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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.

This study aimed to quantify the Haller vessel and choriocapillaris (CC) parameters in drusen subtypes in nonexudative age-related macular degeneration (AMD) and pachydrusen. Ninety-five eyes of 80 patients and 28 control eyes were categorized into soft drusen, subretinal drusenoid deposit (SDD), soft drusen plus SDD, pachydrusen, and control groups. The diameter, length and intersections of Haller vessels and the total area, size and number of CC flow voids were quantified using en face optical coherence tomography (OCT) or OCT angiography. The pachydrusen group showed the largest Haller vessel area and diameter and shortest total length but similar CC parameters to those in the control group. The soft drusen plus SDD group showed the largest CC flow void area and size, while the Haller parameters were similar to those in the control group. The area and size of the flow voids in the SDD group were smaller than those in the soft drusen plus SDD group. Based on unsupervised machine learning, the eyes were classified into 4 clusters—the control, pachydrusen, soft drusen plus SDD and soft drusen plus SDD groups. Cluster 3 showed a larger diameter and shorter total length of the Haller vessels than cluster 4.

To evaluate the real-world treatment outcomes in patients with neovascular age-related macular degeneration (nAMD) in Korea, focusing on retinal fluid resolution. This multi-institutional retrospective chart review study, analyzed medical records of patients with nAMD (age ≥ 50 years) who received their first anti-vascular endothelial growth factor (VEGF) treatment in ophthalmology clinics across South Korea between January 2017 and March 2019. The primary endpoint was the proportion of patients with retinal fluid after 12 months of anti-VEGF treatment. The association between fluid-free period and VA gains was also evaluated. A total of 600 patients were enrolled. At baseline, 97.16% of patients had retinal fluid; after 12 months of anti-VEGF treatment, 58.10% of patients had persistent retinal fluid. VA improvements were relatively better in patients with absence of retinal fluid compared with presence of retinal fluid (+ 12.29 letters vs. + 6.45 letters at month 12; P P

Purpose We report the clinical outcomes of retinal capillary hemangioma (RCH) after the application of various treatments. Methods We performed a retrospective chart analysis of eight eyes treated for RCH between August 2009 and January 2018. During the follow-up period, the status and progression of the RCHs were checked by fundus photography, fluorescein angiography, and optical coherence tomography, and additional treatments were applied when necessary. Results Three of the five patients had bilateral RCH, and two had unilateral RCH. Six eyes received laser photocoagulation; two eyes received cryotherapy, and one eye received intravitreal Avastin injection. Three eyes each had intravitreal triamcinolone injection, subtenon triamcinolone injection, and intravitreal dexamethasone injection to control inflammation. Also, two patients took oral prednisolone, and one patient used prednisolone eye drops to control inflammation. Two eyes underwent vitrectomy and scleral buckling due to deterioration of the epiretinal membrane and vitreal traction, respectively. As a result of those treatments, the tumors were stable in five of the eight eyes. However, one eye is now in a pre-phthisis state, and one patient who refused treatment showed progression of the tumor, epiretinal membrane, and traction. Conclusions Because RCHs vary in size, the degree of inflammation, and symptoms, this disorder should be actively treated on a case-by-case basis. Fluorescein angiography should be used periodically to determine recurrence of the tumor or inflammation, and the appropriate treatment should be repeated as necessary. Moreover, regular systemic screening tests for von Hippel-Lindau disease should be performed in RCH patients to ensure that they have no abnormalities other than in the eye.

To evaluate changes in peripapillary microvascular parameters in diabetes mellitus (DM) patients using optical coherence tomography angiography (OCTA). Seventy-one diabetic patients (40 in the no diabetic retinopathy [DR] group and 31 in the non-proliferative DR [NPDR] group) and 50 control subjects. OCTA (Zeiss HD-OCT 5000 with AngioPlex) 6 × 6 mm scans centered on the optic disc were analyzed. Peripapillary vessel density (VD), perfusion density (PD) in superficial capillary plexus (SCP) were automatically calculated. The average macular ganglion cell-inner plexiform layer (mGC-IPL) and peripapillary retinal nerve fiber layer (pRNFL) thicknesses of the no DR and NPDR groups were significantly thinner than those of the control group. The no DR and NPDR groups showed lower peripapillary VD and PD in SCP compared with the control group. Using univariate regression analyses, the average mGC-IPL thickness, the pRNFL thickness, the no DR group and NPDR group were significant factors that affected the peripapillary VD and PD in SCP. Multivariate regression analyses showed that the grade of DR was a significant factor affecting the peripapillary VD and PD in SCP. OCTA revealed that peripapillary microvascular parameters in the no DR and NPDR groups were lower than those of normal controls. The peripapillary VD and PD in SCP were correlated with the mGC-IPL thickness, the pRNFL thickness, and the no DR and NPDR groups. Changes in peripapillary OCTA parameters may help with understanding the pathophysiology of DM and evaluating a potentially valuable biomarker for patients with subclinical DR.

PURPOSE To evaluate the changes of axial length (AXL) in eyes with unilateral idiopathic central serous chorioretinopathy (CSC) after resolution of serous retinal detachment. METHODS A total of 31 patients diagnosed with idiopathic unilateral CSC were included in this study. The changes of AXL according to serous retinal detachment were examined. The keratometric value and AXL were measured using partial coherence interferometry. Serous retinal detachment and central macular thickness (CMT) were measured by spectral domain optical coherence tomography. RESULTS The mean age of the 31 CSC patients, including 19 males, was 42.7 years. The AXL was significantly increased from 23.41 to 23.58 mm after resolution of serous retinal detachment (p < 0.001). The CMT was significantly decreased from 413.4 to 226.8 μm after resolution of serous retinal detachment (p < 0.001). The differences in AXL correlated with CMT differences and subretinal fluid height (r = -0.616, p < 0.001 and r = -0.637, p < 0.001, respectively), and the best-corrected visual acuity was significantly different after resolution of serous retinal detachment (p < 0.001). CONCLUSIONS In unilateral idiopathic CSC with serous retinal detachment, a shortened AXL in the acute phase was restored after resolution of serous retinal detachment.

