Safety of Intracameral Moxifloxacin/Dexamethasone fixed-dose formulation on the Corneal Endothelium in a rabbit model

Objective@#To determine the safety of intracamerally injected preservative-free 0.5% moxifloxacin/0.1% dexamethasone fixed-dose combination on the corneal endothelium in a rabbit model and compare it to intracamerally injected preservative-free 0.5% moxifloxacin. @*Methods@#This experimental study included twenty eyes from ten albino rabbits. The eyes were assessed for baseline corneal clarity and anterior chamber (AC) inflammation using slit-lamp biomicroscopy. A specular microscope measured the corneal endothelial cell density (ECC) and corneal thickness (CT). Intracameral injections of 0.1 mL 0.5% moxifloxacin ophthalmic solution were administered to the 10 right eyes (IPFM group) and 0.1 mL of 0.5% moxifloxacin/0.1% dexamethasone fixed-dose preparation were administered to the 10 left eyes (IPFMDex group). In both groups, ECC, CT, corneal clarity, and AC inflammation at Day 1 (one day post-injection) and Day 7 (seven days post-injection) were compared with Day 0 (baseline). The IPFMDex group was also compared with the IPFM group at Days 0, 1, and 7. The endothelial cells of harvested corneas from both groups at Day 1 and 7 were stained with trypan blue and alizarin red, and compared for endothelial cell damage (ECD). Data were analyzed using paired and independent sample t-tests.@*Results@#In both the IPFM and IPFMDex groups, ECC and CT at Day 1 (IPFM: ECC p=0.07, CT p=0.76; IPFMDex: ECC p=0.41, CT p=0.94) and Day 7 (IPFM: ECC p=0.95, CT p=0.28; IPFMDex: ECC p=0.29, CT p=0.34) were not different from Day 0 (baseline). No significant difference in ECC, CT, and ECD were found between the IPFM and IPFMDex groups at Day 1 (ECC p=0.82, CT p=0.36, ECD p=0.96) and Day 7 (ECC p=0.95, CT p=0.22, ECD p=0.61). Throughout the study, the cornea in both groups were clear and showed no signs of AC inflammation. @*Conclusion@#Intracameral injection of preservative-free moxifloxacin/dexamethasone fixed-dose formulation was safe on the rabbit corneal endothelium and was no different from preservative-free moxifloxacin.

Safety of intracameral moxifloxacin/dexamethasone fixed-dose formulation on the corneal endothelium in a rabbit model

@#<p style="text-align: justify;"><strong>OBJECTIVE:</strong> To determine the safety of intracamerally injected preservative-free 0.5% moxifloxacin/0.1% dexamethasone fixed-dose combination on the corneal endothelium in a rabbit model and compare it to intracamerally injected preservative-free 0.5% moxifloxacin.</p> <p style="text-align: justify;"><strong>METHODS:</strong> This experimental study included twenty eyes from ten albino rabbits. The eyes were assessed for baseline corneal clarity and anterior chamber (AC) inflammation using slit-lamp biomicroscopy. A specular microscope measured the corneal endothelial cell density (ECC) and corneal thickness (CT). Intracameral injections of 0.1 mL 0.5% moxifloxacin ophthalmic solution were administered to the 10 right eyes (IPFM group) and 0.1 mL of 0.5% moxifloxacin/0.1% dexamethasone fixed-dose preparation were administered to the 10 left eyes (IPFMDex group). In both groups, ECC, CT, corneal clarity, and AC inflammation at Day 1 (one day post-injection) and Day 7 (seven days post-injection) were compared with Day 0 (baseline). The IPFMDex group was also compared with the IPFM group at Days 0, 1, and 7. The endothelial cells of harvested corneas from both groups at Day 1 and 7 were stained with trypan blue and alizarin red, and compared for endothelial cell damage (ECD). Data were analyzed using paired and independent sample t-tests.</p> <p style="text-align: justify;"><strong>RESULTS:</strong> In both the IPFM and IPFMDex groups, ECC and CT at Day 1 (IPFM: ECC p=0.07, CT p=0.76; IPFMDex: ECC p=0.41, CT p=0.94) and Day 7 (IPFM: ECC p=0.95, CT p=0.28; IPFMDex: ECC p=0.29, CT p=0.34) were not different from Day 0 (baseline). No significant difference in ECC, CT, and ECD were found between the IPFM and IPFMDex groups at Day 1 (ECC p=0.82, CT p=0.36, ECD p=0.96) and Day 7 (ECC p=0.95, CT p=0.22, ECD p=0.61). Throughout the study, the cornea in both groups were clear and showed no signs of AC inflammation.</p> <p style="text-align: justify;"><strong>CONCLUSION:</strong> Intracameral injection of preservative-free moxifloxacin/dexamethasone fixed-dose formulation was safe on the rabbit corneal endothelium and was no different from preservative-free moxifloxacin.</p>

