Timolol 0.1% Gel versus Timolol 0.5% Eyedrops in the Prophylaxis of Ocular Hypertension after Phacoemulsification Surgery

Prophylactic treatment of intraocular pressure elevation after uncomplicated cataract surgery in nonglaucomatous eyes - a systematic review

The purpose of this systematic review was to evaluate the literature regarding prophylactic treatment of intraocular pressure (IOP) elevation after uncomplicated cataract surgery to provide an evidence-based guideline for cataract surgeons. The relevant literature was identified in EMBASE and PubMed. The risk of bias was assessed according to the 'Cochrane Handbook for Systematic Reviews of Interventions' and the ROBINS-I tool. The Grading of Recommendation, Assessment, Development and Evaluation (GRADE) criteria were used to rate the quality of evidence, and relevant data were systematically extracted to evaluate the pressure-lowering effect of the active substances. The primary outcomes for this systematic review were the absolute and relative pressure-lowering effect of the different drugs after 3-8 hr and 1 day after surgery. In total, 23 randomized controlled trials and one nonrandomized controlled study consisting of 45 treatment arms with 14 different active substances were included in the qualitative synthesis. According to the GRADE criteria, nine trials were graded as 'high' quality of evidence, 12 trials as 'moderate', while three trials were given the grade 'low' quality of evidence. The primary outcomes showed most consistency between the trials, which studied the effect of timolol, and presented a relative effect from 18.6% to 29.6% at 3-8 hr and 9.8% to 23.6% at day 1. This systematic review indicates that timolol, latanoprost and travoprost alone or medications containing timolol as an additive active substance, such as dorzolamide + timolol, brinzolamide + timolol and brimonidine + timolol, are characterized by a good relative IOP-lowering effect, which can be gained by a single dose postoperatively.

Timolol 0.1% in Glaucomatous Patients: Efficacy, Tolerance, and Quality of Life

Glaucoma is a progressive, chronic optic neuropathy characterized by a typical visual field defects. Four main classes of topical medication are actually available on the market: beta-blockers, prostaglandins, alpha2-agonists, and topical carbonic anhydrase inhibitor to treat intraocular pressure (IOP). The aim of this review is to outline the efficacy of timolol and to evaluate the impact of this treatment on patients' quality of life. Among beta-blockers, timolol is most used at three different concentrations: 0.1%, 0.25%, and 0.5%. While the first one is a gel, the other two products are solution. Timolol has few topical side effects, while it has some important systemic side effects on the cardiac and respiratory systems. The balance between efficacy and safety is always the main aspect to care patients. Because of the less efficacy of timolol 0.1% solution, the possibility to use carbomers as vehicle in the gel drops helped timolol 0.1 to be used in clinics, extending the time contact between the active ingredient and the surface of the cornea. Using preservative-free timolol 0.1 for treatment, IOP was at the same level of the other beta-blockers at higher concentration, but it was better tolerated. Preservative-free treatment improved the quality of life reducing dry-eye like symptoms; furthermore, the presence of an artificial tear in the medication bottle could help adherence. The once daily dosing improves compliance.

Early postoperative intraocular pressure elevation following cataract surgery

PURPOSE OF REVIEW

The aim of this review was to assess the risk factors and course of postoperative intraocular pressure (IOP) increase in order to determine the optimal the treatment.

RECENT FINDINGS

Early postoperative IOP elevation following cataract surgery is a frequent adverse event, and might represent 88% early postoperative complications. The risk factors for IOP elevation following phacoemulsification cataract surgery include residual viscoelastic material, resident performed surgery, glaucoma, pseudoexfoliation syndrome, axial length over 25 mm, tamsulosin intake, topical steroid application in steroid responders. A day-1 postoperative follow-up might be questioned, even in glaucoma patients, as in IOP spikes the topmost IOP elevation occurs 3-4 h postoperatively.

SUMMARY

Several IOP-lowering agents have been evaluated, but none has completely prevented the occurrence of IOP spikes. We recommend applying a combination of dorzolamide/timolol and brinzolamide topically in high-risk patients, particularly with preexisting optic nerve damage. Corticosteroid cessation usually results in a reduction of the IOP to normal levels in steroid responders. Additional studies are required to assess the optimal treatment, especially in glaucoma patients.

Thermo-sensitive gel in glaucoma therapy for enhanced bioavailability: In vitro characterization, in vivo pharmacokinetics and pharmacodynamics study

AIMS

Glaucoma is a chronic ophthalmic disease, which has become one of the leading causes to progressive and irreversible blindness. Current ophthalmic drug delivery to treat glaucoma is mostly eyedrop, whose rapid elimination on corneal surface can lead to poor bioavailability. The present study was aimed to develop a timolol maleate loaded thermo-sensitive gel (TM-TSG) with improved bioavailability to treat glaucoma.

MAIN METHODS

TM-TSG was prepared by homogeneously dispersing 0.3% (w/v) timolol maleate, 24.25% (w/v) poloxamer 407 (P407) and 1.56% (w/v) poloxamer 188 (P188) into phosphate buffer solution (pH = 7.4) and the formulated TM-TSG was characterized.

KEY FINDINGS

TM-TSG was stored in liquid form at room temperature (25 °C) and transited to semisolid gel at physiological temperature (32 °C). The rheological property of TM-TSG was in favor of uniform distribution of drug. TM-TSG showed good stability at different conditions including centrifugation, autoclaving and different temperature. In vivo pharmacokinetic studies indicated that TM-TSG could enhance absorption of TM in aqueous humor and improve the ocular bioavailability in comparison of commercial TM eyedrops. In vivo experiment result showed that TM-TSG had greater effect in treating glaucoma than TM eyedrops by sustainably lowering intraocular pressure (IOP) for a week. Moreover, slit lamp test and histopathological analysis demonstrated that TM-TSG had excellent biocompatibility.

SIGNIFICANCE

TM-TSG could be a promising ophthalmic delivery system for glaucoma therapy.