Iris Trabecular Contact May Predict Six-Year Angle Closure Risk

A new study presented last week at ARVO found both the presence and length of iris trabecular contact to be important predictors of angle closure progression.  Photo: Michael Cymbor, OD, and Emilie Seitz, OD. Click image to enlarge.  A recent study used anterior segment OCT (AS-OCT) to measure iris trabecular contact in primary angle closure suspects (PACS), which the authors hypothesized may help predict progression from PACS to primary angle closure (PAC). They determined that the measurement could help identify PACS eyes more likely to experience angle closure in the next six years. In the Zhongshan Angle Closure Prevention Trial, individuals aged 50 to 70 with bilateral PACS were assessed. Each participant had one eye monitored without treatment to see if it developed abnormally high eye pressure, peripheral anterior synechiae or acute angle closure. The study defined various lengths of iris trabecular contact and noted whether these were present in different parts of the eye.The findings from 825 untreated eyes (791 non-progressors, 34 progressors) of 825 participants indicated that the presence of iris trabecular contact in the nasal or either horizontal sector significantly increased the risk of the condition worsening. In particular, longer iris trabecular contact in the nasal sector was associated with higher progression. Conversely, the presence of iris trabecular contact in the superior, inferior and temporal sectors did not correlate with disease progression.“Presence of iris trabecular contact in either horizontal sector and longer iris trabecular contact in the nasal sector are predictive of six-year angle closure progression,” the researchers summarized in their ARVO abstract. “Qualitative and quantitative assessment of iris trabecular contact in PACS eyes using AS-OCT could help identify PACS eyes at higher risk for more severe angle closure disease,” they stated.Original abstract content ©2025 Association for Research in Vision and Ophthalmology. Hong KL, Xu B, Wang W, et al. Presence and length of iris trabecular contact as predictors of six-year angle closure progression: the Zhongshan Angle Closure Prevention Trial. ARVO 2025 annual meeting.