Comparison of Iridocorneal Angle Assessments in Open-Angle Glaucoma and Ocular Hypertension Patients: Anterior Segment Optical Coherence Tomography and Gonioscopy

Abstract

Purpose To quantitatively compare iridocorneal angle assessments using gonioscopy and anterior segment optical coherence tomography (AS-OCT). Patients US and Chinese patients with open-angle glaucoma (OAG) and/or ocular hypertension (OHT). Methods Analysis was pooled from 2 multicenter, noninterventional studies conducted in the US and China. Gonioscopy Shaffer grade and an AS-OCT method that approximates the angle width relative to local morphologic variations were compared by measuring the same iridocorneal angles. A third, separate, single-center, noninterventional study was conducted to verify results observed from the pooled analysis. Results From the pooled studies, a total of 239 eyes were measured using Shaffer grade and AS-OCT. Of these, 6 were Shaffer grade 2, 37 in Shaffer grade 3, and 196 in Shaffer grade 4. There was a trend of increasing Shaffer grade with increasing AS-OCT angle width. Open iridocorneal angles, Shaffer grade ≥3, had a ~98% sensitivity and 88% positive predictive value for identifying AS-OCT angle width ≥300 µm, using the AS-OCT method. To verify these results, a total of 28 right eyes were imaged for the third study. A trend of increasing Shaffer grade with increasing AS-OCT angle width was observed, and angles with Shaffer grade ≤2 had AS-OCT angle width <300 µm. Conclusion The AS-OCT method can determine the space in the anterior chamber and can potentially identify angles that are the appropriate size for certain glaucoma devices. Information gathered from AS-OCT can provide additional comprehensive and quantitative assessment to gonioscopy.

Anterior Segment Changes in Patients With Glaucoma Following Cataract Surgery

“…The most prevalent form of the condition is primary open-angle glaucoma (POAG), which is particularly insidious as it typically progresses without symptoms until significant vision loss has occurred [2]. There is evidence that anterior segment parameters have a significant role in the pathophysiology of several types of glaucoma, including POAG [3][4][5][6]. It is important to note that, following an uneventful phacoemulsification surgery, anterior segment variables tend to change, including anterior chamber depth and angle width.…”