Weight of Different Intraocular Lenses: Evaluation of Toricity, Focality, Design, and Material

Abstract

Purpose. To evaluate the weight of intraocular lenses (IOLs) depending on their material, dioptric power, toricity, focality, and haptic design. Methods. Twenty-eight different IOL models from nine different medical companies (a total of 38 IOLs) and 1 capsular tension ring (CTR) were evaluated. IOLs were weighed using a precision scale, in hydrated conditions, as an approximation to their intraocular status. Results. Hydrophilic IOLs were heavier than hydrophobic lenses ( $p<0.001$ ). Regarding toricity, no statistical differences were found comparing toric to non-toric models ( $p=0.1$ ). Likewise, no differences were found between multifocal IOLs and monofocal IOLs ( $p=0.19$ ). Dioptric power did not affect IOL weight: IOLs of <15DP had similar weights to those of ≥15D and IOLs of ≥24D had similar weights to those of <24 D ( $p=0.86$ and $p=0.59$ , respectively). Plate-design IOLs were significantly heavier than 1-piece C-loop ( $p<0.001$ ), 3-piece C-loop ( $p<0.001$ ), and 4-haptic lenses ( $p=0.001$ ). Conclusions. Of the characteristics analyzed that might influence IOL weight, lenses with hydrophilic material and plate-haptic design were found to be heavier. Toricity, focality, and dioptric power had no influence on IOL weight.