Effect of Decentration, Rotation, and Tilt on Objective Optical Quality of Plate Haptic Toric Intraocular Lenses in the Early Postoperative Period

Abstract

Purpose: This study aimed to determine the influence of decentration, rotation, and tilt on objective optical quality of plate haptic toric intraocular lenses (tIOLs).

Methods: The area ratio of modulation transfer function (MTF), strehl ratio of point spread function (PSF), and higher order aberrations (HOAs) for 3 mm and 5 mm pupil diameter (PD) were evaluated at postoperative 1 month. The retroillumination images pictured by OPD-scan III were used to quantify the degree of decentration and rotation, whereas the tIOL tilt was directly obtained by the tilt aberration. Patients were separated into two subgroups based on tIOL misalignment cutoff values.

Results: There were 29 eyes (24 patients) in the study. The decentration of more than 0.25 mm did not substantially differ from those less than or equal to 0.25 mm. PSF of 3 mm PD and MTF, intraocular HOAs, and trefoil aberration for 3 mm and 5 mm PD significantly deteriorated with a rotation of more than 3 degrees, whereas only intraocular HOAs for 5 mm PD and coma for 3 mm and 5 mm PD were significantly severe with a tilt of more than 0.1 µm and 0.25 µm in corresponding PD. Furthermore, tIOL rotation and tilt were highly correlated with intraocular trefoil aberration and coma, respectively.

Conclusions: The decentration of the monofocal bitoric IOLs is more tolerant to optical quality degradation after 1 month of surgery but more sensitive to intraocular trefoil aberration caused by rotation and coma aberration induced by tilt.

Translational relevance: As far as we know, this is the first study to investigate the relationship between the plate haptic bitoric IOL misalignment and objective optical quality measured by OPD-scan III in the real world, which may provide reference information for IOL selection to improve surgical outcomes.

Figure 1.

Schematic diagram of tIOL decentration (a) and misalignment angle (b) measurement method.

Figure 2.

The double angle plots of pre-operative corneal astigmatism and postoperative refractive astigmatism.

Figure 3.

Subgroup comparison of intraocular (left) and ocular (right) aberrations among at different pupil diameters (PDs). Error bars represent standard errors of the mean. HOAs, higher order aberrations; RMS, root mean square.