Degree of angle closure and extent of peripheral anterior synechiae: an anterior segment OCT study

• Published in: British journal of ophthalmology Vol. 92; no. 1; pp. 103 - 107
• Main Authors: Su, D H W, Friedman, D S, See, J L S, Chew, P T K, Chan, Y-H, Nolan, W P, Smith, S D, Huang, D, Zheng, C, Li, Y, Foster, P J, Aung, T
• Format: Journal Article
• Language: English
• Published: BMA House, Tavistock Square, London, WC1H 9JR BMJ Publishing Group Ltd 01.01.2008; BMJ; BMJ Publishing Group LTD
• Subjects: Aged; Anterior Eye Segment - pathology; Biological and medical sciences; Female; Glaucoma; Glaucoma and intraocular pressure; Glaucoma, Angle-Closure - complications; Glaucoma, Angle-Closure - pathology; Gonioscopy; Humans; Iris Diseases - diagnosis; Iris Diseases - etiology; Iris Diseases - pathology; Male; Medical imaging; Medical sciences; Middle Aged; Miscellaneous; Ophthalmology; Prospective Studies; Software; Studies; Tissue Adhesions - diagnosis; Tissue Adhesions - etiology; Tissue Adhesions - pathology; Tomography, Optical Coherence - methods; Trabecular Meshwork - pathology; Singapore; Eye disease; Ophthalmology; Anterior segment; Angle closure glaucoma
• ISSN: 0007-1161; 1468-2079; 1468-2079
• DOI: 10.1136/bjo.2007.122572

Aims:To evaluate the relationship between angle width as determined by anterior segment optical coherence tomography (AS-OCT) and the presence of peripheral anterior synechiae (PAS).Methods:This was a prospective observational case series in which 203 subjects with primary angle closure or open angles were recruited. Images of the nasal, temporal and inferior angles were obtained with AS-OCT in dark conditions. Subjects then underwent gonioscopy by an independent examiner who was masked to the AS-OCT findings. PAS were identified by gonioscopy and defined as abnormal adhesions of the iris to the angle that were at least half a clock hour in width and present to the level of the anterior trabecular meshwork or higher. The total clock hours of PAS were recorded.Results:Sixty-eight subjects (33.5%) were PACS, 76 subjects (37.4%) had PAC/PACG, 14 (6.9%) had primary open angle glaucoma, and 45 (22.2%) subjects were normal with open angles. There was a weak but significant correlation between the angle opening distance (AOD), trabecular iris space area (TISA) and angle recess area (ARA) with clock hours of PAS (Spearman’s correlation coefficients = −0.30, −0.32 and −0.32, respectively, p<0.001). The mean values of the AOD, TISA and ARA in the nasal, temporal and inferior quadrants were significantly less in eyes with PAS compared with those without (p<0.001, Mann–Whitney U test). Analysis by quadrant showed that these parameters were smaller in the nasal and temporal quadrants in eyes with PAS (p<0.01).Conclusions:Angle width determined by AS-OCT and the extent of PAS were weakly correlated, and angle width was significantly smaller in eyes with PAS.