Abstract
Purpose :
Historically, clinicians were taught that an intraocular pressure (IOP) above 21 was abnormal and that patients with IOPs >21 should be treated for glaucoma. We now know that IOP is a continuous risk factor for glaucoma and that there is no evidence to support an IOP cutoff of >21 to decide whether to treat. However, it is difficult for humans to cognitively interpret continuous risk factors, and it is possible that clinicians may continue to use this historical cutoff for clinical decision making. We used a large, multicenter electronic heath record (EHR) database to evaluate if the historical cutoff of IOP >21 still influences clinical decision making.
Methods :
The Sight OUtcomes Research CollaborativE (SOURCE) is a large, multicenter repository containing EHR data from academic eye centers across the US. We identified all clinic encounters in the database for patients over age 40 with IOP measurements ranging from 12 to 22. We determined if a decision was made to initiate IOP-lowering treatment at each encounter (new prescription for IOP lowering medication within 1 week of encounter, selective laser trabeculoplasty within 4 weeks, or glaucoma surgery within 8 weeks). We used mixed effects logistic regression to model the rate at which eyes were treated based on the IOP level. The models all included a continuous IOP variable and random effects for visit provider, patient, and eye to account for within-provider, within-patient, and within-eye correlation. We estimated the change in treatment odds at each point and compared specific IOP levels (19, 20, 21, 22) to see if there was a change in the rate of treatment at IOP 22.
Results :
Our analysis included 1,974,608 IOP measurements from 185,023 eyes from 94,413 unique patients from 7 sites. We found that the odds ratio for treatment for IOPs of 19, 20, and 21 were between 1.03 and 1.05, while the odds ratio for treatment for an IOP of 22 was 1.11. The IOP of 22 had a larger effect than the other IOP levels (p<0.01).
Conclusions :
The historical cutoff of IOP >21 continues to influence clinician decision making, though we now know that IOP is a continuous risk factor for glaucoma. This supports the need for clinical decision support to help clinicians use IOP as a continuous risk factor to guide clinical decision making.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.