The aim of this study is to analyze similarities and evaluate interchangeability of Visante and Cirrus OCT (optical coherent tomography)and to compare agreement between gonioscopy and the two systems for evaluation of anterior segment parameters.

All participants underwent routine ophthalmic examination by their physician. Three independent examiners performed gonioscopy using Spaeth Gonioscopic Grading System. Findings were recorded independently along with risk assessment of angle being closed as: high, medium, and low or no risk. Patient information was not available to doctor during gonioscopy. One eye of each patient was imaged using both Visante and Cirrus OCT. Imaging was performed under scotopic and photopic conditions and obtained from horizontal (3:00 and 9:00 o'clock) and vertical (6:00 and 12:00 o'clock) meridians. The same experienced independent examiner performed all Cirrus measurements. Visante was performed by 3 trained technicians using same protocol.

OCT images were exported and masked to be evaluated for presence of open or closed anterior chamber angle. Masked images were presented with no other patient information available to two examiners with glaucoma training working together to score on basis of iridocorneal angle as, closed (0 degree), high possibility (10 degree), medium risk (20 degree), and low or no risk (> 30 degree).

Inclusion Criteria:

• 18 years of age and older with open angle, narrow angle and angle closure

Exclusion Criteria:

• All lasers or intraocular surgery (cataract, glaucoma, retina, cornea)

Phakic patients with open, narrow angle and angle closure glaucoma without prior intraocular surgery, including laser iridotomy or topical miotic use, were recruited for this study after Informed Consent was obtained.

Manuscript has been published in the Journal of Glaucoma.