Influence of ophthalmic viscosurgical devices on intraoperative aberrometry

Abstract

To determine whether the presence of an ophthalmic viscosurgical device (OVD) in the anterior chamber influences intraoperative aberrometry and the suggested intraocular lens (IOL) power. Advanced Vision Care, Los Angeles, and Specialty Surgery Center, Beverly Hills, California, USA. Prospective interventional case series. Eyes scheduled for routine phacoemulsification and were divided into 6 equal groups, with each having 1 of 6 OVDs. After cataract removal, carefully controlled aberrometry was performed with the anterior chamber filled with balanced salt solution (BSS). Immediately thereafter, the BSS was replaced by 1 of the OVDs and the aberrometry repeated. The IOL power was selected from the BSS reading, and clinical manifest refraction was performed 3weeks after surgery. The mean absolute error (MAE) was determined and compared with the extrapolated refraction had the IOL power been selected from the aberrometry reading under OVD. The study comprised 120 eyes, 20 in each group. The IOL power determination was lower with OVD filling the chamber. For Discovisc and Amvisc Plus, the MAE determinations were statistically different because the suggested IOL power was approximately 0.50 diopter less than with a BSS fill. For the remaining OVDs (Amvisc, Healon, Healon GV, and Provisc), the MAE differences were insignificant. The strong correlation between differences in the index of refraction between BSS and specific OVDs appeared to be causal. Surgeons should be aware of the influence of OVDs on the accuracy of intraoperative aberrometry because specific agents can alter the optical results and suggested IOL power. Dr. Masket is a consultant to Wavetec Vision Systems, Inc., and Alcon Laboratories, Inc., and has a research grant from Alcon Laboratories, Inc. Dr. Fram has a research grant from Wavetec Vision Systems, Inc. Dr. Holladay is a consultant to Wavetec Vision Systems, Inc.