Many studies have reported the effect of hypertension on microcirculation of the retina. Advance of optical coherence tomography angiography (OCTA) allows us more detailed observations of microcirculation of the retina. Therefore, we compared OCTA parameters between chronic hypertension (disease duration of at least 10 yrs; Group A, 45 eyes), relieved hypertensive retinopathy (grade IV HTNR vs. C; 19.4 mm−1vs. 20.1 mm−1, Group B vs. D; 19.8 mm−1vs. 21.8 mm−1, all p vs. C; 0.35 mm2vs. 0.30 mm2, Group B vs. D; 0.36 mm2vs. 0.29 mm2, all p

The purpose of this study was to investigate changes in peripapillary microvasculature using optical coherence tomography angiography (OCTA) in systemic hypertension (HTN) patients. This was a cross-sectional study. Based on the duration of HTN, seventy-eight HTN patients were divided into two groups. (HTN group 1

The retina is the primary site of Toxoplasma gondii infection in the eye, and choroidal neovascularization in ocular toxoplasmosis is one of the most important causes of visual impairment. Vascular endothelial growth factor (VEGF) is one of the key regulators of blood vessel development, however, little is known about the mechanisms of T. gondii-induced VEGF production in ocular toxoplasmosis. Here, we investigate the effect of T. gondii on VEGF production regulation in human retinal pigment epithelium ARPE-19 cells and attempted to unveil the underlying mechanism of this event by focusing on the interaction between parasite and the selected host intracellular signaling pathways. T. gondii infection increased the expression of VEGF mRNA and protein in ARPE-19 cells in parasite burden- and infection time-dependent manner. The proportional increase of VEGF upstream regulators, HIF-1α and HO-1, was also observed. T. gondii induced the activation of host p-AKT, p-ERK1/2, and p-p38 MAPK in ARPE-19 cells in a parasite-burden dependent manner. However, VEGF expression decreased after the pre-treatment with PI3K inhibitors (LY294002 and GDC-0941), ERK1/2 inhibitor (PD098059), and p38 MAPK inhibitor (SB203580), but not JNK inhibitor (SP600125), in a dose-dependent manner. The anti-VEGF agent bevacizumab or VEGF siRNA transfection prominently inhibited the activation of p-AKT and p-ERK1/2, but not p-p38 MAPK and JNK1/2 in T. gondii-infected ARPE-19 cells. Bevacizumab treatment or VEGF siRNA transfection significantly inhibited the proliferation of T. gondii tachyzoites in the host cell, dose-dependently, but not invasion of parasites. VEGF-receptor 2 (VEGF-R2) antagonist, SU5416, attenuated VEGF production and tachyzoite proliferation in T. gondii-infected ARPE-19 cells in a dose-dependent manner. Collectively, T. gondii prominently induces VEGF production in ARPE-19 cells, and VEGF and AKT/ERK1/2 signaling pathways mutually regulate each other in T. gondii-infected ARPE-19 cells, but not p38 MAPK and JNK1/2 signaling pathways. VEGF and VEGF-R2 control the parasite proliferation in T. gondii-infected ARPE-19 cells. From this study, we revealed the putative mechanisms for VEGF induction as well as the existence of positive feedback between VEGF and PI3K/MAPK signaling pathways in T. gondii-infected retinal pigment epithelium.

There is a myopic shift in the final measured spherical equivalent following combined phacovitrectomy compared to the predicted postoperative value. This change in myopia is known to be associated with gas tamponade, but it also occurs in patients who do not have gas tamponade, and even when vitrectomy is performed in the pseudophakic eye. In this study, we focused on the long-term reproducibility of axial length after combined phacovitrectomy in patients with macula-sparing rhegmatogenous retinal detachment. Before surgery, one year after surgery, and two years after surgery, bilateral axial lengths were measured using partial interferometry. To confirm whether axial lengths changed after surgery, we conducted confidence analyses using the intraclass correlation coefficient (ICC), coefficient of variation (CV), and test–retest standard deviation (TRTSD). The preoperative mean axial length was 25.03 ± 1.69 mm in the affected eyes and 24.96 ± 1.70 mm in the fellow eyes. The ICC, CV, and TRTSD were 0.97, 0.45, and 0.114 in affected eyes and 0.98, 0.66, and 0.167 in fellow eyes, respectively, which shows a high level of reproducibility. Prediction errors for postoperative spherical equivalents measured using partial interferometry were −0.41 ± 0.67 diopters (p = 0.001), respectively, which shows a remarkable myopic shift. Correlation analyses indicated that this myopic shift was significant in eyes with a shallower anterior chamber and a thicker lens. In macula-sparing RRD patients, the axial length showed excellent long-term reproducibility two years after vitrectomy, cataract surgery, and gas tamponade. The myopic shift after surgery was therefore caused by factors that may have affected the intraocular lens position, such as preoperative anterior chamber depth and lens thickness, rather than a change in the axial length.

To develop a controlled-release fertilizer (CRF) suitable for nutrient absorption characteristics of Phalaenopsis, four kinds of new controlled-release fertilizer (NCRF 1–4) with different dissolution rates were developed and studied to determine the concentration and amount suitable for growth of Phalaenopsis. To make NCRF, new acryl-based polymers were developed and used as fertilizer coating solutions. In addition, a fluidized bed coater for coating fertilizer was developed and used in this study. To test the growth of Phalaenopsis, 10-month-old Phalaenopsis seedlings were planted in plastic pots (diameter 10 cm) filled with 100% Sphagnum moss and cultivated for approximately 100 days from May 29, 2015, to September 11, 2015. NCRF 1, NCRF 2, and Osmocote, an imported fertilizer, consistently exhibited release patterns of fertilizer nutrients in a directly proportional form; however, NCRF 3 and NCRF 4 displayed a sigmoid-like tendency of fertilizer nutrient release with a slower initial dissolution rate. Furthermore, leaf length, leaf width, fresh weigh, and root weight of Phalaenopsis were the highest when growing in 1.5 g/pot of NCRF 3 fertilizer, and the pH and electrical conductivity (EC) of the soil were stable at this concentration of NCRF 3. Based on our results, we suggest that 1.5 g/pot of NCRF 3 fertilizer is the ideal concentration and fertilizer for growing Phalaenopsis.

