Purpose: We investigated the ophthalmic manifestations of Korean patients with Williams syndrome registered at a single regional rare disease center over the past 30 years. Methods: We conducted a retrospective analysis of the medical records of 19 patients who underwent complete ophthalmic examinations among 56 patients diagnosed with Williams syndrome and enrolled between September 1994 and August 2024. Results: Nineteen patients with Williams syndrome (7 boys and 12 girls) underwent their first ophthalmic examination at a mean age of 2.6 ± 2.8 years and were followed for 5.5 ± 5.1 years. Of these, 16 patients (84%) had cardiovascular abnormalities, 2 (11%) had infantile hypercalcemia, and 17 (89%) exhibited developmental delay. All patients displayed characteristic facial features with puffy eyelids. Congenital nasolacrimal duct obstruction occurred in 3 patients (16%) and resolved spontaneously. A stellate iris pattern involving approximately half the iris width was observed in 10 patients (53%). Strabismus was present in 13 patients (68%), including 6 with exotropia (1 with Duane retraction syndrome type 2) and 7 with esotropia. At the final refractive assessment (mean age 8.1 ± 2.5 years), 4 patients had hyperopia, 4 had myopia (including 1 with high myopia), 4 had astigmatism, and 3 had anisometropia; 7 patients (37%) required spectacle correction. Of the 11 patients with measurable visual acuity, 5 (45%) had amblyopia. Retinal vascular tortuosity was observed in 11 patients (58%), and attenuated retinal vessels in 10 (53%). Optical coherence tomography performed in 5 patients with normal visual acuity revealed markedly reduced central macular thickness in all, and a wide foveal pit in 1 patient. Conclusions Williams syndrome is associated with diverse ophthalmic manifestations that warrant regular and comprehensive ophthalmic follow-up.

Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Purpose: This study aimed to compare perioperative and postoperative outcomes of single-port laparoscopic articulated instrument-assisted versus da Vinci SP-assisted totally extraperitoneal (TEP) inguinal hernia repair using a propensity score-matched multi-institutional cohort. Methods: Between April 2022 and July 2025, 221 patients underwent TEP unilateral inguinal hernia repair at four institutions. Among them, 33 patients underwent da Vinci SP-assisted repair (Intuitive Surgical) and 188 underwent single-port laparoscopy using the articulated instrument, ArtiSential (LivsMed). Propensity score matching was performed in a 1:1 ratio based on demographic and clinical variables, resulting in 30 matched patients in each group. Perioperative outcomes and postoperative complications were analyzed. Results: After matching, baseline characteristics were well balanced between the groups.Operative time was significantly longer in the da Vinci SP group than in the ArtiSential group (median [interquartile range], 82.0 [67.5–105.0] vs. 35.0 [28.5–47.5] minutes; p < 0.001). No open conversions occurred, and conversions to transabdominal preperitoneal repair were rare and comparable. Mesh size selection differed significantly, with smaller meshes more frequently used in the da Vinci SP group (p < 0.001). Postoperative outcomes, including length of hospital stay, overall complication rates, chronic pain, and recurrence, were similar between the groups. No major complications, readmissions, or reoperations were observed. Conclusion Articulated instrument-assisted TEP inguinal hernia repair demonstrated a significantly shorter operative time than da Vinci SP-assisted repair, while perioperative safety and postoperative outcomes were comparable.

Purpose: To introduce subepithelial pterygium pedicle (SPP) and to investigate the effect of SPP length on the anterior corneal curvature including keratometry and aberrations. Methods: In this single-center retrospective cohort, 72 eyes of 72 patients with primary nasal pterygium were analyzed using anterior segment (AS) swept-source optical coherence tomography (SS-OCT; Anterion). We evaluated SPP length, horizontal invasion length (HIL), and corneal profiles including keratometry, root mean square values for lower- and higher-order aberrations, and first- to fourth-order wavefront aberrations. Correlations between SPP length and these parameters were assessed after adjusting for HIL. The SPP cutoff for significant anterior horizontal tilt deterioration was determined using receiver operating characteristic (ROC) analysis and validated by analysis of covariance controlling for HIL. Results: SPP was detected in 57 of 72 eyes (79.2%), with a mean length of 842.3 ± 408.1 μm. A significant positive correlation was found between SPP length and HIL (r = 0.376, p = 0.001). After adjusting for HIL, SPP length remained significantly associated with anterior corneal horizontal tilt (p = 0.026), whereas no significant correlations were observed with other refractive or aberration parameters. ROC curve analysis identified an SPP length of approximately 850 μm as the threshold for predicting anterior horizontal tilt ≥3.65 μm. Consequently, this cutoff significantly differentiated subgroups after adjusting for HIL, showing a marked increase in horizontal tilt in eyes with SPP ≥850 μm (p = 0.016), indicating mechanical distortion. Conclusions SPP length, a subepithelial microstructural parameter visualized by AS SS-OCT, independently correlates with anterior horizontal tilt after adjustment for HIL. This finding suggests that SPP length serves as a microstructural indicator of horizontal mechanical corneal distortion in eyes with pterygium.

