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: 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 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 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: To compare the degree of meibomian gland drop-out associated with Demodex infestation using non-contact meibography. Methods: We performed noncontact meibography using an infrared digital camera on 24 adult subjects infested by Demodex and 40 without infestation. The right upper and lower lids were scored based on the loss of meibomian glands, and the scores of the upper and lower eyelids were summed to obtain the total meiboscore for each subject. Meiboscores were evaluated according to Demodex infestation and gender in each group. Results: Sixty-four eyes of 64 people were enrolled in this study. The study subjects had an average age of 67.9 years (range, 40-79 years; men, 65.2 years; women, 69.1 years). There was a significant association between Demodex infestation and total meiboscore and upper and lower eyelid meiboscores (p = 0.000, p = 0.002, p = 0.004, respectively). There was no significant difference in the meiboscores between men and women. Age and meiboscore suggested a weak positive correlation; however, the R2 value was low, due to the concentrated age distribution of the study population. Conclusions Based on noncontact meibography, the authors concluded that the prevalence of changes in the meibomian glands was significantly related to Demodex infestation; however, there was no significant difference between men and women.

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.

Purpose: To report a case of secondary Descemet membrane endothelial keratoplasty (DMEK) for graft failure after primary DMEK.Case summary: A 47-year-old female underwent primary DMEK in her left eye with a diagnosis of Fuchs’ endothelial dystrophy. At 6 weeks later, corneal stromal edema with epithelial and subepithelial bullae was first observed. From that point on, the condition of the cornea and the visual acuity continued to degrade. After 7 months, a second DMEK procedure (i.e., a repeat DMEK) for graft failure was performed successfully without any complications. Since the second procedure, the cornea has been clear, and the best-corrected visual acuity has remained at 0.6 for 8 months. Conclusions To manage graft failure after primary DMEK, we performed a second DMEK procedure. The removal of the previous graft was easy, and there were no complications. Thus, repeat DMEK may be a feasible procedure.

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.

Purpose: To report a case of secondary Descemet membrane endothelial keratoplasty (DMEK) for graft failure after primary DMEK.Case summary: A 47-year-old female underwent primary DMEK in her left eye with a diagnosis of Fuchs’ endothelial dystrophy. At 6 weeks later, corneal stromal edema with epithelial and subepithelial bullae was first observed. From that point on, the condition of the cornea and the visual acuity continued to degrade. After 7 months, a second DMEK procedure (i.e., a repeat DMEK) for graft failure was performed successfully without any complications. Since the second procedure, the cornea has been clear, and the best-corrected visual acuity has remained at 0.6 for 8 months. Conclusions To manage graft failure after primary DMEK, we performed a second DMEK procedure. The removal of the previous graft was easy, and there were no complications. Thus, repeat DMEK may be a feasible procedure.