A short term study of the additive effect of timolol and brimonidine on intraocular pressure.

PURPOSE: To evaluate the additive ocular hypotensive effect of the combination of brimonidine and timolol on intraocular pressure (IOP) reduction in patients with glaucoma. METHODS: This was a prospective, randomized, double-masked, crossover study in 20 patients with primary open angle glaucoma (POAG) on therapy receiving timolol maleate 0.5% twice daily, with IOP greater than or equal to 22 mmHg in one eye. The treatment period was 3 weeks and during this period timolol + brimonidine or timolol + placebo were applied topically twice daily and IOP, blood pressure, heart rate and pupil size were measured. RESULTS: Combined therapy (timolol + brimonidine) had clinically significant IOP-lowering effect during the treatment period P << 0.01). The mean diurnal IOP was significantly reduced by an average of 5.1-5.9 mmHg (21.2-24.5%) compared with baseline value. The timolol + placebo combination had no clinically significant IOP-lowering effect (P > 0.05). No clinically significant side effects were observed during the treatment of both groups. CONCLUSIONS: This study showed that the combination of topically applied brimonidine and timolol cause a marked and sustained IOP reduction.

Adverse effects of topical antiglaucoma drugs on the ocular surface.

PURPOSE: This study was designed to determine the effect of long-term antiglaucoma topical medication on the ocular surface; measuring basal Schirmer's and tear break-up time tests using conjunctival impression cytology. METHODS: The ocular surfaces of 30 control subjects (group 1), 24 primary open-angle glaucoma patients treated with 0.5% betaxolol hydrochloride (group 2), 27 primary open-angle glaucoma patients treated with 0.5% timolol maleate (group 3) and 26 primary open-angle glaucoma patients treated with 0.5% betaxolol and 1% dipivefrin hydrochloride (group 4) were evaluated. Basal Schirmer's and tear break-up time tests were measured and ocular surface changes were determined by impression cytology. Impression cytology specimens of each group were graded and scored in the range 0-3 according to Nelson's method. RESULTS: Patients in groups 2, 3 and 4 showed statistically significant fewer normal basal Schirmer's tests (wettability) and tear break-up time tests (P < 0.01). Also, the conjunctival impression cytology scores were significantly higher in groups 2, 3 and 4 than in group 1 (P < 0.01). CONCLUSIONS: The conclusion was that it is possible that conjunctival surface and tear film function change after the long-term use of antiglaucoma medication.

Extracapsular cataract extraction with posterior chamber lens implantation in capsular glaucoma.

PURPOSE: To evaluate intraocular pressure (IOP) control after extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (PCIOL) implantation in patients with capsular glaucoma (CG) and coexisting cataract. METHODS: This prospective study included 20 patients (20 eyes) having CG and cataract whose IOPs were under 22 mm Hg and controlled with antiglaucoma medication. All patients had ECCE with PCIOL implantation and the follow-up period was at least 18 months. IOP was measured postoperatively at 3, 6, 9, 12 and 18 months and compared with preoperative IOP. RESULTS: Following the cataract extraction, PCIOL implantation produced a statistically significant reduction in IOP at all time points compared with the preoperative IOP during the study period (p < 0. 001). The mean preoperative IOP was 18.25 +/- 1.83 mm Hg; postoperatively at 1 month, it was 13.45 +/- 2.06 mm Hg; at 3 months 14.80 +/- 2.50 mm Hg; at 6 months 15.35 +/- 1.27 mm Hg, at 12 months 14.85 +/- 1.87 mm Hg and at 18 months 15.15 +/- 1.42 mm Hg (p < 0. 0008). The mean reduction in IOP was 16.98% from baseline at 18 months postoperatively. The mean number of antiglaucoma medication was reduced from 1.35/eye preoperatively to 0.60/eye postoperatively at 18 months (p < 0.0007). CONCLUSION: The result of our study revealed that ECCE with PCIOL implantation may be a reliable choice in controlling IOP in patients with CG.

