Aim — to analyze changes in various biometric parameters after vitrectomy. Material and methods. A total of 50 patients (50 eyes) were followed up. All of them underwent vitrectomy for idiopathic epiretinal fibrosis and macular hole. In addition to the standard ophthalmic examination, we performed a combined ultrasound study and ultrasound biomicroscopy before and after the surgery (at 2—3 weeks and 6 months). Variation statistics was applied to assess the results using the SPSS Statistica 20 software. Results. According to ultrasound biomicroscopy, the following parameters increased: anterior chamber depth, trabecular-ciliary process distance, posterior chamber maximal depth and volume, and fiber length within the zonule of Zinn. In the late postoperative period (6 months after the surgery), there was an increase in lens volume and anterior-posterior ocular axis by the average of 0.15±0.04 mm. Against this background, clinical refraction shifted toward myopia by the average of 0.68±0.05 diopters in the early postoperative period and 1.7±0.15 diopters at 6 months. Conclusion. With the help of modern ultrasound examinations we have identified biometric changes in the anterior segment of vitrectomized eyes. We have also established a myopic shift of clinical refraction, which is most likely to be due to the increase in axial eye length and lenticular changes.