Association Between Laser Interferometric Measurement of Fundus Pulsation and Pneumotonometric Measurement of Pulsatile Ocular Blood Flow in Patients With Age-related Macular Degeneration

Several methods have been proposed for the measurement of pulsatile ocular blood flow (POBF). The pneumatic tonometer, which is commercially available, assesses POBF by measurement of intraocular pressure (IOP) changes during the cardiac cycle. The investigators have recently developed a method for the measurement of ocular fundus pulsation, which is based on laser interferometry. In contrast to the Langham system the method is non-contractile and yields a high topographic resolution. Moreover, the pneumatic tonometer assesses the ocular pressure pulse, whereas ocular fundus pulsation is a point measure of the ocular volume pulse. These two parameters are related by the ocular rigidity, which refers to the mechanical properties of the eye coats. Age-related macular degeneration (AMD) is the most common cause of blindness in the industrialized nations. The mechanisms behind this severe eye disease are, however, still obscure. It has been hypothesized that alterations in choroidal blood flow and ocular rigidity may contribute to the development and progression of AMD. However, there is currently little data to confirm this hypothesis. The present study is an attempt to investigate choroidal blood flow and ocular rigidity by employing laser interferometric measurement of fundus pulsation and pneumotonometric measurement of fundus pulsation.