The objective of this study was to examine the safety and intraocular pressure (IOP)-lowering efficacy of a fixed combination of brinzolamide 1% + brimonidine 0.2% (BBFC) after six months of treatment in patients with open-angle glaucoma or ocular hypertension.This was a randomized, multicenter, double-masked, three-month, three-arm contribution-of-elements study with a three-month safety extension. Patients were randomly assigned 1:1:1 to treatment with BBFC, brinzolamide 1%, or brimonidine 0.2% after a washout period. Patients dosed their study medications three times daily at 8 am, 3 pm, and 10 pm for six months. Patients returned for visits at two weeks, six weeks, three months, and six months. IOP measurements were used to assess efficacy. Safety assessments were adverse events, corrected distance visual acuity, slit-lamp biomicroscopy, pachymetry, perimetry, fundus parameters, and cardiac parameters.A total of 690 patients were randomized. Six-month mean IOP values were similar to those at three months, when the mean IOP in patients treated with BBFC was significantly lower than that of either monotherapy group. A total of 175 patients experienced at least one treatment-related adverse event (BBFC, 33.0%; brinzolamide, 18.8%; brimonidine, 24.7%), eight of which were severe, and five resulted in discontinuation. Seventy-seven patients discontinued participation due to treatment-related adverse events (BBFC, 17.2%; brinzolamide, 2.1%; brimonidine, 14.5%). There were 21 serious adverse events (n = 7 in each group), none of which was related to treatment. Resting mean pulse and blood pressure with BBFC were similar to those with brimonidine, demonstrating modest, clinically insignificant decreases. No new or increased risks were identified with use of BBFC relative to either monotherapy.This study showed that, after six months of treatment, the safety profile of BBFC was similar to that of its individual components and its IOP-lowering activity was similar to its efficacy at three months, when it was superior to both brinzolamide 1% alone and brimonidine 0.2% alone.

Purpose.

To compare the effects of silver nanoparticles (AgNPs) and Mitomycin C (MMC) on intraocular pressure (IOP) and external, histologic, and immunohistochemical bleb characteristics in a rabbit model of filtration surgery. Methods. Filtration surgery with concurrent topical application of either AgNPs or MMC was performed on fourteen pigmented Dutch belted rabbits. IOP and bleb characteristics were compared on post-operative day 1, and weeks 1 through 6. Hematoxylin and eosin staining and smooth muscle actin (SMA) immunohistochemistry were performed at post-operative week 6.

Results.

Average IOP across all time points was reduced 5.8 mmHg and 3.8 mmHg in AgNP and MMC treated eyes, respectively. At week 6, IOP was reduced 4.1 mmHg and 0.2 mmHg in AgNP and MMC treated eyes, respectively. Blebs were smaller, thicker, and less ischemic in AgNP treated eyes. AgNP treated eyes showed less fibrosis and more stromal edema, suggesting increased filtration, and also had fewer SMA positive myofibroblasts, suggesting reduced bleb contraction. AgNP treated eyes showed more lymphocytes than MMC treated eyes. There were few complications in both groups.

Conclusions.

In a rabbit model of filtration surgery, AgNPs are a reasonable alternative to MMC as adjunctive therapy. Compared to MMC, AgNPs result in an improved and sustained reduction of IOP and promote blebs with decreased fibrosis and ischemia as well as increased filtration despite a smaller overall size. This combination may offer an opportunity to promote long-term surgical IOP reduction with an improved complication profile.

Purpose:

  To investigate the effect of silibinin in myofibroblast transdifferentiation and in animal trabeculectomy models.

Methods:

  The effect of silibinin on the expression of α-smooth muscle actin (α-SMA) and vimentin in response to transforming growth factor-β1 (TGF-β1) was determined in human tenon fibroblasts (HTFs). Cell migration and collagen contraction arrays were used to demonstrate the functionality of silibinin-modulated HTFs. ELISA analysis was used to determine the effect of silibinin on the release of type 1 collagen and connective tissue growth factor (CTGF). The effect of silibinin on the activation of the TGF-β receptor-related pathway was evaluated by Western blotting. A rabbit model of trabeculectomy was established to assess the effect of silibinin in vivo.

Results:

  TGF-β1 elevated the expression of α-SMA and vimentin in HTFs; this elevation was inhibited by silibinin. TGF-β1 increased cell migration and collagen contraction of HTFs, which were also suppressed by silibinin. The production of both CTGF and type 1 collagen in TGF-β1-treated HTFs was inhibited by silibinin. The effects of silibinin on TGF-β1-stimulated HTFs were mediated via the down-regulation of TGF-β receptor-related SMAD signalling pathways. In the rabbit model of trabeculectomy, silibinin increased the period of decreasing intraocular pressure after trabeculectomy and reduced the production of collagen and α-SMA at the site of blebs in vivo.

Conclusion:

  Silibinin inhibited the TGF-β receptor-related signalling pathway in TGF-β-treated HTFs and several of the downstream events associated with myofibroblast transdifferentiation. Silibinin also improved the outcome of trabeculectomies by reducing the fibrotic response in the bleb tissue in vivo.