Glaucomatous visual field (VF) progression rates are similar between Black and White patients, despite Black participants having a higher intraocular pressure (IOP) under treatment, according to a study published in the American Journal of Ophthalmology.
Researchers included 516 eyes (156 Black, 360 White) of 346 participants (108 Black, 238 White) from the African Descent and Glaucoma Evaluation Study (ADAGES) (Clinical Trials Identifier: NCT00221923) to investigate whether treatment effects could explain outcome disparities between Black and White glaucoma patients. Patients had a mean (95% CI) follow-up time of 11.0 (10.5 to 11.5) years and 15.0 (14.1 to 15.8) visits, and Black patients were significantly younger than those in the White cohort (mean age, 59.7 vs 66.9 years, respectively, P <.01). Researchers excluded patients with fewer than 5 VF tests, less than 2 years of follow-up, and diseases affecting the optic nerve or VF from the analysis. They calculated VF mean deviation (MD) slopes over time with linear regression models and considered socioeconomic variables (SE), rates of glaucoma surgery, medications, treated intraocular pressure (IOP), and central corneal thickness (CCT) in their investigation.
Researchers noted similarities in measurements between the Black and White groups with respect to mean CCT, SE, and treatment with topical medications (P =.21, P =.56, and P =.90, respectively). The rate of VF mean deviation change was also similar between Black and White participants (-0.24 [-0.31 to -0.17] vs -0.32 [-0.36 to -0.27] dB/year, respectively, P =.11), despite African-American patients having a higher mean IOP than White participants (14.9 [14.5 to 15.4] vs 14.0 [13.6 to 14.4] mmHg, P =.03) and fewer trabeculectomies (29.5% vs 50.0%, P <.01).
Investigators report that mitigation of healthcare access disparities including “improved access to medication, more frequent visual field testing, [and] improved adherence to office visits through phone calls” may have helped to equalize VF progression between patient groups. They also highlight the role the difference in age may have played between the groups, “Given that the rate of visual field progression was similar between Black and White race participants, but Black race individuals were younger at baseline, a larger proportion of Black race glaucoma participants may develop visual impairment in their lifetime compared to White race participants.”
Study limitations include failure to adjust tonometric measurements for CCT, failure to account for IOP fluctuations taking place outside of standard office hours, and the significant difference in age between Black and White participants.
Melchior B, Valenzuela IA, De Moraes CG, et al. Glaucomatous visual field progression in the African Descent and Glaucoma Evaluation Study (ADAGES): eleven years of follow-up. Am J Ophthalmol. Published online February 13, 2022. doi:10.1016/j.ajo.2022.02.003