The relationship of ultrasonic and mechanical properties of human nuclear cataract. A pilot study

Abstract

Cataract is the leading cause of blindness worldwide and cataract extractions account for the majority of all ophthalmic procedures. The continuous improvement of surgical techniques enables the operative procedure to become safer and the postoperative results better. The success of operation depends greatly on the mechanical properties of the lens nucleus. Phacoemulsification of a hard nucleus is associated with an increase in phacoemulsification time and power and therefore dissipated energy. If be possible to measure the stiffness of lens nucleus pre-operatively it would help to permit proper surgical planning and successful cataract extraction. The aim of the pilot study was to investigate experimentally the relationship between the clinical appearance, ultrasonic and mechanical characteristics of nucleus cataract. The relationship of parameters of human nuclear cataract has been evaluated using optical (LOCS III classification system), ultrasonic (calculation of ultrasound attenuation coefficient) and mechanical methods (evaluation of lens stiffness). First, we examined experimentally 10 extracted lenses of enucleated dogs’ eyes in order to assess the new method and device of lens stiffness measuring and to evaluate the relationship between lens stiffness and ultrasound attenuation coefficient. After the estimation of relationship between ultrasound attenuation coefficient and lens stiffness, we investigated human cataractous lens as well. These methods are valuable when making the prognosis of the operation term and even operation methodics. Methods for in vivo evaluation of lens hardness and its relationship with the clinical appearance and ultrasound attenuation have clinical and research applications and must be further developed.