Association of Long-term Intraocular Pressure Variability and Rate of Ganglion Complex Thinning in Patients with Glaucoma

Purpose :To evaluate the association of mean intraocular pressure (IOP) and IOP variability (IOP fluctuation (SD of IOP) and the IOP range) with the rate of ganglion cell complex (GCC) layer thinning over time in patients with glaucoma. Design :Prospective cohort study Methods :Participants with at least 4 visits and 2 years of follow-up of optical coherence tomography tests were included. A linear mixed-effect model was used to investigate the association of IOP parameters with the rates of GCC thinning. Subgroup analyses were conducted for eyes with early ((MD ≥−6 dB), and moderate to advanced stage (MD <−6 dB) at baseline. Results :The cohort consisted of 369 eyes of 249 glaucoma patients (282 early glaucoma and 87 moderate to advanced glaucoma) with mean [SD] age of 68.2 (10.7) years over 5.1 years of follow-up. The mean rate of GCC change was −0.59 (95%CI, −0.67 to −0.52) μm per year. In multivariable models, faster annual rate of GCC thinning was associated with a higher IOP fluctuation (−0.17[ 95%CI,−0.23 to −0.11] μm per 1–mm Hg higher, P < 0.001) or higher IOP range (−0.07[95%CI, −0.09 to −0.05] μm per 1–mm Hg higher, P <0.001) after adjustment for mean IOP and other confounding factors. Similar results were found for early and moderate to advanced stages of glaucoma. Conclusions :IOP variability showed an independent association with macular change in patients with glaucoma regardless of severity at baseline, even after adjustment for mean IOP, supporting its potential value as a therapeutic target for clinical decision-making.