Comparison of Individual Retinal Layer Thicknesses between Highly Myopic Eyes and Normal Control Eyes Using Retinal Layer Segmentation Analysis

The incidence of myopia is increasing worldwide, and the investigation on pathophysiology of myopia is becoming more important. This retrospective study aimed to compare the thicknesses of individual retinal layers between high-myopic and control eyes, and to evaluate the effects of age and sex on each retinal layer thickness. We assessed 164 subjects and divided them into two groups based on axial length (AL) (i.e., high-myopic group (AL ≥ 26 mm) and control group (AL < 26 mm)). Individual retinal layer thicknesses of five subfields in the macula were measured using automated retinal segmentation software packaged with the spectral-domain optical coherence tomography and were compared. In high-myopia group, the thicknesses of total retina and all individual retinal layers in central and entire perifoveal subfields were significantly thicker than the corresponding layers in control group after adjustment for ocular magnification (all P < 0.05). There were no significant effects of sex on individual retinal thicknesses, and age had less negative effects on the thicknesses of retina layers in high-myopic eyes than normal eyes. Axially elongated, non-pathologic highly myopic eyes had different structural features than control eyes, with significantly greater individual macular layer thicknesses independent of sex or age.ope

Association between localised retinal nerve fibre layer defects and cardiovascular risk factors

Localised retinal nerve fibre layer defects (RNFLDs) are reported to indicate the degree of glaucomatous damage but can also be sequelae of retinal vascular insufficiency as a result of systemic vascular factors. We investigated the association between RNFLDs and cardiovascular risk factors. RNFLDs were detected in 440 (29.2%) of 1508 subjects. The presence of RNFLDs was associated with higher HbA1c (odds ratio [OR] 1.289, p < 0.001), higher 24-h mean systolic blood pressure (SBP; OR 1.013, p < 0.005), and lower estimated glomerular filtration rate (eGFR; OR 0.995, p < 0.005). An increasing number of RNFLDs was correlated with higher SBP (r = 0.186, p < 0.001), higher HbA1c (r = 0.128, p < 0.010), lower eGFR (r = -0.112, p < 0.020), and younger age (r = -0.303, p < 0.001). Subjects with RNFLDs had a higher predicted 10-year risk of atherosclerotic cardiovascular disease than did those without RNFLDs (9.7% vs 7.9%, p = 0.008 in middle-aged subjects, 25.6% vs 23.2%, p = 0.040 in older subjects). In conclusion, RNFLDs are associated with SBP, eGFR, and HbA1c. Concomitant cardiovascular risk factors should be considered when evaluating patients with localised RNFLDs.ope

Chemokine Receptor Profiles of T Cells in Patients with Age-Related Macular Degeneration

Purpose: To evaluate the expression of multiple chemokine receptors in peripheral blood T cells from patients with age-related macular degeneration (AMD). Materials and methods: Peripheral blood mononuclear cells and/or aqueous humor were obtained from 24 AMD patients and 24 age- and sex-matched healthy controls. Chemokine receptor expression on T cells from peripheral blood was determined by multicolor flow cytometry. The levels of chemokines and cytokines in the aqueous humor from 12 AMD patients and six healthy controls were assessed. Results: AMD patients had increased expressions of CCR4 in CD4+ T cells (p=0.007) and CRTh2 in CD8+ T cells (p=0.002), and decreased expressions of CXCR3 in CD4+ T cells (p=0.029) and CXCR3, CCR5, and CX3CR1 in CD8+ T cells (p=0.005, 0.019, and 0.007, respectively). Monocyte chemoattractant protein-1 levels were increased in the aqueous humor from AMD patients (p=0.018), while the levels of interleukin (IL)-4 and IL-22 were significantly decreased compared to controls (p=0.018 and 0.041, respectively). Conclusion: The chemokine receptor profiles of T cells are altered in AMD patients compared to healthy controls without noticeable associations with chemokine levels in the aqueous humor. Further evaluation is needed to clarify the role of these alterations in AMD pathogenesis.ope

An algorithm for measurement of pack ice concentration and size distribution using localized binarization of quadtree-subdivided image