The retina is the primary site of Toxoplasma gondii infection in the eye, and choroidal neovascularization in ocular toxoplasmosis is one of the most important causes of visual impairment. Vascular endothelial growth factor (VEGF) is one of the key regulators of blood vessel development, however, little is known about the mechanisms of T. gondii-induced VEGF production in ocular toxoplasmosis. Here, we investigate the effect of T. gondii on VEGF production regulation in human retinal pigment epithelium ARPE-19 cells and attempted to unveil the underlying mechanism of this event by focusing on the interaction between parasite and the selected host intracellular signaling pathways. T. gondii infection increased the expression of VEGF mRNA and protein in ARPE-19 cells in parasite burden- and infection time-dependent manner. The proportional increase of VEGF upstream regulators, HIF-1α and HO-1, was also observed. T. gondii induced the activation of host p-AKT, p-ERK1/2, and p-p38 MAPK in ARPE-19 cells in a parasite-burden dependent manner. However, VEGF expression decreased after the pre-treatment with PI3K inhibitors (LY294002 and GDC-0941), ERK1/2 inhibitor (PD098059), and p38 MAPK inhibitor (SB203580), but not JNK inhibitor (SP600125), in a dose-dependent manner. The anti-VEGF agent bevacizumab or VEGF siRNA transfection prominently inhibited the activation of p-AKT and p-ERK1/2, but not p-p38 MAPK and JNK1/2 in T. gondii-infected ARPE-19 cells. Bevacizumab treatment or VEGF siRNA transfection significantly inhibited the proliferation of T. gondii tachyzoites in the host cell, dose-dependently, but not invasion of parasites. VEGF-receptor 2 (VEGF-R2) antagonist, SU5416, attenuated VEGF production and tachyzoite proliferation in T. gondii-infected ARPE-19 cells in a dose-dependent manner. Collectively, T. gondii prominently induces VEGF production in ARPE-19 cells, and VEGF and AKT/ERK1/2 signaling pathways mutually regulate each other in T. gondii-infected ARPE-19 cells, but not p38 MAPK and JNK1/2 signaling pathways. VEGF and VEGF-R2 control the parasite proliferation in T. gondii-infected ARPE-19 cells. From this study, we revealed the putative mechanisms for VEGF induction as well as the existence of positive feedback between VEGF and PI3K/MAPK signaling pathways in T. gondii-infected retinal pigment epithelium.

Subretinal fibrosis has been recognized as a feature of an advanced stage of exudative age-related macular degeneration (AMD) that leads to irreversible loss of vision. This study was aimed at elucidating roles of interlukin-6 (IL-6) in the development of subretinal fibrosis. Immunohistochemistry (IHC) was performed with anti-human IL-6 antibody in surgically excised choroidal neovascular tissues from patients with exudative AMD. The area of subretinal fibrosis was measured in a mouse subretinal fibrosis model with injection of control small interfering RNA(siRNA) or IL-6 siRNA, or isotype control antibody or anti-IL-6 receptor antibody after peritoneal exudative cells (PECs) injection into the vitreous cavity. PECs derived from IL-6+/+ or IL-6-∕- mice were placed into the subretinal space of IL-6+/+ mice. IL-6 was expressed in the stroma and retinal pigment epithelial (RPE) layer in the choroidal neovascular tissues. IL-6 knockdown or blocking of the IL-6 receptor suppressed the formation of subretinal fibroblastic scars. The area of subretinal fibrosis induced by PECs derived from IL-6-∕- mice was less than that induced by PECs from IL-6+/+ mice. The results suggested that IL-6, expressed by activated macrophages, is a crucial mediator that promotes subretinal fibrosis. Targeting IL-6 and the corresponding signaling pathway would be an attractive therapeutic approach not only in choroidal neovascularization, but also in subretinal fibrosis.

Objective To analyse the longitudinal changes in the thickness of the central macula and retinal nerve fibre layer (RNFL) in patients with hypertensive retinopathy (HTNR) using spectral-domain optical coherence tomography (SD-OCT). Methods This was a prospective cohort study. We studied 18 eyes of patients with HTNR of grade IV who had been followed up for more than 1 year, and 36 normal eyes (without any relevant medical history; the control group). Antihypertensive treatment successfully normalized the blood pressure of HTNR patients. The RNFL thickness and that of the central macula of HTNR patients were measured using a Cirrus HD-OCT instrument, and compared with those of the control group. Results At 12 months of follow-up, the mean thickness of the RNFL and central macula was significantly lower in the HTNR group than in the control group (the RNFL was measured first, and then the central macular thickness (CMT): 77.4 ± 9.1 and 233.8 ± 30.8 μm versus 94.1 ± 7.8 and 256.3 ± 28.1 μm, respectively; p

The quality of the scan image is important in peripapillary circulation analysis using optical coherence tomography angiography (OCTA). We aimed to investigate the effects of signal strength (SS) on the peripapillary microvascular density acquired from OCTA. A total of 259 eyes from 259 young healthy subjects were included. Peripapillary OCTA images using 3 × 3 mm angiography scan were acquired from all participants. Subjects were divided into four groups according to the SS: SS 7, SS 8, SS 9, and SS 10. Vessel density (VD) and perfusion density (PD) of the superficial capillary plexus were calculated. VD and PD were compared among the four groups, and linear regression analyses were performed to identify and evaluate the clinical factors associated with average VD. As the SS increased from 7 to 10, the average VD and PD increased; these increases were statistically significant (all, p

