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: 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.

Purpose: Oxaliplatin, a component of the capecitabine plus oxaliplatin (XELOX) regimen, has a more favorable toxicity profile than cisplatin in patients with advanced gastric cancer (GC). However, oxaliplatin can induce sensory neuropathy and cumulative, dose-related toxicities. Thus, the capecitabine maintenance regimen may achieve the maximum treatment effect while reducing the cumulative neurotoxicity of oxaliplatin. This study aimed to compare the survival of patients with advanced GC between capecitabine maintenance and observation after 1st line XELOX chemotherapy. Materials and Methods: Sixty-three patients treated with six cycles of XELOX for advanced GC in six hospitals of the Catholic University of Korea were randomized 1:1 to receive capecitabine maintenance or observation. The primary endpoint was progression-free survival (PFS), analyzed using a two-sided log-rank test stratified at a 5% significance level. Results: Between 2015 and 2020, 32 and 31 patients were randomized into the maintenance and observation groups, respectively. After randomization, the median number of capecitabine maintenance cycles was 6. The PFS was significantly higher in the maintenance group than the observation group (6.3 vs. 4.1 months, P=0.010). Overall survival was not significantly different between the 2 groups (18.2 vs. 16.5 months, P=0.624). Toxicities, such as hand-foot syndrome, were reported in some maintenance group patients. Maintenance treatment was a significant factor associated with PFS in multivariate analysis (hazard ratio, 0.472; 95% confidence interval, 0.250–0.890; P=0.020). Conclusions After 6 cycles of XELOX chemotherapy, capecitabine maintenance significantly prolonged PFS compared with observation, and toxicity was manageable. Maintenance treatment was a significant prognostic factor associated with PFS.

Purpose: To introduce an intuitive method for measuring conjunctival microvascular blood flow velocity by imaging bulbar conjunctival microvessels using a slit-lamp biomicroscope equipped with a zoom lens and an ultra-high-speed camera. Methods: After obtaining consent from 10 patients (1 male, 9 females) who visited Yeouido St. Mary’s Hospital from August 21, 2020, to June 12, 2021, the patients were examined under a slit lamp microscope equipped with an ultra-high-speed camera and zoom lens. The blood flow in the conjunctival microvessels was photographed. The captured images were analyzed with ImageJ software to measure the blood flow velocity in the conjunctival microvessels, and we investigated whether the blood flow velocity correlated with the vessel diameter and age. Results: The median age of the subjects was 49.0 years. The mean conjunctival blood flow velocity in 53 microvessels was 0.786 ± 0.468 mm/s. The median conjunctival microvascular diameter was 7.06 μm (interquartile range 5.84 to 9.23 μm). The conjunctival microvascular diameter and blood flow velocity were not significantly correlated (Spearman’s p = 0.177), and the subjects’ age and conjunctival microvascular blood flow velocity were also not correlated (Spearman’s p = 0.669). Conclusions In this study, the blood flow velocity in the bulbar conjunctival microvessels could be measured easily by means of image analysis using a slit-lamp microscope equipped with an ultra-high-speed camera with a zoom lens.

Purpose: To derive the optimized intraocular lens (IOL) constants from automated and manifest refraction after cataract surgery in Korean patients, and to evaluate whether there is a difference in optimized IOL constants according to the refraction method. Methods: This retrospective multicenter cohort study enrolled 4,103 eyes of 4,103 patients who underwent phacoemulsification and in-the-bag IOL implantation at 18 institutes. Optimized IOL constants for the SRK/T, Holladay, Hoffer Q, and Haigis formulas were calculated via autorefraction or manifest refraction of samples using the same biometry and IOL. The IOL constants derived from autorefraction and manifest refraction were compared. Results: Of the 4,103 eyes, the majority (62.9%) were measured with an IOLMaster 500 followed by an IOLMaster 700 (15.2%). A total of 33 types of IOLs were used, and the Tecnis ZCB00 was the most frequently used (53.0%). There was no statistically significant difference in IOL constants derived from autorefraction and manifest refraction when IOL constants were optimized with a large number of study subjects. On the other hand, optimized IOL constants derived from autorefraction were significantly smaller than those from manifest refraction when the number of subjects was small. Conclusions It became possible to use the IOL constants optimized from Koreans to calculate the IOL power. However, if the IOL constant is optimized using autorefraction in a small sample group, the IOL constant tends to be small, which may lead to refractive error after surgery.

Background/Aims: We investigated changes in recurrence rates and significant recurrence predictors over time after complete cure of hepatocellular carcinoma (HCC). Methods: A total of 1,491 patients with first-time diagnosis of Barcelona Clinic Liver Cancer stage A HCC, completely cured by treatment between 2007 and 2016, were recruited from two Korean tertiary institutes. Results: The mean age of the population (1,144 men and 347 women) was 58.6 years. Of the total population, 914 patients (61.3%) had liver cirrhosis. Nine-hundred and forty-one (63.1%) and 550 (36.9%) patients were treated with surgical resection and radiofrequency ablation (RFA), respectively. One-year cumulative incidences of HCC recurrence were 14.3%, 9.9%, and 5.1% from the time of treatment, 3 years after treatment, and 5 years after treatment, respectively. Upon multivariate analysis, multiple tumors, maximal tumor size ≥3 cm, and high Model for End-Stage Liver Disease scores were independently associated with increased HCC recurrence risk from the time of treatment and 1 and 2 years after curative treatment (all p<0.05, except for maxi-mal tumor size ≥3 cm for recurrence 2 years after treatment). Meanwhile, liver cirrhosis and RFA were independently associated with the increased HCC recurrence risk for almost all time points (liver cirrhosis: all p<0.05; RFA: all p<0.005 except for recurrence from 5 years after treatment). Conclusions The recurrence rate of HCC after curative treatment gradually decreased over time. Two years after treatment, when tumor-related factors lose their prognostic implications, may be used as a cutoff to define the boundary between early and late recurrence of HCC.

Purpose: To report a case of a successful secondary Descemet membrane endothelial keratoplasty in failed penetrating keratoplasty. Case summary: A 46-year-old male with keratoconus in both of his eyes underwent penetrating keratoplasty in his right eye 30 years ago and in his left eye 14 years ago. From one and a half year ago, the patient’s visual acuity decreased in his left eye due to graft failure. For treatment, secondary Descemet membrane endothelial keratoplasty was performed. Partial detachment of Descemet membrane was observed at 13 days after the operation, and an additional air injection was performed. At 8 months after the operation, the patient’s uncorrected visual acuity improved to 0.5 and the cornea maintained its clearance without rejection. Conclusions Secondary Descemet membrane endothelial keratoplasty was successfully performed in a patient with failed penetrating keratoplasty.