk of developing diabetes mellitus. The recommendations for screening diabetes and glucose-lowering agents have been revised and updated. New sections for continuous glucose monitoring, insulin pump use, and non-alcoholic fatty liver disease in patients with diabetes mellitus have been added. The KDA recommends active vaccination for coronavirus disease 2019 in patients with diabetes during the pandemic. An abridgement that contains practical information for patient education and systematic management in the clinic was published separately.

Methodology and Rationale for Ophthalmic Examinations in the Seventh and Eighth Korea National Health and Nutrition Examination Surveys (2017–2021)

This report provides a detailed description of the methodology for ophthalmic examinations according to the Korea National Health and Nutrition Examination Survey (KNHANES) VII and VIII (from 2017 to 2021). The KNHANES is a nationwide survey which has been performed since 1998 in representatives of whole Korean population. During the KNHANES VII and VIII, in addition to the ophthalmic questionnaire, intraocular pressure measurement, visual field test, auto refractometry, axial length and optical coherence tomography measurements were included. This new survey will provide not only provide normative and pathologic ophthalmic data including intraocular pressure, refractive error, axial length, visual field and precise measurement of anterior segment, macula and optic nerve with optical coherence tomography, but also a more accurate diagnosis for major adult blindness diseases, including age-related macular degeneration, diabetic retinopathy, glaucoma, and other ocular diseases, for the national Korean population.

Hyperglycemia and Hypo-HDLcholesterolemia Are Primary Risk Factors for Age-related Cataract, and a Korean-style Balanced Diet has a Negative Association, based on the Korean Genome and Epidemiology Study

Background@#The prevalence of cataracts is steadily increasing among the middle-aged and elderly worldwide. We hypothesized that adults aged > 50 years with age-related cataracts (ARCs) have an association with metabolic syndrome (MS) and its components, and MS has interactions with different dietary patterns and lifestyles that affect ARC risk. We examined the hypothesis using the Korean Genome and Epidemiology Study (KoGES; a large-scale hospital-based cohort study), which collected data between 2004–2013. @*Methods@#Participants ≥ 50 years old were classified as cases (1,972 ARC patients) and controls (38,290 healthy controls) based on a diagnosis of cataract by a physician. MS and its components were defined using WHO definitions for Asians. Dietary consumption was evaluated using a validated semi-quantitative food frequency questionnaire (SQFFQ), which contained 106 foods, and dietary patterns were analyzed by principal component analysis. After adjusting for potential covariates, logistic regression was used to investigate associations between MS and its components and between dietary patterns and a positive cataract history. @*Results@#ARC had a positive association with MS after 1.32-fold adjusting for age, sex, residence area, body mass index, and energy intake. Plasma glucose and HbA1c concentrations exhibited an increased ARC risk in the participants with MS by 1.50- and 1.92-fold and without MS by 1.35 and 1.88-fold, respectively. Serum high-density lipoprotein (HDL) concentrations were negatively associated with ARC risk only in the MS patients, but not without MS. However, blood pressure, abdominal obesity, and serum triglyceride concentrations did not associate with ARC risk regardless of MS. High intake of a Koreanbalanced diet (KBD) containing fermented food exhibited a negative association with ARC risk (OR = 0.81) only in the MS group. The fat and coffee intake had a negative association with ARC only in the non-MS group. Current- and former-smokers were positively associated with ARC risk. @*Conclusion@#Persons who have hyperglycemia and low-HDL-cholesterolemia had increased susceptibility of ARC prevalence. A KBD with a proper amount of fat (≥ 15%) is recommended, and smoking should be prohibited.

2021 Clinical Practice Guidelines for Diabetes Mellitus in Korea

The Committee of Clinical Practice Guidelines of the Korean Diabetes Association (KDA) updated the previous clinical practice guidelines for Korean adults with diabetes and prediabetes and published the seventh edition in May 2021. We performed a comprehensive systematic review of recent clinical trials and evidence that could be applicable in real-world practice and suitable for the Korean population. The guideline is provided for all healthcare providers including physicians, diabetes experts, and certified diabetes educators across the country who manage patients with diabetes or the individuals at the risk of developing diabetes mellitus. The recommendations for screening diabetes and glucose-lowering agents have been revised and updated. New sections for continuous glucose monitoring, insulin pump use, and non-alcoholic fatty liver disease in patients with diabetes mellitus have been added. The KDA recommends active vaccination for coronavirus disease 2019 in patients with diabetes during the pandemic. An abridgement that contains practical information for patient education and systematic management in the clinic was published separately.

