Isolation and Evaluation of the Antagonistic Activity of Cnidium officinale Rhizosphere Bacteria against Phytopathogenic fungi (Fusarium solani).

Cnidium officinale Makino, a perennial crop in the Umbeliperae family, is one of Korea's representative forest medicinal plants. However, the growing area of C. officinale has been reduced by plant disease and soil sickness caused by fusarium wilt. This study isolated rhizosphere bacteria from C. officinale, and their antagonistic activity was evaluated against Fusarium solani. Particularly, four isolated strains, namely, PT1, ST7, ST8, and SP4, showed a significant antagonistic activity against F. solani. An in planta test showed that the mortality rates of shoots were significantly low in the PT1-inoculated group. The fresh and dry weights of the inoculated plants were also higher than that of the other groups. The 16S rRNA gene sequencing identified the strain PT1 as Leclercia adecarboxylata, and downstream studies confirmed the production of antagonism-related enzymes such as siderophore and N-acetyl-ß-glucosaminidase. The phosphorous solubilizing ability and secretion of related enzymes were also analyzed. The results showed that PT1 strain could be utilized as promising plant growth-promoting rhizobacteria (PGPR) and biocontrol agents (BCAs).

Development of a deep learning system to detect glaucoma using macular vertical optical coherence tomography scans of myopic eyes.

Myopia is one of the risk factors for glaucoma, making accurate diagnosis of glaucoma in myopic eyes particularly important. However, diagnosis of glaucoma in myopic eyes is challenging due to the frequent associations of distorted optic disc and distorted parapapillary and macular structures. Macular vertical scan has been suggested as a useful tool to detect glaucomatous retinal nerve fiber layer loss even in highly myopic eyes. The present study was performed to develop and validate a deep learning (DL) system to detect glaucoma in myopic eyes using macular vertical optical coherence tomography (OCT) scans and compare its diagnostic power with that of circumpapillary OCT scans. The study included a training set of 1416 eyes, a validation set of 471 eyes, a test set of 471 eyes, and an external test set of 249 eyes. The ability to diagnose glaucoma in eyes with large myopic parapapillary atrophy was greater with the vertical than the circumpapillary OCT scans, with areas under the receiver operating characteristic curves of 0.976 and 0.914, respectively. These findings suggest that DL artificial intelligence based on macular vertical scans may be a promising tool for diagnosis of glaucoma in myopic eyes.

Retinal Nerve Fiber Layer Defect Associated With Progressive Myopia.

PURPOSE: The purpose of this study was to report a case with bilateral paravascular inner retinal defects (PIRDs) enlarging with progressive myopia, which had different structural characteristics from the glaucomatous retinal nerve fiber layer (RNFL) defect. PATIENTS AND METHODS: A 10-year-old girl with high myopia was referred to a glaucoma clinic for evaluation of RNFL defects shown in color fundus photographs. Fundus photographs and optical coherence tomography examinations were serially reviewed to examine the changes in the RNFL. RESULTS: Cleavage of inner retinal layers involving the layers deeper than the RNFL was identified in optical coherence tomography, which appeared and enlarged in both eyes along with progressive myopia and axial elongation during the follow-up period of 8 years. CONCLUSIONS: PIRD developed and enlarged with progressive myopia and axial elongation in childhood. It should be differentiated from the widening of RNFL defect shown with glaucoma progression.

Impact of peripapillary retinoschisis on visual field test results in glaucomatous eyes.

