Techniques de mesure du pouvoir accommodatif chez le sujet phake et le sujet pseudo-phake, distinction entre insuffisances accommodatives mécaniques et neurologiques

Abstract

The methods available for studying accommodation are evaluated: Donder's "push-up" method, dynamic retinoscopy, infrared optometry using the Scheiner principle, and wavefront analysis are each discussed with their inherent advantages and limitations. Based on the methodology described, one can also distinguish between causes of accommodative insufficiency. Dioptric insufficiency (accommodative lag) that remains equal at various testing distances from the subject indicates a sensory/neurologic (afferent), defect, whereas accommodative insufficiency changing with distance indicates a mechanical/restrictive (efferent) defect, such as in presbyopia. Determining accommodative insufficiency and the cause can be particularly useful when examining patients with a variety of diseases associated with reduced accommodative ability (e.g., Down syndrome and cerebral palsy) as well as in evaluating the effectiveness of various potentially accommodating intraocular lens designs.