Dry eye and glaucoma may be the two most confounding conditions ophthalmologists face. Late last year, the US Food and Drug Administration (FDA) approved three new treatments for dry eye disease (DED) and one new procedure for glaucoma, which means ophthalmologists will soon have the opportunity to incorporate these therapies into their practices. Meanwhile, several investigative treatments for both chronic ailments will continue to move forward.
Undry Those Eyes
Based on a 2022 study in JAMA Ophthalmology, about 27 million Americans have some form of DED or meibomian gland dysfunction. Treatments aim to preserve and enhance tears and tear production to counteract the grittiness and itchiness that accompany DED.
"For decades, we only had one treatment [cyclosporine] for dry eye, then the second one a few years ago, which is lifitegrast, but nothing innovative until very recently," Marjan Farid, MD, director of cornea, cataract and refractive surgery at the Gavin Herbert Eye Institute at the University of California-Irvine, told Medscape Medical News.
"In 2023, I feel that innovation from the pharmaceutical standpoint in this space really exploded, and it's very exciting because dry eye disease is such a multifactorial disease that you can't just go after one angle," said Farid, who is also chair of the American Society of Cataract and Refractive Surgery's cornea clinical committee. "You really need to be able to attack dry eye disease from multiple areas, when the meibomian glands are involved, or whether or not there's blephartitis."
Marjan Farid, MD
You really need to be able to attack dry eye disease from multiple areas, when the meibomian glands are involved, whether there's blephartitis.
The three treatments for DED the FDA approved last year are lotilaner 0.25% ophthalmic solution, which targets the Demodex mites that cause of Demodex blepharitis, a trigger for DED; perfluorohexyloctane ophthalmic solution; and cyclosporine ophthalmic solution 0.1%. The latter two agents coat the ocular surface — perfluorohexyloctane acting as a shield to prevent tear evaporation and cyclosporine 0.1% using perfluorobutylpentane to allow the immunosuppressant cyclosporine to penetrate deeper into the eye.
This year, Farid said, while ophthalmologists will be adopting those treatments, they'll also be watching three emerging treatments poised to report results from clinical trial or take other steps toward FDA approval. They include:
- Selenium sulfide 0.5% ophthalmic ointment will move into phase 3 trials. This ointment is applied directly to the lower eyelid to open the meibomian gland (MGs), secretions from which prevent tear evaporation and tear overflow. Results last year from a phase 2 trial demonstrated improvement in MG secretions in treated patients. "It's a very unique compound because it's the only compound that could potentially open the meibomian gland orifices along lid margin and improve the quality of secretions," Farid said.
- Reproxalap, a reactive aldehyde species (RASP) inhibitor, will be the subject of a new drug application (NDA) resubmission this year. RASPs have been found in elevated levels in ocular and systemic inflammatory disease. The FDA last year notified drug developer Aldeyra Therapeutics that an additional trial was needed to demonstrate efficacy in treating symptoms of DED. Aldeyra said it would resubmit the NDA and report topline trial results in the first half of the year. "That's a really nice anti-inflammatory eye drop that works early in the inflammatory cascade," Farid said. "It acts almost like a steroid does without having the side effects of the steroid."
- AR-15512, a topical transient receptor potential melastatin 8 agonist, may also be the subject of an NDA this year. Topline results from two phase 3 trials last year demonstrated a clinically meaningful increase in tear production.
The Centers for Disease Control and Prevention estimates 3 million Americans have glaucoma. The use of daily eye drops to lower intraocular pressure (IOP) has been a mainstay of glaucoma therapy treatment for decades. However, a 2018 study put the rates of nonadherence as high at 67%.
In part to skirt the adherence issue, several approaches have evolved to lower IOP without relying on drops. They include laser treatments to perforate the eye's trabecular meshwork and improve the outflow of aqueous humor, minimally invasive glaucoma surgery to create a small tunnel or even insert a shunt to enable aqueous outflow, and, more recently, implantable depots that release IOP-lowering drugs within the eye over months.
