Predicted and actual refraction after intraocular lens implantation in eyes with silicone oil

Abstract

Objective: To determine the difference between the predicted and postoperative refraction in eyes with silicone oil that had extracapsular cataract extraction (ECCE) and intraocular lens (IOL) implantation.Setting: Ophthalmology department providing primary, secondary, and tertiary care in central Israel.Methods: Eight patients with silicone-oil-filled eyes following vitreoretinal procedures had ECCE and IOL implantation. The IOL power calculation was performed with the modified SRK II, the SRK/T, and the Holladay emmetropia/ametropia formulas, using the axial length of the eye, measured prior to the silicone oil injection, and the keratometric readings. The predicted and postoperative refractions were compared.Results: The postoperative refraction was more hyperopic than predicted by an average of 4.08 diopters (D) for the SRK II formula, 3.91 D for the SRK/T formula, and 4.01 D for the Holladay emmetropia/ametropia formula. Removing the silicone oil from two eyes several months after cataract extraction reduced the deviation from the predicted refraction to 0.25 and 0.80 D.Conclusion: The presence of silicone oil in the vitreous space induces a hyperopic shift in eyes having ECCE and IOL implantation. This hyperopic shift should be considered when calculating the IOL power if a long-term tamponade with the oil is planned. If the silicone oil is to be removed shortly after the cataract extraction, the IOL power should be calculated solely from the formula.