Field‐wide Quantification of Aniseikonia Using Dichoptic Localization

Abstract

SIGNIFICANCE We validated a novel paradigm to measure aniseikonia across the visual field and used a mathematical approach that is able to describe the magnitude and shape of aniseikonia in a concise, clinically meaningful fashion. PURPOSE The measurement of aniseikonia has been performed clinically for more than half a century; however, amalgamation of field-wide local variations in binocular spatial localization into clinically applicable global metrics has yet to be attempted. Thus, the goal of the current study was twofold: first, to measure field-wide aniseikonia and second, to compare how local and global metrics each capture optically induced aniseikonia. METHODS Twelve visually normal observers performed a dichoptic localization task at 24 locations in the visual field. This was done in four conditions: (A) while wearing red-green filters, (B) while wearing green-red filters, (C) while wearing a monocular 5% overall size lens, and (D) while wearing a monocular 6% meridional size lens. The physical settings at perceptual equality were then used to compute both local (relative magnification) and global (coefficients for Zernike terms) descriptors of aniseikonia. RESULTS The comparison of each lens condition to the baseline condition confirmed predicted shifts in both the sign and magnitude of aniseikonia at both the local and global levels; however, the intraobserver levels of precision were moderate, and systematic underestimations were present across all locations in conditions C and D. CONCLUSIONS Local and global analyses derived from dichoptic localization data were both able to capture optically induced changes in binocular spatial perception; however, solutions that address the diagnostic and therapeutic challenges associated with this paradigm are needed before clinical implementation can proceed.

Prediction of ocular magnification and aniseikonia after cataract surgery

“…The main reason for this not being considered in daily clinical routine is that direct measurement of ocular magnification or aniseikonia is difficult and sometimes unreliable. There are existing computer-based test strategies for aniseikona (Rutstein et al 2006;Fullard et al 2007) or classical test strategies (Willeford et al 2020;Krarup et al 2021).…”

Prediction of ocular magnification and aniseikonia after cataract surgery

“…The main reason for this not being considered in daily clinical routine is that direct measurement of ocular magnification or aniseikonia is difficult and sometimes unreliable. There are existing computer-based test strategies for aniseikona (Rutstein et al 2006;Fullard et al 2007) or classical test strategies (Willeford et al 2020;Krarup et al 2021).…”

Meridional ocular magnification after cataract surgery with toric and non-toric intraocular lenses

“…Cohort studies or case reports which deal with aniseikonia are therefore rare. There are existing computer-based test strategies for aniseikona [ 3 , 8 ] or classical test strategies [ 9 , 10 ].…”

Prediction of ocular magnification and aniseikonia after cataract surgery

“…The main reason for this not being considered in daily clinical routine is that direct measurement of ocular magnification or aniseikonia is difficult and sometimes unreliable. There are existing computer-based test strategies for aniseikona (Rutstein et al 2006;Fullard et al 2007) or classical test strategies (Willeford et al 2020;Krarup et al 2021).…”

Meridional ocular magnification after cataract surgery with toric and non-toric intraocular lenses

“…Cohort studies or case reports which deal with aniseikonia are therefore rare. There are existing computer-based test strategies for aniseikona [ 3 , 8 ] or classical test strategies [ 9 , 10 ].…”

Prediction of ocular magnification and aniseikonia after cataract surgery

“…The main reason for this not being considered in daily clinical routine is that direct measurement of ocular magnification or aniseikonia is difficult and sometimes unreliable. There are existing computer-based test strategies for aniseikona (Rutstein et al 2006;Fullard et al 2007) or classical test strategies (Willeford et al 2020;Krarup et al 2021).…”

Meridional ocular magnification after cataract surgery with toric and non-toric intraocular lenses

“…Cohort studies or case reports which deal with aniseikonia are therefore rare. There are existing computer-based test strategies for aniseikona [ 3 , 8 ] or classical test strategies [ 9 , 10 ].…”