Purpose: To characterize perioperative changes in posterior corneal curvature (PCC) following pterygium excision using anterior segment (AS) swept-source optical coherence tomography (SS-OCT), and to identify the critical threshold of horizontal invasion length (HIL) predicting significant PCC alterations. Methods: This retrospective cohort study included 85 eyes of 77 patients with primary nasal pterygium. PCC parameters, including posterior keratometry (K) average, posterior steep K, posterior flat K and posterior corneal astigmatism, were measured preoperatively and postoperatively using AS SS-OCT (Anterion). Perioperative PCC changes were analyzed in relation to HIL and postoperative duration. Subgroup analyses were performed to identify the HIL cutoff value associated with statistically significant changes in posterior K average. Results: Significant postoperative flattening was observed in both posterior K average (from –6.27 ± 0.24 to –6.23 ± 0.23 diopters [D], p < 0.001) and posterior flat K (from –6.14 ± 0.23 to –6.09 ± 0.23 D, p < 0.001), accompanied by a significant increase in posterior corneal astigmatism (from –0.25 ± 0.12 to –0.29 ± 0.17 D, p = 0.003). The magnitude of posterior flattening showed a significant positive correlation with HIL (r = 0.384, p < 0.001) but was not correlated with postoperative duration (p = 0.428). In subgroup analysis, eyes with HIL ≥3.5 mm exhibited a significant change in posterior K average (p < 0.001), whereas those with HIL <3.0 mm and HIL <3.5 mm showed no significant change (p = 0.065 and p = 0.443, respectively). Conclusions Pterygium excision leads to significant posterior corneal flattening proportional to HIL, with 3.5 mm identified as a clinically relevant cutoff. Although the refractive impact may be subtle, surgeons should be aware of these posterior corneal changes as a consistent morphological response, especially in eyes with HIL ≥3.5 mm.

Purpose: To determine the corneal stabilization timeline after pterygium excision adjusted for horizontal invasion length (HIL). Methods: In this single-center retrospective cohort study, we analyzed 88 eyes of 80 patients with nasal or temporal primary pterygium who underwent excision and perioperative evaluation with anterior segment (AS) swept-source optical coherence tomography (SS-OCT; Anterion). Anterior simulated mean keratometry (SimKmean; 3-mm ring) and HIL were measured on AS SS-OCT. Keratometric stabilization was assessed at postoperative cutoffs of 8, 12, 16, 20, and 24 weeks using analysis of covariance (ANCOVA) with HIL as a covariate. Subgroup analysis was performed after stratifying by the median HIL (3.82 mm). Results: Mean anterior SimKmean increased from 42.95 ± 1.79 diopters (D) preoperatively to 43.73 ± 1.53 D postoperatively (p < 0.001). Preoperative HIL correlated positively with the perioperative SimKmean change (r = 0.728, p < 0.001). While postoperative duration showed no significant unadjusted correlation with keratometric change (r = −0.133, p = 0.218), partial correlation controlling for HIL was negative (r = −0.248, p = 0.021), indicating diminishing change over time after severity adjustment. ANCOVA demonstrated significant stabilization at 16 weeks (p = 0.036). In the HIL ≥3.82 mm subgroup, SimKmean change was greater before 20 weeks than after 20 weeks (1.73 ± 1.59 D vs. 0.59 ± 0.74 D, p = 0.030), whereas no significant time-point differences were found for HIL <3.82 mm. Conclusions Corneal keratometric stabilization after pterygium excision depends on preoperative HIL. A minimum of 16 weeks is recommended before cataract surgery planning, with at least 20 weeks for eyes with HIL ≥3.82 mm.

