Purpose: To evaluate the effectiveness of an instrument devised for slit-lamp examination of donor corneas suspended in preservation medium. Methods: The study examined two donor corneas received at Yeouido St. Mary's Hospital in February 2023 and March 2023. The instrument has three main components: a plastic holder to hold the preservation medium bottle, a cube with a mirror for reflecting the slit beam, and a stand to attach the device to the slit-lamp. Using the instrument, the donor corneas were examined via slit-lamp: microscopy with the endothelium facing upward and downward. Specular microscopy and anterior segment optical coherence tomography (OCT) were also performed on the preserved donor corneas. Results: Slit-lamp examination of donor corneas in preservation medium using the instrument showed overall corneal buttoning and optical sections of the donor cornea. Using specular reflection and retroillumination, the endothelial layer was partially visible. However, specular microscopy and anterior segment OCT could not examine the donor cornea in preservation medium using the instrument. Conclusions The devised instrument facilitates slit-lamp examination of donor corneas in preservation medium, enabling a qualitative assessment of donor corneas before corneal transplantation surgery.

Purpose: This study investigated the causative microorganisms, antibiotic susceptibility, and risk factors of infectious keratitis over the past 10 years. Methods: Data from patients with infectious keratitis who underwent microbial culture tests from 2012 to 2021, obtained from anonymized data systems, were analyzed. Microbial culture results and antibiotic susceptibility profiles were examined. A retrospective analysis of the medical records of patients with infectious keratitis during the same period was conducted to investigate the clinical characteristics and risk factors. Results: Data from 1,837 cases of infectious keratitis were extracted from anonymized records. The culture positive rate among patients was 46.0% (1,137/2,474), with coagulase-negative Staphylococcus (CoNS) being the most common causative organism (27.8%). Increased resistance to cefazolin and cefotaxime was observed in gram-negative bacteria, while there were no significant temporal changes in quinolone resistance in gram-positive or negative bacteria. A retrospective medical record analysis of 288 cases revealed that older patients, as well as those with an initial corrected visual acuity < 0.1, a history of ocular surgery, pre-existing ocular conditions, prior steroid eye drops, or glaucoma eye drops, had significantly higher rates of culture positivity. Multivariate analysis identified risk factors for severe keratitis requiring surgical intervention as a symptom-to-presentation period of 7 days or longer (p = 0.048) and pre-existing ocular conditions (p = 0.040). Conclusions CoNS was the most common microorganism causing infectious keratitis over the past decade. There has been an increase in resistance to cephalosporin antibiotics among gram-negative bacteria. Patients with pre-existing ocular conditions may require surgical intervention, so infectious keratitis in these patients requires greater attention.

Purpose: In the present study, we determined the prevalence of obstructive meibomian gland dysfunction (MGD), hyposecretory MGD, grossly normal MG, and hypersecretory MGD in patients with dry eye syndrome using lipid layer thickness (LLT) and MG dropout. Methods: Eighty-eight patients with dry eye syndrome were included in the study. Patients were categorized into four groups according to the LLT and weighted total meiboscore. The proportion of patients in each group was calculated. The age, sex, Ocular Surface Disease Index, LLT, Schirmer, tear film breakup time, cornea stain, weighted total meiboscore, expressibility, and quality of meibum were compared between the four groups. Results: Fifteen eyes (17.0%) had obstructive MGD, two eyes (2.3%) had hyposecretory MGD, 40 eyes (45.5%) had grossly normal MG, and 17 eyes (19.3%) had hypersecretory MGD. The obstructive MGD group was younger than the grossly normal MG group. In obstructive MGD, the ratio of men to women was higher than that of the other groups. However, Ocular Surface Disease Index, Schirmer, tear film breakup time, and corneal stain did not show statistically significant differences between the four groups. The meibum expressibility of the hyposecretoy MGD group was worse than those of the other groups. The meibum expressibility of the hyposecretoy MGD group was poor than those of the obstructive and hypersecretory MGD group. Conclusions This categorization was expected to help determine the best treatment method for dry eye syndrome, according to the MG status.

Purpose: In the present study, we introduce human lacrimal gland imaging using an ultrasound biomicroscopy (UBM) with a soft cover and show their findings Methods: The representative UBM findings of palpebral lobes in seven subjects (four with non-Sjögren dry eye syndrome, one with Sjögren syndrome, and two healthy subjects) were described in this study. To prolapse the palpebral lobe, the examiner pulled the temporal part of the upper eyelid in the superotemporal direction and directed the subject to look in the inferonasal direction. We scanned the palpebral lobes longitudinally and transversely using UBM. We used an Aviso UBM with a 50 MHz linear probe and ClearScan. Results: In UBM of two healthy subjects, the echogenicity of the lacrimal gland was lower than that of the sclera and homogeneous. But the parenchyma of a patient with Sjögren dry eye syndrome was quite inhomogeneous compared to the healthy subjects. In two patients with dry eye syndrome, we were able to observe some lobules in the parenchyma. We could find excretory ducts running parallel at the surface of the longitudinal section in some subjects. In the longitudinal UBM scan of a subject, we observed a tubular structure at a depth of 1,500 μm that was considered a blood vessel. It ran from the superonasal to the inferotemporal direction. In a subject, we observed a large cyst beneath the conjunctiva. Conclusions Lacrimal gland imaging using UBM has both advantages of optical coherence tomography and sonography, and could be useful for evaluating dry eye syndrome.

