Glaucoma Review Summarizes Current Diagnostic and Treatment Practices

Joshua Stein, MD, MS

January is National Glaucoma Awareness Month.

A review article published this month details the current understanding of practices related to the diagnosis and management of glaucoma.

The review—published by Joshua Stein, MD, MS, W.K. Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, and colleagues—was informed by relevant literature written between January 2010-August 2020.

As such, they included 70 articles that they considered relevant for the clinician in daily practice. Among these articles were 14 clinical trials, 9 population-based studies, 19 systematic reviews or meta-analyses, and 6 clinical practice guidelines or position papers.

Risk Factors

Thus, according to the literature, glaucoma is considered the leading cause of irreversible blindness globally. Further, it is the leading cause of blindness among Black persons (6.1%) — which is more than double the risk of White persons (2.8%).

Glaucoma has a greater prevalence among Latino (4.1%) and Asian American persons (3.5%) than among non-Hispanic white persons.

“Risk factors for glaucoma include older age, nonwhite race, family history of glaucoma, and elevated intraocular pressure (IOP),” Stein and team wrote. “Elevated IOP is the only known modifiable risk factor for glaucoma, and all existing interventions work by lowering IOP.”

They also noted that certain medical conditions—including immune system disorders (sarcoidosis, rheumatoid arthritis, etc.), certain infectious diseases (herpes simplex virus, varicella zoster virus, etc.), some endocrine disorders (diabetes, Cushing syndrome), as well as conditions that might affect ocular perfusion (obstructive sleep apnea, migraine)—predispose individuals to glaucoma.

Certain medications like corticosteroids, antidepressants, and topiramate may further increase risk of glaucoma.

And finally, the authors acknowledged that glaucoma has an estimated heritability of 70%. Those with first-degree relatives of person with glaucoma have a 22% lifetime risk for glaucoma—compared with 2.3% among other persons.

Screening for Glaucoma

It is useful and cost-effectiven to screen populations at high-risk for glaucoma, including persons with a positive family history or non-white race.

Further, the review emphasized that patients with glaucoma diagnoses should be monitored regularly—at least once yearly—by an eye care professional. The importance of monitoring is to track potential eye disease progression.

Current diagnostic testing includes perimetry, gonioscopy, IOP measurement, corneal thickness measurement, and ONH and RNFL evaluation using optical coherence tomography and fundus photography.

“Researchers have been using machine-learning modeling techniques to help identify patients who have glaucoma that will likely progress over time, predict future visual field loss, and determine an appropriate target IOP level that will stabilize the disease,” the authors wrote.

Treatment of Glaucoma

As aforementioned, treatment of glaucoma includes lowering IOP in patients.

“Decisions regarding which patients to treat and how aggressively to lower their IOP to reduce the risk for progression should be individualized,” Stein and colleagues noted.

“Considerations include the amount of existing glaucomatous damage, overall health, and patient preferences.”

They indicated that aggressive lowering of IOP should be undertaken if the existing glaucoma damage is more severe. Even more, if progression continues despite reaching a certain target IOP, then the target should be re-evaluated and lowered.

Achieving IOP lowering can be achieved with various classes of glaucoma medications, including, but not limited to, prostaglandin analogues, topical beta-blockers, alpha-agonists for open-angle glaucoma and topical / oral carbonic anhydrase inhibitors, topical alpha-agonists, and topical beta-blockers for angle-closure glaucoma.

Other treatment options for open-angle glaucoma include laser trabeculoplasty and incisional surgery.

For angle-closure glaucoma, and following acute lowering of IOP, clinicians can choose to proceed with various laser or surgical options, depending on significance of cataracts.

Conclusions

The authors thus emphasized the importance of early diagnosis and treatment of glaucoma, which may ultimately help in slowing the progression of the disease as well as minimize functional impairment.

“Since patients are often asymptomatic until late in the disease course, they must have regular follow-up (interval individualized according to risk, usually 1-4 times yearly if stable) by an eye care professional to monitor for signs of progression and need for additional therapy,” they stressed.

Ensuring patients monitor adverse events and remain adherent to medications is of utmost importance for clinician care of glaucoma.

The article, “Glaucoma in Adults—Screening, Diagnosis, and Management: A Review,” was published online in JAMA.