Measurement Of The Sulcal Angle In Eyes With Primary Open Angle And Primary Closed Angle Glaucoma Post Phacoemulsification.

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

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

Retrospective study of 44 patients with either POAG or PACG who had undergone routine phacoemulsification. Their anterior segments were evaluated with Zeiss Visante AS-OCT in 2 cross sectional cuts. The novel sulcal angle was defined to be complementary to the iridocorneal angle and was created by the arms constructed by a line tangential to the corneal endothelium and a line extending from the iris root to the point of the iris tip. The angle was measured by proprietary software. Images were analyzed by two independent observers. Statistical analyses included mean dimensions and variances between graders in each quadrant. Reliability between graders was calculated by intraclass coefficients.

25 eyes (56.8%) were categorized as POAG and 19 eyes as PACG (43.2%). Following phacoemulsification, the mean sulcus angles were 138 ± 3.99 degrees (temporally), 137.81  ± 4.36 (nasally), 140.1 ± 4.17 degrees (superiorly), 141 ± 4.09 inferiorly). Intraclass correlations between graders were 0.144 to 0.313. There was no significant difference between POAG and POAG eyes post phacoemulsification 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 phacoemulsificationo. Further studies using ultrasound biomicroscopy of the sulcal angle may lead to more accurate determination of this novel posterior segment parameter.