Effects of brinzolamide on rabbit ocular blood flow in vivo and ex vivo

Examination of retinal vascular density changes via optical coherence tomography angiography in patients with glaucoma

PURPOSE

The aim of this study was to investigate the changes in vessel density (VD) in glaucoma patients and to investigate the relationship between VD and structural parameters using optical coherence tomography angiography.

METHODS

Our study included 25 primary open-angle glaucoma (POAG) patients, 25 pseudoexfoliation glaucoma (PXG) patients and 25 healthy individuals. All patients underwent 6 × 6 mm retinal angiography (upper limit: internal limitan membrane [ILM], lower limit: 10 µm inferior to inner plexiform layer) and 4.5 × 4.5 mm disk angiography (upper limit: ILM, lower limit: posterior border of the retinal nerve fiber layer [RNFL]) via an optical coherence tomography (OCT) system (AngioVue, Optovue). Measures of vascular density were as follows: total area VD (tVD), intrapapillary VD (iVD), peripapillary VD (pVD) and parafoveal VD (pfVD). In addition to performing comparisons, the correlations between pVD, retinal nerve fiber layer (RNFL) thickness and optic nerve head measurement results were investigated.

RESULTS

A total of 75 individuals were included in our study. In the POAG and PXG groups, tVD and pVD values were significantly lower than the control group (median tVDs were: 45.4, 45.9, 50.0, and median pVDs were: 50.0, 50.3, 53.1, respectively) (confidence intervals were: - 9.8/- 1.1 for pVD and - 8.6/- 1.4 for tVD). Significantly lower pf-VD values were detected in the PXG group compared to the control group (p < 0.05). There were strong positive correlations between RNFL thickness and pVD in in glaucoma groups (p < 0.001). There was no correlation between pVD and disk area, intraocular pressure and age in glaucoma patients. Patients using beta-blockers had significantly lower tVD and pVD values compared to those who did not (p < 0.05).

CONCLUSION

The low VD values in glaucomatous eyes and the strong correlations between that values and RNFL thickness demonstrate a relationship between structural parameters and vascular parameters.

Efficacy and Safety of Brinzolamide as Add-On to Prostaglandin Analogues or β-Blocker for Glaucoma and Ocular Hypertension: A Systematic Review and Meta-Analysis

Background: Brinzolamide as a carbonic anhydrase inhibitor could be combined with other intraocular pressure (IOP) lowering drugs for glaucoma and ocular hypertension (OHT), but the efficacy was controversial. So, this study was used to assess the efficacy and safety of brinzolamide as add-on to prostaglandin analogues (PGAs) or β-blocker in treating patients with glaucoma or OHT who fail to adequately control IOP.

Methods: We searched PubMed, Embase, MEDLINE, Cochrane Library, and clinicaltrials.gov from inception to October 4, 2018. Randomized controlled trials of brinzolamide as add-on to PGAs or β-blocker for glaucoma and OHT were included. Meta-analysis was conducted by RevMan 5.3 software.

Results: A total of 26 trials including 5,583 patients were analyzed. Brinzolamide produced absolute reductions of IOP as an adjunctive therapy for patients with glaucoma or OHT. Brinzolamide and timolol were not significantly different in lowering IOP as add-on to PGAs (9 am: P = 0.07; 12 am: P = 0.66; 4 pm: P = 0.66). Likewise, brinzolamide was as effective as dorzolamide in depressing IOP (9 am: P = 0.59; 12 am: P = 0.94; 4 pm: P = 0.95). For the mean diurnal IOP at the end of treatment duration, there were no statistical differences in above comparisons (P > 0.05). Compared with brimonidine (b.i.d.), there was a significant reduction of IOP in brinzolamide (b.i.d.) at 9 am (P < 0.0001); however, the difference was cloudy in thrice daily subgroup (P = 0.44); at 12 am, brinzolamide (b.i.d.) was similar to brimonidine (b.i.d.) in IOP-lowering effect (P = 0.23), whereas brimonidine (t.i.d.) led to a greater effect than brinzolamide (t.i.d.) (P = 0.02). At 4 pm, brinzolamide (b.i.d.) was superior IOP-lowering effect compared with brimonidine (b.i.d.) (P = 0.0003); conversely, the effect in brinzolamide (t.i.d.) was lower than brimonidine (t.i.d.) (P < 0.0001). For the mean diurnal IOP, brinzolamide was lower in twice daily subgroup (P < 0.00001); brimonidine was lower in thrice daily subgroup (P < 0.00001). With regard to the safety, brinzolamide and dorzolamide had a higher incidence of taste abnormality; moreover, brinzolamide resulted in more frequent blurred vision; dorzolamide resulted in more frequent ocular discomfort and eye pain. Timolol resulted in more frequent blurred vision and less conjunctival hyperemia. Brimonidine resulted in more frequent ocular hyperemia. As to other adverse events (AEs) (conjunctivitis, eye pruritus, foreign body sensation in eyes, and treatment-related AEs), brinzolamide was similar to other three active comparators.

Conclusions: Brinzolamide, as add-on to PGAs or β-blocker, significantly decreased IOP of patients with refractory glaucoma or OHT and the AEs were tolerable.