Meta-analysis of Intravitreal Injection of Anti-vascular Endothelial Growth Factors for Diabetic Macular Edema

PURPOSE: Intravitreal aflibercept, ranibizumab, bevacizumab, and dexamethasone are the most widely used drugs in the treatment of diabetic macular edema (DME). The aim of this study was to compare the efficacy and safety of anti-vascular endothelial growth factors and dexamethasone for the treatment of DME. METHODS: There were nine previous systematic reviews on this topic; we updated these high-quality reviews. Seven studies were added to two studies following a literature search. Efficacy outcomes were 1) average improvement in visual acuity, 2) proportion of patients who experienced an improvement in vision (an increase in best-corrected visual acuity (BCVA) of ≥ 15 in the Early Treatment Diabetic Retinopathy Study [ETDRS]), and 3) proportion of patients who experienced worsening vision (a decrease in BCVA of ≥ 15 in the ETDRS). Safety outcomes included systemic adverse events and ocular-related adverse events. RESULTS: The mean difference in the BCVA for ranibizumab versus bevacizumab treatment was 0.16 (95% confidence interval [CI]: −0.02, 0.34), and that for ranibizumab versus aflibercept was −0.08 (95% CI: −0.26, 0.10). The mean difference in the change of BCVA for aflibercept versus ranibizumab was −0.20 (95% CI: −0.40, −0.01), and that for aflibercept versus bevacizumab was −0.34 (95% CI: −0.53, −0.14). Other efficacy outcomes showed similar trends, and there was no significant difference between treatments. There was also no significant difference in both systemic and ocular adverse events rates between the treatments. CONCLUSIONS: In DME patients, the efficacy of aflibercept was found to be higher with respect to BCVA changes compared with ranibizumab or bevacizumab. However, there were no significant difference in terms of visual acuity improvement or visual acuity of more than 15 letters, nor in terms of anti-vascular endothelial growth factors (as a safety outcome).

Intravitreal Injection of Anti-vascular Endothelial Growth Factor in Age-related Macular Degeneration: a Systematic Review

PURPOSE: To compare the efficacy and safety of intravitreal injections of bevacizumab, ranibizumab, and aflibercept for the treatment of new patients with age-related macular degeneration (AMD). METHODS: We conducted an update of the most recent and high quality systematic reviews (Canadian Agency for Drug Technology in Health [CADTH] 2016). Three randomized clinical trials were added to 13 trials identified from the CADTH report. The efficacy outcomes were 1) average improvement in visual acuity, 2) proportion of patients who experienced an improvement in vision (an increase in best-corrected visual acuity (BCVA) of ≥ 15 on Early Treatment Diabetic Retinopathy Study [ETDRS] letters), and 3) proportion of patients who experienced worsening of vision (decrease in BCVA of ≥ 15 ETDRS letters). In addition, safety outcomes included systemic adverse events and ocular-related adverse events. To analyze the outcomes of 16 randomized controlled trials, we conducted meta-analyses on the outcome measures. RESULTS: There was no significant difference in efficacy outcomes among anti-vascular endothelial growth factor (anti-VEGF) drugs. The mean difference in BCVA between ranibizumab and bevacizumab was 0.33 (95% confidence interval [CI]: −1.29, 1.95), and the odds ratio (OR) for a vision gain in the BCVA of ≥ 15 ETDRS letters for the ranibizumab versus aflibercept treatment was 1.02 (95% CI: 0.80, 1.30). There was also no significant difference in safety outcomes, except in terms of arterial thromboembolic events (ranibizumab vs. bevacizumab; OR: 2.15; 95% CI: 1.04, 4.41). CONCLUSIONS: The efficacy of anti-VEGF drugs for AMD patients was not significantly different. The safety of the drugs was also not significantly different, except in terms of arterial thromboembolic events.

