Ocular Oscillometry in Cerebrovascular Disease

Abstract

Recent experience with endarterectomy and bypass grafting for carotid occlusive disease has made the early diagnosis of this condition clinically important.¹ Unfortunately, ophthalmodynamometry, which is often helpful in making this diagnosis, is an inaccurate and unreliable procedure.^2-5 It has been suggested that ocular hemodynamics might be better evaluated using a sensitive instrument to amplify the ocular pulse seen during tonometry and tonography.⁶ With this principle in mind, the following apparatus was developed in the ophthalmic laboratories of University Hospitals. Materials and Methods A perilimbal suction cup was attached to a transducer, vacuum trap, and 50 cc syringe as described in Fig 1. The suction cup was modified by the addition of a polyethylene sidearm tube to facilitate removal of air from the system. In order that the transducer might be used in its optimum pressure range, the pressure gradient across the transducer was reduced to zero. This