Early and late corneal astigmatism outcomes after pars plana vitrectomy for replacement of dislocated intraocular lens to iris-clips

Intraocular lens dislocation is a relatively common late-complication after routine cataract surgery. In a case of absence of capsular support the exchange of dislocated intraocular lens (IOL) with iris-clip lense is one of the first-choice treatment, but with surgery – induced complications which are changing over the postoperative period. The aim of the study was to evaluate and compare the early and late outcome of pars plana vitrectomy for replacement of dislocated IOL to iris-clip IOL by measuring the changes of corneal astigmatism in a pre- and postoperative period. Prospective study included 31 eyes of 31 patients (mean age: 77,61 ± 1,29(SD) years; range: 65-87 years), who underwent pars plana vitrectomy surgery for replacement of dislocated IOL to iris-clip IOL in Pauls Stradins Clinical University Hospital between 2018 and 2020. Data were collected by measuring corneal astigmatism using anterior segment optical coherence tomography at the preoperative examination and at the postoperative follow-up visit up to 24 months after surgery.  As an early outcome of corneal astigmatism was classified measurements made up to 1 year after surgery, but as a late outcome was classified examination performed after 1 year since surgery.  The mean surgery induced corneal astigmatism value for all cases was 3,88±0,60 (SD) dioptries. The mean increase of corneal astigmatism for patients who were examined up to 1 year after surgery was 5,57±0,74(SD) dioptries, while for the patients who were examined after 1 year since surgery – 1,34±0,35(SD) dioptries. Statistically significant difference between early and late corneal astigmatism outcome was deteceted (p<0.001; unpaired t-test). 1. The early outcome revealed a high surgery induced corneal astigmatism. 2. The corneal astigmatism is decreasing during postoperative period. 3. The corneal astigmatism is statistically significant lower after 1 year since surgery. 4. The postoperative recovery period lasts over 1 year.