BACKGROUND/AIMS: To investigate the influence of peripapillary retinoschisis (PRS) on visual field (VF) test results in patients with primary open angle glaucoma (POAG). METHODS: Thirty eyes of 30 patients with POAG who had PRS at least once were included. All eyes were followed-up for a minimum 5 years at 4-6-month intervals. The occurrence of PRS was determined by circumpapillary retinal nerve fibre layer B-scan on spectral-domain optical coherence tomography (OCT). The global and regional VF deviations just prior to and immediately after PRS formation, or just prior to and immediately after PRS resolution (if it occurred), were compared. VF sensitivity within the region corresponding to the OCT sector where PRS occurred was determined according to the Garway-Heath map. RESULTS: Global MD (p=0.345) and regional VF deviations (p=0.255) did not differ significantly between immediately after and just prior to PRS formation. Global MD (p=0.846) and regional VF deviations (p=0.758) were also similar between immediately after and just prior to PRS resolution. CONCLUSION: PRS has no short-term effect on the VF sensitivity. Therefore, VF test can still be useful for evaluating glaucomatous damage even in the presence of PRS compared with OCT.

Association of the presence of allergic disease with subsequent risk of liver cancer in a nationwide retrospective cohort among Koreans.

A number of studies have proposed an inverse association between allergic diseases and risk of cancer, but only a few studies have specifically investigated the risk of primary liver cancer, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). The aim of this study was to evaluate the association of allergic diseases with risk of primary liver cancer. We conducted a retrospective cohort study of the Korean National Health Insurance Service database consisted of 405,512 Korean adults ages 40 and above who underwent health screening before January 1st, 2005. All participants were followed up until the date of liver cancer, death, or December 31st, 2013, whichever happened earliest. Those who died before the index date or had pre-diagnosed cancer were excluded from the analyses. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for risk of primary liver cancer according to the presence of allergic diseases, including atopic dermatitis, asthma, and allergic rhinitis. The aHR (95% CI) for overall liver cancer among allergic patients was 0.77 (0.68-0.87) compared to those without allergic disease. Allergic patients had significantly reduced risk of HCC (aHR, 0.72; 95% CI 0.62-0.85) but not ICC (aHR, 0.95; 95% CI 0.73-1.22). The presence of allergies was associated with significantly lower risk of liver cancer among patients whose systolic blood pressure is lower than 140 mmHg (aHR, 0.64; 95% CI 0.62-0.78 for overall liver cancer; aHR, 0.64; 95% CI 0.52-0.78 for HCC) but this effect was not observed among patients whose systolic blood pressure is higher than 140 mmHg (aHR, 0.91; 95% CI 0.71-1.18 for overall liver cancer; aHR, 0.91; 95% CI 0.71-1.18 for HCC) The aHR (95% CI) for overall liver cancer of allergic patients with and without chronic hepatitis virus infection were 0.60 (95% CI 0.44-0.81) and 0.77 (95% CI 0.64-0.93), respectively. In addition, allergic patients without cirrhosis showed significantly lower risk of overall liver cancer (aHR, 0.73; 95% CI 0.63-0.83). Patients with allergic diseases have significantly lower risk of primary liver cancer compared to those without allergic diseases, which supports the rationale for immunotherapy as an effective treatment for liver cancer.

Difference in topographic morphology of optic nerve head and neuroretinal rim between normal tension glaucoma and central retinal artery occlusion.

Although central retinal artery occlusion (CRAO) has its own defining pathomechanism and clinical characteristics, morphologic feature of the optic nerve head (ONH) during its later stage is not diagnostic, which makes it difficult to differentiate CRAO from other optic neuropathies. This cross-sectional study was performed to investigate the differences in the topographic morphology of the ONH in eyes with normal-tension glaucoma (NTG) and CRAO. Thirty-one eyes with NTG; 31 eyes with CRAO; and 31 healthy fellow eyes of the subjects with CRAO were included. ONH morphology was evaluated by measuring horizontal rim width (HRW), minimal rim width in the selected horizontal image (MRW), and lamina cribrosa curvature index (LCCI) in horizontal B-scan images obtained using enhanced depth-imaging optical coherence tomography. HRW was smaller and LCCI was larger in NTG eyes than in both CRAO and healthy fellow eyes (both P < 0.001), while both were comparable between CRAO and healthy fellow eyes. MRW differed significantly among the three groups, being smallest in NTG eyes followed by CRAO and healthy fellow eyes (P < 0.001). NTG and CRAO eyes with a similar degree of RNFL loss differed in ONH morphology, indicating that mechanisms of ONH damage differ between these two conditions.