Status of Usage of Anti-vascular Endothelial Growth Factor in Age-related Macular Degeneration

PURPOSE: To evaluate the current use of intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) in patients with age-related macular degeneration (AMD). METHODS: We analyzed the number and medical costs of patients with AMD diagnosed by the National Health Insurance Corporation (2007–2016). We also analyzed the number and medical costs of such patients who received anti-VEGF treatment, and analyzed the frequency, period of use, and average medical cost of anti-VEGF use in AMD patients. Finally, we evaluated the use of anti-VEGF injections for new AMD patients. RESULTS: The number of patients with AMD was 236,158 in 2009 and 537,528 in 2016, which represented a 2.3-fold increase over 8 years. Of these, the number of patients undergoing anti-VEGF therapy increased steadily from 9,961 in 2009 to 35,762 in 2016. The mean number of cycles of ranibizumab or aflibercept per patient was 4.87 ± 3.37, and the mean interval between treatments was 2.89 months. On average, 6.2 injections were performed in the first year of diagnosis, and the frequency of use decreased with time, with an average of 1.2 cycles after 4 years of diagnosis. Among all AMD patients in 2016, the total medical cost of those treated with anti-VEGF was 76.9 billion won, and the average medical cost per person was 2,162,145 won. CONCLUSIONS: The use of two drugs, ranibizumab and aflibercept, as reflected in public health insurance claims, steadily increased over the study period. Notably, there was a tendency to substitute aflibercept for ranibizumab.

Socioeconomic Costs of Age-related Macular Degeneration in Korea

PURPOSE: To estimate the annual socioeconomic costs of age-related macular degeneration (AMD) in the Republic of Korea. METHODS: We estimated the costs of illness to society of AMD patients, including medical, nonmedical, and productivity costs. The medical costs included official and nonofficial medical costs, and the nonmedical costs consisted of transportation, time, and nursing costs. We used Korea National Health Insurance Claims Database, National Health Insurance Service-National Sample Cohort, and Korea Health Panel study data in the analysis. RESULTS: The socioeconomic costs of AMD were estimated to be 694 billion Korean won (KRW) in 2016. This figure was divided into 501 billion KRW (72.1%) for medical costs, 61 billion KRW (8.8%) for nonmedical costs, and 133 billion KRW (19.1%) for productivity costs. The annual per capita socioeconomic cost of AMD was 1.32 million KRW. CONCLUSIONS: We determined the scale and composition of the socioeconomic costs of AMD. Importantly, the productivity costs accounted for approximately 20% of all costs, suggesting that AMD had a significant impact on productivity. Because the disease costs of AMD are expected to increase continuously with the aging population, effective planning at the governmental level for prevention and treatment of AMD should be considered to reduce socioeconomic costs.

Use of Anti-vascular Endothelial Growth Factors for Diabetic Retnopathy: National Health Insurance Claims Data

PURPOSE: To evaluate the current use of intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) in patients with diabetic retinopathy. METHODS: We determined the current number of diabetic retinopathy patients and their medical expenditure using National Health Insurance Service claims data (2007-2016). We also analyzed the medical costs of patients with diabetic retinopathy who received anti-VEGF treatment, including ranibizumab and aflibercept. We then evaluated aspects of the use of anti-VEGF injections, such as frequency and intervals, in newly diagnosed diabetic retinopathy patients who received anti-VEGF treatment, along with their medical costs. RESULTS: The number of patients with diabetic retinopathy was 397,956 in 2009 and 721,310 in 2016, a 1.8-fold increase over 8 years. Of these, the number of patients undergoing anti-VEGF therapy was 4,283 in 2015 and 4,270 in 2016. Of the diabetic retinopathy patients in 2016, the total medical cost of those treated with anti-VEGF was 1.5 billion won, and the average medical cost per person was 3,531,064 won. CONCLUSIONS: Based on the National Health Insurance claims data, the use of ranibizumab and aflibercept is increasing. The results of this study suggest that diabetic retinopathy will become an important public health issue.

