Acta Biomedica Scientifica (Feb 2015)
Regularities of changes of irido-ciliary-lenticular interrelations during presbyopia evelop-ment in patients with different types of refraction
Abstract
The presbyopia formation in patients with different types of refractive errors has its own characteristics, which are unexplored. The purpose of this study was to identify the regularities of changes of irido-ciliary-lenticular relationships in presbyopia formation in different refractive conditions. 170 patients with various types of refraction (emmetropia, myopia, hyperopia) with or without presbyopia were examined. The infrared pupillometry, the ultrasound biomicroscopy and examination of the eye anterior segment under rotary Scheimpflug camera («Pentacam») were performed besides standard ophthalmic examination. In patients with emmetropic refraction the increase in the size of the lens, the reduction of the thickness of the ciliary body, the narrowing the diameter of the pupil in both photopic and scotopic conditions, the increase in the largest range of pupillary excursion and the first signs of intraocular asymmetry were noted during the formation of presbyopia. Presbyopes with axial myopia were distinguished from presbyopes with emmetropia by more pronounced constriction of the pupil in scotopic lighting conditions and increased intraocular initial asymmetry. The degree of increase in the anterior-posterior size of the lens in presbyopia formation was the most pronounced in the hyperopic eyes. The loss of accommodation in hyperopeswas accompanied by hypertrophy of anterior part of the ciliary muscle and an increase in pupil diameter. The development of presbyopia in patients with different types of refraction increases the initial differences of irido-ciliary-lenticular relationships.