Association between corneal refractive surgery and the prevalence of glaucoma: Korea National Health and Nutrition Examination Survey 2010-2012.

AIM: To determine the relationship between corneal refractive surgery and the prevalence of glaucoma in the Korean population. METHODS: Data were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES), a population-based cross-sectional study using a complex, stratified, multistage, probability-cluster survey. This study included 604 eyes that had undergone myopic corneal refractive surgery, and 3389 control eyes without a history of any ocular surgery and having a spherical equivalent (SE) <-3.00 D, obtained from the KNHANES database for the years 2010-2012. Glaucoma diagnosis was based on the International Society of Geographical and Epidemiological Ophthalmology criteria. The association between a history of corneal refractive surgery and the prevalence of glaucoma was analysed using logistic regression analysis, after adjusting for potential confounding factors. RESULTS: Glaucoma prevalence did not differ between eyes that had and had not undergone corneal refractive surgery (p=0.675). After adjusting for age, sex, SE, and intraocular pressure, multivariate logistic regression analysis found that corneal refractive surgery was significantly associated with an increased risk of glaucoma (OR 9.14, p=0.002; 95% CI 2.22 to 37.69). Subgroup analysis that only included control eyes with a refraction cut-off <-3.70 D found that corneal refractive surgery was not significantly associated with glaucoma. CONCLUSIONS: History of corneal refractive surgery was associated with a higher prevalence of glaucoma in the Korean population. However, this association was not observed in eyes with a higher degree of myopia.

Comparison of Optic Nerve Head Microvasculature Between Normal-Tension Glaucoma and Nonarteritic Anterior Ischemic Optic Neuropathy.

Purpose: To compare the microvasculature of the optic nerve head (ONH) and peripapillary tissues in eyes with normal-tension glaucoma (NTG) and nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA). Methods: Thirty-eight eyes with treatment-naïve NTG, 38 eyes with NAION matched for retinal nerve fiber layer (RNFL) thickness in each superior and inferior quadrant, and 38 healthy eyes matched by age were included. ONH and peripapillary retinal microvasculature was evaluated in en face images obtained using OCTA. Vessel density (VD) was calculated as the percent area occupied by vessels in the measured region in each layer segmented into the prelaminar tissue (PLT), lamina cribrosa (LC), and peripapillary retina (PR). Results: VDs in the PLT and LC were lower in NTG eyes than in both NAION and healthy eyes (P ≤ 0.008), and did not differ between the NAION and healthy eyes. VDs in the PR did not differ between the NTG and NAION eyes. In intersectoral comparisons, VDs in the PLT (P = 0.030) and LC (P = 0.028) were lower in the affected than in the unaffected sector of eyes with NTG, but the differences did not occur in eyes with NAION. VD in the PR was lower in the affected than in the unaffected sector in both NTG and NAION eyes (both P < 0.001). Conclusions: Despite similar degrees of RNFL loss and VD decreases in the PR, VDs in the ONH differed between eyes with NTG and NAION, indicating different mechanisms of vascular impairment and ONH damage in each condition.

Progressive retinal nerve fibre layer thinning and choroidal microvasculature dropout at the location of disc haemorrhage in glaucoma.

