Purpose: To report the clinical utility of the Barrett True-K formula in predicting multifocal intraocular lens (IOL) power in a patient with corneal deformation caused by radial keratotomy (RK), where postoperative refractive power prediction is challenging.Case summary: A 61-year-old male who underwent RK 30 years ago presented for cataract surgery. Slit-lamp examination showed eight RK incisions in each eye. Refractive error was +3.25 D sph; -1.75 D cyl, axis 70 in the right eye and +2.75 D sph; -1.00 D cyl, axis 110 in the left. Uncorrected visual acuity was 0.32 in the right eye and 0.63 in the left. IOL power was calculated using the Barrett True-K formula on the IOLMaster 700, with a target refraction of -0.25 D, and a multifocal IOL was implanted. Six months after cataract surgery, both eyes achieved a fraction close to emmetropia, with best corrected visual acuity of 0.63 in the right eye and 1.0 in the left. No significant refractive shifts or other complications were observed during surgery or 6-month follow-up. Conclusions The Barrett True-K formula, which measures the actual corneal refractive power to compensate for corneal deformation, is expected to be clinically useful for multifocal IOL implantation during cataract surgery in eyes after RK.

Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Bowel preparation is a key determinant of colonoscopy quality; however, inadequate cleansing remains common among patients with overlapping clinical and logistical barriers. In routine practice, preparation failure may prolong procedures, reduce diagnostic confidence, and necessitate early repeat colonoscopy. We review major society guidelines and selected studies addressing bowel preparation in inflammatory bowel disease (IBD), chronic kidney disease (CKD), older adults, chronic constipation, and hospitalized patients. Across these settings, the most consistently supported measures include split-dose administration, completion of the final dose close to the time of colonoscopy in accordance with local fasting and sedation policies, and structured patient instructions reinforced through follow-up communication. A standardized assessment of preparation quality is recommended to support quality improvement and appropriate follow-up. Risk stratification can help identify patients who may benefit from intensified preparation pathways, including those with prior inadequate preparation, severe constipation, frailty, or inpatient status. Safety considerations are particularly important in CKD, in which oral sodium phosphate should be avoided and magnesium-containing agents used cautiously; polyethylene glycol-based solutions are generally preferred. In IBD, regimen selection should also consider endoscopic interpretability because sodium phosphate preparations have been associated with preparation-related mucosal abnormalities that may confound the assessment of subtle inflammatory findings. Among hospitalized patients, system-level barriers often predominate, and protocolized pathways may improve workflow and patient comfort while maintaining cleansing effectiveness. We propose a practical, risk-stratified approach to regimen selection, timing, rescue strategies, and safety monitoring that can be implemented in high-volume clinical practice.

Background: and Purpose Intraoperative visual evoked potential (VEP) monitoring has been studied mainly in pituitary adenoma, while its role in nonpituitary suprasellar tumors has remained unclear. This study evaluated the predictive usefulness of intraoperative VEP monitoring during endoscopic endonasal surgery (EES) and aimed to identify optimal alarm criteria for visual outcomes. Methods: We retrospectively analyzed a cohort of 87 patients who underwent EES with intraoperative VEP monitoring between April 2021 and September 2023. Visual outcomes were evaluated preoperatively and at short-term (≤3 months) and long-term (12 months) followups, with visual deterioration at these time points defined as worsening of either visual acuity or the visual field. Reductions in the VEP amplitude were quantified using both the maximum intraoperative decrease and the final amplitude after recovery. Receiver operating characteristic (ROC) curve analyses were performed to identify the optimal alarm thresholds, and the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for short-term and long-term visual deteriorations. Results: Short-term and long-term visual deteriorations were detected in 12 (9.2%) and 5 (3.8%) of the 130 analyzed eyes, respectively. ROC curve analyses identified ≥40% and ≥30% reductions in the N75–P100 amplitude as optimal alarm criteria for short-term and long-term visual deteriorations, respectively. A 30% reduction without intraoperative recovery demonstrated markedly higher sensitivity than the conventional 50% alarm threshold for short-term (58.3% vs. 33.3%) and long-term (80.0% vs. 20.0%) outcomes, while maintaining acceptable specificity (82.2% and 80.8%, respectively). Conclusions A 30% reduction in amplitude represents a more-sensitive and clinically relevant alarm threshold than a 50% reduction for intraoperative VEP monitoring during EES for nonpituitary suprasellar tumors. Incorporating both the magnitude and recovery pattern of VEP amplitude changes may improve the accuracy of predictions of long-term visual deterioration. However, the potential for false positives warrants cautious interpretation, and further studies are needed to validate the impact of intraoperative VEP monitoring on visual outcomes.

