Refractive predictability in eyes with intraocular gas tamponade – results of a prospective controlled clinical trial

Lars Wagenfeld,1 Kristin Hermsdorf,1 Birthe Stemplewitz,1 Vasyl Druchkiv,1 Andreas Frings2 1Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Hamburg, 2Department of Ophthalmology, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany Purpose: To determine the postoperative refractive error in eyes with intraocular gas tamponade in combined phacovitrectomy using a Z-haptic intraocular lens (IOL).Methods: This prospective non-randomized case-control study compared patients with combined phacovitrectomy with or without intraocular gas tamponade to cataract surgery-only. The main outcome measure was the IOL power prediction error (PE). Secondary outcome measures were spherical equivalent, anterior chamber depth (ACD), and axial length.Results: Thirty-four patients with epiretinal membranes and 18 patients with cataract only were enrolled. There were no statistically significant (P>0.05) differences of IOL power PE or postoperative ACDs (P=0.952–1.00). Nevertheless, IOL power PE indicated a myopic shift in cases with phacovitrectomy independent of gas tamponade (P=1.00). No statistically significant between-group differences between secondary outcome measures were observed. Conclusion: A myopic shift after phacovitrectomy seems to be independent of the use of intraocular gas tamponade. When using a Z-haptic IOL, aiming for slight residual hyperopia (+0.50 D) is suggested in patients having phacovitrectomy. Keywords: IOL power prediction error, myopic shift, intraocular gas tamponade, biometry, pars plana vitrectomy, axial lengt