BACKGROUND/AIMS: To investigate whether parapapillary choroidal microvasculature dropout (MvD) is associated with progressive retinal nerve fibre layer (RNFL) thinning in eyes with primary open-angle glaucoma (POAG) and disc haemorrhage (DH). METHODS: Parapapillary microvasculature was evaluated by swept-source optical coherence tomography (OCT) angiography (OCTA) in 50 eyes with POAG and DH, 1 year before, at the time of and 1 year after the detection of DH. MvD was defined as an area in the parapapillary deep layer of focal sectoral dropout with no visible microvascular network. Progressive changes in OCT RNFL thickness were compared in groups of eyes with and without MvD. RESULTS: Cumulative prevalence of MvD was 76.0% (38 eyes) at 1 year after detection of DH. All MvDs were detected in the same sectoral locations as DH. In eyes with MvD, global RNFL thickness and sectoral RNFL thickness at the location of DH were significantly reduced, both from 1 year before to the time of DH detection (both p<0.001) and from DH detection to 1 year later (both p<0.001). In eyes without MvD, however, the reductions in global (p=0.011) and sectoral (p=0.007) RNFL thickness were significant only from DH detection to 1 year later. CONCLUSION: In eyes with POAG, RNFL thinning was spatially consistent and progressive at the location of MvD accompanied by subsequent DH and continued to progress after the occurrence of DH. When DH was not accompanied by MvD, progressive RNFL thinning was more likely to occur after the detection of DH.

Influence of Choroidal Microvasculature Dropout on the Rate of Glaucomatous Progression: A Prospective Study.

PURPOSE: To determine the prognostic significance of choroidal microvasculature dropout (MvD) to predict the future rate of progressive retinal nerve fiber layer (RNFL) thinning in eyes with primary open-angle glaucoma (POAG). DESIGN: Prospective, longitudinal case series. PARTICIPANTS: This study enrolled 101 eyes of 101 patients with POAG who underwent OCT angiography (OCTA) imaging of the optic nerve head at baseline and were followed up for at least 2 years thereafter, during which RNFL thickness was measured by serial spectral-domain OCT. METHODS: The peripapillary microvasculature was evaluated by examining en face OCTA images. Choroidal MvD was defined as a focal sectoral capillary dropout with no visible microvascular network in the choroidal layer. The rate of RNFL thinning was determined by linear regression of serial OCT RNFL thickness measurements. MAIN OUTCOME MEASURES: Influence of the presence of an MvD on the rate of subsequent RNFL thinning. RESULTS: Microvasculature dropout was identified in 48 eyes (47.5%). The rate of global RNFL thinning was significantly faster in eyes with MvD than eyes without MvD (-1.6±0.8 vs. -1.2±0.9 µm/year, P = 0.018). Eyes with MvD in the inferior hemisphere (n = 41) showed a faster rate of inferior RNFL thinning than eyes without MvD (P = 0.036). Eyes with MvD in both the superior and inferior hemispheres (n = 5) showed faster rates of superior (P = 0.027) and inferior (P = 0.016) RNFL thinning than eyes without MvD. Multivariate regression analysis showed that MvD at baseline (P = 0.003) and the presence of disc hemorrhage during follow-up (P = 0.001) were independently associated with a faster rate of global RNFL thinning. CONCLUSIONS: Microvasculature dropout was an independent predictor of a faster rate of progressive RNFL thinning in patients with POAG. Microvasculature dropout location was topographically associated with the location of faster RNFL thinning.

Glaucoma-like Parapapillary Choroidal Microvasculature Dropout in Patients with Compressive Optic Neuropathy.