Background and Objectives: Clinical characteristics and outcomes in acute heart failure (AHF) vary by phenotype. We assessed phenotype-specific features, treatment patterns, and outcomes in a nationwide Korean cohort. Methods: The Korean Heart Failure III registry prospectively enrolled 7,351 AHF admissions at 47 hospitals. Among 6,777 patients with available left ventricular ejection fraction (EF), phenotypes were defined as heart failure with reduced EF (HFrEF, ≤40%), mildly reduced EF (HFmrEF,41–49%), or preserved EF (HFpEF, ≥50%). The primary endpoint was a 12-month composite of all-cause death or heart transplantation, evaluated from index admission and, among hospital survivors, from discharge. We used inverse probability weighting (multinomial generalized boosted models with stabilized, trimmed weights) and weighted Cox proportional-hazards models to estimate hazard ratios (HRs). Results: Phenotype distribution was 58.9% HFrEF, 13.6% HFmrEF, and 27.5% HFpEF. Crude 12-month composite rates from index admission were 13.4% (HFrEF), 12.7% (HFmrEF), and 16.8% (HFpEF). After weighting, from index admission, HFmrEF (HR, 0.892; 95% confidence interval [CI], 0.731–1.088) and HFpEF (HR, 1.101; 95% CI, 0.939–1.291) did not differ from HFrEF; from discharge, HFpEF had modestly higher risk (HR, 1.207; 95% CI, 1.008–1.445) whereas HFmrEF did not (HR, 1.039; 95% CI, 0.844–1.279). Hyponatremia and chronic kidney disease were consistent adverse markers, while angiotensin-converting enzyme inhibitor/ angiotensin II receptor blocker use at discharge was protective. Conclusions Across the EF spectrum, phenotypes showed distinct profiles and risk. Postdischarge risk was modestly higher in HFpEF, supporting phenotype-tailored care and systematic discharge optimization in Korean patients with AHF.

Intracranial hypotension typically presents with orthostatic headache caused by cerebrospinal fluid (CSF) hypovolemia, most commonly resulting from spontaneous or iatrogenic CSF leaks. Traumatic rupture of an occult congenital sacral meningocele following a minor injury is exceptionally rare and may be diagnostically challenging. We report the case of a 40-year-old woman in Korea who developed sudden severe orthostatic headache immediately after a minor coccygeal contusion. Magnetic resonance myelography demonstrated a 5.8-cm dural ectasia/meningocele at the S3 level with a focal CSF fistula extending into the presacral space, accompanied by a tethered cord and an intradural lipoma. Given the anticipated risks associated with definitive surgical repair, a targeted trans-sacrococcygeal epidural blood patch was administered, resulting in substantial symptomatic improvement. This case highlights that while most post-traumatic CSF leaks occur at the cervical or thoracic level, occult spinal dysraphism should be considered a rare predisposing factor in post-traumatic orthostatic headache, particularly when trauma involves the sacrococcygeal region or when standard imaging findings are unrevealing. This finding also suggests that targeted caudal epidural blood patches may serve as a reasonable and less invasive treatment option when surgical intervention carries a high risk.