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>

Correlation between average retinal nerve fiber layer thickness and rim area of the spectral-domain OCT with the Humphrey visual field index in eyes with glaucoma

@#<p style="text-align: justify;"><strong>OBJECTIVE:</strong> To determine the correlation between the average retinal nerve fiber layer (RNFL) thickness and optic nerve head rim area (RA) measured with a spectral-domain optical coherence tomography (OCT) with the visual field index (VFI) using the Humphrey Visual Field Analyzer in glaucoma patients.<br /><strong>METHODS:</strong> Eighty-five consecutive patients diagnosed with glaucoma underwent spectral-domain OCT of the optic disc and Humphrey perimetry. A glaucoma specialist confirmed the presence of glaucomatous optic neuropathy based on findings in the optic nerve head photographs, OCT measurements of the RNFL and optic disc, and standard automated perimetry. The correlation of the average RNFL thickness and rim area with the VFI was determined using the Spearman's correlation coefficient analysis.<br /><strong>RESULTS:</strong> A total of 121 glaucomatous eyes of 85 patients were included in the study. There were 47 males and 38 females, ages ranging from 12 to 94 years. The average RNFL thickness, RA, and VFI were 67.9 ± 12.3 ?m, 0.65 ± 0.3 mm2, and 56 ± 32%, respectively. The average RNFL thickness (r = 0.35) showed a stronger positive correlation with VFI than RA (r = 0.15), but the difference was not statistically significant.<br /><strong>CONCLUSION:</strong> The average RNFL thickness and rim area of the spectral-domain OCT demonstrated a positive correlation with the VFI of the Humphrey Visual Field Analyzer. The OCT parameters, exemplified by average RNFL and RA, were not good indicators for VFI.</p>

Correlation of average RNFL thickness using the STRATUS OCT with the perimetric staging of glaucoma

Objective@#To determine the correlation between average peripapillary retinal nerve fiber layer (RNFL) thickness measured with time domain optical coherence tomography (TD-OCT) in normal and glaucoma eyes. @*Methods@#This was a cross-sectional study of 281 eyes randomly selected from a previous study. Assessment of glaucomatous damage was done by glaucoma specialists who based their diagnosis on the visual field tests and optic disc photos, independent of OCT results. Eyes were classified into the following groups: normal, mild, moderate, or severe glaucoma. Severity of glaucoma was based on visual field abnormalities following a modified HodappAnderson-Parish criteria for staging. Average RNFL thickness of normal and glaucoma subgroups, as measured with STRATUS–OCT, were analyzed using single ANOVA test. Association between average RNFL thickness and severity of glaucomatous visual field loss was evaluated using the Pearson’s correlation coefficient analysis. @*Results@#183 eyes had no glaucoma; 27 had mild, 32 had moderate, and 39 had severe glaucoma. Mean average peripapillary RNFL thickness (μm) in the normal, mild, moderate, and severe glaucoma groups were 98.05(±13.46), 76.27(±11.79), 76.42(±16.01), and 56.17(±14.92) respectively. Significant differences were seen in the average RNFL thickness among the groups (P<0.05), except in eyes with mild to moderate glaucoma. A moderately strong correlation of -0.57 (P<0.05) was observed between average RNFL thickness and the stage of glaucoma. @*Conclusion@#TD-OCT showed moderately strong correlation between the average RNFL thickness and perimetric stages of glaucoma. Average RNFL thickness is a good parameter to discriminate normal from glaucoma eyes.