Purpose To evaluate changes in peripapillary microvascular parameters in the fellow eyes of patients with unilateral retinal vein occlusion (RVO) using optical coherence tomography angiography (OCTA) and to determine the relationships between peripapillary microvasculature and retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness. Methods Eighty-three patients with unilateral RVO (50 patients with branch RVO and 33 with central RVO) and 83 normal controls were enrolled. OCTA (Cirrus HD-OCT 5000 with AngioPlex) 6 × 6-mm scans centered on the optic disc were acquired. Peripapillary vessel density (VD) and perfusion density (PD) were automatically calculated. Results The average RNFL and GC-IPL thicknesses in the fellow eyes of RVO patients were significantly thinner than in normal controls (93.5 vs. 96.6 μm, P = 0.013 and 81.3 vs. 84.1 μm, P = 0.003, respectively). In the fellow eyes of patients with unilateral RVO, the peripapillary VD of the inner ring, outer ring, and full area (17.47, 18.50, and 17.89, respectively) were significantly lower than those of controls (17.87, 18.87, and 18.27, respectively). The peripapillary PD of the inner ring, outer ring, and full area (0.456, 0.467, and 0.456, respectively) were also significantly lower than those of controls (0.468, 0.476, and 0.466, respectively). RNFL and GC-IPL thicknesses were correlated with both peripapillary VD and PD. Conclusions OCTA revealed that peripapillary microvascular parameters in the fellow eyes of patients with unilateral RVO were decreased, and GC-IPL and RNFL thinning were also observed. The RNFL and GC-IPL thicknesses were positively correlated with both peripapillary VD and PD.

Background Limited data exist on real-world treatment patterns for diabetic macular edema (DME) in Korea. In this study, we investigated DME treatment patterns from 2009 to 2014 and the impact of baseline treatment on healthcare resource utilization and visual acuity (VA) outcomes. Methods A retrospective cohort chart review of DME patients treated at 11 hospital ophthalmology clinics between January 1, 2012 and December 31, 2013 was conducted. We collected data on demographics, healthcare resource utilization (clinic visits, treatment visits, and visits for ocular investigations), distribution of DME treatments, and VA. Results Overall, 522 DME patients (men, 55.2%; mean age, 59 years; mean HbA1c [n = 209], 8.4%) with 842 DME eyes were evaluated. For all treatments, healthcare resource utilization was significantly higher during the first 6 months versus months 7–12, year 2, or year 3 (P ≤ 0.001), but was highest for patients whose first treatment was an anti-vascular endothelial growth factor (VEGF) treatment (visits/quarter; anti-VEGF, 1.9; corticosteroids, 1.7; laser, 1.4). Use of macular laser therapy decreased (44% to 8%), whereas use of anti-VEGF injections increased (44% to 69%) during the study period. However, VA improvement was not commensurate with healthcare resource utilization of anti-VEGF treatment (mean VA gain, 2.7 letters). Conclusion A trend toward increasing use of intravitreal anti-VEGF injections for DME treatment was observed in Korea. However, the frequency of dosing and monitoring was lower in clinical practice versus major clinical trials, which may have led to the less-than-favorable improvements in visual outcomes., Graphical Abstract

Purpose To analyze longitudinal thickness changes in the overall macula, ganglion cell-inner plexiform layer (GC-IPL), and peripapillary retinal nerve fiber layer (pRNFL) using spectral-domain optical coherence tomography in branch retinal artery occlusion (BRAO). Methods A prospective analysis was conducted in patients with BRAO. The thicknesses of the overall macula, GC-IPL, and pRNFL were measured at the initial visit, and at 1, 3, 6, and 12 months. Changes in the occluded areas of the affected and unaffected eyes were analyzed, and the nonoccluded areas were compared. Results In the occluded areas of the affected eyes, the only overall macular thickness was significantly greater when compared with that of unaffected eyes at the initial visit. At 1 month, the thickness of GC-IPL alone in the occluded areas of affected eyes decreased significantly when compared with that of unaffected eyes. The average thicknesses of all parameters in the occluded areas at 3, 6, and 12 months were significantly reduced compared with those of the unaffected eyes. In addition, the thickness of pRNFL in the nonoccluded vertical mirror areas at 6 and 12 months was significantly reduced compared with those of the unaffected eyes. Conclusions In BRAO patients, the occluded areas of affected eyes showed significant changes in the overall macular, GC-IPL, and pRNFL thicknesses when compared with those at initial visits and normal fellow eyes. The time points at which each thickness changed significantly were different.

To investigate the risk factors for breakthrough vitreous hemorrhage (VH) after intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection in age-related macular degeneration (AMD) accompanied by submacular hemorrhage (SMH). We retrospectively reviewed the medical records of patients diagnosed with AMD combined with SMH, and enrolled 31 patients. We formed an age- and sex-matched control group of patients with submacular hemorrhage who did not develop breakthrough VH after intravitreal injection during 6 month follow-up. The mean patient age was 70.8 ± 10.3 years in the breakthrough VH group. Of the 31 patients, 8 were diagnosed with choroidal neovascularization (CNV), 22 with polypoidal choroidal vasculopathy (PCV), and 1 with retinal angiomatous proliferation (RAP). PCV was associated with a significantly higher incidence of VH (odds ratio, 35.01; p = 0.001). The size of the SMH was 22.7 ± 12.4 disc areas (DAs) in the breakthrough VH group and 5.4 ± 6.9 DAs in the control group, and was thus significantly related to the development of VH (p p = 0.014). There was no significant difference between the types of anti-VEGF agents. When taking anticoagulant medications, a SMH of large diameter, and PCV subtype were risk factors for breakthrough VH after anti-VEGF injection.

