[A method for determining peroperative centering and monitoring the development of postoperative decentration of...

After implantation of intraocular lenses (IOL) Purkinje images 3 and 4 (Pi3 and Pi4) are clearer on the anterior and posterior surface of its optical part (subsequently only lens). Along with the corneal Pil this phenomenon was already used in clinical work for more accurate calculations of the degree of decentration and tilt of the lens in the eye. The authors describe a simplified method for assessment of the position of the lens by means of Pil, 3 and 4, using apparatuses with an approximately coaxial light. The method uses overlapping of Pi1, 3 and 4 in perfect centering of the lens in the axis of the eye (it is assessed by drawing a perpendicular line on the centre of the cornea) and marked dislocation of Pi3 in the direction of decentration of the planoconvex lens with the convexity facing the cornea. The inclination of the lens must be eliminated according to positions Pi1 and Pi4. The method is suitable for peroperative centering and for assessment of the direction and extent of decentration of these lenses. The authors discuss the possible use of this method also in biconvex and planoconvex lenses with the convexity facing the retina. In a group of 10 implanted planoconvex lenses the authors demonstrate the possibility of perfect peroperative centring of the lens and other applications of the method. Incorrect position of the IOL at the end of the operation, which can be one of the factors of later complications, did not change during the early postoperative period.