Sulcal Angle Measurements In Pseudophakic Glaucomatous Eyes Using Anterior Segment Coherence Tomography

To compare the sulcal angle in primary open angle glaucoma (POAG) and (PACG) eyes that had undergone phacoemulsification using anterior segment optical coherence tomography (AS-OCT).

Singapore National Eye Centre is a tertiary center located in Singapore. It provides specialist eye care to more than 50 percent of patients in the public sector.

Retrospective study of 44 patients with either primary open angle glaucoma (POAG) or primary angle closure glaucoma (PACG) who had undergone routine phacoemulsification. Their anterior segments were evaluated with Zeiss Visante AS-OCT in 2 cross sectional cuts. The sulcal angle was defined to be complementary to the iridocorneal angle and created by the arms constructed by a line that runs parallel to the corneal endothelium (used as a surrogate for its clarity) and a line extending from the iris root to the iris tip. The angle was measured by proprietary software. Images were analyzed by two independent observers. Statistical analyses included mean dimensions and reliability between graders was calculated by intraclass coefficients.

There were 27 males and 17 females, with a mean age of 68. 25 eyes (56.8%) were diagnosed with POAG and 19 eyes with PACG (43.2%). There were 2 unusable images. Following phacoemulsification, the mean sulcus angles were 137.9 ± 3.99 (temporal), 137.8  ± 4.36 (nasal), 140.1 ± 4.17 (superior), and 141 ± 4.09 (inferior). Intraclass correlations between graders were 0.144 to 0.313. There was no significant difference between POAG and PACG eyes regarding the sulcal angle.

AS-OCT can be used for quantitative analysis of the sulcal angle but intraclass coefficients suggest poor correlation between graders. There was no significant difference between the sulcal angle in POAG or PACG eyes post phaco. Further studies using ultrasound biomicroscopy of the sulcal angle may lead to more accurate determination of this novel anterior segment parameter and facilitate creation of novel glaucoma devices.