Design: Cross-sectional study.
Participants: Four hundred seventy-three eyes from 239 participants with suspected or established primary open-angle glaucoma sampled from 4 outpatient clinics in Australia between August 2016 and December 2019.
Methods: Participants underwent Icare HOME (Icare Oy, Vanda, Finland) tonometer measurements to record IOP 4 times daily for 5 days. Unreliable measurements were excluded. A minimum of 2 days with at least 3 reliable measurements were required. We used a validated IOP PRS derived from 146 IOP-associated variants in a linear regression model adjusted for central corneal thickness and age.
Main Outcome Measures: Highest recorded early morning IOP and mean IOP within and outside office hours. Early morning IOP spikes were defined by a higher early morning IOP than the maximum in-office hours IOP.
Results: Reliable measurements were obtained from 334 eyes of 176 participants (mean age, 64 ± 9 years). Eyes in the highest IOP PRS quintile showed an early morning IOP increase of 4.3 mmHg (95% confidence interval [CI], 1.4–7.3; P = 0.005) and mean increase in IOP outside office hours of 2.7 mmHg (95% CI, 0.61–4.7; P = 0.013) than the lowest quintile, which were significant independently after accounting for a recent in-clinic IOP measured by Goldmann applanation tonometry. Eyes in the highest PRS quintile were 5.4-fold more likely to show early morning IOP spikes than the lowest quintile (odds ratio 95% CI, 1.3–23.6; P = 0.023).
Conclusions: A validated IOP PRS was associated with higher early morning IOP and mean IOP outside office hours. These findings support a role for genetic risk prediction of susceptibility to elevated IOP that may not be apparent during in-clinic hours, requiring more detailed clinical phenotyping using home tonometry, the results of which may guide additional interventions to improve IOP control.
- Diurnal IOP
- Genetic risk prediction
- Home tonometry
- iCare HOME
- Intraocular pressure
- Polygenic risk score