Changes in peripheral visual field perception after intraocular lens implantation

Abstract

Aims/Purpose: To assess whether the eccentricity of the perception of objects in the peripheral visual field changes when a crystalline lens is replaced by an intraocular lens (IOL).Methods: The effect of the IOL on the eccentricity at which peripheral objects are perceived was assessed using phakic and pseudophakic versions of the same eye model. Non‐sequential ray tracing simulations were used to determine the relation between the input eccentricity at which an object was positioned in the visual field and the corresponding eccentricity at which the object was perceived by the eye in every eye model. Two different IOL designs were evaluated in the pseudophakic eye model. For each IOL design five different axial positions and seven different intrinsic powers were tested. Subsequently, the results of the pseudophakic eye models were compared to the results of the phakic model.Results: For central vision, the perceived eccentricity differed less than 1 degree between the phakic and pseudophakic models. For peripheral vision, the light rays were refracted to a more central retinal location in pseudophakic eyes than in phakic eyes, therewith shifting perceived eccentricity. The amount of the perceived shift depended on the IOL design and its axial position. The maximal shift within the evaluated pseudophakic models was 5.4 degrees towards central vision.Conclusions: IOL implantation has a minor effect on how the central visual field is perceived, but it can alter the eccentricity at which objects in the peripheral visual field are perceived by over 5 degrees. Such a shift in eccentricity can, for instance, affect how peripheral visual complaints, such as negative dysphotopsia, are experienced.