Search

Purpose: This study was carried out to determine the ocular pharmacokinetics, efficacy and potential endothelial toxicity of moxifloxacin (MF) after a single intracameral bolus injection of 500 µg/0.1 ml in a rabbit model. Materials and methods: Forty-eight eyes of 24 New Zealand White Rabbits were separated into six groups, each including four rabbits. 0.1 ml of 0.5% intracameral moxifloxacin (500 µg) injection was injected to the right eyes and 0.1 ml of balanced salt solution to the left eyes (control). Aqueous humor (AH) and vitreous samples were collected at the 0.5th, 1st, 3rd, 6th, 12th and 24th hours from both eyes of group 1, 2, 3, 4, 5 and 6, respectively. MF concentrations were determined by high performance liquid chromatography. These were compared with the minimum inhibitory concentrations (MIC) and mutant prevention concentrations (MPC) for frequent endophthalmitis pathogens. Electron and light microscopical evaluation of the corneas were performed. Results: Moxifloxacin reaches higher concentration than the MIC of all common endophthalmitis pathogens in the AH and exceeds the mutant prevention concentration levels for Streptococcus pneumonia, Streptococcus viridans, flouroquinolone susceptible Coagulase-negative staphylococcus and flouroquinolone susceptible Staphylococcus aureus for 6 h. The half-life of moxifloxacin in the AH was 2.2 h. Electron and light microscopic evaluation revealed no noticeable sign of toxicity. Conclusions: Peroperative intracameral moxifloxacin injection for endophthalmitis prophylaxis is a safe and effective method in uncomplicated phacoemulsification surgery. [ABSTRACT FROM AUTHOR]

To investigate the visual field with FASTPAC 30-2 program before and after hemodialysis in patients with end stage renal disease. Twenty eyes of 20 patients on regular hemodialysis were included in the study. Twenty eyes of 20 healthy patients were chosen as control group. Intraocular pressures (IOP) were measured one hour before and one hour after the same hemodialysis session, and visual field was tested at the same times. When IOP was compared before and after hemodialysis, no statistically significant difference was found (p > 0.05), however Mean Deviation (MD) (p = 0.008) improved after hemodialysis. When we compared first global indices of the control group with pre-hemodialysis global indices, we noted significant difference in MD (p = 0.009). Visual field testing should be done after hemodialysis in patients who are on regular hemodialysis program. [ABSTRACT FROM AUTHOR]

Dry eye disease (DED) is a common condition with signs and symptoms that vary depending on a wide range of environmental factors to which people are exposed in their daily lives. Factors such as variable temperature, airflow velocity, relative humidity, seasonality, and pollutants can alter the rate of tear film evaporation, improving or exacerbating symptoms of DED. Results from currently available clinical tests do not always correlate well with patient-reported symptoms, and the continually changing environment and variability in DED symptoms present challenges for the design and conduct of clinical trials. Controlled adverse environment chambers allow standardization of temperature, humidity, and airflow and may minimize potential confounding factors in clinical investigations. Their use can promote accurate study of the pathophysiology of DED, discovery of disease biomarkers, and assessment of the effect of various therapeutic approaches on patients’ symptoms. Controlled adverse environment chambers have been used to simulate indoor surroundings such as airplane cabins and to test their effects on contact lens wearers. This review summarizes how these chambers may be useful for the development, approval, and differentiation of potential new treatments for DED. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the efficacy and safety of suramin, genistein and collagen matrix for the prevention of inflammation, the reduction of fibrosis and the delay in adjustment after strabismus surgery on a rabbit model. Methods: By using an adjustable suture technique, a recession of the superior rectus muscle (SRM) was made in 36 eyes of 18 rabbits. Three study groups were created using genistein, suramin and collagen matrix (n = 6 per group). Two control groups utilized dimethyl sulphoxide (DMSO) (n = 6) and balanced salt solution (n = 12). The adjustments and measurements were made on days 2, 7, 14. After enucleation was done on day 21, the degree of inflammation was evaluated quantitatively in histopathological sections and immunohistochemical investigations were performed for tissue expression of cytoplasmic vascular endothelial growth factor (VEGF), MAC 387, TGF-β and bFGF. Results: The adhesions between conjunctiva and SRM were significantly less in the collagen matrix and suramin groups (p = 0.002) and adhesions between the sclera and SRM were considerably reduced in the genistein and DMSO groups (p = 0.006) on day 7. Force exerted for adjustment was significantly less in the collagen matrix and suramin groups on day 14 (p = 0.006). Expression of b-FGF was significantly lower in the conjunctival epithelium in the suramin and genistein groups (p = 0.0001 for both). TGF-β was significantly lower (p = 0.001) in the suramin group and VEGF expression was totally absent. MAC 387 expression was lower in the genistein and suramin groups (p = 0.0001). Conclusion: Suramin, genistein and collagen matrix successfully reduce adhesions, and facilitate adjustment following recession surgery. Both suramin and genistein effectively suppress growth factor expression, while collagen matrix offers the longest time interval for adjustability after strabismus surgery. [ABSTRACT FROM PUBLISHER]