PURPOSE: To characterize peripapillary choroidal microvasculature dropout (MvD) in patients with compressive optic neuropathy (CON) as compared with those with open-angle glaucoma (OAG) using OCT angiography (OCTA). DESIGN: Cross-sectional, observational study. PARTICIPANTS: Eighty-eight eyes of 44 patients with CON; 88 eyes of 88 patients with OAG matched by age, spherical error, and OCT-determined retinal nerve fiber layer thickness (RNFLT); and 88 eyes of 44 control participants matched by age and spherical error. METHODS: Peripapillary microvasculature was evaluated, and peripapillary vessel density was measured in en face images segmented into inner-retinal and choroidal layers using swept-source OCTA. An MvD was defined as a focal sectoral capillary dropout with no visible microvascular network in the choroidal layer. MAIN OUTCOME MEASURES: Comparative characteristics of MvD in eyes with CON and OAG. RESULTS: Microvasculature dropout was observed in 30 eyes (34.1%) of 22 patients (50.0%) with CON, and in 48 eyes of 48 patients (54.5%) with OAG (P = 0.011). All MvDs in the CON group were located in the temporal parapapillary sector, whereas MvDs in the OAG group were located in the temporal-inferior (n = 36) and temporal-superior (n = 4) sectors. At their locations, MvDs in the CON group were accompanied by significant reductions in retinal vessel density and RNFLT, but this was not observed in the OAG group. The presence of MvD was associated significantly with female gender (P = 0.020) and thinner global retinal nerve fiber layer (P = 0.006) in the CON group, but not in the OAG group. CONCLUSIONS: OCT angiography of the peripapillary area showed retinal and choroidal microvasculature impairment in patients with both CON and OAG. However, the features and associated characteristics of MvD differed between these groups, suggesting that the pathogenesis of peripapillary microvascular impairment may be diverse.

Comparison of Lamina Cribrosa Morphology in Normal Tension Glaucoma and Autosomal-Dominant Optic Atrophy.

Purpose: To compare lamina cribrosa (LC) morphology in patients with normal tension glaucoma (NTG) and autosomal-dominant optic atrophy (ADOA). Methods: This cross-sectional study matched 24 patients diagnosed with ADOA (24 eyes) by age and retinal nerve fiber layer thickness with 48 patients diagnosed with NTG (48 eyes) by age with 48 healthy controls (48 eyes). Optic nerve heads were scanned by enhanced-depth imaging (EDI) optical coherence tomography (OCT). The LC curvature index (LCCI) and LC depth (LCD) on B-scan images obtained using EDI-OCT were measured at seven locations spaced equidistantly across the vertical optic disc diameter and compared among the NTG, ADOA, and control groups. Results: Mean LCCI and LCD were significantly greater in NTG than in ADOA and healthy eyes (P < 0.001 each) but did not differ significantly in ADOA and healthy eyes. Conclusions: NTG eyes have a more posteriorly curved and deeper LC than ADOA and healthy eyes. This finding provides insight into the role of LC morphology in NTG and provides a clinical clue to distinguish between NTG and ADOA.

Comparison of Lamina Cribrosa Morphology in Eyes with Ocular Hypertension and Normal-Tension Glaucoma.

Purpose: To characterize differences in the lamina cribrosa (LC) morphology between healthy, ocular hypertension (OHT), and naive normal-tension glaucoma (NTG) eyes. Methods: Each group consisted of 80 eyes of 80 participants who were matched for age, sex, and axial length. The participants underwent enhanced-depth-imaging volume scanning of the optic nerve head using spectral-domain optical coherence tomography. The lamina cribrosa curvature index (LCCI) and lamina cribrosa thickness (LCT) were measured in horizontal B-scan images spaced equidistantly across the vertical diameter of the optic disc. Results: The LCCIs in all seven planes were smaller in both OHT and healthy eyes than in NTG eyes (all P < 0.001), and did not differ significantly between the OHT and healthy eyes. The LCTs in all three planes were greatest in OHT eyes followed by healthy and then NTG eyes (all P < 0.001). Overall, the larger LCCI was associated with smaller LCT (P < 0.001). Conclusions: The LC was thin and steeply curved in NTG eyes than in healthy and OHT eyes. In OHT eyes, the LC was thick, and its curvature was comparable to healthy eyes. Longitudinal studies are required to examine whether the straight and thickened LCs in OHT eyes precede the onset of OHT or are a protective response to elevated intraocular pressure.

Relationship between lamina cribrosa curvature and the microvasculature in treatment-naïve eyes.

