Optical and visual quality of real intraocular lenses physically projected on the patient's eye

Evaluation of Visual Outcomes, Postoperative Angle Alpha, and Angle Kappa After Implantation of Isofocal Intraocular Lenses

Purpose

To evaluate the effect of angles kappa and alpha on the visual outcomes after implantation of isofocal intraocular lens (IOL) during cataract surgery.

Methods

This prospective study involved 66 eyes undergoing cataract surgery with Isopure IOLs. Exclusion criteria comprised irregular corneal astigmatism exceeding 1.0D, and ocular co-morbidities affecting visual outcomes post-surgery. Evaluation parameters included postoperative refraction, uncorrected and corrected-distance visual acuity (UDVA, CDVA), uncorrected intermediate visual acuity (UIVA), and distance-corrected intermediate visual acuity (DCIVA) at 80 cm. Additionally, postoperative angles alpha, kappa, and wavefront aberrations at a 3-mm pupil using ray tracing were assessed post-surgery at least 60 days later.

Results

Patients had a mean age of 64.48 ± 9.92 years. Mean postoperative manifest refraction spherical equivalent (MRSE) was -0.21 ± 0.27 D. Mean UDVA and CDVA were LogMAR 0.06 ± 0.04 and 0.02 ± 0.06, respectively. Mean UIVA LogMAR 0.32 ± 0.08 while mean DCIVA was LogMAR 0.29 ± 0.08. Postoperative angles kappa and alpha were 0.39 ± 0.14 mm and 0.45 ± 0.15 mm, respectively. Mean postoperative ocular RMS higher-order aberrations (HOAs) 0.23 ± 0.08. Spherical aberration, coma, and trefoil averaged 0.05 ± 0.07, 0.12 ± 0.03, and 0.07 ± 0.03, respectively. No significant correlations were observed between postoperative angle kappa and alpha with UDVA, CDVA, or HOAs. A non-significant weak positive correlation was noted between angle kappa and UIVA/DCIVA, while no correlation was found between angle alpha and UIVA/DCIVA.

Conclusion

No substantial correlations were found between various postoperative angles kappa and alpha values and postoperative visual acuity metrics (UDVA, CDVA, UIVA, and DCIVA) or higher order ocular aberrations (including, spherical aberration, coma, and trefoil with a 3.0 mm diameter) in pseudophakic eyes implanted with isofocal intraocular lenses (IOLs).

Tolerance to residual astigmatism of an isofocal intraocular lens

PURPOSE

To evaluate the impact of residual astigmatism on the optical and visual performance of an enhanced-monofocal isofocal intraocular lens (EM Isopure, BVI medical, Belgium) compared to a monofocal one (Micropure, BVI medical, Belgium).

METHODS

Laboratory investigation and prospective, comparative and randomized clinical study. Optical quality was assessed on an optical bench for 2.0, 3.0, and 4.5 mm pupils. The effect of residual astigmatism was investigated from through-focus images recorded with increasing amounts of regular positive astigmatism induced with a deformable mirror. To evaluate the impact of residual astigmatism, 28 eyes of 28 patients were randomly assigned to either group. Residual astigmatism was induced with positive and negative cylinder lenses at 90 and 180°. Visual acuity (VA) was measured at each step.

RESULTS

The optical performance of both IOLs was quite similar for 2.0 and 3.0 mm pupils. For 4.5-mm pupil, the EM Isopure showed a significant reduction of its optical quality in comparison with the monofocal IOL. When visual performance was evaluated, no statistically significant differences were found for any power of induced astigmatism. More differences were found when positive induced astigmatism was compared within each group, and VA was better when the astigmatism was induced at 180° vs. 90°. The greatest differences were found for and induced positive astigmatism of + 1.50D (p = 0.009 for Isopure and p = 0.023 for Micropure).

CONCLUSIONS

The tolerance to residual astigmatism of the EM Isopure lens is similar to that of a reference monofocal lens with pupils up to 3.5 mm.

