Optical aberrations, accommodation, and visual acuity with a bioanalogic continuous focus intraocular lens after cataract surgery

How Reliable Is Pyramidal Wavefront-Based Sensor Aberrometry in Measuring the In Vivo Optical Behaviour of Multifocal IOLs?

Cataract or refractive lens surgery, along with the implantation of multifocal intraocular lenses (MF-IOL), enables a complete range of functional far, near and intermediate vision. Refractive, diffractive and extended depth of focus (EDoF) or combination of these principles represent the technology used to obtain this multifocality. Aberrometry makes it possible to study the aberrations induced by MF-IOLs. Among the different optical principles available to measure ocular aberrations, pyramidal wavefront-based sensor (PWS) aberrometry shows the highest resolution with MF-IOLs. Retinal image quality measured by a PWS aberrometer differed significantly according to the technology of the implanted lens. Monofocal and diffractive lenses showed the highest values of far-distance retinal image quality, followed by refractive and EDoF lenses; however, retinal image quality analysed in diffractive lenses appears to be more dependent on residual refractive error. Considering this limitation, PWS-aberrometry could be used to compare diffractive lenses. Nevertheless, further studies are needed to provide additional information about the clinical retinal image quality of MF-IOLs and to help surgeons in the important preoperative selection of IOLs.

Latest Development in Extended Depth-of-Focus Intraocular Lenses: An Update

In recent years, there has been an overwhelming influx of different types of intraocular lenses (IOLs) as treatment for presbyopia. The extended depth-of-focus (EDOF) technology creates a single elongated focal point to enhance depth of focus, in contrast to the multiple foci of multifocal (MF) lenses. In this way, the EDOF lenses aim to reduce photic phenomena, glare, and halos, which have been reported in MF IOLs. A potential disadvantage of this is a blur due to decreased retinal image quality when the amount of the aberrations is increased excessively. Multifocality and EDOF characteristics are not exclusive of each other. Frequently, EDOF IOLs are combined with MF optical designs, a bifocal IOL may exhibit EDOF characteristics, likewise an aspheric monofocal IOL or a diffractive or refractive trifocal IOL. Thus, EDOF lenses are commonly subjected to confusion. A wide range of different types of EDOF lenses are available on the market to surgeons. In this practical update, we aim to clarify what is a true EDOF lens, classify the different types of the EDOF lenses based on their optical principle and review their recently reported outcomes. Comprehensive patient examination and selection, combined with knowledge of the most updated options and adequate patient counseling, can avoid dissatisfaction and yield the desired outcomes.

[Pseudo-accommodative intraocular lenses]

This article reviews pseudo-accommodative intraocular lenses (IOLs), providing an analysis of the terminology used in this field of ophthalmology and describing the design of modern IOLs, the technological features used to achieve pseudo-accommodation that meets the needs of patients, particularly the new extended depth of focus (EDOF) IOL technology. The article presents the main types of extended depth of focus IOLs, their description, advantages and disadvantages, as well as comparison with multifocal and monofocal IOLs based on clinical studies conducted in different countries.

Two-dimensional biomaterials: material science, biological effect and biomedical engineering applications

To date, nanotechnology has increasingly been identified as a promising and efficient means to address a number of challenges associated with public health. In the past decade, two-dimensional (2D) biomaterials, as a unique nanoplatform with planar topology, have attracted explosive interest in various fields such as biomedicine due to their unique morphology, physicochemical properties and biological effect. Motivated by the progress of graphene in biomedicine, dozens of types of ultrathin 2D biomaterials have found versatile bio-applications, including biosensing, biomedical imaging, delivery of therapeutic agents, cancer theranostics, tissue engineering, as well as others. The effective utilization of 2D biomaterials stems from the in-depth knowledge of structure-property-bioactivity-biosafety-application-performance relationships. A comprehensive summary of 2D biomaterials for biomedicine is still lacking. In this comprehensive review, we aim to concentrate on the state-of-the-art 2D biomaterials with a particular focus on their versatile biomedical applications. In particular, we discuss the design, fabrication and functionalization of 2D biomaterials used for diverse biomedical applications based on the up-to-date progress. Furthermore, the interactions between 2D biomaterials and biological systems on the spatial-temporal scale are highlighted, which will deepen the understanding of the underlying action mechanism of 2D biomaterials aiding their design with improved functionalities. Finally, taking the bench-to-bedside as a focus, we conclude this review by proposing the current crucial issues/challenges and presenting the future development directions to advance the clinical translation of these emerging 2D biomaterials.

Long-Term Evaluation of Visual Outcomes and Patient Satisfaction after Binocular Implantation of a Bioanalogic Lens

Purpose

Long-term evaluation of the visual refractive outcomes and the quality of life after implantation of the WIOL-CF (Medicem, Czech Republic) in both eyes.

Design

retrospective, nonrandomized noncomparative case series.

Methods

50 eyes of 25 patients, including 11 women (44%) and 14 men (56%). The age range of the patients was 38 to 77 years (mean age 55.48 ± 10.97 years). All patients underwent bilateral implantation of the WIOL-CF. Exclusion criteria were previous ocular surgeries except for cataract surgery and refractive lens exchange, irregular corneal astigmatism of >1.0 diopter, and ocular pathologies or corneal abnormalities. Postoperative examinations were performed at 14 days and 3, 6, 12 months of surgery; the last follow-up was between 24 and 36 months after the procedure. All exams included manifest refraction, monocular uncorrected visual acuity (UCVA) and distance-corrected visual acuity (DCVA) in 5 m (Snellen), monocular uncorrected visual acuity in 70 cm and 40 cm (Jeager) and binocular UCVA, DCVA in 5 m, 70 cm, and 40 cm, binocular contrast sensitivity (CS) under photopic conditions, binocular defocus curves, high-order aberrations, quality-of-vision VF-14 questionnaire, and spectacle independence.

