and corneal antioxidant enzyme activities after refractive corneal surgery AbstractPurpose Refractive corneal surgery induces keratocyte apoptosis and generates reactive oxygen radicals (ROS) in the cornea. The purpose of the present study is to evaluate the correlation between keratocyte apoptosis and corneal antioxidant enzyme activities after different refractive surgical procedures in rabbits. Methods Rabbits were divided into six groups. All groups were compared with the control group (Group 1), after epithelial scraping (Group 2), epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK: Group 3), transepithelial PRK (Group 4), creation of a corneal flap with microkeratome (Group 5) and laserassisted in situ keratomileusis (LASIK, Group 6). Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nickend labelling assay (to detect DNA fragmentation in situ) and light microscopy were used to detect apoptosis in rabbit eyes. Glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities of the corneal tissues were measured with spectrophotometric methods. Results Corneal Gpx and SOD activities decreased significantly in all groups when compared with the control group (PϽ0.05) and groups 2, 3 and 6 showed a significantly higher amount of keratocyte apoptosis (PϽ0.05). Not only a negative correlation was observed between corneal SOD activity and keratocyte apoptosis (cc: ؊0.3648) but Gpx activity also showed negative correlation with keratocyte apoptosis (cc: ؊0.3587). Conclusion The present study illustrates the negative correlation between keratocyte apoptosis and corneal antioxidant enzyme activities. This finding suggests that ROS may be partly responsible for keratocyte apoptosis after refractive surgery.
Purpose: To evaluate the keratocyte apoptosis and effects of topical vitamin E on keratocyte apoptosis after photorefractive surgery. Methods: Rabbits were divided into 7 groups, and all groups were compared with controls after epithelial scraping, epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK), transepithelial PRK, production of a corneal flap with microkeratome and laser-assisted in situ keratomileusis (LASIK). The effects of topical Vitamin E treatment were investigated in the traditional PRK group. The terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy have been used to detect apoptosis in rabbit cornea. Results: Transepithelial PRK induced minimal keratocyte apoptosis, less than in all other refractive surgical procedures. The greatest amount of keratocyte apoptosis was observed after traditional PRK (p = 0.001), therefore we tested the effects of topical vitamin E in this group. The number of apoptotic keratocytes significantly reduced after vitamin E therapy (p < 0.005). Conclusion: Keratocytes undergo apoptosis after refractive surgery in response to mechanical epithelial removal, preparing of corneal flap and excimer laser stromal photoablation. The topical application of vitamin E immediately after surgery can prevent keratocyte apoptosis, and this result suggests that free radicals may be partly responsible for keratocyte apoptosis after excimer laser keratectomy.
We investigated the nasal mucociliary clearance time in 17 patients who underwent a primary unilateral external dacryocystorhinostomy operation. Mucociliary clearance function in both nasal cavities was assessed with the saccharin test. The results were compared with each other using paired samples t-test. We found significantly worse mucociliary clearance time on the operated side (mean: 6.3 min) than on the non-operated side (mean: 5.5 min) (P = 0.004). External dacryocystorhinostomy negatively affected the mucociliary clearance function in this study.
Single dose intravitreal triamcinolone acetonide injection is sufficient for controlling the active lesions in serpiginous choroiditis. It needs further evaluation as an alternative treatment for achieving rapid and significant visual acuity recovery.
In suspected extraocular muscle ruptures, orbital imaging methods and surgical exploration should be considered promptly. MRI may be mandatory to demonstrate the severed muscles in cases with persistent diplopia and normal CT. Prognosis is usually better in patients having partial extraocular muscle damage and treatment options should be evaluated on patient basis.
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