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Abstract #8232 Published in IGR 4-3
Orbscan: a new device for iridocorneal angle measurement
Allouch C; Touzeau O; Borderie V; Puech M; Ameline B; Scheer S; Laroche LJournal Français d'Ophtalmologie 2002; 25: 799-806
PURPOSE: To evaluate the accuracy and reproducibility of iridocorneal angle measurement obtained with a slit-lamp method (Orbscan). METHODS: The iridocorneal angle was measured in 100 normal eyes of 50 patients, using the Orbscan II device. Angles were measured in eight meridians using both the 'plane' and 'polynomial' modes. For each eye, two examinations were taken successively, and the reproducibility was calculated by analyzing the difference between both measurements. Angle value was correlated with subjective spherical equivalent and other biometric measurements obtained by Orbscan (i.e., anterior chamber depth, axial length, corneal diameter). RESULTS: Reproducibility of the angle measurement was significantly better with the plane mode than with the polynomial mode (5.4% ± 4.7 versus 7.2% ± 6.2; p < 0.001). Reproducibility significantly varied with localization (p < 0.001). Significant differences were found between reconstruction modes (49.3 ± 4.6° for the plane mode versus 42.8 ± 6.7° for the polynomial mode (p < 0.001)) and according to localization (p = 0.02). Correlation with the other biometric measurements was higher for the plane mode than for the polynomial mode. Angle measurement with the plane mode showed significant correlation with subjective spherical equivalent (rS = -0.59; p < 0.001), the anterior chamber depth measurement (rS = -0.74; p < 0.001), the axial length measurement (rS = -0.34; p ,KD> 0.002), and the corneal diameter measurement (rS = -0.34; p < 0.002). CONCLUSIONS: The iridocorneal angle measurement obtained with the plane mode showed high reproducibility, and it significantly correlated with clinical parameters. It appears to be useful for clinical applications.LA: French
C. Allouch, MD, Pole Saint Antoine, CHNO des Quinze-Vingts, 28 rue de Charenton, 75571 Paris Cedex 12, France
Classification:
6.9.5 Other (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)