Purpose: This study aims to determine whether the translucency-based clinical grade of pterygium shows independent relationships with anterior and posterior corneal curvature and anterior wavefront aberrations, with adjustment for horizontal invasion length (HIL) measured by anterior segment (AS) swept-source optical coherence tomography (SS-OCT). Methods: This study involved 53 eyes from 51 patients diagnosed with primary nasal pterygium. The clinical grade of the pterygium was evaluated using T grade based on the fibrovascular translucency. AS SS-OCT (Anterion, Heidelberg Engineering) provided HIL (in millimeters), thickness (in micrometers), anterior/posterior keratometry at the 3.0-mm ring, and anterior corneal wavefront metrics within a 6.0-mm zone. The device was also used to evaluate the magnitudes for the individual first-to fourth-order aberrations of the anterior corneal fields. Also, the fourth- to seventh-order root mean square (RMS), RMS lower-order aberration (LoA), and RMS higher-order aberration (HoA) values were collected. For statistical analysis, Spearman rank correlation test and Pearson correlation test were performed, along with partial correlation test adjusted for HIL. Results: The mean age of subjects was 59.3 ± 11.4 years, and 51.0% were female. T grade correlated positively with HIL. HIL showed strong associations with anterior simulated keratometry (Sim K) average, anterior Sim K steep, anterior Sim K flat, and anterior corneal astigmatism—but not with posterior corneal parameters. HIL also showed significant correlations with multiple anterior corneal wavefront parameters. After adjustment for HIL, T grade remained independently correlated with anterior Sim K flat, RMS LoA, and defocus; no significant relationships were observed with other Zernike terms or posterior metrics. Additionally, T grade was positively correlated with pterygium thickness. Conclusions T grade adds independent, complementary information (associations with flat keratometry, LoA RMS, and defocus) even after controlling for HIL. Incorporating T grade into preoperative assessment may improve estimation of optical burden and surgical prognosis.

Objective: This study aimed to evaluate the feasibility, safety, and oncologic outcomes of irreversible electroporation (IRE) using a clustered electrode in patients with locally advanced pancreatic cancer (LAPC). Materials and Methods: In this single-center prospective cohort study, 13 patients with LAPC (median age, 60 years; range, 48–78 years) underwent clustered electrode IRE between September 2022 and September 2024. Patient characteristics, procedural details, and clinical outcomes were recorded. Endpoints included technical success, procedure-related complications, overall survival (OS), and progression-free survival (PFS). Results: Tumors were located in the pancreatic head in four patients (30.8%) and in the body/tail in nine (69.2%). The median tumor size was 2.4 cm (1.5–4.0 cm), and vascular invasion was present in all patients. Technical success was achieved in all patients. Intraoperative IRE was performed in 11 (84.6%) patients, and 2 (15.4%) patients underwent percutaneous IRE. Gastrointestinal bleeding events as major complications occurred in two patients (15.4%) and, both were successfully controlled by embolization. No 60-day mortality was observed. At a median follow-up of 24.5 months (range, 9.9–33.4 months) after IRE, median OS and PFS from IRE were 20.1 and 14.5 months, respectively. Conclusion IRE using clustered electrodes for LAPC appears to be a feasible therapeutic approach, offering reliable technical success and acceptable safety. Survival outcomes are encouraging; however, larger, controlled studies are required.

Background: and Purpose Whole-exome sequencing (WES) is a valuable tool for identifying causative mutations in adult moyamoya disease (MMD), thereby advancing our understanding of the genetic mechanisms underlying this condition. Here, we conducted the first WESbased association study aimed at identifying genetic modifiers implicated in MMD. Methods: This WES study involved 160 patients with MMD and 189 controls from a multicenter hospital-based biobank, and evaluated combined annotation-dependent depletion (CADD) scores. Mutant-allele frequencies were compared in 369,121 individuals derived from the UK Biobank (UKB) WES. Mutant-allele risk scores (MARSs) were created based on WESidentified mutations. Gene-based association analyses and pooled analyses in East-Asian populations were further performed. Results: Fourteen mutations reached the genome-wide significance criterion (p<5×10-8 ), among which the p.R4810K mutation in the ring finger protein 213 gene (RNF213) showed the strongest significance (odds ratio=117.4, p=8.54×10-24 ). Notably, two mutations—p.G576S (alpha-glucosidase [GAA]) and p.D54N (charged multivesicular body protein 6 [CHMP6])— exhibited high CADD scores of 32 and 25, respectively, whereas the RNF213 p.R4810K mutation demonstrated a moderate deleteriousness score of 10.63. Fourteen mutations exhibited significant differences in allele frequencies between patients and UKB controlled data (p<1×10-8 ).The MARS9 model (incorporating nine missense mutations) showed better predictability for MMD (90.89%). The analysis of gene-based associations revealed four candidate genes: GAA, RNF213, CHMP6, and CARD14 (p=5×10-19 to 4×10-7 ). The subsequent pooled analyses validated four mutations in East Asian populations: p.V1195M, p.D1331G, p.S2334N, and p.R4810K (p<3×10-8 ). Conclusions This pioneering study has corroborated the significance of p.R4810K and identified several causative mutations predisposing patients to MMD, which helps to improve the understanding of its polygenetic nature.