Budget Impact Analysis of Anti-vascular Endothelial Growth Factor in Patients with Diabetic Macular Edema

PURPOSE: This study investigated the optimal strategy to minimize budgetary constraints on National Health Insurance (NHI) services, while maximizing the number of diabetic macular edema (DME) patients who receive anti-vascular endothelial growth factor (anti-VEGF) therapy. METHODS: We estimated the potential budget impact of anti-VEGF treatments in DME patients based on perceived upcoming changes in reimbursement fees over the next 5 years (2018–2022). Four scenarios were evaluated: (1) current anti-VEGF treatment patterns, (2) the hypothetical reimbursement fee, (3) the introduction of a new molecule similar to current anti-VEGF treatments, and (4) the prescription of an off-label drug, bevacizumab. The number of patients, anti-VEGF treatments, and medical costs for each scenario were calculated using claims data from the Korean NHI system and anti-VEGF prescription data from a single hospital. RESULTS: The potential budget impact of anti-VEGF injections in patients with DME over the next 5 years was estimated to be about 97.7 billion and 106.2 billion KRW for scenarios 1 and 2, respectively. In scenario 3, in which a biosimilar product to anti- VEGF is used, the estimated budget of the NHI system would be approximately 98.4 billion KRW. If an off-label drug is reimbursed, roughly 79.5 billion KRW will be required for the NHI system's budget. CONCLUSIONS: If the revised fee structure for AMD patients is similarly applied to anti-VEGF injections for DME patients, the NHI fiscal requirements will increase disproportionately over the next 5 years compared to current reimbursement conditions. Given the growth of DME patients in toda's patient population, the use of a biosimilar or off-label drug is a financially viable alternative to reduce the overall burden on the NHI system.

Cost-utility Analysis of Primary Open-angle Glaucoma according to Follow-up Observation Period

PURPOSE: To evaluate the cost-utility based on the quantitative relationship between glaucoma follow-up and glaucoma progression. METHODS: The Markov model was constructed and analyzed to determine the cost-effectiveness of primary open-angle glaucoma. The Markov model set up a virtual cohort of Korean over 40 years of age with early glaucoma. The costs associated with glaucoma treatment were assessed from a social point of view, and the utility was calculated using the quality adjusted life years according to the glaucoma states. Glaucoma health status was divided into 5 stages (early, middle, late, unilateral, bilateral blindness). The transition probability was set in one direction from mild to severe, and the length of each cycle was set at one year. The incremental cost effectiveness ratio (ICER) was calculated and compared with each other different follow-up periods. Sensitivity analysis was conducted to determine how the uncertainty of the variables used in this study affected the outcome. RESULTS: ICER of 3-month follow-up was 28,244,398 won/quality adjusted life years (QALY) compared 6-month follow-up, and ICER of 6-month follow-up was 13,615,443 won/QALY compared to 12-month follow-up. If the probability of progression of glaucoma in 6-months follow-up observations increases by more than 10% over 3-month periodic follow-up and the progression probability of 12-month follow-up increases by more than 15% follow-up compared to 3-months follow-up, 3-months follow-up was found to be a cost-effective strategy. On the other hand, 6-month follow-up was found to be cost-effective if probability of progression of 6-month follow-up was less than 10% increase of 3-month follow-up and 15% increase of 6-months follow-up. CONCLUSIONS: Cost-effective follow-up strategies differed according to the probability of progression of glaucoma, and 3-month or 6-month follow-up strategies were cost-effective and acceptable in Korea's health care system.

