Purpose:

 To determine the relationship between ITC measured using AS-OCT and gonioscopy 

Methods:

 A retrospective chart review of gonioscopy and AS-OCT images (Casia SS-1000, Tomey, Nagoya, Japan) between September 2010 – August 2011. Eyes which had previous ocular surgery or intraocular injections were excluded. Age, sex, race, and Shaffer gonioscopy grade were recorded. 2D scan images were reviewed by 2 readers using proprietary software to determine the scleral spur location (SS) and the end of the angle opening (EAO) at 0, 90, 180 and 270 degrees. The mean SS and EAO locations were used as the final locations. ITC was defined as EAO more than 80 µm central from the SS. Trabecular iris contact length (TICL) was defined as the distance from SS to EAO if ITC was observed. Frequency (%) of ITC and mean (± standard deviation) of TICL were summarized for each gonioscopy grade by each quadrant. 

Results:

 Fifty four eyes from 54 patients with a mean age of 52 ± 16 years were included. Thirty one (57%) were female, 32 (60%) were white, 12 (22%) were Hispanic and 6 (11%) where black 

Conclusions:

 AS-OCT measurements of ITC corresponded with gonioscopy. TICL was typically approximately 500 microns in length in eyes with narrow angles. It is possible that ITC in gonioscopically open angles may represent the presence of iris processes, which do not extend as far anteriorly