Metric-Based Visual Acuity and Defocus Curve Simulation of Two Multifocal Intraocular Lens Models

Figures & data

Figure 1 Flow chart for metric-based visual acuity simulation. IOL, intraocular lens; LIB, light-in-the-bucket; VA, visual acuity.

Table 1 Parameters and Corresponding Values Used in the 2-Surface Reduced Eye Model

Parameter	Value
Wavelength, nm	550
Refractive index of aqueous humor, naq	1.336
Refractive index of IOL, nIOL	1.551
Mean ± SD pupil diameter, mm	3.50±0.80
Mean ± SD anterior chamber depth, mm	4.60±0.30
Mean ± SD corneal power, D	43.4±2.2

Abbreviation: IOL, intraocular lens.

Figure 2 Through-focus MTF at 50 line pair/mm generated by 2-surface eye model (red open circles, red line) compared with Alcon-Navarro eye model (blue line). MTF, modulation transfer function.

Table 2 Summary of Clinical and Simulated Binocular Visual Acuity at 4 m (Distance) and at 80 cm, 60 cm, and 40 cm

	TFNT00, Simulated	TFNT00, Clinical ^b	SN6AD1, Simulated	SN6AD1, Clinical ^b
Iteration/sample size	1000	134	1000	116
4 m	−0.027	−0.037	−0.039	−0.030
80 cm ^a	0.095	0.083	0.171	0.190
60 cm ^a	0.054	0.058	0.134	0.137
40 cm	0.096	0.066	0.052	0.040

Notes: ^aNote that values at 60 cm (−1.67 D) were linearly interpolated from clinical and simulated visual acuity at 67 cm (−1.5 D) and 50 cm (−2.0 D); values at 80 cm (−1.25 D) were linearly interpolated from −1.0 D and −1.5 D. ^bData on File. Alcon Laboratories, Fort Worth, TX.

Figure 3 Simulated defocus curve vs clinical defocus curve of SN6AD1. Data on File. Alcon Laboratories, Fort Worth, TX.

Abbreviation: DCVA, distance-corrected visual acuity.

Figure 4 Simulated defocus curve of TFNT00 vs clinical defocus curve from a clinical trial.⁹ DCVA, distance-corrected visual acuity.

Bala C, Martinez AA, Kohnen T Multicenter visual outcomes evaluation of a new trifocal presbyopia correcting IOL – 12 month results. Presented at: American Society of Cataract and Refractive Surgery, April 13-17, 2018; Washington, DC.

 Google Scholar