Recently, many research works on the icebreaking vessels have been published as the possibility of passing Arctic routes has been increasing. The model ship test on the pack ice model in the ice basin is actively carried out as a way to investigate the performance of icebreaking vessels. In this test, The concentration as well as the individual area of pack ice are important since they directly affect the performance. However, it is difficult to measure the concentration because not only the pack ice has uneven shape but also it keeps floating around in the basin. In this paper, an algorithm to identify the concentration of pack ice is introduced. From a digital image of pack ice obtained in the ice basin, the goal is to measure the area of pack ice using an image processing technique. Instead of the general global binarization that yields numerical errors in this problem, a local binarization technique, coupled with image subdivision based on the quadtree structure, is developed. Also the individual area and size distribution of each pack ice patch is calculated using the edge detection and the watershed technique. The obtained results are compared with the manually measured data to prove its accuracy.제 1 장 서 론 1.1 북극항로 1.2 쇄빙선 및 내빙선 기초연구 1.3 선행연구 1.4 개요 제 2 장 OpenCV 및 디지털 영상 처리 2.1 OpenCV 2.3 디지털 영상처리 및 활용 분야 2.4 디지털 영상 및 종류 2.5 컬러영상의 색 공간 2.6 영상 히스토그램 2.7 이진화와 임계값 2.8 엣지 검출 및 윤곽 추출 2.9 형태학 처리 2.10 Distance transform 2.11 워터쉐드 제 3 장 팩아이스 영상 특징 및 이진화 3.1 팩아이스 영상 특징 3.2 최적 임계값 3.3 구획화를 이용한 국부 이진화 제 4 장 쿼드트리 분할을 활용한 알고리즘 4.1 쿼드트리 개념 4.2 개발 알고리즘 4.3 히스토그램 분석 및 피크 분류 (#1) 4.4 1피크 히스토그램 영상 분석 (#2) 4.5 2피크 히스토그램 영상의 필터링 수행 (#3) 제 5 장 개별 면적 분포도 5.1 중첩 팩아이스 분리 5.2 워터쉐드 개별 추출 알고리즘 5.3 워터쉐드를 활용한 개별 팩아이스 추출 알고리즘 제 6 장 예제 6.1 국부 이진화 개발 알고리즘 효과 6.2 국부 이진화 개발 알고리즘을 이용한 집적도 측정 6.3 국부 이진화 개발 알고리즘 정확도 검토 6.4 개별 팩아이스 추출 및 면적 분포도 6.5 팩아이스 집적도 및 개별 팩아이스 면적 분포도 측정 모듈 제 7 장 결론 참고문헌Maste

Acute Retinal Necrosis Masked by Clinical Features of Orbital Inflammation

Purpose: To describe a case of acute retinal necrosis with clinical features of orbital inflammation. Case summary: A 33-year-old female presented with right eye injection, chemosis, and pain. At the first visit, the uncorrected visual acuity and intraocular pressure of her right eye were 20/20 and 20 mmHg, respectively. Slit-lamp examination showed in flammatory cell 2+ in the anterior chamber of the right eye; an evaluation of the peripheral retina was not conducted. The next day, computed tomography (CT) was performed due to aggravation of the orbital inflammation. High-dose intravenous methyl prednisolone injection was initiated on the finding of posterior scleritis with orbital inflammation on CT scans; peripheral retinal necrosis and obstructive vasculitis were also noted. Clinically determined to be acute retinal necrosis, the patient began sys temic antiviral therapy. A diagnostic anterior chamber paracentesis was positive for herpes simplex virus type 2 by polymerase chain reaction. The patient was treated with intravenous acyclovir and intravitreal injections of foscarnet, as well as barrier laser therapy. After two weeks of treatment, the patient was discharged with oral valacyclovir. During the three months of follow-up, the visual acuity of the right eye was hand motion, due to chronic optic disc swelling with chronic macular edema and macular degeneration. Neither eye showed retinal lesion progression. Conclusions: Rarely, acute retinal necrosis is accompanied by clinical manifestations of orbital inflammation. Therefore, if pa tients have uveitis with orbital inflammation, it is important to consider the possibility of acute retinal necrosis and to examine the peripheral retina carefully.ope

Tomographic Structural Changes of the Inner Retina after Internal Limiting Membrane Peeling for Idiopathic Epiretinal Membrane

Purpose: To investigate the tomographic structural changes in the retinal layers after internal limiting membrane (ILM) peeling for idiopathic epiretinal membrane (ERM). Methods: Sixty-nine eyes treated with vitrectomy and ILM peeling for idiopathic ERM were analyzed. Parafoveal retinal thickness was measured at baseline and 6 months after surgery. Results: Total retinal thickness decreased significantly in the nasal and temporal subfields after surgery (p < 0.001), whereas the inner nuclear layer and outer nuclear layer showed nasal thickening (all, p < 0.001). The postoperative temporal/nasal subfield thickness ratio of each layer was significantly lower than that of fellow eyes. Eyes with larger ILM peeling showed a significantly lower temporal/nasal subfield thickness ratio (p = 0.033) than those with smaller sizes. Conclusions: The retinal thickness of each layer showed anatomical changes from ILM peeling and ERM removal. Nasal parafoveal thickening and temporal thinning occurred in the inner retinal architecture, which might be affected by ILM peeling size.ope

