Ultrasound biomicroscopy in examination of stability of position of toric lens of patients with corneal astigmatism after operative therapy of cataract
Background. General criteria, for implantable toric intraocular lens is not only neutralization of corneal astigmatism but also the stability of its position toward to meridian of corneal for a long period of time. Ultrasound biomicroscopy is the method that allow not only visualized structures of front eye segments but also objectively estimate changes of structures space relations in dynamics. Methods. 42 patients was examined from 16-75 years (58 eyes) with right corneal astigmatism, operated by the method of phacoemulsification with implantation of toric lens of AcrySof Toric (Alcon, USA) model. Examination been provided on the 1, 7, 30 day and after 3, 6 months after operation including eidoptometry, autorefractometry, examination on slit lamp and ultrasound biomicroscopy on Accutome UBM plus (США) machine. Results. For the period of examination the mean of rotation angle of lens was 3,3°, on 28 eyes (48,3 %) rotation was not registered. Thickness of the crystalline capsule of lens was 16,4±1,9 mkm, reaching after 6 months 30,3±3,4 mkm. On all time of examination period was registered decrease of size of capsulorhexis on 0,85±0,32 mm. Was founded direct correlation between increase of angle of rotational instability of lens and distance scleral spur- eye optics rim. Conclusions. Rotational instability of intraocular lens directly correlate with angulation of its optical part, part of capsulorhexis das not have line relation with rotational angle. Ultrasound biomicroscopy allow to define signs of rotational instability of intraocular lens with directed optical axis, and also understand of its development and to define possibilities of reposition