Diagnostic accuracy of the optical coherence tomography in assessing glaucoma among Filipinos. Part 2: Optic nerve head and retinal nerve fiber layer parameters

Objective@#To determine the accuracy of the optic nerve head (ONH) and retinal nerve fiber layer (RNFL) parameters using the Stratus OCT in the diagnosis of glaucoma and to determine the validity of these measurements. @*Methods@#Glaucoma suspects undergoing glaucoma diagnostic tests were recruited consecutively. The numerical results of the Stratus OCT fast optic disc and fast RNFL protocols were analyzed against an independent assessment by glaucoma experts who were blinded as to the results of the OCT. An ROC curve analysis was applied to derive estimates of diagnostic accuracy and multi-level likelihood ratios.@*Results@#A total of 119 subjects assessed as glaucoma and 397 subjects assessed as normal were included. All ONH and RNFL OCT parameters showed statistically significant differences in mean values between the 2 groups. The ROC curve identified the vertical integrated rim area (AUC: 0.822), the cup-disc area ratio (AUC: 0.816), and the horizontal integrated rim width (AUC: 0.794) as the best optic disc parameters; and the RNFL average thickness (AUC: 0.827), the superior quadrant (AUC: 0.807), and the inferior quadrant (AUC: 0.804) as the best RNFL parameters. Multi-level likelihood ratios for ONH and RNFL parameters were calibrated using a projected posttest probability of 70% for a positive test result (therapeutic threshold) and a 10% posttest probability for a negative result (diagnostic threshold). @*Conclusion@#The results showed that statistically significant mean differences in ONH and RNFL parameters did not translate into a high predictive ability for each individual parameter. Single cut-off value for each OCT parameter based on the best sensitivity and specificity combination did not result in high predictive values for any single parameter. Multi-level likelihood ratios for the best ONH and RNFL parameters were derived to increase the diagnostic capability of the Stratus OCT.

Diagnostic accuracy of the optical coherence tomography in assessing glaucoma among Filipinos. Part 1: Categorical outcomes­ based on a normative database

Objective@#To determine the accuracy of the optic nerve head (ONH) and retinal nerve fiber layer (RNFL) parameters using the Stratus OCT in diagnosing glaucoma among Filipino patients and to determine the validity of the OCT measurements compared with a reference standard. @*Methods@#Glaucoma suspects were recruited consecutively from patients undergoing diagnostic tests. The results of the Stratus OCT fast RNFL protocol were analyzed against the independent assessment by glaucoma experts who were blinded. Outcomes included RNFL thickness values of ≤5 percentile and ≤1 percentile of the normative database for each RNFL sector, quadrant, and for the average RNFL thickness. Estimates of diagnostic accuracy with 95% confidence intervals were calculated.@*Results@#A total of 119 subjects assessed as glaucoma and 397 subjects assessed as normal were included in the analysis. Using the best categorical criterion for abnormality (average RNFL thickness of ≤1 percentile of the normative database), the OCT had a specificity of 98% (95% CI 96 - 99) and a sensitivity of 37% (95% CI 28 - 46). The criterion with the highest sensitivity was the presence of at least one sector with thickness at ≤5 percentile. @*Conclusion@#The Stratus OCT demonstrated a specificity of 98% and a sensitivity of 37% for the diagnosis of glaucoma using as a criterion an average RNFL thickness of ≤1 percentile of the normative database. It was a poor screening test for glaucoma suspects, although it showed some promise as a confirmatory test.

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.