Expression of IRFs and iNOS in the Mouse Cornea with Pseudomonas Aeruginosa Keratitis

PURPOSE: To investigate the expression of IRF-1, IRF-7 and iNOS in the mice model of Pseudomonas aeruginosa keratitis. The enzymatic activity of iNOS and its expression were also investigated. METHODS: With western blot analysis, the protein expression of IRF-1, IRF-7 (at 24 hours), and iNOS (at 12 hours and 24 hours) were evaluated in the mouse model of P. aeruginosa keratitis. iNOS enzymatic activity was determined with a scintillation counter. IRF-1 and IRF-7 expression were localized with immunofluorescent labeling. The wounded control group was given the same corneal wound without bacterial inoculation, and the fellow eyes served as normal controls. RESULTS: Expression of IRF-1, IRF-7 and iNOS was highly upregulated in corneas with P. aeruginosa keratitis compared to normal or wounded corneas. iNOS enzymatic activity also was higher in infected than normal corneas. In wounded corneas, NOS2 expression and activity slightly increased at 12 hours after the infection. Intense IRF-1 immunopositivity was seen in the epithelial layer of infected corneas. Some corneal stromal cells and endothelial cells showed moderate positive labeling in infected corneas. IRF-7 showed intense labeling in the epithelial layer and endothelial cells of normal as well as infected corneas. Increased IRF-7 labeling was observed in epithelial cells in the ulcerated region of infected corneas. CONCLUSIONS: These results suggest that IRF-1, IRF-7 and iNOS may play a regulatory role in the immune responses and wound healing process in P. aeruginosa keratitis.

The Antibiotic Effect of BAC-STAT LASIK Ring in LASIK

PURPOSE: An attempt was made to determine if the pre-LASIK operative BAC-STAT LASIK Ring plays a role in reducing postoperative infection. METHODS: Candidates for this study were 72 eyes of 36 patients, scheduled to undergo LASIK operation. Eyes were divided into two groups: right eyes with preoperative BAC-STAT bacteriostatic LASIK Ring (BAC-STAT LASIK Ring: American Optisurgical Inc., Lake Forest, California, U.S.A.) and one minute of irrigation (experimental group), and left eyes with only preoperative BSS irrigation (control group). The authors tried to demonstrate a difference of identified pathogens between the two groups after a growth of bulboconjunctival lesion in blood agar plate (BAP), MacConkey agar plate (MCA), Thioglycolate medium broth (TG), and Ogawa egg medium. RESULTS: Among the patients receiving only BSS irrigation, pathogens were identified in eight eyes before surgery and in four eyes after surgery in BAP and MCA medium. Among the patients receiving BAC-STAT LASIK Ring and irrigation, pathogens were identified in nine eyes before surgery and in three eyes after surgery in BAP and MCA culture medium. In addition, among the control population, pathogens were found in 21 eyes both before and after surgery in TG culture medium. However, among the experimental population, pathogens were grown in 23 eyes before surgery but in only 14 eyes after surgery. No growth of pathogens was reported in all patients before and after surgery in a 4-week Ogawa egg culture medium. CONCLUSIONS: This study suggests that preoperative BAC-STAT LASIK Ring insertion followed by irrigation decreases the incidence of postoperative infection.

The Effect of Nerve Growth Factor on Corneal Sensitivity after Laser in Situ Keratomileusis

PURPOSE: To determine if topically administered nerve growth factor (NGF) plays a role in accelerating the recovery of corneal sensitivity after laser in situ keratomileusis (LASIK). METHODS: A prospective double-masked study comparing the effect of topical NGF or balanced salt solution on corneal sensitivity after LASIK in rabbits was performed. Pre- and postoperative corneal sensitivity was assessed using the Cochet-Bonnet esthesiometer. RESULTS: Eyes that were treated with topical NGF demonstrated an earlier and faster recovery of corneal sensitivity after LASIK (p=0.0071). A statistically significant difference in corneal sensitivity was found between the topical NGF and control group at the postoperative time points of 2 weeks (p=0.0098), 3 weeks (p=0.0309), and 4 weeks (p=0.0276). CONCLUSIONS: Our results suggest that topically administered NGF plays a significant role in accelerating corneal reinnervation after LASIK.

Effect of Antibiotic Suplementation of Balanced Salt Solution(BBS) Infusion During Cataract Surgery in vitro Experimental Model

We studied the effect of antibiotics (vancomycin(20microgram/ml) and gentamicin(8microgram/ml)) supplemented Balanced Salt Solution(BBS) infusion in reducing bacterial colonization during cataract surgery for an in-vitro eye model using sterilized Marty surgical simulator. We inoculated 107 logarithmic growth phase organisms of either gram(+), Staphylococcus aureus or gram(-), Pseudomonas aeruginosa into the anterior chamber prior to cataract surgery. Eyes using BSS infusion without antibiotic suplementation during cataract surgery served as controls. The contents of the anterior chamber were aspirated at the end of simulated cataract surgery and innoculated on appropriate culture media. The culture media were incubated at 37degrees C for 24hours and subsequently quantitative bacteriologic analysis was performed. There was no statistically significant difference between eyes which received antibiotic supplemented BSS infusion compared with eyes which received non-antibiotic supplemented BSS infusion at the end of the operation, but there was statistically significant difference between two groups 24 hours later(p<0.05).