Apport de la tomographie en cohérence optique dans l’évaluation de l’angle irido-cornéen du camerounais

Abstract

Our work was aimed at determining the sensitivity and specificity of anterior segment OCT (AS-OCT) in the evaluation of the iridocorneal angle (ICA) in Cameroon. We conducted a cross-sectional, analytical study from January 2 to June 30, 2019 in Yaoundé. One hundred and twenty five patients over 35 years of age underwent three-mirror manual glass gonioscopy and AS-OCT. The angle was defined as occludable on manual gonioscopy if the posterior trabecular meshwork, was not visible and on OCT if there was contact between the iris root and the posterior surface of the peripheral cornea. Quantitative parameters (angle opening distance, angle recess area, and trabecular-iris space area) in the nasal and temporal quadrants were recorded for the analysis. Men accounted for 56.20% of the 96 patients selected (192 eyes). The mean age was 54.78±10 years. The prevalence of occludable angles was 18.75% (18/96 patients) and 28.125% (27/96 patients) on manual and automated gonioscopy respectively. Schaeffer-Etienne grades ≤2 were identified in 43/192 (21.94%) nasal quadrants and 33/192 (19.18%) temporal quadrants. The area under the curve (AUC) was maximal for the 500 μm goniometric parameters (> 0.8). An Angle Opening Distance ≤333.50 μm was found in 52/192 nasal quadrants (27.10%) and 53/192 (27.60%) temporal. The sensitivity and specificity of AS-OCT in the detection of occludable angles at 500 μm, were 62.8% and 83.2% respectively in the nasal quadrant, and 66.7% and 80.5% respectively in the temporal quadrant. There was a positive correlation between goniometric parameters on AS-OCT and gonioscopy (P=0.01). Given its higher specificity, AS-OCT should be a supplemental examination in the analysis of an angle which appears closed on manual gonioscopy.