[Medicated prevention of scarring after glaucoma surgery]

Role of the chloride channel blocker in the formation of filtering tract scars after glaucoma surgery in rats

Filtration surgery is commonly performed for glaucoma treatment to reduce intraocular pressure (IOP); however, scarring of the filtering bleb is the main cause of failure. In this study, we evaluated the effects of the chloride channel blocker 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) on scar formation in filtering blebs. A glaucoma filtering surgery model was generated using Sprague-Dawley rats, divided into the control and NPPB groups receiving injections of different NPPB concentrations. The IOP of all rats decreased 1-day post-surgery and gradually increased afterward. However, IOP in rats from the NPPB groups recovered more slowly than that of the control group rats. In addition, the area and survival times of filtering blebs in rats from the NPPB groups were substantially larger and longer than those in the control group. Twenty-eight days after surgery, the protein and mRNA expression of collagen I, fibronectin and α-smooth muscle actin in the filtering area of rats from the NPPB groups were significantly lower than that in the control group rats. Collectively, our study demonstrates that NPPB inhibits filtering bleb scar formation, maintains filtering bleb morphology and prolongs filtering bleb survival time by inhibiting the differentiation of conjunctival fibroblasts and extracellular matrix synthesis.

[Trabeculectomy with mitomycin C and Ologen® implant in comparison to classical trabeculectomy]

BACKGROUND

Trabeculectomy (TE) with mitomycin C (MMC) is considered the gold standard in glaucoma surgery. A new modification is the use of an Ologen® implant (AEON Astron Europe B.V., Leiden, Netherlands) during TE, which was analyzed and compared to the standard TE in this retrospective study.

PATIENTS AND METHODS

On 70 eyes Ologen® was applied during surgery (group 2), whereas 98 eyes were operated on without the implant (group 1). Both surgical procedures were compared regarding the efficiency of lowering the intraocular pressure (IOP), the number of glaucoma medications, the rate of complications and follow-up treatment. Data were collected up to 24 months after surgery.

RESULTS

In group 1 the IOP was lowered from 28.0 mmHg (95% confidence interval, CI 26.6-29.4 mmHg) to 16.0 mmHg (14.0-18.1) after 24 months. In group 2, the pressure dropped from 28.5 mmHg (26.8-30.1) to 14.3 mmHg (11.7-17.0). The IOP reduction was significant in both groups (p < 0.001), there was no significant difference between the groups (p > 0.05). Glaucoma-related follow-up treatments were performed more often in group 1 but the difference was not significant.

CONCLUSION

Both procedures significantly lower the IOP and the number of glaucoma medications. For our cases, TE with Ologen® and MMC is considered to be superior to TE with MMC regarding the lower rates of follow-up treatments as it is less time-consuming for the patients and the clinic.

[Modern possibilities of pathogenetically oriented therapy for dry eye syndrome]

In recent years, anti-inflammatory therapy has become a significant part of the complex approach to treatment of patients with dry eye syndrome (DES), with cyclosporine preparations becoming increasingly important in the structure of the therapy. Taking into account the immunosuppressive effect of cyclosporine A, which is realized through hindering the activation of T-lymphocytes in the tissues of the ocular surface, its topical application in DES has a pronounced pathogenetic focus. Numerous clinical studies have shown that instillations of cyclosporine into the conjunctival cavity contribute to an increase in total tear production, as well as recovery of the density of goblet cells in the conjunctiva of DES patients. The positive effect of cyclosporine A instillations has been convincingly demonstrated in the complex therapy of patients with vernal and atopic corneal conjunctivitis, Thygeson's superficial punctate keratitis, autoimmune keratitis, meibomian gland dysfunction, etc. However, one significant problem associated with cyclosporine A instillations is the irritating effect of the drug. That prompted the development of a drug that is safe and tolerable during instillations into the conjunctival cavity - preservative-free 0.1% cyclosporine A labelled Ikervis (Santen, Japan). The drug carrier is artificial tear Cationorm (Santen), which has an advantage of stabilizing the tear film and protecting the ocular surface from the irritating effect of cyclosporine. According to numerous clinical studies, Ikervis instillations can improve the effectiveness of complex therapy in patients with DES (especially secondary to Sjögren syndrome, Stevens-Johnson syndrome, graft-versus-host disease), with allergic diseases of the cornea and conjunctiva (spring, atopic corneal conjunctivitis), with corneal transplant disease, and other similar conditions. The high efficacy and safety of Ikervis constitute the reason to recommend it for wide clinical use.