Effect of Diquafosol on Hyperosmotic Stress-induced Tumor Necrosis Factor-α and Interleukin-6 Expression in Human Corneal Epithelial Cells

In Vivo Effects of Preservative-free and Preserved Prostaglandin Analogs: Mouse Ocular Surface Study

PURPOSE: Chronic use of topical hypotensive agents induces several side effects caused by preservatives. The purpose of this study was to evaluate the effects of prostaglandin analogs with varying concentrations of benzalkonium chloride (BAC), preservative-free (PF), and alternative preservatives on mouse corneal tissue. METHODS: Thirty-five, 8- to 10-week-old female C57BL/6 mice (five mice for each group) were used for this study. To the control group, we applied normal saline, and to each drug-treated group we applied 0.02% BAC, bimatoprost 0.01% (with BAC 0.02%), latanoprost 0.005% (with BAC 0.02%), travoprost 0.004% (with 0.001% polyquad) or tafluprost 0.0015% with/without 0.001% BAC, once a day (9 p.m.) for 4 weeks. Corneal fluorescein staining was evaluated in all groups. After harvest, the corneal tissues were embedded in paraffin and then Hematoxylin-Eosin stain was performed for histopathological examination. Immunofluorescence staining was done against TNF-alpha, IL-6, HLA DR, pJNK, and pAkt. RESULTS: In corneal fluorescein staining, severe punctate epithelial keratitis was seen in the groups of 0.02% BAC, 0.02% BAC containing bimatoprost 0.01% and latanoprost 0.005%. The surface desquamation, irregular surface, loss of cell borders, anisocytosis and stromal shrinkage were observed in the groups of BAC-containing eye drops. Moreover, the groups treated with BAC-containing eye drops have high inflammatory markers, significantly decreased cell viability-related signal, pAkt, and higher apoptosis-inducing signal, pJNK, than the control group. On the other hand, travoprost 0.004% and PF tafluprost 0.0015% have less cellular morphologic changes, lower inflammation, and higher cellular viability than BAC-containing formulations. CONCLUSIONS: Corneal damage, increased inflammation and apoptosis and low cell viability were observed in BAC-containing groups. PF or alternatively preserved glaucoma medications seem to be a reasonable and viable alternative to those preserved with BAC.

The Effect of Subconjunctival Bevacizumab Injection before Conjunctival Autograft for Pterygium

PURPOSE: To evaluate the effect of subconjunctival bevacizumab injection before conjunctival autograft for pterygium. METHODS: Twenty-five eyes (25 patients) with pterygium received a subconjunctival injection of 2.5 mg (0.1 mL) bevacizumab 1-2 weeks prior to conjunctival autograft surgery. The control group (25 eyes of 25 patients) received the same operation. Two weeks, 1 month and every month after the surgery, the vascularization of surgical site, the recurrence rate and the effect of wound healing were analyzed. RESULTS: The bevacizumab group showed a decreased conjunctival vascularity grade compared with the control group based on light microscopy. The bevacizumab group also showed lower vascular epithelial growth factor (VEGF) compared with the control group using immunohistochemical analysis and western blot. There was no recurrence in both groups, but, persistent autograft edema was observed at 8 weeks postoperatively in the bevacizumab group. CONCLUSIONS: Although preoperative injection of bevacizumab effectively reduced vascularity and VEGF concentration of pterygium tissue, prolonged autograft edema was observed. Based on these results, bevacizumab inhibits lymphangiogenesis as well as angiogenesis. Therefore, delayed wound healing should be considered when subconjunctival bevacizumab injection is administered before pterygium surgery.

In Vitro Effects of Preservative-free and Preserved Prostaglandin Analogs on Primary Cultured Human Conjunctival Fibroblast Cells

PURPOSE: Long-term use of topical medication is needed for glaucoma treatment. One of the most commonly prescribed classes of hypotensive agents are prostaglandin analogs (PGs) used as both first-line monotherapy; as well as in combination therapy with other hypotensive agents. Several side effects of eye drops can be caused by preservatives. The purpose of this study was to evaluate the effects of PGs with varying concentrations of benzalkonium chloride (BAC), alternative preservatives, or no preservatives on human conjunctival fibroblast cells. METHODS: Primary human conjunctival fibroblast cells were used in these experiments. Cells were exposed to the following drugs: BAC at different concentrations, bimatoprost 0.01% (with BAC 0.02%), latanoprost 0.005% (with BAC 0.02%), tafluprost 0.0015% with/without 0.001% BAC and travoprost 0.004% (with 0.001% Polyquad) for 15 and 30 minutes. Cell cytotoxicity was evaluated by phase-contrast microscopy to monitor morphological changes of cells, Counting Kit-8 (CCK-8) assay to cell viability, and fluorescent activated cell sorting (FACS) analysis to measure apoptosis. RESULTS: BAC caused cell shrinkage and detachment from the plate in a dose-dependent manner. Morphological changes were observed in cells treated with bimatoprost 0.01% and latanoprost 0.005%. However, mild cell shrinkage was noted in cells treated with tafluprost 0.0015%, while a non-toxic effect was noted with travoprost 0.004% and preservative-free tafluprost 0.0015%. CCK-8 assay and FACS analysis showed all groups had a significantly decreased cell viability and higher apoptosis rate compared with the control group. However, travoprost 0.004% and preservative-free tafluprost 0.0015% showed lower cytotoxicity and apoptosis rate than other drugs. CONCLUSIONS: This in vitro study revealed that BAC-induced cytotoxicity is dose-dependent, although it is important to emphasize that the clinical significance of toxicity differences observed among the different PGs formulations has not yet been firmly established. Alternatively preserved or preservative-free glaucoma medications seem to be a reasonable and viable alternative to those preserved with BAC.