AimTo analyse the repeatability of vessel density (VD) measurements using optical coherence tomography angiography (OCTA) in patients with retinal diseases.MethodsTwo consecutive VD measurements using OCTA were analysed prospectively in patients with retinal diseases (diabetic macular oedema (DME), retinal vein occlusion (RVO) with macular oedema, epiretinal membrane (ERM), wet age-related macular degeneration (AMD)). The intraclass correlation coefficient (ICC), coefficient of variation (CV) and test-retest SD of VD measurements were assessed, and linear regression analyses were conducted to identify factors related to repeatability.ResultsA total of 134 eyes were analysed involving 20 eyes with DME, 44 eyes with RVO with macular oedema, 50 eyes with ERM and 20 eyes with wet AMD. The mean age was 64.9 years, and the mean best-corrected visual acuity (BCVA) was 0.24. The mean central macular thickness (CMT) was 391.6 µm, and the mean ganglion cell-inner plexiform layer (GC-IPL) thickness was 61.4 µm. In all four diseases, the ICC and CV of the full VD were 0.812 and 6.72%, respectively. Univariate analyses showed that the BCVA (B, 8.553; p=0.031), signal strength (B, −1.688; p=0.050), CMT (B, 0.019; p=0.015) and mean GC-IPL thickness (B, −0.103; p=0.001) were significant factors that affected the repeatability. Multivariate analyses of these factors showed a significant result for the GC-IPL thickness.ConclusionsMeasurements of the VD using OCTA showed relatively good repeatability for various retinal diseases. The BCVA, signal strength, CMT and GC-IPL thickness affected the repeatability, so these factors should be considered when analysing the VD.

In this paper, 4K-UHDTV or 8K-UHDTV and UHD-3DTV that the next generation broadcasting implementation and the possibility of direct receiving environment construction is analyzed on the terrestrial broadcasting. Particularly, we investigated the possibility by analyzing the previous and related works with regard to UHDTV transmission by DVB-T2 that is one of the best commercialized transmission mode. In order that the UHDTV broadcasting succeeds once again after completion of digital terrestrial switch over at the end of 2012, the ultra high resolution image transfer is important. However, the direct, the indoor and ubiquitous receiving environment is important in not only TV but also the personal type multimedia terminal in the sense of UHDTV service penetration. Therefore, in this paper, by using SFN and high error-correcting mode in DVB-T2 standard, the efficient frequency utilization and effective reception environment construction is illustrated. Particularly, SFN network constitution by 2 mutually different frequencies including the VHF bandwidth and UHF band, and etc. is shown. And the method that builds the free wireless receive environment by using SFN low power radio repeater and for home use gap filler is proposed. And the effect and frequency amount required are presented, when UHDTV broadcasting use 10MHz bandwidth.

We investigated the demographic characteristics and risk factors of Korean patients with naIve central or branch retinal vein occlusion (CRVO or BRVO). This study enrolled 41 clinical sites throughout Korea and included 557 consecutive patients with retinal vein occlusion (RVO) from May through November 2010. A total of 557 patients with new-onset RVO participated in this study. Two hundred and three (36.4%) patients were diagnosed with CRVO and 354 (63.6%) patients were diagnosed with BRVO. Comparisons between the two groups showed that the prevalence of diabetes mellitus was significantly higher in CRVO patients and hypertension was significantly higher in BRVO patients (P = 0.001 and 0.002, respectively). Poor baseline visual acuity was significantly associated with female and old age in BRVO patients (P = 0.002 and 0.013, respectively), whereas the wide intraretinal hemorrhage (CRVO, P = 0.029; BRVO, P < 0.001) and the macular ischemia (CRVO, P < 0.001; BRVO, P < 0.001) were associated with both groups. The study results show the clinical features of RVO in Korean patients. Hypertension is strongly associated with BRVO and diabetes mellitus is more strongly associated with CRVO in Korean patients with RVO. As the first nationwide study performed by the Korean Retinal Society, the results of this study can be applied to future studies on RVO.

Purpose We measured the thicknesses of the ganglion cell and inner plexiform layer (GCIPL), the macula, and the retinal nerve fiber layer (RNFL) using spectral-domain optical coherence tomography in patients with idiopathic macula holes to analyze the repeatability of these measurements and compare them with those of the fellow eye. Methods We evaluated 85 patients who visited our retinal clinic. The patients were divided into two groups according to their macular hole size: group A had a size of

Retinitis pigmentosa (RP) is a collection of diseases in which rod photoreceptors die from a variety of mutations. After rods die, the level of tissue oxygen in the outer retina becomes elevated and there is progressive oxidative damage to cones that ultimately triggers apoptosis. In this study, we investigated the hypothesis that NADPH oxidase and/or xanthine oxidase serve as critical intermediaries between increased tissue oxygen and the generation of excessive reactive oxygen species that cause oxidative damage to cones. Apocynin, a blocker of NADPH oxidase, but not allopurinol, a blocker of xanthine oxidase, markedly reduced the superoxide radicals visualized by hydroethidine in the outer retina in the retinal degeneration-1 (rd1+/+) model of RP. Compared to rd1+/+ mice treated with vehicle, those treated with apocynin, but not those treated with allopurinol, had significantly less oxidative damage in the retina measured by ELISA for carbonyl adducts. Apocynin-treated, but not allopurinol-treated, rd1+/+ mice had preservation of cone cell density, increased mRNA levels for m- and s-cone opsin, and increased mean photopic b-wave amplitude. In Q344ter mice, a model of dominant RP in which mutant rhodopsin is expressed, apocynin treatment preserved photopic electroretinogram b-wave amplitude compared to vehicle-treated controls. These data indicate that NADPH oxidase, but not xanthine oxidase, plays a critical role in generation of the oxidative stress that leads to cone cell death in RP and inhibition of NADPH oxidase provides a new treatment strategy.