"Glaucoma is a disease that has a slow onset, so you have to diagnose it as early as possible," Andrew Iwach, MD, a glaucoma specialist in San Francisco and clinical spokesperson for the American Academy of Ophthalmology, told Medscape Medical News. "One challenge with glaucoma is its chronic nature. There are different methods that are being looked at to achieve sustained release of drugs — ways you can implant a little bolus of this medicine," Iwach added.
Glaucoma also requires regular monitoring of changes in IOP, Iwach noted. "During COVID, there was an increased interest in during this remotely,” he said. A remote monitoring platform, Peripherex, was registered last year with the FDA. It consists of a diagnostic online visual field test that can enable patients with glaucoma to provide data on disease changes from home.
A laser platform, the Belkin Eagle Nd:YAG laser for performing selective laser trabeculoplasty (SLT), in December 2023 received FDA clearance. Iwach said this is the first innovation in lasers in 20 years in that it eliminates the need for placing a diagnostic lens on the eye itself to direct the laser pulses, a technique called direct SLT. It uses a computer-driven tacking device.
Looking Ahead
A laser in development is ViaLase, which offers femtosecond laser image-guided high-precision trabeculotomy or FLigHT. The VIA-002 study, which began enrolling patients in September 2023, is comparing ViaLase with SLT to determine reduction in unmedicated IOP at 6 and 12 months. A small feasibility study published last year demonstrated safety of the procedure with an average reduction in IOP of 34.6% at 24 months.
Microshunts inserted into the eye also have been used to reduce IOP. An early stage study is evaluating a new-generation, minimally invasive shunt that, once implanted, allows the ophthalmologist to adjust the level of aqueous outflow in an office-based procedure.
Another December 2023 FDA approval was iDose TR, an implant loaded with the prostaglandin analog travoprost 75 mcg. The implant is scheduled for commercial release in the first quarter of 2024, with a projected wholesale acquisition cost of $13,950 per dose or implant.
Two phase 3 trials compared two iDose TR models with two different travoprost release intervals, defined as the fast- and slow-release iDose TR models, respectively, with topical timolol ophthalmic solution, 0.5% twice a day. The trials demonstrated comparable IOP reduction between all three vehicles. At 12 months, 81% of iDose TR subjects required no IOP-lowering topical medications across both trials.
Also in development is an implant that uses a cilioscleral technique to preserve the anterior chamber of the eye, reducing the risk for complications, such as endothelial cell loss or a filtration bleb, that can occur with other implant procedures. Preliminary results of a 12-month study of 57 patients fitted with a new design with the cilioscleral interpositioning device (CID) showed it lowered IOP an average of 13.9 mmHg vs 15.1 mmHg in earlier studies with the device. In the latest study, more than 85% of patients reported being medication free at 12 months. The CID procedure spares the conjunctiva, requiring only a local incision, according to its developers.
As for topical agents that reduce IOP, cannabinoids may soon find their way into the glaucoma specialist's toolbox. A phase 2 trial evaluating SBI-100 ophthalmic emulsion started enrolling patients late last year. SBI-100 OE is a synthetic prodrug of tetrahydrocannabinol that can bind and activate cannabinoid receptor type 1 in ocular tissues. The trial is scheduled for completion later this year. A phase 1 trial last year demonstrated an average reduction in IOP of 24%.
Another area of focus is on the use of preservatives in topical drops. "One of big issues we're dealing with is preservatives because you're marinating these eyes over years with these drops," Iwach said. Late last year, the first preservative-free form of latanoprost ophthalmic solution 0.005% launched in the United States. Other delivery systems that remove preservatives from topical drops and preservative-free formulations are in the investigative stage, he said.
Farid disclosed financial relationships with Alcon Laboratories, Allergan/AbbVie, Bausch + Lomb, Bio-Tissue, CorneaGen, Harrow, Kala Pharmaceuticals, and Tarsus Pharmaceuticals. Iwach disclosed a previous financial relationship with Belkin Vision as well as relationships with Alcon Laboratories and Innovia.
Richard Mark Kirkner is a medical journalist based in the Philadelphia area.