Advances in Eye Care - Glaucoma Treatment

By the end of the year 2020, it is a fitting time to take stock of recent clinical developments, latest technology after reviewing the areas of expertise to shape their specialty to improve the patient care for the future.

Traditional tube shunt and trabeculectomy remained the mainstay therapies for effectively lowering intraocular pressure (IOP). But ophthalmologists have been facing some safety concerns like early or late failures, infections, hypotension and other complications. The question arises how can ophthalmologists provide an alternative treatment like micro-invasive glaucoma surgery (MIGS), through bypassing the resistance of the trabecular meshwork via a tiny stent to increases outflow facility, which resulted in reduced physiological trauma, medication burden, negligible complications with rapid postop recovery and minimal need for follow-up.

By the end of the year 2020, it is a fitting time to take stock of recent clinical developments, latest technology after reviewing the areas of expertise to shape their specialty to improve the patient care for the future.

Traditional tube shunt and trabeculectomy remained the mainstay therapies for effectively lowering intraocular pressure (IOP). But ophthalmologists have been facing some safety concerns like early or late failures, infections, hypotension and other complications. The question arises how can ophthalmologists provide an alternative treatment like micro-invasive glaucoma surgery (MIGS), through bypassing the resistance of the trabecular meshwork via a tiny stent to increases outflow facility, which resulted in reduced physiological trauma, medication burden, negligible complications with rapid postop recovery and minimal need for follow-up. With the passage of time, the Micro- Invasive Glaucoma Surgery (MIGS) has became a vital part of the treatment with a range of different new devices approved by the FDA in 2016. But COMPASS XT study indicated a rising rate of endothelial cell loss. Nevertheless, Ophthalmologists devised innovative techniques like endoscopic cyclo-photocoagulation to target the outflow pathways.

However, the treatment with drugs didn’t end with MIGS in spite of difficulty with frequent administration of drops and side effects of oral medication, which led to sustained delivery as the next wave of treatment with IOP-lowering implant Durysta (Allergan) placed in the anterior chamber via a preloaded, single-use implantation. This applicator delivered 10 μg Bimatoprost— similar to a single drop of 0.03% ophthalmic solution. Durysta reduced IOP by close to 30% and patients to remained drug free for at least one year. The FDA approved the implant for only a single use in each eye.

In order to eliminate the side effects to ocular surface, a number of other sustainedrelease technologies, which will be a paradigm shift, are in the pipeline, such as punctal plugs (Therapeutix), internally placed reservoirs (Glaukos), and external rings (from Allergan). Both MIGS and enhanced drug delivery treatments are dramatically changing the approach in severe and difficult-to-treat patients such as normal-tension glaucoma. FDA has approved the filtration shunt technology with the Ahmed Valve-Ahmed Clear Path (designed by a Pakistani Scientist) allows for less-intrusive placement as well as a more natural fit in the eye. Because it’s sutured more anteriorly than previous filtration devices, it provides the surgeon with a better view when securing the implant in the eye. The Xen Gel Stent (from Allergan) also allows for a less-invasive approach to trans-scleral surgery via a preloaded ab-interno injection technique. Two intriguing shunts are also on the FDA approval list. The Preser-Flo Micro-Shunt (Santen) involves the creation of a full-thickness fistula from the anterior chamber across to the subconjunctival space and is designed to prevent hypotony. The Beacon Aqueous Microshunt (Micro-Optx), on the other hand, shunts aqueous humor from the anterior chamber to the ocular surface. Both products look promising new devices against filtration. In addition, exciting non-invasive, nonphar ¬maceutical approaches are on the horizon for patients running out of options. For example, the Mercury Multi-Pressure Dial (Equinox) consists of a pair of goggles that draw a vacuum around each eye’s peri-orbital area. Each goggle is connected to a pressure-modulating pump, which, when activated, establishes a targeted negative pressure in the micro-environment surrounding the eye. This release of atmospheric pressure placed on the eye results in the almost-instantaneous lowering of IOP even in low pressures.

Today, Glaucoma surgeons are experiencing a revolution through multiplicity of treatment to provide the non-invasive IOP-lowering therapies to help those patients with the most difficult-totreat disease.

 

Madiha Durrani., MCPS.,FRCS,

Ophthalmologist Calgary, Canada

0015877005104