Oxidative and nitrosative damage are major contributors to cone cell death in retinitis pigmentosa (RP). In this study, we explored the effects of augmenting components of the endogenous antioxidant defense system in models of RP, rd1, and rd10 mice. Unexpectedly, overexpression of superoxide dismutase 1 (SOD1) in rd1 mice increased oxidative damage and accelerated cone cell death. With an elaborate mating scheme, genetically engineered rd10 mice with either inducible expression of SOD2, Catalase, or both in photoreceptor mitochondria were generated. Littermates with the same genetic background that did not have increased expression of SOD2 nor Catalase provided ideal controls. Coexpression of SOD2 and Catalase, but not either alone, significantly reduced oxidative damage in the retinas of postnatal day (P) 50 rd10 mice as measured by protein carbonyl content. Cone density was significantly greater in P50 rd10 mice with coexpression of SOD2 and Catalase together than rd10 mice that expressed SOD2 or Catalase alone, or expressed neither. Coexpression of SOD2 and Catalase in rd10 mice did not slow rod cell death. These data support the concept of bolstering the endogenous antioxidant defense system as a gene-based treatment strategy for RP, and also indicate that coexpression of multiple components may be needed.

Purpose We investigated longitudinal changes in retinal nerve fiber layer (RNFL) thickness following vitrectomy for epiretinal membrane (ERM). Methods Thirty-one patients who underwent pars plana vitrectomy with internal limiting membrane (ILM) peeling for ERM were included. Average thickness and four quadrants of RNFL thicknesses were determined before and at 1, 3, 6, and 12 months after surgery by spectral-domain optical coherence tomography (SD-OCT). As macular lesions could affect RNFL thickness, we evaluated changes in RNFL thickness by dividing the RNFL into 12 o'clock hourly positions, defining pathologic area adjacent to the lesion and nonpathologic area. Results Retinal nerve fiber layer thickness of the affected eyes increased at 1 month after vitrectomy and later decreased compared to baseline values. Temporal quadrant RNFL thickness was statistically significantly thicker in affected eyes at baseline and at 1 month after surgery and thinner after 12 months than fellow eyes. Retinal nerve fiber layer thickness in pathologic area decreased after surgery, and the RNFL was statistically significantly thinner at 3, 6, and 12 months postoperatively, compared to the baseline thickness. The RNFL thickness of pathologic area of affected eyes compared to fellow eyes was thicker both at baseline and 1 month after surgery but thinner at 12 months compared to baseline values. Conclusions Postoperative RNFL thickness after vitrectomy combined with ERM removal tended to decrease postoperatively. Retinal nerve fiber layer thicknesses in temporal pathologic area were significantly reduced at 3, 6, and 12 months postoperatively compared to baseline values, whereas RNFL thicknesses in nasal nonpathologic area exhibited no significant postoperative changes. We found that ERM itself and the removal procedure resulted in decreased RNFL thickness.

인제대학교 의과대학 해운대백병원 안과학교실, 경북대학교 의학전문대학원 안과학교실, 충남대학교 의학전문대학원 안과학교실, 순천향대학교 의과대학 부천병원 안과학교실, 경희대학교 의과대학 안과학교실, 장우혁안과, 고려대학교 의과대학 안과학교실, 부산대학교 의학전문대학원 안과학교실 Department of Ophthalmology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea Department of Ophthalmology, Kyungpook National University School of Medicine, Daegu, Korea Department of Ophthalmology, Chungnam National University School of Medicine, Daejeon, Korea Department of Ophthalmology, Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea Department of Ophthalmology, Kyung Hee University School of Medicine, Seoul, Korea Chang’s Retina Center, Daegu, Korea Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea Department of Ophthalmology, Pusan National University School of Medicine, Yangsan, Korea

Purpose: To evaluate the significance of axial length, which is a known risk factor of retinal vein occlusion, we measured the axial lengthby using contact A-scan sonography and partial interferometry and compared the two values. Methods: This study included 19 patients complaining of visual symptoms and who were diagnosed with unilateral retinal vein occlusion (RVO) with macular edema (ME). Affected eyes were classified as the study group, and healthy fellow eyes were classified as the control group. We measured the central macular thickness (CMT) and axial length (AL) of the affected and fellow eyes and compared them. CMT was measured by optical coherence tomography (Stratus OCT, Carl Zeiss, Jena, Germany), and AL was measured by interferometry (IOL Master, Carl Zeiss, Jena, Germany). Results: In RVO patients, CMT was significantly different between affected eyes (485.7 ± 111.3 μm) and fellow eyes (197.8 ± 29.7 μm; p < 0.001). Axial length measured by A-scan sonography was 23.06 ± 0.86 mm in the affected eyes and 23.28 ± 0.93 mm in the healthy eyes, which was statistically different (p < 0.001). However, using partial interferometry, the AL was 23.35 ± 0.87 mm in the affected eyes and 23.38 ± 0.95 mm in the healthy eyes. No significant difference was found. Conclusions: We confirmed that short AL, which was once thought to be a risk factor of RVO, results from the properties of the instruments used for measurement. Moreover, we verified that partial interferometry is more accurate for measurement of AL than A-scan sonography when retinal vein occlusion is associated with ME. J Korean Ophthalmol Soc 2016;57(8):1228-1232