Clinical outcomes of combined pars plana vitrectomy and scleral fixation of the intraocular lens with a suspension bridge method in eyes with aphakia or insufficient capsular support

Purpose: To describe a modified technique of scleral fixation for intraocular lens (IOL) implantation and report the clinical outcomes of combined pars plana vitrectomy and scleral IOL fixation using the suspension bridge method. Methods: This retrospective case series included 57 eyes (56 patients) of aphakia or phakic and pseudophakic eyes with insufficient capsular support that underwent IOL implantation or dislocated IOL repositioning with scleral fixation using the 'suspension bridge' method by a single surgeon between 1 July 2010 and 1 March 2019. Preoperative status, changes in visual acuity, refractive outcomes as spherical equivalent and related complications were assessed with a minimum follow-up of 3 months. Results: The mean follow-up period was 25.5 ± 25.4 months. Preoperative visual acuity (logarithm of the minimum angle of resolution) was 1.32 ± 0.68 (20/400 Snellen), and it significantly improved to 0.80 ± 0.53 (20/125), 0.59 ± 0.56 (20/80) and 0.24 ± 0.37 (20/35) at 1 week, 1 month and 3 months, respectively (p < 0.001). Postoperative complications included corneal wound dehiscence (n = 1), vitreous incarceration (n = 1), optic-iris capture (n = 6) and cystoid macular oedema (n = 1). The above-mentioned complications were successfully corrected with simple procedures. However, one case of IOL dislocation required reoperation. Conclusion: The modified technique of the suspension bridge method precludes the need for a scleral flap, with the advantage of easy adjustment of the IOL position. It is a simple and feasible technique with good surgical results and low complication rates.ope

Comment on: Tikhonenko et al. (2010) Remodeling of retinal fatty acids in an animal model of diabetes: a decrease in long-chain polyunsaturated fatty acids is associated with a decrease in fatty acid elongases Elovl2 and Elovl4. Diabetes;59:219-227.

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Short-Term Outcomes of the First in Vivo Gene Therapy for RPE65-Mediated Retinitis Pigmentosa

Here, we report early treatment outcomes of gene therapy for early onset retinitis pigmentosa (RP) (Leber congenital amaurosis) associated with biallelic RPE65 mutation in a 30-year-old female patient. Initially, her visual acuity (VA) was 20/200, and her visual field (VF) was severely constricted to the center in the left eye. Her electroretinography showed nearly extinct signals. Full-field stimulus threshold test (FST) revealed diminished dark-adapted light sensitivity. Voretigene neparvovec-rzyl (VN) is the first in vivo viral gene therapy agent to be approved. At 3 months after subretinal injection of VN in the left eye, VA, VF, and FST showed sustained improvement. She did not exhibit any signs of adverse effects from the treatment. Gene therapy for RP proved to be an effective and safe treatment in an advanced case of RPE65-associatied early onset RP.ope

Voretigene Neparvovec for the Treatment of RPE65-associated Retinal Dystrophy: Consensus and Recommendations from the Korea RPE65-IRD Consensus Paper Committee

Mutations in the RPE65 gene, associated with Leber congenital amaurosis, early-onset severe retinal dystrophy, and retinitis pigmentosa, gained growing attention since gene therapy for patients with RPE65-associated retinal dystrophy is available in clinical practice. RPE65 gene accounts for a very small proportion of patients with inherited retinal degeneration, especially Asian patients. Because RPE65-associated retinal dystrophy shares common clinical characteristics, such as early-onset severe nyctalopia, nystagmus, low vision, and progressive visual field constriction, with retinitis pigmentosa by other genetic mutations, appropriate genetic testing is essential to make a correct diagnosis. Also, fundus abnormalities can be minimal in early childhood, and the phenotype is highly variable depending on the type of mutations in RPE65-associated retinal dystrophy, which makes a diagnostic difficulty. The aim of this paper is to review the epidemiology of RPE65-associated retinal dystrophy, mutation spectrum, genetic diagnosis, clinical characteristics, and voretigene neparvovec, a gene therapy product for the treatment of RPE65-related retinal dystrophy. © 2023 The Korean Ophthalmological Society.ope