Recent advancements in ophthalmologic research have allowed for significant innovations in surgical procedures and care. Not all of these developments are yet FDA-approved, however, they do show promise to help patients retain their sight when confronted by vision-destroying diseases. Below, I highlight a few of the most interesting advancements in current ophthalmology research and practice.
The Emergence of Micro-Invasive Glaucoma Surgery (MIGS)
The emergence of micro-invasive glaucoma surgeries has sparked considerable innovation in the ophthalmologic community over the last decade. Glaucoma currently stands as one of the leading causes in blindness for patients over 60. Conditions that fall into its category are typically caused by abnormally high pressure in the eye and cause permanent damage to a patient’s optic nerve. As the disease advances, glaucoma patients may experience blind spots, tunnel vision, blurred sight, or eye pain; these symptoms can be managed and limited, but not cured or reversed.
Conventional treatments for glaucoma conditions include the use of eye drops, oral medication, laser treatment, surgery, or a combination of the four. These can be effective in slowing the disease, but often come with side effects. Glaucoma medications frequently have systemic and local side effects that include ocular allergies and ocular surface disease. One 2002 study on treatments for ocular hypertension found that roughly 50% of glaucoma patients “require multiple medical treatments with different drugs.”
In contrast, MIGS procedures allow surgeons to intervene earlier and at less risk than conventional treatments allow. It should be noted that MIGS is not a single, defined surgery, but a group of procedures sharing similar characteristics. At a joint workshop in 2014, the American Glaucoma Society and the FDA described a MIGS procedure as being “characterized by the implantation of a surgical device intended to lower IOP via an outflow mechanism with either an ab interno or ab externo approach, associated with very little or no scleral dissection.”
The MIGS approach seems to be promising. One study published in a 2017 issue of Clinical Ophthalmology found that such procedures can lower ocular pressure and limit the need for eye drops or medications. However, MIGS isn’t completely without flaws; another review conducted in 2018 noted that “Complications associated with MIGS, albeit infrequent and mostly transient, do occur despite a less invasive approach than trabeculectomy and tube shunt surgery.”
More research needs to be done to understand how MIGS can fit into mainstream glaucoma care. Given that research, however, the outlook for micro-invasive glaucoma surgery appears promising.
Continued Innovation in Cataract Surgery: the First Trifocals Lens Implant
Intraocular lenses are not new. In 1946, ophthalmologists began using IOLs to replace the natural lens of the eye during cataract surgery. For patients, the replacement could be an unanticipated bonus to cataract removal, as the new lens could provide vision correction. However, the scope of this correction would be limited; for example, a patient might recover with perfect far-vision but still need glasses to read.
In time, researchers eventually developed multifocal lenses. As the name suggests, these could correct for multiple distances — usually near and far. However, while these lenses were better than previous versions, they weren’t perfect. Multifocal lenses often compromised on intermediate vision and were subject to light glares and haloes.
Trifocals are the newest and most effective version of intraocular lenses, allowing for clear vision at all three distances. Patient satisfaction with the implants is high; a study published in a 2019 issue of Eye reviewed outcomes for 114 patients and 227 eyes and found that 98.1% of participants “expressed satisfaction with the IOL implanted” after twelve months. Like earlier iterations, these lenses are predominantly used in cataract surgery and offer vision correction as a beneficial side effect. However, given the success of trifocal IOLs, lens replacement surgery may become a more popular solution for vision correction for seniors in the future.
A New Delivery System for Macular Degeneration Medication
Age-related macular degeneration is the foremost cause of severe vision loss in patients over the age of 50. The CDC estimates that roughly 1.8 million people in the United States have AMD and an additional 7.3 million are at significant risk of suffering vision loss as a result of AMD. The disease occurs when the macula, a small portion of the retina, degenerates. Symptoms include the loss of center vision, limited color vision, and an inability to see objects clearly. There are two varieties of AMD: wet, which can be treated, and dry, which thus far has no effective therapy. Patients with wet AMD can preserve their vision with monthly intraocular injections of drugs that inhibit vascular endothelial growth factor (VEGF).
Given the frequency of injections, treating AMD can be a time-consuming burden on the patient. A recently-engineered port delivery system, however, may allow patients to limit their in-office visits to a few times a year rather than once per month. Patients who opt into the treatment have a small port implanted into the wall of their eye. This implant stores and slowly releases AMD medication over a few months, allowing the patient to go months without an in-office injection. Eventually, however, the port will run dry, necessitating an office visit to refill its medication supply.
The port is still undergoing review, but it recently completed a Phase II clinical trial to positive results. Researchers found that the port “was generally well tolerated and demonstrated a dose response across multiple endpoints in patients with nAMD.” Even more promising, the trial concluded that patient outcomes appeared comparable with those for patients who used monthly doses, despite the fewer number of injections. Enrollment of phase III trials was announced in October of 2018 and will evaluate whether the port delivery system improves on the baseline expectations for best corrected visual acuity at 36 and 40 weeks.