Purpose: To determine the effects of intravitreal anti-vascular endothelial growth factor (VEGF) on thickness of the retinal nerve fiber layer (RNFL) in patients with age-related macular degeneration. Methods: Twenty eyes of 20 patients diagnosed with age-related macular degeneration who underwent intravitreal anti-VEGF injection were studied. Postinjection RNFL thickness was measured using optical coherence tomography. Average thickness, four-quadrant RNFL thicknesses, and intraocular pressure (IOP) in affected eyes were measured before and 6 and 12 months after anti-VEGF injection for comparison. RNFL thickness and IOP in affected and normal fellow eyes were also compared. Given that macular lesions can affect RNFL thickness, the changes in thickness were evaluated by dividing the 12 clock-hour RNFL into the pathologic areas adjacent to the lesion and the non-pathologic area. Results: The mean clock-hour segment in the pathologic area was 4.8 hours. A significantly thicker RNFL was exhibited in temporal quadrants and pathologic areas (p = 0.043 and 0.048, respectively) in affected eyes before injection compared to the baseline RNFL thickness in normal eyes. No significant differences were found in RNFL thickness or IOP between affected and normal eyes after injection. The changes over time in the temporal and pathologic areas were statistically significant at 6 and 12 months after injection compared to baseline data (p < 0.05). No significant differences were displayed in RNFL thickness in the other three quadrants or in non-pathologic areas in either affected or normal eyes. Sequential changes in RNFL thickness in affected eyes were not significant. Conclusions: Repeat intravitreal anti-VEGF treatment did not have a significant effect on RNFL thickness. RNFL thickness significantly decreased with time in the pathologic areas and in the temporal segment adjacent to exudative macular lesions. The reduction in RNFL thickness was most likely associated with changes in the macular lesion rather than with anti-VEGF injection.

In retinitis pigmentosa (RP), various mutations cause rod photoreceptor cell death leading to increased oxygen levels in the outer retina, progressive oxidative damage to cones, and gradual loss of cone cell function. We have been exploring the potential of overexpressing components of the endogenous antioxidant defense system to preserve cone cell function in rd10(+/+) mice, a model of RP. rd10(+/+) mice deficient in superoxide dismutase 1 (SOD1) showed increased levels of superoxide radicals and carbonyl adducts (a marker of oxidative damage) in the retina and more rapid loss of cone function than rd10(+/+) mice with normal levels of SOD1. This suggests that SOD1 is an important component of the antioxidant defense system of cones, but increased expression of SOD1 in rd10(+/+) mice increased oxidative damage and accelerated the loss of cone function. Coexpression of SOD1 with glutathione peroxidase 4 (Gpx4), which like SOD1 is localized in the cytoplasm, but not with catalase targeted to the mitochondria, reduced oxidative damage in the retina and significantly slowed the loss of cone cell function in rd10(+/+) mice. Gene transfer resulting in increased expression of SOD2, but not coexpression of SOD2 and mitochondrial Gpx4, resulted in high levels of H(2)O(2) in the retina. These data suggest that to provide benefit in RP, overexpression of an SOD must be combined with expression of a peroxide-detoxifying enzyme in the same cellular compartment.

Oxidative damage contributes to cone cell death in retinitis pigmentosa and death of rods, cones, and retinal pigmented epithelial (RPE) cells in age-related macular degeneration. In this study, we explored the strategy of overexpressing components of the endogenous antioxidant defense system to combat oxidative damage in RPE cells and retina. In transfected cultured RPE cells with increased expression of superoxide dismutase1 (SOD1) or SOD2, there was increased constitutive and stress-induced oxidative damage measured by the level of carbonyl adducts on proteins. In contrast, RPE cells with increased expression of glutathione peroxidase 1 (Gpx1) or Gpx4 did not show an increase in constitutive oxidative damage. An increase in Gpx4, and to a lesser extent Gpx1, reduced oxidative stress-induced RPE cell damage. Co-expression of Gpx4 with SOD1 or 2 partially reversed the deleterious effects of the SODs. Transgenic mice with inducible expression of Gpx4 in photoreceptors were generated, and in three models of oxidative damage-induced retinal degeneration, increased expression of Gpx4 provided strong protection of retinal structure and function. These data suggest that gene therapy approaches to augment the activity of Gpx4 in the retina and RPE should be considered in patients with retinitis pigmentosa or age-related macular degeneration. Antioxid. Redox Signal. 11, 715–724.

Recently, the proinflammatory cytokine IL-18 has been shown to have a role in angiogenesis. This study aimed to elucidate its role in abnormal neovascularization (NV) in an oxygen-induced retinopathy (OIR) mouse model of the retinopathy seen in human premature newborns. IL-18 was constitutively expressed in the retina in C57BL/6 mice, but expression transiently dropped on Day 17 after birth in mice exposed to 75% oxygen for 5 days between Days 7 and 12. Coincident with the IL-18 reduction in oxygen-treated mice, vascular endothelial growth factor was expressed in the retina, and OIR developed. By Day 24, NV in the retina had regressed to normal levels. By contrast, IL-18 knockout mice, exposed to elevated oxygen concentrations, developed more severe OIR on Day 17, and it is important that this persisted until Day 24. This suggested that IL-18 negatively regulated retinal NV. To investigate this further, we administrated recombinant IL-18 to C57BL/6 mice during the development of OIR but found no significant inhibition of retinopathy. However, when IL-18-binding protein was administered during the OIR recovery phase to neutralize endogenous IL-18, OIR was still apparent on Day 24. We therefore concluded that IL-18 regulates pathogenic retinal NV by promoting its regression rather than inhibiting its development. This suggests some useful, new approaches to treating retinopathy in humans.

