Objective: The purpose of this retrospective study is to check on the added value that the OCT can bring to the patients who have or are suspected to have open angle glaucoma.

Methods: Chart of patients who had a retinal nerve fiber analysis (RNFL) study using the OCT of the Ophthalmic Technologies Inc. (OTI, Toronto, Canada) were reviewed. The Eyes included in the study were those who had available on their chart beside the RNFL analysis a full history et eye examination, intraocular pressure measurement (by non contact et by applanation), a central pachymetry (CCT), a gonioscopy, a cup/disc evaluation (90 D et red free Photos) and a visual field. Correlation between RNFL analysis, CCT, C/D evaluation, et visual fields was done.

Results: A total of around 250 eye files (~120 patients) had complete data. More than 20% of the eyes had repeated examinations spaced by a year. There was a moderate correlation between the visual field defects et the RNFL analysis. The evaluation of the C/D done by the 90 D lens et the measured area on the OCT image also showed a moderate correlation. The correlation between the IOP, the CCT et the RNFL seems to be mild to moderate (N.B. all the statistical analysis is still underway). RNFL analysis was a useful ancillary test in the eyes where it was initially difficult to decide whether to treat the patients or not. Many patients showed abnormal thin RNFL inferotemporal quadrant despite normal visual field examination. Only a minority of patients could not be studied by OCT because of pathologic myopia or media aberrations.

Conclusion: OCT in glaucoma showed good repeatability in the eyes that had more than one analysis. It was also useful in the follow up of patients. RNFL is affected earlier in the disease than the visual field et could be helpful for early glaucoma suspects. Larger series are needed to confirm that. Further study is needed to confirm whether the OCT image can be counted upon for the C/D evaluation. RNFL analysis seems to be a good ancillary test that helps in deciding when to treat patients suspected to have COAG.