The Role of Intraocular Pressure and Systemic Hypertension in the Progression of Glaucomatous Damage to the Macula

Prcis: Macular structural and functional parameters were better correlated with pressure-dependent glaucomatous damage than conventional parameters. Self-reported systemic hypertension (HTN) was not associated with structural or functional progression in this cohort.

Purpose: The aim was to examine the relationships between intraocular pressure (IOP), systemic HTN, and glaucoma progression using structural testing with optical coherence tomography (OCT) and functional testing with visual field (VF).

Patients and methods: A total of 191 eyes of 119 patients enrolled in a prospective, longitudinal study (Structural and Functional Progression of Glaucomatous Damage to the Macula study) with a diagnosis of glaucoma were analyzed. Patients were tested with 10-2 and 24-2 VF and spectral-domain OCT obtained at 4 to 6 month intervals. IOP from each visit was collected. Self-reported diagnoses of HTN were reported in 72 eyes (37%) in the patients included. Linear mixed effects regression was used to test the relationship between summary statistics from VF and OCT and HTN diagnosis. The goodness-of-fit of relationships was assessed with Bayesian information criterion.

Results: Mean follow-up IOP was most associated with the following OCT parameters: global macula ganglion cell layer (GCL), inferior macula GCL, mean macular vulnerability zone GCL, and mean less vulnerable zone macula GCL, and with the following VF parameters: 10-2 PSD and 10-2 MD. There was no significant difference in rates of progression between HTN and non-HTN patients for any OCT or VF parameter. Models with the best goodness-of-fit for the relationship between HTN and progression were the same as those observed for IOP.

Conclusion: Macular structural and functional parameters are more sensitive to IOP in terms of glaucomatous progression when compared with more conventional parameters. While HTN was not significantly associated with progression using any parameter, macular structural and functional parameters had a better goodness-of-fit to model progression and may be useful as endpoints.