Association between Psychological Stress and Glaucoma: Korea National Health and Nutritional Examination Survey 2008–2012

PURPOSE: To evaluate the possible association between psychological stress and glaucoma, given that there are emerging issues and controversy regarding whether psychological stress is one of contributing factors of glaucoma development. METHODS: We used the medical records of 16,426 patients from the Korean National Health and Nutritional Examination Survey 2008–2011. Glaucoma was defined based on examinations including the intraocular pressure, optic disc, visual field, and retinal nerve fiber layer. Stress was evaluated using five questionnaires regarding sustained stress, depression, feelings of suicide, history of suicide attempt/s, and history of psychological counseling. We used univariable and multivariable logistic regression analyses after adjusting confounding factors for glaucoma. RESULTS: Univariable logistic regression analysis revealed no significant association between glaucoma and psychological stress (odds ratio [OR] = 0.84; confidence interval [CI] = 0.70–1.01), depression (OR = 1.22; CI = 0.97–1.55), suicide attempt/s (OR = 0.73, CI = 0.33–1.59), and psychological counseling (OR = 0.72, CI = 0.43–1.21). Using univariate analysis, only the feelings of suicide factor (OR = 1.28, CI = 1.02–1.60) was significantly associated with glaucoma. Using multivariable analysis after adjusting for confounding factors, no significant association was found in any psychological stress factor. CONCLUSIONS: There was no significant association between psychological stress and glaucoma. The results of this study indicated that the pathogenesis of glaucoma is more consistent with the pathogenesis of physiological causes such as age or hypertension, rather than indirect causes such as stress.

Socioeconomic Costs of Glaucoma in Korea

PURPOSE: The purpose of this study was to estimate the socioeconomic costs of glaucoma in Korea. It is to be used as an academic reference regarding policy making for the introduction of glaucoma screening tests in the national health check-ups. METHODS: We estimated the socioeconomic costs of glaucoma from a societal perspective, which included medical, nonmedical, and productivity costs. The medical costs consisted of official and nonofficial medical costs, and the nonmedical costs consisted of transportation, time, and nursing costs. We used the National Health Insurance Service-National Sample Cohort 2002–2013 and the Korea Health Panel study. RESULTS: The socioeconomic costs of glaucoma were estimated to be 3,000 billion Korean won (KRW) in 2013. These total costs were divided into 1,539 billion KRW (51.3%) for medical costs, 1,292 billion KRW (43.1%) for nonmedical costs, and 168 billion KRW (5.6%) for productivity costs. CONCLUSIONS: Glaucoma is a large economic burden from a societal perspective. The nonmedical and productivity costs, as well as the medical costs are especially high. Because the disease costs of glaucoma are expected to increase continuously, political support for early detection of glaucoma should be considered.

Final Impact of Anti-Vascular Endothelial Growth Factor Treatment in Age-related Macular Degeneration

PURPOSE: To evaluate the effects of anti-vascular endothelial growth factor (VEGF) treatment on the healthcare-related finances of patients with age-related macular degeneration. METHODS: Changes in health care financing due to newly introduced benefit standards were predicted over the coming 5-year period (2018–2022). We also analyzed the financial impact of scenarios in which agents similar to anti-VEGF, such as the over-licensed drug bevacizumab, were introduced. For this purpose, the future number of patients receiving anti-VEGF treatments was estimated for various scenarios based on National Health Insurance Corporation claims data followed by an estimate of the financial burden. RESULTS: In the case of age-related macular degeneration, the current standard of care (14 times in a lifetime) was maintained in scenario 1. In 2018, the insurance budget for the coming 5-year period was estimated at approximately 440.3 billion won. The insurance cost for that period was estimated at approximately 560.1 billion won under the revised standard of December 2017 (scenario 2). For scenarios wherein, after 2020, similar treatments (scenario 3) and bevacizumab (scenario 4) were introduced, the estimated health insurance costs were 521 billion won and 419.7 billion won, respectively. CONCLUSIONS: Health insurance costs are projected to increase substantially due to the elimination of the 14 time pay standard; however, the actual budget will only moderately increase, due to new limitations of visual acuity ≤ 0.1 or in case of scarring/ atrophic lesions. Clinically similar agents and bevacizumab could be considered as alternatives to anti-VEGF treatment for age-related macular degeneration.