BACKGROUND/AIMS: To investigate the relationship between the lamina cribrosa (LC) curvature and the microvasculature within the LC in treatment-naïve eyes with normal-tension glaucoma (NTG) and in healthy eyes. METHODS: Forty-one eyes with treatment-naïve NTG and 41 age and sex-matched healthy control eyes were included. The optic nerve head (ONH) area was scanned using spectral-domain optical coherence tomography (OCT) to examine the LC curvature quantified as the LC curvature index (LCCI). OCT angiography of the ONH area was performed to determine the LC vessel density (LCVD) in the en face images obtained from the layer segmented at the level of the LC. The LCVD was calculated as the percentage area occupied by vessels within the measured region. RESULTS: The LCCI was larger (9.53±1.33 vs 6.55±1.02, p<0.001) and LCVD was smaller (28.0%±6.1% vs 35.2±6.3%, p<0.001) in NTG eyes than in healthy eyes. There were overall significant associations of a smaller retinal nerve fibre layer (RNFL) thickness (p<0.001), a smaller visual field mean deviation (MD) (p=0.003) and a larger LCCI (p≤0.004) with a smaller LCVD. In NTG group, the LCVD was positively associated with the RNFL thickness (p=0.012) and visual field MD (p=0.023), and negatively associated with the axial length (p≤0.013) and LCCI (p≤0.007). In healthy group, a smaller RNFL thickness (p=0.023) was associated with a smaller LCVD. CONCLUSION: A larger LCCI was significantly associated with a smaller LCVD in treatment-naïve NTG eyes but not in healthy eyes, indicating that mechanical strain potentially influences the perfusion within the LC in eyes with NTG.

Factors Associated with the Prognosis after Operation in Children with Recurrent Intermittent Exotropia.

BACKGROUND: To describe factors affecting the prognosis after operation for recurrent intermittent exotropia (X[T]) in children. METHODS: Clinical records of 50 patients who underwent operation for recurrent X(T) by a single surgeon were reviewed. The age at diagnosis of X(T), and first and second operations, deviation angle at distance and near, surgical method, concurrent vertical strabismus, stereoacuity, and Worth's Four Dot (W4D) examination before reoperation were analyzed, along with the postoperative deviation angle. A successful surgical outcome was defined as orthophoria, esodeviation ≤ 5 prism diopters, or exodeviation ≤ 10 prism diopters at distance. RESULTS: Among the 50 recurrent exotropes who underwent surgery and were followed up for more than 1 year postoperatively, 13 showed recurrent exotropia and 1 showed consecutive esotropia. The mean age at reoperation was 8.49 ± 2.19 years, and the mean duration of postoperative follow-up was 27.78 ± 12.02 months. Good near fusion before reoperation was a significant factor in the success of surgery (P = 0.006). Smaller postoperative deviation angle measured immediately and 2 months after surgery were related to smaller final deviation angle (P = 0.027 and P = 0.022, respectively). CONCLUSION: Peripheral suppression lowers the success rate of operation for recurrent X(T) in children. Overcorrection rather than orthotropia should be the target of immediate postoperative deviation angle. Peripheral suppression status and immediate and 2-month postoperative deviation angle may be important clues for predicting the final result of operation for recurrent X(T).

Elucidation of the Strongest Factors Influencing Rapid Retinal Nerve Fiber Layer Thinning in Glaucoma.

Purpose: To determine which groupings of prognostic factors best explain the rapid progressive retinal nerve fiber layer (RNFL) thinning in patients with primary open-angle glaucoma (POAG). Methods: Optic nerves of 111 POAG patients who were followed for at least 2.5 years, during which the RNFL thickness was measured by serial spectral-domain optical coherence tomography (OCT) were included. Eyes were imaged using enhanced depth-imaging spectral-domain OCT and swept-source OCT angiography to determine the lamina cribrosa curvature index (LCCI), and the presence of a choroidal microvasculature dropout (cMvD), respectively. The rate of RNFL thinning was determined by linear regression of serial OCT RNFL thickness measurements. A regression tree model was used to find groupings of factors that best explain the rate of future RNFL thinning. Results: Disc hemorrhage, larger LCCI, and presence of cMvD were associated with faster global RNFL thinning in the multivariate regression analysis. The regression tree analysis revealed three stratified groups based on the rate of RNFL thinning, divided by the LCCI and the presence of cMvD. Eyes with LCCI ≥11.87 had the fastest RNFL thinning (-2.4 ± 0.8 µm/year, mean ± SD). Among eyes with LCCI <11.87, the presence of cMvD was the strongest factor influencing faster RNFL thinning (-1.5 ± 0.8 µm/year). Eyes with LCCI <11.87 and without a cMvD exhibited the slowest RNFL thinning (-0.8 ± 0.9 µm/year). Conclusions: Our regression tree model demonstrated that larger LCCI, and then the presence of cMvD were the first and second strongest prognostic factors for faster progressive RNFL thinning. Further studies may be needed to confirm these findings.

