Magnification and visual acuity in highly myopic phakic eyes corrected with an anterior chamber intraocular lens versus by other methods

Purpose: To calculate retinal magnification and visual acuity in highly myopic phakic eyes corrected with anterior chamber intraocular lenses (IOLs) versus correction by other methods. Setting: Laboratory of Optics, University Alicante, Alicante, Spain. Methods: Relative retinal magnification (RRM) was used to study changes in retinal image size induced by different correcting systems. Relative spectacle magnification (RSM) was used to compare these systems with the emmetropic eye. The matrix method was used to calculate RRM, RSM, and visual acuity in 12 theoretical cases of myopia in eyes with axial lengths from 27.0 to 33.0 mm and corneal powers from 42.00 to 48.00 diopters. Results: The RRM, RSM, and visual acuity increased as corneal power increased for a myopic eye of fixed length. Changing the plane of correction from the spectacle or cornea to the intraocular increased retinal magnification, which increased visual acuity. Conclusion: Visual acuity in myopic eyes corrected with an IOL will be better than that in myopic eyes corrected by other means because of the retinal magnification induced by the IOL, which increases visual acuity one line or more.