[Investigation of iridotrabecular contact in primary angle closure].

Abstract

Purpose: This study compares and evaluates the parameters of iridotrabecular contact (ITC) in patients with primary angle closure disease (PACD) with natural lenses and pseudophakia based on anterior segment imaging data from swept-source optical coherence tomography (SS-OCT).

Material and methods: This retrospective study analyzed data from 92 patients aged 32 to 89 years, and included 56 patients with PACD (43 with natural lenses and 13 with pseudophakia) and 36 in the control group (21 with natural lenses and 15 with pseudophakia). All participants underwent SS-OCT (CASIA2; Tomey Corporation, Japan), which included an assessment of the ITC Index and ITC Area.

Results: The ITC parameters in PACD, both with and without pseudophakia, were significantly higher than in the corresponding control groups. In pseudophakic PACD patients, the ITC Index was 8.7±7.2%, and the ITC Area was 0.82±0.54 mm², compared to 0.00±0.00% and 0.00±0.00 mm² in the pseudophakic control group (all p=0.01). For the PACD group with natural lenses, the ITC Index was 45.4±21.8%, and the ITC Area was 5.81±3.9 mm², compared to 0.05±0.11% and 0.56±1.17 mm² in the corresponding control group (all p=0.00). Significantly higher ITC values were found in the PACD group with natural lenses compared to those with pseudophakia (ITC Index 45.4±21.8% vs. 8.7±7.2%, respectively, p=0.00; ITC Area 5.81±3.9 mm² vs. 0.82±0.54 mm², respectively, p=0.00).

Conclusion: Significantly higher ITC values were demonstrated in PACD patients with natural lenses compared to those with pseudophakia. However, the persistence of residual angle closure in primary angle-closure glaucoma after lens extraction suggests the feasibility of proactive surgical intervention at earlier stages of the disease.