Elevated Intraocular Pressure Immediately after Cataract Surgery and Future Risk of Primary Open-Angle Glaucoma in the IRIS® Registry (Intelligent Research in Sight)

Objective

This study evaluated associations between postoperative intraocular pressure (IOP) after cataract surgery and the future risk of developing primary open-angle glaucoma (POAG) in patients without prior glaucoma, glaucoma suspect, or ocular hypertension diagnoses.

Design

Retrospective cohort study.

Subjects

1 912 101 individuals without prior glaucoma, glaucoma suspect, or ocular hypertension diagnoses who underwent their first cataract surgery in the American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight).

Methods

The highest IOP recorded on postoperative days 0 to 2 was used for analysis. For Kaplan–Meier survival estimates and Cox proportional hazards model analysis, IOP was dichotomized into normal (≤21 mmHg) and high (>21 mmHg) and assessed for associations with POAG. The stratified Cox model quantified the associations between IOP and the risk of POAG across different demographic groups. Additionally, postoperative IOP was divided into decile categories, and hazard ratios (HRs) of the risk of POAG were estimated for each, with the 40% to 60% IOP range as the reference, adjusting for demographic factors.

Main Outcome Measures

Cumulative probability of POAG diagnosis and HRs for POAG development.

Results

The median time to development of POAG was 682 days (interquartile range 191–1467 days). Kaplan–Meier estimates showed that the 4000-day cumulative probability of POAG diagnosis for the high IOP group was nearly double the normal group (3.4% vs. 1.7%, P < 0.0001). The Cox proportional hazards model identified high postoperative IOP, older age, male sex, and Asian, Black, Native Hawaiian, and Other Pacific Islander races, as well as Hispanic ethnicity, as risk factors for POAG. In the stratified Cox analysis, high postoperative IOP was consistently associated with increased risk of POAG across demographic subgroups. The highest IOP decile was associated with increased risk of POAG (HR 2.42; 95% confidence intervals [CI] 2.26–2.58), while the lowest decile was not (HR 0.88, 95% CI 0.81–0.95). Similar trends were observed with risks of other types of glaucoma.

Conclusions

Elevated postoperative IOP after cataract surgery is a risk factor for future POAG development, independent of age, sex, race, and ethnicity.

Financial Disclosure(s)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.