More than 4.2 million Americans live with glaucoma, or about 1.6% of the country’s adult population, and only half are aware they have the disease. Glaucoma is a leading cause of blindness, and while there is no cure, early detection can slow or stop progression. The medical community has numerous therapies to deploy, but continued research, and development is paramount as the country’s population ages and grows more at risk with each passing day.
Early Detection Poses Challenge
Glaucoma may strike individuals of any age, but it is most prevalent in people over the age of 60. For Black Americans, the rate of prevalence ticks up much earlier, at about 40 years of age, and people with diabetes or a family history of the condition are also more susceptible. Because glaucoma is asymptomatic in initial stages, early diagnosis is challenging.
The disease occurs when the optic nerve and the retinal ganglion cells — which relay visual inputs to the central nervous system — are damaged; elevated pressure in the eye, or intraocular pressure, is the main culprit. When fluid accumulates in the eye, such as from overproduction or improper drainage, it increases intraocular pressure and also the risk of developing glaucoma. Symptoms appear slowly, with changes in peripheral vision occurring before forward-facing vision becomes compromised.
Comprehensive eye exams can catch glaucoma in earlier stages, as these screenings involve optic nerve examination, intraocular pressure measurement, visual field testing and risk factor assessment. Patients must be proactive about regular screenings because once vision is lost, it cannot be repaired or restored. Available therapies can stop glaucoma’s progression and generally focus on alleviating intraocular pressure, but early diagnosis remains key.
Building on Existing Diagnostic Tools
Advances in diagnostic tools can give clinicians more and better information for treating glaucoma. Optical coherence tomography (OCT), for instance, uses light-wave imaging to help assess the optic nerve’s structural integrity. More recently, OCT angiography (OCTA) has been adopted to consider the optic nerve’s support system, such as blood supply. Functional imaging may be the next wave, as it should enable clinicians to identify cells under oxidative stress and take corrective action before irreversible damage is done.
Understanding a patient’s visual field is critical to identifying ocular diseases, and virtual reality goggles are emerging as a user-friendly, portable device. Doheny Eye Institute, dedicated to vision science, is investigating VR to enhance existing field vision testing and foresees future assessments that could bypass patient response. With its predictive powers, AI should also have a diagnostic role; AI may identify factors that clinicians could overlook when determining the risk of disease, progression, and aggressiveness so that patients can be treated early and accordingly.
Treatment Options Keep Evolving
Patients have various treatment options for glaucoma and generally take one of three paths: medication, laser or surgery. In the past five years, two new medications have surfaced, each with a novel mechanism of action that is additive to clinicians’ arsenals. The rho kinase inhibitor works to lower intraocular pressure, while a nitric oxide medication has dual action, reducing pressure and improving blood flow and oxygen to the optic nerve head. Research organizations like Doheny Eye Institute are also investing in the drug delivery arena, seeking ways to reduce patient error in medication administration and improve outcomes.
Laser treatment is nothing new in treating glaucoma, but techniques and instruments are constantly being refined. Laser trabeculoplasty has gained more acceptance, and as a minimally invasive procedure, it provides relief by reducing intraocular pressure. A more recent introduction, micropulse transscleral laser therapy also relieves intraocular pressure but by delivering energy in short pulses, which appears to minimize collateral tissue damage.
Should patients be beyond medication or non-invasive procedures, incisional surgery remains an option to improve natural drainage of the eye or insert an implant to create an accessory drainage pathway. Advances in surgical procedures, implants and devices continue to be sought after in research circles.
The Future Lies in Neuroprotection
Glaucoma research is a dynamic field, and an emergent focus is neuroprotection, where treatment extends beyond decreasing intraocular pressure to intervention in the chemical pathways that lead to the death of retinal ganglion cells. This exciting area considers protective effects, such as a drug therapy that could prevent cells from dying. It also explores how cells could be resuscitated, or what interventions could return damaged cells to their full functionality. Ultimately, this field of study is working toward neuro regeneration, where neural pathways may be fully restored so that lost vision may be regained.
With continued advances in glaucoma-related research and development across the board — from diagnostics and devices to pharmaceuticals and drug delivery to laser and surgical procedures — the future for patients is looking brighter. Maintaining momentum will be key for researchers to achieve the ultimate goal and find a cure for existing and future glaucoma patients.