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms that mainly occur in the stomach and small intestine; those arising in the esophagus are rarer. A 54-year-old woman was referred to our hospital with a one-month history of dysphagia. Esophagogastroduodenoscopy (EGD), performed approximately five months earlier, had not revealed any specific findings. However, an EGD performed in our hospital showed the presence of a round, protruding lesion (approximately 40×30 mm in size), with a normal overlying mucosal surface, 35–39 cm from the upper incisor. Chest computed tomography (CT) revealed a large esophageal mass. Enucleation was performed on the esophageal mass, and a GIST was diagnosed using immunochemical staining. Imatinib mesylate administration was initiated two months postoperatively. The patient was stable, without any evident recurrence in the 8-month postoperative follow-up EGD and chest CT examinations. Therefore, physicians should consider that patients with worsening dysphagia may have an underlying organic condition, such as an acute increase in size of an esophageal GIST, even if recent examinations were unremarkable.

Background/Aims: Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia. This research aimed to evaluate the clinical features and outcomes of PVT in patients with IBD at a leading hospital in South Korea. Methods: This retrospective analysis reviewed adult patients diagnosed with both IBD and PVT from 1989 to 2021 at a renowned South Korean medical center. The study focused on patient characteristics, specifics of PVT, administered treatments, and outcomes, all confirmed through enhanced CT scans. Results: A total of 78 patients met the study’s criteria. Notably, only 20.5% (16/78) were treated with oral anticoagulants; however, a vast majority (96.2%; 75/78) achieved complete radiographic resolution (CRR). When comparing patients receiving anticoagulants to those who did not, a significant preference for anticoagulant use was observed in cases where the main portal vein was affected, as opposed to just the left or right veins (p = 0.006). However, multivariable analysis indicated that neither anticoagulant use nor previous surgeries significantly impacted CRR. Conclusions Patients with IBD and PVT generally had favorable outcomes, regardless of anticoagulant use.

Purpose: To investigate ocular manifestation of immune reconstitution inflammatory syndrome (IRIS) in HIV patients after starting highly active antiretroviral therapy (HAART) and its relationship to T cell immunity. Methods: HIV patients with ocular IRIS after HAART were retrospectively reviewed. Clinical presentations with previous opportunistic infection, duration from initiation of HAART to IRIS, blood CD4+, CD8+ T cell count, and HIV RNA copies before HAART and at IRIS were analyzed. Results: Among 19 patients (27 eyes) included, the most common previous opportunistic infection was cytomegalovirus (17 patients, 89.5%) followed by tuberculosis choroiditis (2 patients, 10.5%). The clinical manifestations included vitritis (20 eyes, 74.0%), retinitis (14 eyes, 51.9%), and anterior uveitis (5 eyes, 18.5%). The median duration from initiation of HAART to IRIS was 70 days. CD4+ T cell count before HAART increased at IRIS (p < 0.001). CD8+ T cell count before HAART was negatively correlated with duration from HAART to IRIS (p < 0.001). The cutoff value of CD8+ T cell count for discerning early or late onset of ocular IRIS was 258/mm3 (p = 0.001). When divided into two groups by CD8+ T cell count of 258/mm3, 90% patients with CD8+ T cell count higher than 258/mm3 before HAART developed ocular IRIS within 70 days. Conclusions There was a negative relationship between CD8+ T cell count before HAART and duration from HAART to ocular IRIS. Ocular IRIS with higher CD8+ T cell count before HAART developed earlier after HAART initiation compared to those with lower CD8+ T cell count.

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms that mainly occur in the stomach and small intestine; those arising in the esophagus are rarer. A 54-year-old woman was referred to our hospital with a one-month history of dysphagia. Esophagogastroduodenoscopy (EGD), performed approximately five months earlier, had not revealed any specific findings. However, an EGD performed in our hospital showed the presence of a round, protruding lesion (approximately 40×30 mm in size), with a normal overlying mucosal surface, 35–39 cm from the upper incisor. Chest computed tomography (CT) revealed a large esophageal mass. Enucleation was performed on the esophageal mass, and a GIST was diagnosed using immunochemical staining. Imatinib mesylate administration was initiated two months postoperatively. The patient was stable, without any evident recurrence in the 8-month postoperative follow-up EGD and chest CT examinations. Therefore, physicians should consider that patients with worsening dysphagia may have an underlying organic condition, such as an acute increase in size of an esophageal GIST, even if recent examinations were unremarkable.