Results

Significant improvement in monocular visual acuity at all distances was demonstrated; the mean postoperative spherical equivalent was 0.32 ± 0.45D. The postoperative means of binocular distance UCVA and BCVA were also improved (p < .001) and so were the mean uncorrected intermediate VA (2.053 ± 1.268) and near uncorrected VA (2.737 ± 1.447). There was a significant improvement in contrast sensitivity at all spatial frequencies and higher-order aberration, compared to preoperative results.

Conclusions

The evaluation of a WIOL-CF showed good distance, intermediate, and near visual acuity. Contrast sensitivity increased after surgery in all spatial frequencies. Patient satisfaction was high despite some optical phenomena. The rate of postoperative spectacle independence also turned out high. Financial Disclosure. No author has a financial or proprietary interest in any material or method mentioned.

Extended depth-of-focus technology in intraocular lenses

The extended depth-of-focus (EDOF) intraocular lens (IOL) is an emerging technology that is designed to improve range of vision, especially at intermediate distances. In this review, we describe the clinical performance of 4 emerging EDOF IOL technologies; that is, small aperture, bioanalogic, diffractive optics, and nondiffractive optical manipulations. The American Academy of Ophthalmology generated a consensus statement for EDOF IOLs that provided benchmarks and recommendations for classifying an implant as an EDOF IOL as well as standardized testing criteria for evaluating performance. Although many types of EDOF technologies are being developed, there are important differences in their performance that require further testing and evaluation.

A Comparative Evaluation of Visual, Refractive, and Patient-Reported Outcomes of Three Extended Depth of Focus (EDOF) Intraocular Lenses

Objective

To compare visual, refractive, and patient-reported outcomes of patients implanted with one of three types of extended depth of focus (EDOF) intraocular lenses.

Setting

Asian Eye Institute, Philippines.

Design

Retrospective cohort study.

Methods

Subjects implanted with Symfony (Johnson and Johnson, USA), IC-8 (AcuFocus, USA), and WIOL (Medicem, Czech Republic) EDOF intraocular lenses were recruited. Spherical equivalent, uncorrected and corrected visual acuity, defocus curve, and modulation-transfer function, Strehl ratio, and visual Strehl optical transfer function values, photic phenomena, and questionnaire answers were measured and assessed.

Results

A total of 32 eyes with the Symfony lens, 30 with the IC-8 lens, and 32 with the WIOL lens were included in the study. Mean postoperative spherical equivalent was -0.24 D for the Symfony, -0.17 D for the IC-8, and 0.27 D for WIOL. There were no significant differences in postoperative monocular and binocular uncorrected and corrected visual acuity. On a monocular defocus curve, the IC-8 and Symfony showed significantly better vision than WIOL. The Symfony had significantly better modulation-transfer function, Strehl ratio, and visual Strehl optical transfer function. No difference was seen among the three lenses with regard to glare or starburst, while patient satisfaction remained high in all groups for far, intermediate, and near vision.

Conclusion

All eyes implanted with the three EDOF designs achieved excellent far and intermediate vision, with acceptable near vision. The IC-8 and Symfony exhibited a better range of vision on defocus-curve testing. The Symfony showed superior results in quality of vision. Patient satisfaction was high in all three EDOF groups.

Extended Depth-of-Field Intraocular Lenses: An Update

Extended depth-of-focus (EDOF) is a new intraocular lens (IOL) technology in the treatment of presbyopia. In contrast to multifocal (MF) IOLs, EDOF lenses create a single elongated focal point, rather than several foci, to enhance depth of focus. In this way, EDOF IOLs aim to reduce photic phenomena, glare, and halos, which have been reported in MF IOLs. A potential disadvantage is a decrease of retinal image quality if the amount of the aberrations is excessively increased. Frequently, EDOF IOLs are combined with MF optical designs; for this reason, EDOF IOLs are commonly a subject of confusion with optical multifocality concepts. The aim of this article is to clarify what an EDOF IOL is and to discuss the recently reported outcomes with these IOLs. We propose naming lenses that have combined optical designs as "hybrid IOLs."

Initial Clinical Outcomes of a New Extended Depth of Focus Intraocular Lens

PURPOSE

To evaluate clinical and patient-reported outcomes of a new extended depth of focus intraocular lens (IOL).

METHODS

Data of patients treated between September 2017 and September 2018 who underwent a refractive lens exchange/cataract surgery with an implantation of the AT LARA 829MP IOL (Carl Zeiss Meditec AG, Jena, Germany) and attended the 1-week, 1-month, and 3-month follow-up visit were reviewed.

RESULTS

At 3 months, the percentage of eyes within ±0.50 diopters (D) of emmetropia was 86.7%. The mean binocular uncorrected distance visual acuity was -0.05 ± 0.09 logMAR and the mean binocular unaided near vision was 0.26 ± 0.14 logMAR. Of all patients, 90.3% were satisfied with their vision. The percentage of patients spectacle-free for near and distance vision was 83.6% and 95.4%, respectively. On a scale from 1 (no difficulty) to 7 (severe difficulty), there was an average 1.2 to 1.4 units increase in glare, halo, and starburst between the preoperative and 1-month visit, and a decrease of 0.2 to 0.3 units between the 1- and 3-month visit.

CONCLUSIONS

The new extended depth of focus IOL provided reasonable unaided near and distance vision, as well as spectacle independence and patient satisfaction. Some optical side effects were reported in the early postoperative period. [J Refract Surg. 2019;35(7):426-433.].