Effect of conjunctival structure and inflammatory cell counts on intraocular pressure after trabeculectomy.

PURPOSE: To evaluate the conjunctival structure and inflammatory cell counts and to determine the predictive value of these histological parameters for postoperative intraocular pressure (IOP) levels after trabeculectomy. METHODS: A clinical and histological study was performed on consecutive patients. Postoperative (mean 32. 8 +/- 18.4 months; range 6-60 months) conjunctival biopsies of 36 eyes of 28 primary open-angle glaucoma patients who had trabeculectomy between 1992 and 1995 were included in the study. According to postoperative pressure control, patients with < or = 16 mm Hg and those with >16 mm Hg were taken as groups 1 and 2, respectively. The control group (group 3) consisted of 15 age-matched patients without glaucoma, who had received no topical therapy. We compared the conjunctival structure and cell counts within these groups. Goblet cells, acute inflammatory cells, chronic inflammatory cells, fibroblasts, epithelial thickness, vascular density, mucopolysaccharides and collagen compositions were determined in groups 1, 2 and 3. RESULTS: The number of goblet cells was significantly higher in group 1 (6.74 +/- 7.23) than group 2 (3. 09 +/- 2.77; p = 0.017). No statistical difference was observed in the number of acute inflammatory cells, chronic inflammatory cells, fibroblasts, epithelial thickness, vascular density, mucopolysaccharide or collagen compositions between groups 1 and 2 (p > 0.05). In addition, when groups 1 and 2 were compared with the control group, there was a significant decrease in goblet cells (p < 0.001), an increase in acute inflammatory cells, chronic inflammatory cells, fibroblasts, epithelial thickness and vascular density (p < 0.001), but there was no significant difference in mucopolysaccharide and collagen compositions (p > 0.05). CONCLUSIONS: This study suggests that at the time of surgery a high number of goblet cells may be a predictor of lowered IOP (< or = 16 mm Hg) following trabeculectomy without antimetabolite.

In vitro potency and stability of fortified ophthalmic antibiotics.

PURPOSE: This study evaluates the in vitro potency, stability and contamination of the fortified ophthalmic antibiotic preparations of cefazolin, vancomycin, gentamicin and tobramycin stored for 4 weeks. The effects of the different solvents and storage temperatures on the antimicrobial potency and stability were also examined. METHODS: The fortified stock solution of cefazolin and vancomycin were prepared by reconstituting with 0.9% sodium chloride and with artificial tears. Gentamicin and tobramycin were prepared by adding parenteral forms into their commercial ophthalmic solutions. The antimicrobial potency was measured by the minimum bactericidal concentration for cefazolin (33.3 mg/mL) and vancomycin (31 mg/mL) against Staphylococcus aureus, and for tobramycin (13.5 mg/mL) and gentamicin (13.5 mg/mL) against Pseudomonas aeruginosa. The stability of solution was evaluated by measuring absorbance spectra and pH. During the study period the levels of contamination of the stock solutions were examined by culturing on blood and on Sabouraud-dextrose media. RESULTS: There were no differences in the antimicrobial potency of the cefazolin, vancomycin and tobramycin within the 4-week period; however, the potency of gentamicin was decreased at both temperatures after 21 days. It was found that different solvents or storage temperatures had no effect on the potency. Throughout the 4-week period, no change was found in the absorbance spectra of gentamicin and tobramycin, whereas the absorbance spectra of cefazolin and vancomycin stored at 24 degrees C increased in both of the solvents used (P<0.05). In all of the antibiotics, pH changed at 24 degrees C after 7-10 days; however, at 4 degrees C, only the pH of tobramycin exhibited changes after 14 days (P<0.05). No contamination was detected in the stock solutions during the study period. CONCLUSION: Topical fortified antibiotic solutions used for longer than 7 days should be stored at < or =4 degrees C, those stored at 24 degrees C should be discarded after 7 days.