Search

To treat unilateral limbal stem cell (LSC) deficiency, we developed cultivated autologous limbal epithelial cells (CALEC) using an innovative xenobiotic-free, serum-free, antibiotic-free, two-step manufacturing process for LSC isolation and expansion onto human amniotic membrane with rigorous quality control in a good manufacturing practices facility. Limbal biopsies were used to generate CALEC constructs, and final grafts were evaluated by noninvasive scanning microscopy and tested for viability and sterility. Cultivated cells maintained epithelial cell phenotype with colony-forming and proliferative capacities. Analysis of LSC biomarkers showed preservation of "stemness." After preclinical development, a phase 1 clinical trial enrolled five patients with unilateral LSC deficiency. Four of these patients received CALEC transplants, establishing preliminary feasibility. Clinical case histories are reported, with no primary safety events. On the basis of these results, a second recruitment phase of the trial was opened to provide longer term safety and efficacy data on more patients.

Objective: To study in a masked fashion whether an objective histological feature associated with keratoconus (KCN) occurs in donor corneas in eyes originally receiving a corneal graft for KCN., Methods: Two ocular pathologists performed a retrospective masked histological analysis of slides from donor buttons recovered from 21 eyes with a history of KCN undergoing repeat penetrating keratoplasty (failed-PK-KCN), 11 eyes that underwent their first PK due to KCN (primary KCN), and 11 eyes without history of KCN which underwent PK for other conditions (failed-PK-non-KCN). Breaks/gaps in Bowman's layer served as the pathological feature indicative of recurrent KCN., Results: Breaks in Bowman's layer were present in 18/21 (86%) of the failed-PK-KCN group, 10/11 (91%) of the primary KCN group, and in 3/11 (27%) of the failed-PK-non-KCN group. Pathological evidence suggests that the prevalence of breaks is significantly higher in grafted patients with a history of KCN than non-KCN controls (OR: 16.0, 95% CI 2.63 to 97.2, Fisher's exact test p=0.0018) with a conservative Bonferroni criterion of p <0.017 to account for multiple group comparisons. There was no statistically significant difference found between the failed-PK-KCN and primary KCN groups., Conclusions: This study provides histological evidence that breaks and gaps in Bowman's layer, consistent with those found in primary KCN, may develop within the donor tissue in eyes with a history of KCN., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To determine whether the lipid peroxidation inhibitor tirilazad mesylate can block the death of retinal ganglion cells induced by the inhibition of oxidative phosphorylation and glycolysis., Methods: Rat retinal ganglion cells were labeled retrogradely with the fluorescent tracer DiI, and mixed cultures were prepared. Cell death was induced with chemical hypoxia, hypoglycemia, or glycolysis inhibition, and the effect on cell survival of tirilazad mesylate was assessed., Results: Tirilazad mesylate enhanced relative ganglion cell survival after plating, with detectable effects at 200 nM and a maximal increase above diluent control of 148% +/- 2% at 20 microM. Relative survival at 24 hours in the presence of the complex IV inhibitor sodium cyanide (3 mM) was significantly greater when it was co-incubated with tirilazad mesylate than with diluent control (91.8% +/- 4.6% versus 39.3% +/- 7.1%; P = 0.008). Enhanced relative survival with tirilazad mesylate also was seen in cultures containing reduced glucose media., Conclusions: The lipid peroxidation blocker tirilazad mesylate inhibits retinal ganglion cell death in vitro. Because irreversible loss of retinal ganglion cells is the final common pathway in a variety of optic neuropathies, this or similar agents may be useful in animal models of optic neuropathies.