Vision Loss from Glaucoma in Some, but Not Most, if Untreated or Delayed Treatment

Article: Treatment not always needed to prevent vision loss in patients with elevated eye pressure
Source: Washington University School of Medicine in St. Louis, via ScienceDaily  and NEI
Published: April 15, 2021

The Ocular Hypertension Treatment Study, a 7-year longitudinal clinical trial, recently published follow-up results 20 years after the initial launch of the trial evaluating the effect of glaucoma eye drops to preserve vision for patients with elevated eye pressure. The study involved 1,600 patients nationally who were at moderate to high risk for glaucoma due to elevated intraocular pressure (IOP). Although treatment was shown to be highly effective, reducing the incidence of glaucoma by 50% to 60% after five to seven years, the study found surprisingly that only 25% of study participants went on to develop vision loss from glaucoma in at least one eye, compared to the prior conventional wisdom that most patients would develop glaucoma if left untreated. This low incidence of vision loss was the case despite 46% of the study participants showing evidence of glaucoma in at least one eye. Furthermore, the risk of delayed treatment was relatively low. Participants who were randomly assigned to the observation group, before being switched to treatment after seven years, had only slightly greater risk of vision loss compared to participants who used eye-pressure-lowering drops from the start of the study. These findings of low incidence of vision loss due to elevated IOP is pertinent in the sense that while eye drops are effective, there can be obstacles due to cost, adverse effects, and adherence. The study also provided information regarding patient demographics. Although one-quarter of the study participants were African-American, a group with a higher incidence of vision loss from glaucoma, the study found that Black individuals had similar outcomes to other racial groups when matched for the same level of risk. The researchers caution that treatment is not a one-size-fits-all approach, and the sample size is small. Nonetheless, studies like these provide a starting point for conversations to arrive at the best approach.

Personal commentary: The mention of cost, adverse effects, and adherence difficulties is an opportunity to include that there are other first-line treatment options for glaucoma. Selective laser trabeculoplasty (SLT) is not effective in all patients, but if considering cost, adverse effects, and adherence, it is beneficial to suggest it as one of those starting point options.

My rating of this study: ⭐⭐⭐

Kass MA, Heuer DK, Higginbotham EJ, et al. "Assessment of Cumulative Incidence and Severity of Primary Open-Angle Glaucoma Among Participants in the Ocular Hypertension Treatment Study After 20 Years of Follow-up." JAMA Ophthalmology. 139(5):558-566. 15 April 2021. https://doi.org/doi:10.1001/jamaophthalmol.2021.0341