Kim MS, et al. J Korean Med Sci. 2019 May;34(21):e161. https://doi.org/10.3346/jkms.2019.34.e161

Objectives. To investigate the mechanism of rhegmatogenous retinal detachment (RRD) in young and elderly Korean patients based on the results of axial length distribution. Subjects/Methods. We retrospectively reviewed the medical records of 1599 patients with RRD who had bilateral axial length data examined at one center between 2003 and 2018. Axial lengths were measured using ultrasound or IOLMaster500. The frequency of RRD and axial length distribution according to age groups were investigated. Results. Patients with RRD displayed a bimodal distribution across ages with two age groups showing the highest peak at 55–59 years and a second peak at 25–29 years of age. The mean axial length was significantly longer in patients younger than 50 years old than that in patients ≥ 50 years old (26.18 ± 1.86 mm vs. 24.55 ± 1.67 mm, respectively, p < 0.001). The percentage of patients with high myopia (axial length ≥ 26 mm) in patients < 50 years old was higher than that in those ≥ 50 years old (51.9% vs. 15.0%, respectively, p < 0.001; odds ratio, 6.11; 95% confidence interval, 4.83 to 7.74). Conclusions. We found a difference in the prevalence of myopia between young and elderly patients with RRD, which corresponds to a bimodal distribution of RRD incidence in East Asian countries. Our data indicate that myopia or high myopia-induced early vitreous detachment appears to be a major mechanism of occurrence of RRD in young East Asian patients, while senile vitreous liquefaction and detachment is the main mechanism of RRD in elderly patients.

Kim MS, et al. J Korean Med Sci. 2024 Jun;39:e203. https://doi.org/10.3346/jkms.2024.39.e203

We investigated organ specific Toxocara canis larval migration in mice infected with T. canis larvae. We observed the worm burden and systemic immune responses. Three groups of BALB/c mice (n=5 each) were orally administered 1,000 T. canis 2nd stage larvae to induce larva migrans. Mice were sacrificed at 1, 3, and 5 weeks post-infection. Liver, lung, brain, and eye tissues were collected. Tissue from 2 mice per group was digested for larval count, while the remaining 3 mice underwent histological analysis. Blood hematology and serology were evaluated and compared to that in a control uninfected group (n=5) to assess the immune response. Cytokine levels in bronchoalveolar lavage (BAL) fluid were also analyzed. We found that, 1 week post-infection, the mean parasite load in the liver (72±7.1), brain (31±4.2), lungs (20±5.7), and eyes (2±0) peaked and stayed constant until the 3 weeks. By 5-week post-infection, the worm burden in the liver and lungs significantly decreased to 10±4.2 and 9±5.7, respectively, while they remained relatively stable in the brain and eyes (18±4.2 and 1±0, respectively). Interestingly, ocular larvae resided in all retinal layers, without notable inflammation in outer retina. Mice infected with T. canis exhibited elevated levels of neutrophils, monocytes, eosinophils, and immunoglobulin E. At 5 weeks post-infection, interleukin (IL)-5 and IL-13 levels were elevated in BAL fluid. Whereas IL-4, IL-10, IL-17, and interferon-γ levels in BAL fluid were similar to that in controls. Our findings demonstrate that a small portion of T. canis larvae migrate to the eyes and brain within the first week of infection. Minimal tissue inflammation was observed, probably due to increase of anti-inflammatory cytokines. This study contributes to our understanding of the histological and immunological responses to T. canis infection in mice, which may have implications to further understand human toxocariasis.

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.

Introduction: The aim of this study was to report surgical outcomes and risk factors for primary surgical failure following rhegmatogenous retinal detachment (RRD) repair. Methods: In this retrospective cohort study, RRD patients who underwent primary surgery at a tertiary center between January 1, 2006, and December 31, 2020, were enrolled. Surgical failure was defined as reoperation within 60 days postoperatively due to retinal re-detachment and putative risk factors for surgical failure were analyzed. Results: Of 2,383 eyes (2,335 patients), 1,342 (56.3%) underwent vitrectomy and 1,041 (43.7%) underwent scleral buckling. The surgical failure rate was 9.1% overall, and 6.0% and 13.1% for the vitrectomy and scleral buckling groups, respectively. In the multivariate logistic regression analysis, surgical failure was associated with surgical experience (first-year fellow vs. senior professor) (odds ratio [OR]: 1.66; p = 0.018), scleral buckling (OR: 2.33; p < 0.001), and longer axial length (AL; ≥26.5 mm) (OR: 1.49; p = 0.017). In each surgical approach, age 40 years (OR, 1.84; p = 0.004), male sex (OR: 1.65; p = 0.015), and first-year fellows compared to senior professors (OR: 1.95; p = 0.013) in the scleral buckling group were associated with surgical failure. Lens status were not associated with the surgical failure rate. Conclusion: In this large retrospective study using data from Korea, vitrectomy was superior to scleral buckling in terms of primary anatomical outcomes in the management of RRD. First-year fellows were a risk factor for surgical failure, especially for scleral buckling. Longer AL was a significant parameter for predicting the success rates.