DROPLESS DRUGS

Up to 90 per cent of glaucoma patients do not take their eye drops as prescribed, with many quitting after six months. More than half of chronic users develop ocular surface disease symptoms.

Many older and disabled patients lack the manual dexterity needed to administer eye drops. Even when drops make it into the eye, penetration is uncertain and drug concentrations peak and trough.

All that may soon change. Several new drug delivery technologies that replace or greatly reduce the need for eye drops are available or nearing approval, Eric D Donnenfeld MD, New York University, told Glaucoma Day at the 2015 ASCRS•ASOA Symposium & Congress in San Diego, USA.

Cataract applications

Intracameral antibiotics for preventing endophthalmitis after cataract surgery are one eye drop substitute already available. Since the landmark ESCRS Endophthalmitis Study that found a five-fold reduction in endophthalmitis risk for intracameral cefuroxime compared with topical antibiotics (Barry P et al. JCRS 2006; 32:407-410), several very large studies have demonstrated similar results with intracameral moxifloxacin in Japan (Matsuura K et al. JCRS 2013; 39:1702–1706) and various antibiotics in the USA (Shorstein N et al. JCRS 2013; 39:8-14).

“This is an idea whose time has come. A lot of thanks go to Peter Barry and the ESCRS,” Dr Donnenfeld said.

Omidria (Omeros), a 4.0ml solution of phenylephrine 1.0 per cent and ketorolac 0.3 per cent added to 500ml standard irrigation solution, is another new approach.

The solution prevented miosis during cataract surgery in more than 97 per cent of patients compared with about 73 per cent receiving standard preoperative topical mydriatics and anaesthetics alone in phase III FDA clinical trials (Omeros Corp data. Lindstrom R et al. Clin Opthalmol 2014; 8:1735-1744), Dr Donnenfeld said.

The combination, recently approved by the FDA, also worked better than injecting phenylephrine alone. Perioperative eye drops can be greatly reduced with intravitreal injection of 0.2cc of triamcinolone with moxifloxacin and/or vancomycin (Imprimis Pharmaceuticals), Dr Donnenfeld said.

“To my great surprise patients have embraced this. They have really liked this technology that removes drops or reduces drops,” he added.

Drug-eluting bioabsorbable hydrogel plugs placed in the canaliculus (Ocular Therapeutix) have reduced flare cells with dexamethasone for 30 days in a phase III trial, and lowered intraocular pressure (IOP) for 30 days with travoprost as much as a timolol in a phase I trial.

“The future of ophthalmic pharmaceuticals is clearly drug delivery. It may be nanotechnology drops, sustained delivery, external inserts, punctal plugs, or intracameral or intravitreal delivery, but I can promise you this will be disruptive and it will happen very quickly,” Dr Donnenfeld said.

Eric Donnenfeld: ericdonnenfeld@gmail.com