Purpose: To evaluate the ocular surface changes in a rabbit dry eye model by using a modified impression cytology technique. Methods: Nitrocellulose filter paper with a pore diameter of 0.45 μ m was used to collect the specimens from 12 rabbits that were injected with atropine every day for 3 days. Filter papers were kept in distilled water overnight and then dried to increase cell pickup. Samples were stained with periodic acid-Schiff. The mean temporal and superior bulbar conjunctival goblet cell densities were counted. The data were compared with transmission (ocular surface) and scanning electron microscopic (filter paper) examination of the ocular surface. Results: In the acute stage of atropine injection, there was not a major change in the goblet cell count. Although the goblet cell distribution was variable over the ocular surface, the average cell density was 55.4 ± 22 in the superior quadrant and 69.2 ± 9 in the temporal quadrant. In the 3-day atropine-injection group, there was a marked decrease in goblet cells, and there was mucin accumulation rather than accumulation of the goblet cells. No morphologic differences could be observed with scanning electron microscopy between the regular nitrocellulose filter paper and the paper kept in distilled water. Conclusions: The findings indicate that keeping the filter paper in distilled water and then drying it improves cell pickup and ocular surface evaluation in rabbits. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of alpha-1 adrenergic blockers on pupil diameter (PD) in rats. Methods: Four groups, with 10 rats each, were designed to receive terazosin, tamsulosin, doxazosin, and no medication. Dilated pupil diameter (PD) measurements were performed 24 hr before, 24 hr after, and 30 days after the initiation of medication, and after 30 days of washout. The intergroup and intragroup differences in PD were evaluated using one-way ANOVA and Wilcoxon signed rank test, respectively. Results: In day 1, PD decreased in both eyes significantly only in tamsulosin and doxazosin groups, but these effects became insignificant at 30 days of treatment (p > 0.05). The control group showed no significant difference in PD (p > 0.05). PD values returned to baseline after the washout period in all groups. Conclusions: A significant reduction in PD occurred in two of the three groups with alpha-1 adrenergic blockers (tamsulosin and doxazosin), but this effect was not sustained at 30 days. Further functional and structural studies of the iris are needed to determine the clinical significance of these findings. [ABSTRACT FROM AUTHOR]

To evaluate histopathologic and clinical response to silicone plug insertion in dry eye patients. Punctal plugs were placed in 32 eyes of 18 dry eye patients with aqueous deficiency who were on maximum medical therapy and who had Schirmer testing with topical anesthetic measuring less than 5 mm. Pre-treatment and post-treatment (6 weeks and 1 year) evaluations included temporal and inferior quadrant impression cytology examinations, Schirmer-1, BUT, corneal fluorescein and rose-bengal staining patterns and questionnaire scores. The cytology samples were graded according to the method described by Nelson. There was an improvement in subjective symptoms of patients 6 weeks after punctal occlusion. Corneal fluorescein and rose-bengal staining scores decreased from a mean of 5.33 ± 1.74 to 1.37 ± 1.48 and from 5.90 ± 1.2 to 2.45 ± 1.89 (p < 0.05) respectively. BUT values increased from 2.98 ± 1.1 to 11.3 ± 3.1 seconds (p < 0.05) at 6 weeks post-treatment. Increase in goblet cell density was observed after punctal occlusion at 6 weeks (p < 0.05) and at 1 year (p < 0.05) compared to the pre-treatment values. After occlusion, 3% of temporal specimens had Grade 0 squamous metaplasia, 63% had Grade 1, 34% had Grade 2; while 25% of inferior specimens had Grade 0, 56% had Grade 1, 19% had Grade 2 squamous metaplasia. Punctum plug occlusion in keratoconjunctivitis sicca provides improvement of tear film stability, ocular surface staining scores, conjunctival squamous metaplasia grades and globlet cell density. Increased ocular surface exposure to essential tear components with punctal occlusion may be important for the genesis of these changes. [ABSTRACT FROM AUTHOR]