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[Vector analysis of surgically induced astigmatism after combined operation of phacoemulsification, intraocular lens implantation and pars plana vitrectomy].

BACKGROUND
To evaluate the changes in corneal shape after phacoemulsification, PC IOL implantation and pars plana vitrectomy.


MATERIAL AND METHODS
This study comprised 25 eyes of 25 patients who received phacoemulsification, 5.5 mm PMMA IOL implantation through 6 mm clear cornea incision with one single suture, and pars plana vitrectomy in one step - group A. To unique and compare the differences in surgical induced astigmatism (SIA) between combined procedures and two steps procedures, 2 control groups in one step surgery (only phacoemulsification with PCIOL--group B or only pars plana vitrectomy--group C) with the same shape and location of incision in cataract surgery and sclerotomy sites were analyzed.


RESULTS
The highest value of SIA was in group A which was not statistic significant different than group B (p = 0.97). In-group C, SIA was the lowest, and there was also not significant difference between groups A (p = 0.063). The differences in SIA between group B and C were statistic irrelevant too. (P = 0.09) Shifts in axis to with the rule component were noted in 43.9 % of cases in-group A, 40.79% in-group B, and 58.96% in-group C. The highest shift in axis to against the rule meridian was observed in-group B (tab. 2) and in direction with the rule in-group C.


CONCLUSIONS
No statistical significance was observed in the amounts of the induced astigmatism and refractive cylinder among the group of combined phacoemulsification, IOL implantation and pars plana vitrectomy. However, optical rehabilitation can be delayed by a postoperative astigmatism.