New Glaucoma Medications

Pharmacological advances may reduce patients’ need for multiple eyedrops. Roibeárd O’hÉineacháin reports from the 39th Congress of the ESCRS in Amsterdam

New IOP-lowering topical medications with complementary modes of action and new drug delivery systems may help reduce or eliminate the need for multiple eyedrops in glaucoma treatment, reports Simonetta Morselli MD.

Dr Morselli noted that research shows most glaucoma patients will need multiple eyedrops over time. For example, in the Collaborative Initial Glaucoma Treatment Study (CIGTS), 75% of patients required two or more eyedrops to achieve their target pressure in the first two years. Similarly, in the Ocular Hypertension Treatment Study (OHTS), 49% of patients needed two or more eyedrops to have a 20% reduction of IOP after five years.

The inconvenience and discomfort of having to use multiple eyedrops a day can have a considerable impact on a patient’s quality of life and may cause long-term harm to the conjunctiva, Dr Morselli said. Many glaucoma patients may therefore adhere poorly to their eyedrop regimens. In addition, some patients have ocular or systemic diseases that make eyedrops difficult and sometimes impossible to use. She noted that in a survey she and her associates conducted in Italy, 80% of patients were not able to apply drops correctly.

NEW IOP-LOWERING MEDICATIONS Several new IOP-lowering medications with alternative modes of action have entered the market that may reduce the need for multiple drops eyedrop, Dr Morselli said. They include nitric oxide (N0)-donating prostaglandin analogues, such as Latanoprostene bunod (Vyzulta™, Bausch and Lomb), and Rho-Kinase (ROCK) inhibitors such as netarsudil (Rhopressa, Aerie Pharmaceuticals).

Latanoprostene bunod has two modes of action. It metabolises into latanoprost acid, which increases aqueous humour outflow through the uveoscleral pathway. Butanediol mononitrate releases N0 and increases outflow through the trabecular meshwork and Schlemm’s canal.

In the international multicentre APOLLO study, openangle glaucoma and ocular hypertension patients receiving latonoprostene bunod had IOP reductions from 8.0 mmHg to 9.0 mmHg, compared to reductions of only 6.5 mmHg to 7.5 mmHg among patients receiving timolol.

ROCK inhibitors like netarsudil lower IOP by relaxing the trabecular meshwork, increasing trabecular outflow. In a study involving nearly 900 patients, almost twice as many patients who received a fixed combination of netarsudil and latanoprost (Rocklatan, Aerie Pharmaceuticals) achieved a 30% reduction in IOP compared to those receiving latanoprost alone. Three times as many patients in the Rocklatan group achieved an IOP reduction of 40% as in the latanoprost monotherapy group.

ALTERNATIVES TO DROPS Dr Morselli noted that new sustained-release drug delivery systems for IOP lowering medications are showing promising results in clinical trials and preclinical testing. They include topical bimatoprost inserts designed for placement in the upper fornix, Travaprost and latanoprost punctal plugs, implants placed in the anterior chamber, and drug-eluting IOLs.

In addition, evidence continues to confirm the efficacy of selective laser trabeculoplasty (SLT) in reducing the glaucoma patients’ need for IOP-lowering medication. For example, in the LIGHT trial 74 2% of treatment-naive patients with primary open-angle glaucoma or OHT randomised to SLT required no eyedrops and none required glaucoma surgery to maintain target intraocular pressure at three years follow-up.i

i Gazzard G. et al, The Lancet 2019, 393; 10180: 1505–1516.

Simonetta Morselli MD is Head of the Ophthalmology Department, S. Bassiano Hospital, Bassano del Grappa, Italy. simonetta.morselli@gmail.com