This study aims at determining the thickness of the tear lipid layer (LL) observed from a placido-disc-based tear film analyzer. We prospectively collected reflections of placido-disk LL images using a tear film analyzer (Keratograph^® 5M, Oculus) from subjects with dry eye symptoms. The LL thickness (LLT) over the inferior half of the cornea was estimated with the use of interference color analysis and the preprocessing of images with and without ring segmentation were obtained and analyzed. Moreover, LLTs before and after 1 h of applying topical ointment (Duratears, Alcon) were compared to validate the estimation of LLT. Our results suggested that the tear LLT can be assessed using a placido-disk-based tear film analyzer and interference color analysis. We verified a high correlation between non-segmented and segmented LL images and estimated LLT increase after applying ointment. In addition, we concluded that LLT can be evaluated by direct interference analysis without segmentation preprocessing.

Multiple vaccines are now being used across the world, and several studies have described cases of corneal graft rejection following the administration of the COVID-19 vaccine. The purpose of this article is to review the corneal adverse event that occurred following COVID-19 vaccine administration. The literature search was conducted in March 2022 using MEDLINE, PubMed, and the Cochrane Database of Systematic Reviews. A total of 27 articles, including 37 cases, have documented corneal adverse events that occurred following COVID-19 vaccination. The mean age was 60 ± 14.9 years (range, 27–83 years). The most common events were acute corneal graft rejection (n = 21, 56.8%), followed by herpes zoster ophthalmicus (n = 11, 29.7%) and herpes simplex keratitis (n = 2, 5.4%). The mean time from vaccination to the event was 10 ± 8.5 days (range, 1–42 days) after the first or second dose of vaccine. All patients with corneal graft rejection, immune-mediated keratolysis, and peripheral ulcerative keratitis (PUK) (n = 24, 64.9%) were managed topically with or without oral corticosteroids. Patients with herpes zoster ophthalmicus and herpes simplex keratitis were managed with oral antiviral agents. Two patients received penetrating keratoplasty due to keratolysis after invalid topical treatment. Disease resolution was noted in 29 patients (78.3%), whereas 3 (8.1%) had persistent corneal edema after graft rejection, 1 (2.7%) had corneal infiltration after HZO, and 4 (10.8%) were not mentioned in the articles. Corneal adverse events could occur after COVID-19 vaccination. After timely treatment with steroids or antiviral agents, most of the events were mild and had a good visual outcome. Administrating or increasing steroids before vaccination may be useful for the prevention of corneal graft rejection. However, the prophylactic use of antiviral treatments in patients with a herpes viral infection history is not recommend.

Glucocorticoids play a pivotal role in therapeutic protocols in acute lymphoblastic leukemia (ALL) treatment. Systemic steroids are known to be less likely to elevate the intraocular pressure when compared to topical administration, and reports addressing hypertensive ocular response in the Asian pediatric ALL population are currently limited. We report a case of a nine-year-old girl with acute lymphoblastic leukemia (ALL) who was found to have highly elevated intraocular pressure (IOP) during maintenance treatment when taking oral dexamethasone (6 mg/m²/day). Her IOP increased on day 5 after taking dexamethasone, reached a peak on day 7 or 8, and returned back to baseline on day 13 before anti-glaucoma medications were used. Thus, we prescribed IOP-lowering agents for 10 consecutive days starting on the day oral dexamethasone was administered, and observed that not only did the peak levels lower remarkably, but the IOP levels returned to baseline more rapidly as well.

Corneoscleral-ring-derived extracellular vesicles represent a potential therapeutic strategy for promoting in vitro corneal wound healing. In this study, we successfully isolated and characterized extracellular vesicles from human corneolimbal tissue obtained from 42 donors, with a mean age of 51.62 ± 15.56 years. Donor-related factors such as age, corneal endothelial cell density, and underlying systemic conditions did not confound extracellular vesicle size and concentration with mean peak size of 99.52 ± 13.00 nm by nanoparticle tracking analysis. Western blotting analysis revealed positive Alix, stable expression of CD9 and CD81, and variable expression of CD63. Limbal stem cell (LSC)-associated markers, i.e., ABCG2, p63, Notch-1, and Integrin α9 were positively detected in the isolated extracellular vesicles. Notably, Integrin α9 showed stable and relatively strong expression in all samples serving a specific marker of LSC-derived extracellular vesicles. Functional assays demonstrated that LSC-derived extracellular vesicles exhibited better wound healing potency compared to extracellular vesicles derived from mesenchymal stem cells (MSCs). These findings suggest that corneoscleral-ring-derived extracellular vesicles express distinct LSC markers, including Integrin α9, and hold significant potential for application in corneal wound healing and ocular surface regeneration.