Myopic shift in a pseudophakic eye with an accommodating IOL following vitrectomy with gas tamponade

PURPOSE: To report the case of a patient with Crystalens, an accommodating posterior-chamber intraocular lens (IOL), who experienced a myopic shift following subsequent vitrectomy with gas tamponade. We propose a hypothesis as to why this myopic shift occurred and analyze its validity based on current literature. OBSERVATIONS: A patient had cataract surgery with implantation of a Crystalens AT-50AO +21D. Preoperative A-scan measured anterior chamber depth (ACD) to be 3.69 mm. The refraction was emmetropic following cataract surgery. Nine months later, the patient required pars plana vitrectomy with gas tamponade for a rhegmatogenous retinal detachment, followed by vitrectomy, membrane peel, and air/fluid exchange for epiretinal membrane. The retinal repair was anatomically successful, however, the patient experienced a -1.0 D myopic shift. ACD measurement following vitrectomy was 5.08 mm. CONCLUSIONS AND IMPORTANCE: Myopic shift following vitrectomy with gas tamponade in pseudophakic eyes is widely reported. This patient's myopic shift was assumed due to anterior movement of the Crystalens caused by a gas bubble placed during retinal detachment repair as this is the prevailing theory in the literature [1]. However, a comparison of the patient's ACD measurements does not support the above hypothesis. Further study is needed to determine the mechanism of myopic shift seen in pseudophakic patients following vitrectomy, specifically those with gas.