Evaluation of Parapapillary Choroidal Microvasculature Dropout and Progressive Retinal Nerve Fiber Layer Thinning in Patients With Glaucoma.

Importance: Parapapillary choroidal microvasculature dropout (MvD) is considered one of pathophysiological manifestations of glaucomatous damage. Objective: To evaluate the longitudinal change in the parapapillary choroidal MvD in patients with primary open-angle glaucoma (POAG), and to determine whether this change is associated with progressive retinal nerve fiber layer (RNFL) thinning. Design, Setting, and Participants: This prospective observational case series was conducted at a tertiary referral center in Korea and included 68 patients with POAG who exhibited parapapillary choroidal MvD in en face optical coherence tomography (OCT) angiography (OCTA) images who were enrolled from the ongoing Investigating Glaucoma Progression Study from January 1, 2016, through July 31, 2018. The mean (SD) follow-up period was 2.5 (0.2) years and observers were masked to the clinical characteristics of the participants for measurements. The OCTA images were obtained twice at an interval of at least 2 years, during which the RNFL thickness was measured at least 4 times in serial OCT examinations. Microvasculature dropout was defined as a focal sectoral capillary dropout with no visible microvascular network identified in the choroidal layer. The MvD area was measured in the OCTA images obtained at the baseline and the final follow-up. The significance of changes in the MvD area was defined using the 95% Bland-Altman limits of agreement. The rate of RNFL thinning was determined by linear regression of the serial OCT RNFL thickness measurements. Main Outcomes and Measures: The association between the change in the MvD area and the rate of RNFL thinning. Results: Of 68 Korean participants, 37 (54.5%) were women, and the mean (SD) age was 54.3 (13.1) years. Among 68 eyes, 22 (32.4%) showed increases in the MvD area during the follow-up. Faster global RNFL thinning was associated with a larger baseline parapapillary atrophy ß-zone (ß = -0.55; 95% CI, -0.96 to -0.14; P = .01), disc hemorrhage detection during the follow-up period (ß = -0.75; 95% CI, -1.67 to -0.34; P = .001), and a larger increase in the MvD area (ß = -4.74; 95% CI, -7.72 to -1.75; P = .002). The MvD area was not associated with the rate of RNFL thinning at baseline or the final follow-up. Conclusions and Relevance: Microvasculature dropout enlargement was associated with progressive RNFL thinning in POAG.

Development of Optic Disc Torsion in Children.