Association between Grapes Intake and Diabetic Retinopathy: Inhibitory Effect of Resveratol on Diabetic Retinopathy

PURPOSE: To evaluate the association between grape intake and diabetic retinopathy. METHODS: A population-based cross-sectional study using a nation-wide, stratified, multistage, clustered sampling method included 1,555 subjects aged > or =30 years who participated in the Korean National Health and Nutritional Examination Survey 2008-2011. All participants performed standardized interviews, food frequency questionnaires (FFQ), and comprehensive ophthalmic examinations. Grape intake was evaluated by an FFQ using 10 intervals of average frequency of grape intake during the past year. Diabetic retinopathy (DR) was evaluated by 7 standard retinal fundus photographs after pharmacological pupil dilatation. DR was classified as any DR, proliferative DR, or vision-threatening DR by the modified Air House classification system. RESULTS: The prevalence of diabetes was 16.9 +/- 1.2%. As the grape intake frequency increases in FFQ, the odds ratio (OR) for any DR, proliferative DR, and vision-threatening DR were 0.86 (95% confidence interval [CI], 0.75-0.98), 0.65 (95% CI, 0.48-0.88), and 0.77 (95% CI, 0.60-0.99) respectively. Compared to the group with a grape intake of less than once per month, the OR for any DR, proliferative DR, and vision-threatening DR in the group with a grape intake of more than 2-3 times per month were 0.54 (95% CI 0.33-0.89), 0.25 (95% CI 0.07-0.81), 0.36 (95% CI 0.13-0.95), respectively. CONCLUSIONS: The intake of grapes was inversely associated with the prevalence of DR.

Clinical Course and Risk Factors of Diabetic Retinopathy in Patients with Type 2 Diabetes Mellitus in Korea

BACKGROUND: We investigated clinical course and risk factors for diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM). METHODS: A total of 759 patients with T2DM without DR were included from January 2001 to December 2004. Retinopathy evaluation was performed at least annually by ophthalmologists. The severity of the DR was classified into five categories according to the International Clinical Diabetic Retinopathy Severity Scales. RESULTS: Of the 759 patients, 523 patients (68.9%) completed the follow-up evaluation. During the follow-up period, 235 patients (44.9%) developed DR, and 32 patients (13.6%) progressed to severe nonproliferative DR (NPDR) or proliferative DR (PDR). The mean duration of diabetes at the first diagnosis of mild NPDR, moderate NPDR, and severe NPDR or PDR were 14.8, 16.7, and 17.3 years, respectively. After adjusting multiple confounding factors, the significant risk factors for the incidence of DR risk in patients with T2DM were old age, longer duration of diabetes, higher mean glycosylated hemoglobin (HbA1c), and albuminuria. Even in the patients who had been diagnosed with diabetes for longer than 10 years at baseline, a decrease in HbA1c led to a significant reduction in the risk of developing DR (hazard ratio, 0.73 per 1% HbA1c decrement; 95% confidence interval, 0.58 to 0.91; P=0.005). CONCLUSION: This prospective cohort study demonstrates that glycemic control, diabetes duration, age, and albuminuria are important risk factors for the development of DR. More aggressive retinal screening for T2DM patients diagnosed with DR should be required in order to not miss rapid progression of DR.

Changes in Peripapillary Retinal Nerve Fiber Layer Thickness after Pattern Scanning Laser Photocoagulation in Patients with Diabetic Retinopathy

PURPOSE: To examine the effects of panretinal photocoagulation (PRP) using a pattern scanning laser (PASCAL) system on the retinal nerve fiber layer (RNFL) thickness in patients with diabetic retinopathy. METHODS: This retrospective study included 105 eyes with diabetic retinopathy, which consisted of three groups: the PASCAL group that underwent PRP with the PASCAL method (33 eyes), the conventional group that underwent conventional PRP treatment (34 eyes), and the control group that did not receive PRP (38 eyes). The peripapillary RNFL thickness was measured by optical coherence tomography before, six months, and one year after PRP to evaluate the changes in peripapillary RNFL. RESULTS: The RNFL thickness in the PASCAL group did not show a significant difference after six months (average 3.7 times, p = 0.15) or one year after the PRP (average 3.7 times, p = 0.086), whereas that in the conventional group decreased significantly after six months (average 3.4 times, p < 0.001) and one year after PRP (average 3.4 times, p < 0.001). CONCLUSIONS: The results of this study suggest that the PASCAL system may protect against RNFL loss by using less energy than conventional PRP.