Comparison of modal and zonal wavefront measurements of refractive extended depth of focus intraocular lenses

Extended depth-of-focus (EDoF) intraocular lenses (IOLs) are typically evaluated using commercially available aberrometers. Given the intricate optical design of these IOLs, employing an appropriate wavefront reconstruction method with a sufficient sampling resolution of the aberrometer is crucial. A high-resolution Shack-Hartmann wavefront sensor was developed by magnifying the pupil aperture by a factor of five onto a lenslet array (pitch: 133 µm) and utilizing a full-frame CMOS sensor (24 by 36 mm), resulting in a 26.6 µm sampling resolution. Zonal wavefront reconstruction was used and compared with Zernike-based modal wavefront reconstruction to retain detailed local slope irregularities. Four refractive EDoF IOLs with a power of 20D were examined, and the wavefront difference between the zonal and modal methods, expressed as the root mean squared error (RMSE), remained significant for two of the IOLs up to the 16th-order Zernike spherical aberrations (SAs). Conversely, a negligibly small RMSE was observed for the other two IOLs, as long as the Zernike SAs were higher than the 6th order. The raytracing simulation results from the zonal wavefronts exhibited a stronger correlation with the results of recent optical bench studies than those from the modal wavefronts. The study suggests that certain recent refractive EDoF IOLs possess a complex optical profile that cannot be adequately characterized by limited orders of SAs.

Adaptive optics visual simulators: a review of recent optical designs and applications [Invited]

In their pioneering work demonstrating measurement and full correction of the eye's optical aberrations, Liang, Williams and Miller, [JOSA A14, 2884 (1997)10.1364/JOSAA.14.002884] showed improvement in visual performance using adaptive optics (AO). Since then, AO visual simulators have been developed to explore the spatial limits to human vision and as platforms to test non-invasively optical corrections for presbyopia, myopia, or corneal irregularities. These applications have allowed new psychophysics bypassing the optics of the eye, ranging from studying the impact of the interactions of monochromatic and chromatic aberrations on vision to neural adaptation. Other applications address new paradigms of lens designs and corrections of ocular errors. The current paper describes a series of AO visual simulators developed in laboratories around the world, key applications, and current trends and challenges. As the field moves into its second quarter century, new available technologies and a solid reception by the clinical community promise a vigorous and expanding use of AO simulation in years to come.

Evaluating the effect of ocular aberrations on the simulated performance of a new refractive IOL design using adaptive optics

Adaptive optics (AO) visual simulators are excellent platforms for non-invasive simulation visual performance with new intraocular lens (IOL) designs, in combination with a subject own ocular aberrations and brain. We measured the through focus visual acuity in subjects through a new refractive IOL physically inserted in a cuvette and projected onto the eye's pupil, while aberrations were manipulated (corrected, or positive/negative spherical aberration added) using a deformable mirror (DM) in a custom-developed AO simulator. The IOL increased depth-of-focus (DOF) to 1.53 ± 0.21D, while maintaining high Visual Acuity (VA, -0.07 ± 0.05), averaged across subjects and conditions. Modifying the aberrations did not alter IOL performance on average.

SMILE for the Treatment of Residual Refractive Error After Cataract Surgery

INTRODUCTION

In the context of managing patients' expectations and satisfaction regarding visual acuity after cataract surgery, we aimed to investigate the improvement in visual acuity and patient satisfaction after small-incision lenticule extraction (SMILE) in pseudophakic (trifocal intraocular lens, IOL) patients with residual myopic refraction after cataract surgery.

METHODS

Seventy-six patients (82 eyes) who underwent cataract surgery with ZEISS AT LISA tri 839MP IOL implantation were included in this retrospective study. The included patients were 56-79 years old, wanted spectacle independence, and had preoperative myopic refraction between - 1.0 and - 2.25 diopters (D) and astigmatism between - 0.75 and - 1.75 D. The treatment status of these patients was defined as trifocal IOL (n = 82). SMILE was performed in patients who were dissatisfied after cataract surgery, and these patients were followed up for 1 year on average. We evaluated visual acuity and satisfaction and further examined laser vision correction and satisfaction levels in patients who were dissatisfied after trifocal IOL implantation.

RESULTS

The possible reasons for patient dissatisfaction were reading books, using a computer, and driving at night. After SMILE, the residual myopic refractive error (spherical) decreased significantly from - 2.08 ± 0.28 [- 2.25 to - 1.0] preoperatively to - 0.25 ± 0.20 - 0.5 to 0] 1 year postoperatively (p < 0.001). Additionally, the uncorrected distance visual acuity increased from 0.65 ± 0.08 [0.52-0.7] logMAR preoperatively to 0.09 ± 0.02 [0.05-0.1] logMAR at 1 month postoperatively (p < 0.001), 0.09 ± 0.02 [0.05-0.1] logMAR at 6 months postoperatively, and 0.06 ± 0.02 [0.05-0.1] logMAR at 12 months postoperatively (p < 0.001). Patient satisfaction measures after SMILE (reading, night driving, and using a computer) were significantly improved.

CONCLUSION

SMILE is a reliable method for treating residual refraction after cataract surgery, as it provides results in the shortest time without complications and increases patient satisfaction.

TRIAL REGISTRATION

The protocol was registered on clinicaltrials.gov (NCT04693663).