Vitrectomy with membrane peeling has developed to be the gold-standard in treatment of epiretinal membranes. Due to the possibility of vitrectomy induced cataract, in many ophthalmic surgical centers it has become usual to indicate combined phacoemulsification and vitrectomy in case of existing cataract.

Epiretinal membranes (ERM) and pseudomaculaforamen are disorders involving the posterior pole of the eyeball with consecutive vision loss. ERM can be well visualized with spectral domain optical coherence tomography (SD-OCT). Different study groups showed that even intraoperative use of SD-OCT is possible.

The aim of the study is to document tilt of the intraocular lens in combined phacoemulsification and vitrectomy by photography of purkinjereflexes. During vitrectomy tamonade with air or saline are regarded as equal in substituting the removed vitreous. In case of airtamponade, air will be resolved within several days. As airtamponade induces more anterior movement of the implanted intraocular lens in the superior parts of the lens, tilt can result. Saline doesn´t have any influence on the intraocular lens.

Inclusion Criteria:

• patients sheduled for combined phakoemulsification and 23G pars plana vitrectomy
• Minimum Age of 21 years
• written informed consent

Exclusion Criteria:

• none