PURPOSE To investigate the relationship between spectral-domain optical coherence tomography (SD-OCT) measurements and retinal nonperfusion in patients with branch retinal vein occlusion (BRVO). METHODS Forty-one patients with BRVO who had recovered from macular edema and had been followed for ≥2 years were included via retrospective, medical record review. Patients were divided into two groups that included 20 nonischemic eyes and 21 ischemic eyes, and 41 fellow control eyes were also included. Using SD-OCT, we measured the thickness of the macular layer, ganglion cell-inner plexiform layer (GC-IPL), and retinal nerve fiber layer (RNFL) in both the BRVO-affected and fellow eyes. The eyes were subdivided into affected and nonaffected areas of BRVO. Each area of normal fellow eyes and BRVO eyes was compared between the two groups. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic ability of the OCT measurements for ischemic BRVO. RESULTS The macula, the GC-IPL, and RNFL in the BRVO-affected area were significantly thinner compared to those of the fellow eyes in the two groups. The thickness of macula, GC-IPL, and RNFL in the ischemic BRVO group was also significantly less than in the nonischemic BRVO group. In the ROC curve analysis of a total of 82 eyes, the area under the ROC curve of the RNFL on the ischemic BRVO was the highest at 0.906, followed by the GC-IPL (0.824) and the macula (0.768). CONCLUSIONS The thickness of macula, GC-IPL, and RNFL in the ischemic BRVO group was significantly reduced compared to the nonischemic BRVO group, especially in the RNFL.

PURPOSE To analyze the repeatability of measurements of the thicknesses of the macula, retinal nerve fiber layer (RNFL), and ganglion cell inner plexiform layer (GCIPL) using spectral-domain optical coherence tomography (SD-OCT) in the epiretinal membrane (ERM). METHODS The prospective study analyzed patients who visited our retinal clinic from June 2013 to January 2014. An experienced examiner measured the thicknesses twice using macular cube 512 × 128 and optic disc cube 200 × 200 scans. The repeatability of the thicknesses of the macula, RNFL, and GCIPL were compared using the intraclass correlation coefficient (ICC) of two groups based on the central macular thickness (group A, ≤ 450 μm; group B, > 450 μm). RESULTS A total of 88 patients were analyzed. The average thicknesses of the central macula, RNFL, and GCIPL were 256.5, 96.6, and 84.4 μm, respectively, in the normal fellow eye and 412.3, 94.6, and 56.7 μm in the affected eye. The ICCs of the central macula, RNFL, and GCIPL were 0.995, 0.994, and 0.996, respectively, for the normal fellow eye and 0.991, 0.973, and 0.881 for the affected eye. The average thicknesses of the central macula, RNFL, and GCIPL in group A were 360.9, 93.5, and 63.4 μm, respectively, and the ICCs were 0.997, 0.987, and 0.995. The thicknesses in group B were 489.5, 96.2, and 46.6 μm, respectively, and the ICCs were 0.910, 0.942, and 0.603, significantly lower repeatability compared with group A (P < 0.05). CONCLUSIONS The macular contour change with the ERM results in low repeatability and tendency to be measured thinner in GCIPL thickness using SD-OCT. This can be explained by the unstable gaze of the patient due to decreased visual acuity and autosegmentation error following changes in the macula.

Purpose: To report a case of Pseudomonas aeruginosa infection after scleral buckling for retinal detachment. Case summary: A 68-year-old male presented with a 2-day history of pain in the right eye. The patient had a history of scleral buckling for retinal detachment 10 years earlier and excisional biopsy for conjunctival mass 1 month previously. Biopsy revealed chronic inflammation and granulation tissue formation. Slit-lamp examinations revealed superior conjunctival injection, edema and exposed suture knot. Fundus examination revealed exudative retinal detachment and choroidal detachment. The conjunctival lesion did not improve although the patient was treated with moxifloxacin. After 4 days, bacterial and fungal cultures were performed because the conjunctiva presented with purulent discharge 4 days after treatment. The scleral buckle and suture knot were removed. The cultures revealed growth of Pseudomonas aeruginosa. According to antibiotic sensitivity test results, the authors treated the patient with ceftazidime. The conjunctival lesion, choroidal detachment and exudative retinal detachment were improved. Conclusions: In patients with conjunctival injection, edema, purulent discharge and ocular pain after scleral buckling, presence of infection should be suspected. If scleral buckle infection is suspected, bacterial culture, antibiotics treatment and scleral buckle removal should be considered. J Korean Ophthalmol Soc 2015;56(10):1646-1649

Purpose: To evaluate the visual outcome of combined phacoemulsification, intraocular lens implantation, and vitrectomy for macula-sparing rhegmatogenous retinal detachment. Methods: The results of combined vitrectomy with cataract extraction were retrospectively analyzed in patients with preexisting cataracts and new-onset rhegmatogenous retinal detachment. To qualify, patients must also have had macular sparing in a region 6,000 ㎛ in diameter on optical coherence tomography. The anatomical success rate, visual outcomes, and postoperative complications relating to visual acuity were evaluated. Results: In 56 patients followed postoperatively for more than 12 months, the initial and final surgical success rate was 96.4% and 100%, respectively. The mean preoperative logarithm of the minimum angle of resolution visual acuity was 0.05 and decreased to 0.11 postoperatively (p < 0.001). Of the 56 patients, 20 (35.7%) had worse visual acuity postoperatively, compared with preoperatively (0.06 vs. 0.27, p < 0.001); these cases were comprised of six patients with epiretinal membranes, 12 patients with a posterior capsule opacity, and two patients with cystoid macular edema. In the remaining 36 patients, there were no significant differences in visual acuity preoperatively and postoperatively (0.04 vs. 0.03, p = 0.324). Conclusions: In patients with cataracts who develop macula-sparing rhegmatogenous retinal detachment and whose visual prognosis is excellent assuming the retina can be reattached successfully, combined phacoemulsification, intraocular lens implantation, and vitrectomy might be an effective treatment. However, the visual prognosis is significantly affected by postoperative complications such as an epiretinal membranes, posterior capsule opacity, and cystoid macular edema. Therefore, further studies should examine methods to prevent these postoperative complications.

The cause of central serous chorioretinopathy (CSC) is mostly idiopathic. Other cause such as stressful event or use of corticosteroid has been associated with severe form of CSC. Atypical presentation of CSC has widespread degeneration of retinal pigment epithelium (RPE) or bullous retinal detachment. In this report, we describe a case of bilateral CSC with RPE tear after epidural steroid injection.