Evaluation of a STAT MRI Protocol for Patients with Optic Disc Edema.

Abstract

Background: Evaluating patients with potentially sight-threatening conditions frequently involves urgent neuroimaging, and some providers recommend expediting emergency department (ED) evaluation. However, several factors may limit the practicality of ED evaluation. This pilot study assessed the feasibility and safety of a STAT magnetic resonance imaging (MRI) protocol, designed to facilitate outpatient MRI within 48 hours of referral, compared with ED evaluation for patients with optic disc edema.

Methods: A retrospective chart review was performed. Demographics, clinical data, and baseline ophthalmic measures were compared between patients in STAT and ED groups using the t test or Fisher exact test. Multivariate analyses compared changes in visual acuity (VA), visual field mean deviation (VF MD), retinal nerve fiber layer thickness, and edema grade between presentation and follow-up using a mixed-effects model adjusting for age, sex, and baseline measures.

Results: A total of 70 patients met the study criteria-24 (34.3%) in the STAT MRI cohort and 46 (65.7%) in the ED cohort. Demographic variables were similar between groups. Patients referred to the ED had worse VA ( P < 0.001), larger VF MD ( P < 0.001), and higher edema grade ( P = 0.002) at presentation. Four patients in the ED group and none in the STAT group were found to have space-occupying lesions. Multivariate analyses showed that follow-up measures were significantly associated with their baseline values (all P < 0.001) but not with referral protocol (all P > 0.099). The STAT MRI protocol was associated with lower average patient charges and hospital costs.

Conclusions: The STAT MRI protocol did not result in inferior visual outcomes or delay in life-threatening diagnoses. Urgent outpatient evaluation, rather than ED referral, seems safe for some patients with optic disc edema. These findings support continued utilization of the protocol and ongoing improvement efforts.