Utility of Anterior Segment OCT Measurements for Predicting Severe Eye Pressure Increase after Intravitreal Dexamethasone Implant

Abstract

Background/aims: To assess the utility of non-contact anterior segment ocular coherence tomography (AS-OCT) measurement of the angle recess width (AR) to predict eyes prone to intraocular pressure (IOP) spikes after injection of intravitreal dexamethasone implant in patients with CRVO and BRVO. Methods: Cohort study with fellow-eye control of 34 patients with gonioscopically open angles and RVO undergoing intravitreal injection of dexamethasone implant (Ozurdex). All participants received pre-injection AS-OCT in both eyes using spectral domain Cirrus OCT. Independent masked assessors measured the AR width using electronic imaging calipers. IOP was monitored prior to implant placement, and monthly for 6 months thereafter. Comparisons between AR width and degree of steroid response, phakic status, gender, and prior history of glaucoma were analyzed. Results: Seven eyes (20%) developed severe IOP spikes (IOP ≥ 30 mmHg). There was a highly significant (p=0.0085) difference in angle recess width between severe responders (175.0 ± 27.1 μm) and those eyes with less severe response (272.9 ± 24.3 μm). There was also strong correlation between the AR width in study and fellow eyes (mean 248.1 ± 19.8 vs. 261.9 ± 22.6 μm; R2=0.67). Conclusions: This study reaffirms the potential utility of AS-OCT measurement of AR width as a practical means for helping identify eyes at high risk of ocular hypertension after intravitreal corticosteroid administration.