PURPOSE: To document the development of disc torsion. METHODS: Consecutive disc photographs obtained at an interval of at least 1 year were reviewed retrospectively in 173 eyes of 173 Korean children. The angle of the vertical disc axis (AVDA) was measured in each fundus photograph with the fovea-disc center axis set at 0°. The associated change in the morphology of the optic disc was assessed by measuring the ratio of the horizontal to vertical disc diameters and the ratio of the maximum parapapillary atrophy width to vertical disc diameter. Eyes were divided into two groups with respect to the development of disc torsion: torsion and non-torsion group. Progressive torsion was defined as a change in AVDA between baseline and follow-up photographs beyond the coefficient of intraobserver repeatab ility. Factors associated with optic disc torsion were evaluated using logistic regression analysis. RESULTS: Mean subject age and refractive error at the time of baseline fundus examination were 6.8 ± 1.7 (range, 2 to 11) years and 0.2 ± 2.6 (range, -6.0 to +5.5) diopters, respectively. Mean follow-up period was 44.8 ± 21.1 (range, 12 to 103) months. Forty-two eyes (24%) were classified as torsion group who showed changes in AVDA that were greater than the intraobserver measurement variability (4.5°) during the follow-up period. The development of optic disc torsion was associated with greater myopic shift, a decrease in horizontal to vertical disc diameters, and an increase in parapapillary atrophy width to vertical disc diameter. CONCLUSIONS: Progressive optic disc torsion was a common phenomenon in the children included in this study. Torsion occurred as the result of optic disc tilt in an oblique axis in most cases. The findings provide a framework for understanding torsion-related glaucomatous optic nerve damage.

Lamina Cribrosa Morphology in Glaucomatous Eyes with Hemifield Defect in a Korean Population.

PURPOSE: To compare regional variations in lamina cribrosa (LC) curvature and depth between healthy eyes (group 1) and naïve eyes with primary open-angle glaucoma (POAG) having superior (group 2), inferior (group 3), and both (group 4) hemifield retinal nerve fiber layer (RNFL) defects. DESIGN: Cross-sectional study. PARTICIPANTS: Each group consisted of 39 eyes of 39 Korean patients who were matched for age, sex, and axial length. METHODS: The LC curvature index (LCCI) and LC depth (LCD) were measured in B-scan images obtained using enhanced depth imaging OCT at 7 locations spaced equidistantly across the vertical optic disc diameter. Superior and inferior LCCI and LCD were compared by calculating the superior-to-inferior (Sup/Inf) ratios. MAIN OUTCOME MEASURES: Comparisons of LCCI, LCD, and Sup/Inf ratio among the 4 groups. RESULTS: Compared with healthy eyes (group 1), LCCIs were larger at the superior and middle planes in group 2, at the inferior and middle planes in group 3, and at all planes in group 4 (P ≤ 0.003). The LCD showed similar results, but there was no difference in superior planes between groups 1 and 2. The Sup/Inf ratio of LCCI differed significantly between groups 1 (1.03) and 2 (1.20), groups 1 and 3 (0.79), groups 2 and 3, groups 2 and 4 (0.96), and groups 3 and 4 (all P < 0.001), but not between groups 1 and 4 (P = 0.273). The Sup/Inf ratio of LCD differed only between groups 2 and 3 (P = 0.002). CONCLUSIONS: Eyes with POAG showed regional differences in LC morphology, corresponding with the location of RNFL defects. The regional variations in LCCI suggest that LC morphology in POAG would be better assessed on a regional basis than by a global index.

Virtual-reality Cataract Surgery Simulator Using Haptic Sensory Substitution in Continuous Circular Capsulorhexis.

Cataract is one of the most common geriatric diseases, and surgery is known to be the best treatment. Despite the increasing demand for cataract surgery, the opportunity for novice residents to practice cataract surgery is gradually diminishing as the patient and animal ethics become strict. Therefore, there have been many attempts to overcome the lack of experience by using virtual reality training system. So far, most of the surgical training simulation devices so far focused on visual training, and when they have a haptic sense, they are tethered to a fixed station, which is different from the feeling of moving the actual surgical tool. In this study, we have developed a haptic surgical training tool with sensory substitution and virtual-reality-based cataract surgery simulator. To assess and reproduce the tactile senses during surgery, we prepared viscoelastic lens dummies and measured vibrations in contact and motion required during Continuous Circular Capsulorhexis (CCC). Based on measurement we designed vibration models for haptic sensory substitution and applied them to virtual reality simulator. With complete virtual reality training system, the contact vibration was successfully implemented for virtual contacts to reproduced realistic haptic senses.