Comparison of the in-vitro effects of bevacizumab, mitomycin-C, 5-fluorouracil,and triamcinolone acetonide on the viability of cultured human tenon's fibroblasts

@#<p style="text-align: justify;"><strong>Objective:</strong> To evaluate and compare the effects of bevacizumab, mitoinycin-C (MMC), 5-fluorouracil (5-FU), and triamcinolone acetonide (TA) on the viability of cultured human Tenon's capsule fibroblasts (cHTF) in vitro.</p> <p style="text-align: justify;"><strong>Methods:</strong> Human Tenon's fibroblasts (HTF) were harvested and cultured in a Roswell-Park-Memorial 1-Institute (RPMI) media. MMC, 5-FU, bevaciz. umab, and TA were administered to the cHTF at 3-fold decreasing concentrations starting from 20 ug, 5 mg, 25 mg, and 4 mg respectively. A negative control/untreated group containing RPMI media only was included in the study. Fibroblast cell viability was assessed using resazurin fluorim etric assay. Half¬maximal inhibitory concentration (IC50) was computed for agents which showed significant decrease in cHTF viability compared to the untreated group.</p> <p style="text-align: justify;"><strong>Results:</strong> There was no significant difference in cH IF viability between the untreated control group compared to 5-FU (p=0.97), bevacizumab (p=0.10), and TA (p=0.06) groups. Mitomycin-C showed a significant decrease in cHTF viability (p<0.001) which was dose dependent. The IC50 of MMC was computed at 12.16 ug using the prism software.</p> <p style="text-align: justify;"><strong>Conclusion:</strong> Mitomycin-C demonstrated dose-dependent decrease in viability of cultured human Tenon's fibroblasts. 5-FU, bevacizumab, and triamcinolone did not show this effect.</p> <p style="text-align: justify;"><strong>Key Words:</strong> Mitomycin-C, 5-fluorouracil, Bevaciz. umab, Tria. mcinolone acetonide, Fibroblast, Trabeculectomy</p>

Effect of brimonidine on anterior-chamber angle in patients with narrow angles

Objective@#This study investigated the effect of brimonidine on the anterior-chamber angle in eyes with narrow angles using noncontact three-dimensional anterior-segment analyzer Pentacam.@*Methods@#Nine eyes with narrow angles were distributed to one of three treatment groups—single topical dose of 0.15% brimonidine tartrate, 0.5% timolol maleate (positive control), or balanced salt solution (negative control)—in a prospective, single-masked, crossover, comparative trial. The primary outcome measure was anterior-chamber angle at baseline, and 2 and 4 hours after instillation of the treatment drug. Secondary outcome measures were pupil diameter, intraocular pressure (IOP), and anterior-chamber depth and volume. After a two-week washout period, eyes were crossed over to the other treatment modes. All baseline and posttreatment measurements were taken. Repeated analysis of variance (ANOVA) was used for statistical analysis.@*Results@#Anterior-chamber angle, depth, and volume did not differ significantly for all treatment groups. Brimonidine caused a significant decrease in pupil diameter, most notably 2 hours after instillation, from baseline of 2.36 ± 0.37 mm to 2.17 ± 0.35 mm. (p = 0.03). There was a significant decrease in IOP from baseline to hour 4 after treatment for both brimonidine (11.4 ± 2.2 to 9 ± 1.8 mm Hg, p < 0.001) and timolol (11.9 ± 2.3 to 9.4 ± 2.1 mm Hg, p = 0.003).@*Conclusions@#Brimonidine produced a miotic trend with no significant opening of the anterior-chamber angle in patients with narrow angles.

Fluorophotometric measurements of aqueous-humor flow in post-YAG laser iridotomy for acute angle closure

Objective@#This study compared the rates of aqueous-humor flow and trabecular outflow in eyes that had undergone YAG laser iridotomy (LI) for primary-acute-angleclosure (PAC) attack and primary-angle-closure suspect (PACS).@*Methods@#Patients who had PAC attack in one eye and narrow occludable angles (PACS) in the other eye that had undergone YAG LI were recruited. All underwent complete ophthalmologic examination including gonioscopy, ultrasonic pachymetry, A scan, and fluorophotometry to determine the rate of aqueous-humor flow. The Goldmann equation was used to compute the outflow facility using the values of aqueous flow and intraocular pressure (IOP).@*Results@#Fifty eyes of 25 patients were included, 25 of which had PAC attack and 25 were PACS. The central corneal thickness (CCT), anterior-chamber depth, and anterior-chamber volume of the 2 groups were comparable. PAC-attack eyes had significantly higher IOP (18.4 mm Hg) than the PACS (14.12 mm Hg) (p = 0.001). The mean rate of aqueous flow was 2.50 ± 0.94 µL/min and 2.89 ± 1.17 µL/min in the PAC and PACS respectively (p = 0.20). The mean aqueous-outflow facility was 0.29 ± 0.18 µL/min and 0.59 ± 0.37 µL/min respectively (p = 0.0008).@*Conclusion@#A significantly lower aqueous-outflow facility was demonstrated by fluorophotometry among eyes with PAC. Despite the anatomically open angles, they continued to have higher IOPs.