To determine the myopic shift and cataract change after lens sparing vitrectomy (LSV) in patients with idiopathic epiretinal membrane (ERM) in their 5th and 6th decade of life.

The medical records of patients undergoing LSV for idiopathic ERM from 2008 to 2012 were reviewed. Patients with previous intraocular surgery, preoperative significant cataract, under 40 or over 60 years of age and a follow-up period of less than 6 months were excluded. The change in refractive errors, visual acuity, and cataract grade were evaluated for 6 months after LSV as well as the correlation between myopic shift and cataract change at 6 months after LSV.

Twenty-eight eyes were included in this study. The cataract status worsened by 1.07 levels, myopia progressed by 3.13 diopters ( p < 0.001), and uncorrected visual acuity (log MAR) decreased from 0.73 to 0.98 ( p = 0.022) at 6 months after LSV. Additional cataract surgery was performed in 22 eyes (78.6%) at 13.6 months on average during the follow-up period (average 16.9 months). In 6 eyes (21.4%) having myopic change below 1.0 diopters, crystalline lens was preserved for 36 months after vitrectomy. Conversely, 22 eyes (78.6%) with myopic change over 1.5 diopters required cataract surgery. Therefore, myopic change over 1.5 diopters could be a major postoperative change predicting the necessity for cataract surgery ( p < 0.001).

LSV for ERM caused a significant myopic shift and cataract changes in patients in their 5th and 6th decade of life and additional cataract surgery was required in 78.6% of patients within 3 years after vitrectomy. The myopic shift over 1.5 diopters at 6 months after vitrectomy could be a major postoperative change predicting the necessity for cataract surgery.