The future holds a great deal in glaucoma drug therapy

Reviewed by Justin Schweitzer OD, FAAO

Justin Schweitzer, OD, FAAO, externship director with Vance Thompson Vision, Sioux Falls, SD, reported that glaucoma therapy is rapidly moving past conventional eye drop therapy to provide more innovative and targeted ways to treat glaucoma and lower the patient treatment burden.

Here are some of the highlights.

Ocular surface device

In addition to contact lenses and iontophoresis, a microdose latanoprost ocular surface device (EyeNovia) using the Optejet delivery system delivers more precise dosing with 75% less drug and preservative delivered; 88% of the time, the drug reaches the targeted tissue. In a phase 2 clinical trial of the device, the intraocular pressure (IOP) decreased a mean of 29% compared with baseline.

Punctal plug delivery systems

A punctal plug delivery system (Mati Therapeutics) currently being researched provides a device that delivers latanoprost or travoprost to the eye. In the US, phase 2 multicenter clinical trials in which the plug was inserted into the lower puncta, 2 trials averaged a 94% retention rate and revealed IOP lowering.

Another punctal plug device, the Travoprost Intracanalicular Insert (OTX-TP, Ocular Therapeutix), is a preservative-free bioresorbable, sustained-release insert that provides a continuous and steady release of drug to the ocular surface for up to 90 days. Low adverse events, including dacryocanaliculitis and lacrimal structure disorder in 8.3% and 6.6% of recipients, respectively, have been reported.

Injectable systems

The 10-microgram sustained-release implant, Bimatoprost SR (Durysta, Allergan), is an injectable drug delivery system delivered during an in-office or surgery center procedure. Patients receive 1 intracameral administration. Based on the results of phase 1, 2, and 3 clinical trials, the device received FDA approval to reduce the IOP in patients with open-angle glaucoma and ocular hypertension.

Schweitzer reported that in the phase 1 and 2 clinical trial, no rescue therapy or retreatment was needed in 68% of patients at the 6-month evaluation, in 40% at 12 months, and in 28% at 24 months.

Different concentrations of the Travoprost Intracameral Implant (OTX-TIC, Ocular Therapeutix) are being tested in a phase I, prospective, multicenter, open label study; the concentrations are 15, 15 fast degrading, and 26 micrograms.

Iridocorneal angle device

The Travoprost Intraocular Implant (iDose, Glaukos) is inserted into the anterior chamber angle and is anchored in place behind the trabecular meshwork. This 1.8-millimeter-long 0.5-millimeter-diameter titanium technology achieved 32% to 33% IOP reductions in the US phase 2 trial. At 24 months, 7.7- and 7.4-millimeter decreases, respectively, in the fast- and slow-release arms.

The 36-month data showed that 70% and 68% of patients in the fast-release and slow-release arms, respectively, had IOPs that were well-controlled with the same or fewer IOP-lowering medications in contrast to 46% of the control patients treated with timolol.

The investigators reported that the average IOP decreases compared with baseline at 36 months were 8.3 mmHg and 8.5 mmHg, respectively, in the fast-release and slow-release arms, compared with 8.2 mmHg in the timolol control arm.

Overall, the patients on iDoseperformed similarly to those on timolol at 36 months regarding the mean IOP reductions with fewer topical medications compared with timolol.

The safety profile at 36-months was also favorable with the iDose implant with no clinically relevant corneal endothelial cell loss, no serious corneal adverse events, and no adverse events of periorbital fat atrophy and conjunctival hyperemia reported to date in either iDose arm.