Purpose: This qualitative study aimed to identify the detailed job roles of physician assistants working in surgical departments of tertiary hospitals in Korea. Methods: Data were collected via individual in-depth interviews and analyzed using a content analysis method. Participants were 19 physician assistants (PAs), each of whom had been working for more than one year in tertiary hospitals. Results: Overall, 348 codes were extracted and clustered into 75 subcategories (job roles). Thereafter, 75 subcategories were classified into three categories (nursing roles, medical residents’ roles, and physicians’ roles). Among 75 PA job roles, 1 (1.3%) was a nursing role, 7 (9.3%) were nursing or medical residents’ roles, and 67 (89.4%) were physicians’ roles. Physicians’ roles were mostly surgery-associated functions performed in a variety of settings in numerous different ways. Conclusion Establishing educational systems, qualification standards, and payment systems for the PAs and legalizing their professional status are necessary.

Purpose: To analyze trends in corneal transplantation surgery and determine the number of domestic and imported corneal grafts used in South Korea.Method: The total number of keratoplasties and number of each individual surgical procedure conducted in 2010 and 2020 were identified using Health Insurance Review and Assessment Service data. The number of keratoplasties using domestic corneas in 2010 and 2020 was determined from the annual report of the Korean Network for Organ Sharing (KONOS). The number of keratoplasties using imported corneas was calculated by subtracting the number of keratoplasties using domestic corneas from the total number of keratoplasties. Results: In 2010, 802 keratoplasties were performed in Korea, of which 299 (37.3%) used imported corneas; 715 (89.2%) were penetrating keratoplasties and 87 (10.8%) were anterior lamellar keratoplasties. In 2020, 911 keratoplasties were done in Korea and 564 (61.9%) used imported corneas; 541 (59.4%) were penetrating keratoplasties, 60 (6.6%) were anterior lamellar keratoplasties, and 310 (34.0%) were endothelial keratoplasties. From 2010 to 2020, the number of penetrating keratoplasties in Korea decreased, while the numbers of endothelial keratoplasties and keratoplasties using imported corneas increased. Conclusions There was a 30% decrease in the number of penetrating keratoplasties from 2010 to 2020, and a 30% increase in the numbers of endothelial keratoplasties and keratoplasties using imported corneas. The proportions of endothelial keratoplasties and imported corneas have increased steadily in Korea over the last 10 years.

The Korean Society of Heart Failure (KSHF) guidelines aim to provide physicians with evidencebased recommendations for the management of patients with heart failure (HF). After the first introduction of the KSHF guidelines in 2016, newer therapies for HF with reduced ejection fraction, HF with mildly reduced ejection fraction, and HF with preserved ejection fraction have since emerged. The current version has been updated based on international guidelines and research data on Korean patients with HF. Herein, we present Part II of these guidelines, which comprises treatment strategies to improve the outcomes of patients with HF.

The Korean Society of Heart Failure guidelines aim to provide physicians with evidence-based recommendations for diagnosing and managing patients with heart failure (HF). In Korea, the prevalence of HF has been rapidly increasing in the last 10 years. HF has recently been classified into HF with reduced ejection fraction (EF), HF with mildly reduced EF, and HF with preserved EF (HFpEF). Moreover, the availability of newer therapeutic agents has led to an increased emphasis on the appropriate diagnosis of HFpEF. Accordingly, this part of the guidelines will mainly cover the definition, epidemiology, and diagnosis of HF.

Background/Aims: We used next-generation sequencing (NGS) to analyze resistance-associated substitutions (RASs) and retreatment outcomes in patients with chronic hepatitis C virus (HCV) infection who failed direct-acting antiviral agent (DAA) treatment in South Korea. Methods: Using prospectively collected data from the Korean HCV cohort study, we recruited 36 patients who failed DAA treatment in 10 centers between 2007 and 2020; 29 blood samples were available from 24 patients. RASs were analyzed using NGS. Results: RASs were analyzed for 13 patients with genotype 1b, 10 with genotype 2, and one with genotype 3a. The unsuccessful DAA regimens were daclatasvir+asunaprevir (n=11), sofosbuvir+ribavirin (n=9), ledipasvir/sofosbuvir (n=3), and glecaprevir/pibrentasvir (n=1). In the patients with genotype 1b, NS3, NS5A, and NS5B RASs were detected in eight, seven, and seven of 10 patients at baseline and in four, six, and two of six patients after DAA failure, respectively. Among the 10 patients with genotype 2, the only baseline RAS was NS3 Y56F, which was detected in one patient. NS5A F28C was detected after DAA failure in a patient with genotype 2 infection who was erroneously treated with daclatasvir+asunaprevir. After retreatment, 16 patients had a 100% sustained virological response rate. Conclusions NS3 and NS5A RASs were commonly present at baseline, and there was an increasing trend of NS5A RASs after failed DAA treatment in genotype 1b. However, RASs were rarely present in patients with genotype 2 who were treated with sofosbuvir+ribavirin. Despite baseline or treatment-emergent RASs, retreatment with pan-genotypic DAA was highly successful in Korea, so we encourage active retreatment after unsuccessful DAA treatment.