Setting target IOP may be an inexact science, but doing so—and keeping patients compliant with medication use—does pay off. Despite substantial variability between eyes with manifest glaucoma, researchers recently found that adherence to treatment guidelines helped slow the rate of global glaucomatous visual field (VF) progression at various disease stages.
The study, published in the British Journal of Ophthalmology, included 8,598 24-2 VF tests from 603 glaucomatous eyes. The sample was divided into three groups based on baseline VF mean deviation (MD): better than -5dB (G1), -5dB to -10dB (G2) and worse than -10dB (G3). A team then investigated the relationship between existing IOP guidelines and rates of MD progression in study groups. Target IOP was 21mm Hg in G1, 18mm Hg in G2 and 15mm Hg in G3.
For stable eyes, the median follow-up intraocular pressures (IOP) for each group were 15.0mm Hg, 13.2mm Hg and 11.9mm Hg, respectively. When considering patients with mean follow-up IOP within the limits proposed by current guidelines, the study authors noted that the median MD slopes—a measure of progression severity—were -0.20dB/year for G1, -0.19dB/year for G2 and -0.15dB/year for G3, indicating overall success at matching each target IOP to the level of disease severity in each group.
Melchior B, De Moraes CG, Paula JS, et al. Relationship between mean follow-up intraocular pressure, rates of visual field progression and current target intraocular pressure guidelines. Br J Ophthalmol. October 31, 2020. [Epub ahead of print].