To evaluate changes of the retinal pigment epithelium (RPE) after surgery of an idiopathic macular holes (IMD) and their effect on visual acuity. Methods: Fifty eyes of 44 patients with IMD were subjected to pars plana vitrec- tomy, separation of the adhering cores of the vitreous body and IMD tamponade with 16% C 3 F 8. In 32 eyes autologous thrombocyte concentrate (AKT) was admi- nistered, during the initial operation in 23 eyes and during re-operation in 9 eyes. The patients were followed up for 6-28 months (average 15 months). Changes of RPE were evaluated by biomicroscopy and fluoroangiography. Results: Changes of RPE were observed in 18 eyes (36 %). In this group visual acuity improved in 11 eyes (61 %) and the final mean visual acuity was 0.41. Facet-like foci characterized by minor defects and/or hyperplasia of RPE were found in 27 eyes (54%). In this group visual acuity improved in 19 eyes (70 %) and the final visual acuity, 0.22, and the mean difference between pre- and postopera- tive visual acuity were significantly worse than in the eyes without new changes of RPE (p = 0.0108, and 0.0470 resp.).Disciform (phototoxic) lesions in the macula developed in five eyes (10 %) and were manifested by gross spotty changes of RPE on fluoroangiograms, as a rule by early hypofluorescence and late subretinalstaining. Visual acuity improved slightly on one eye (20 %). AKT did not affect changes of RPE. Conclusions: Changes of RPE after operation of IMD are frequent and may significantly reduce the postoperative visual acuity. Administration of AKT du- ring surgery does not influence the incidence of RPE changes. RPE changes are probably caused by surgical trauma of a compromised macula.

        Key words: idiopathic macular hole, pars plana vitrectomy, retinal pigment