Criteria for interpretation of ocular pneumoplethysmography (Gee).

Ocular pneumoplethysmography (OPG) (Gee) is one of the most widely used tests for evaluation of carotid artery disease. Its usefulness depends on its diagnostic accuracy, which depends on the criteria used for interpretation of OPG tracings. Application of different criteria as suggested in the literature by Gee et al, McDonald et al, Baker et al, Eikelboom, and O'Hara et al on 200 OPG tests compared with angiography resulted in variations of sensitivity from 70% to 95%, specificity from 70% to 94%, and overall accuracy from 75% to 90%. In validating OPG, one has to be aware of these substantial differences. We found the criteria of McDonald et al the most suitable for clinical use.