Abstract
Purpose
To evaluate the association between various intraocular pressure (IOP) metrics and visual field progression in open-angle glaucoma (OAG), when derived from in-office or remote (home) tonometry.Design
Retrospective analysis of longitudinal data.Participants
94 treated patients (150 eyes) with diagnoses of primary OAG, juvenile OAG, pseudoexfoliative glaucoma, or pigmentary glaucoma who were prescribed remote tonometry.Methods
Remote tonometry (iCare HOME, ≥ 7days) and in-office IOP measurements were analyzed using standard IOP metrics (mean, maximum, minimum, range, standard deviation, coefficient of variation) and three novel threshold-based IOP metrics: percentage of measurements above threshold (PMAT), average IOP excess (AIE), and total IOP excess (TIE), which gauge the frequency and magnitude of IOP measurements exceeding a target IOP, each calculated across five thresholds (12, 15, 18, 21mmHg and each patient's target IOP set by their glaucoma specialist). Remote tonometry metrics were computed across the entire monitoring period ("absolute") and as daily aggregated averages ("daily"). Visual field progression rate was assessed through the mean deviation slope derived from ≥3 reliable Humphrey visual fields (HVFs). Generalized estimating equations evaluated associations between IOP metrics and HVF progression rates.Main outcome measures
Association between tonometry-derived IOP metrics and HVF progression rate (dB/year).Results
Mean IOP was between 13-14mmHg and similar between remote and in-office tonometry (p=0.62), while all other standard metrics differed significantly. No standard IOP metric was significantly associated with HVF progression. In contrast, remote tonometry-derived AIE and TIE at the patient-specific target IOP were significantly associated with faster progression (absolute AIE β=-0.34, p=0.003; absolute TIE β=-0.35, p=0.048; daily AIE β=-0.29, p=0.024; daily TIE β=-0.40, p=0.035), while in-office equivalents were not associated with progression rate.Conclusions
In this retrospective cohort, remote tonometry-derived, novel threshold-based IOP metrics describing the frequency and degree of exceeding patient-specific IOP targets were significantly associated with HVF progression in patients with OAG under treatment, whereas standard and in-office IOP metrics were not. These findings suggest that remote tonometry may capture clinically relevant IOP burden not reflected in conventional settings and metrics, and support prospective validation of both remote IOP monitoring and individualized, threshold-based metrics as potential complements to current approaches of glaucoma monitoring.