Quality of vision clinical outcomes for a new fully-refractive extended depth of focus Intraocular Lens

BACKGROUND/OBJECTIVE

To evaluate the visual performance of a purely refractive extended depth of focus (EDF) intraocular lens (IOL).

SUBJECTS/METHODS

A prospective, multi-center, randomized, subject/evaluator-masked study. Subjects were bilaterally implanted with the EDF test (Model ZEN00V, N = 60) or an enhanced monofocal control (Model ICB00, N = 57) IOL. Monocular corrected distance (CDVA), intermediate (DCIVA), near acuities (DCNVA) and patient reported visual symptoms were evaluated at the 6-month visit. Monocular mesopic contrast sensitivity (CS) and depth of focus (DOF) testing were assessed at 3 months.

RESULTS

CDVA (Mean ± SD) was -0.06 ± 0.08 for test and -0.05 ± 0.08 logMAR for control groups. DCIVA was 0.13 ± 0.08 for test and 0.18 ± 0.14 logMAR for control groups (p = 0.0127). DCNVA was 0.37 ± 0.10 for test and 0.43 ± 0.16 logMAR for control groups (p = 0.0137). Test lens was statistically superior for intermediate and near. Overall, 91.7% (halos), 95.0% (starbursts) and 95.0% (glare) of test lens patients reported that they did not experience, were not bothered, or were slightly bothered by specific visual symptoms, compared to 98.2%, 100% and 96.5% in the control group. The DOF range over which monocular visual acuity was 0.20 logMAR or better was -1.6 D for the test lens. Mesopic CS was comparable between both groups, falling within 0.11 log units for all measured cycles per degree with and without glare.

CONCLUSION

The EDF IOL demonstrated extended range of vision and statistically superior intermediate and near performance compared to the monofocal IOL. Distance visual acuity, contrast sensitivity and dysphotopsia profile were similar to the monofocal IOL.

Applications of the pinhole effect in clinical vision science

The pinhole effect is commonly used to discriminate uncorrected refractive error from ocular diseases. A small aperture limits the width of light beams entering the eye, thus increasing the depth of focus. The pinhole effect has also been used in spectacles, contact lenses, corneal inlays, and intraocular lenses (IOLs) to improve reading by compensating for loss of accommodative function. Pinhole spectacles improve near visual acuity, but reduce reading speed, increase interblink interval, and decrease tear break-up time. For contact lenses and IOLs, pinhole devices are usually used in the nondominant eye, which allow compensation of various refractive errors and decrease spectacle dependence. Pinhole corneal inlays are implanted during laser in situ keratomileusis or as a separate procedure. Pinhole IOLs are gaining popularity, particularly as they do not bring a risk of a local inflammatory reaction as corneal inlays do. Disadvantages of using the pinhole effect include high susceptibility to decentration, decrease in retinal luminance levels, and difficulties in performing fundus examinations or surgery in eyes with implanted devices. There are also concerns regarding perceptive issues with different retinal illuminances in the 2 eyes (the Pulfrich effect).

Cataract surgery following refractive surgery: Principles to achieve optical success and patient satisfaction

A growing number of patients with prior refractive surgery are now presenting for cataract surgery. Surgeons face a number of unique challenges in this patient population that tends to be highly motivated to retain or regain functional uncorrected acuity postoperatively. Primary challenges include recognition of the specific type of prior surgery, use of appropriate intraocular lens (IOL) power calculation formulas, matching IOL style with spherical aberration profile, the recognition of corneal imaging patterns that are and are not compatible with toric and/or presbyopia-correcting lens implantation, and surgical technique modifications, which are particularly relevant in eyes with prior radial keratotomy or phakic IOL implantation. Despite advancements in IOL power formulae, corneal imaging, and IOL options that have improved our ability to achieve targeted postoperative refractive outcomes, accuracy and predictability remain inferior to eyes that undergo cataract surgery without a history of corneal refractive surgery. Thus, preoperative evaluation of patients who will and will not be candidates for postoperative refractive surgical enhancements is also paramount. We provide an overview of the specific challenges in this population and offer evidence-based strategies and considerations for optimizing surgical outcomes.

Radial keratotomy and cataract surgery: A quest for emmetropia

A 75-year-old man with an ocular history of 8-cut radial keratotomy (RK) in both eyes presented for cataract surgery evaluation. He was previously correctable in spectacles in years prior despite his irregular corneas to 20/25 in the right eye and 20/30 in the left eye. He recently noticed a change in his overall visual function with significant nighttime glare and difficulty reading despite spectacle correction. Of note, he was unable to tolerate contact lenses and was resistant to refitting despite additional encouragement. Cataract surgery was delayed for many years, given he was correctable in spectacles and the concern of uncovering a highly aberrated cornea after removing his cataracts (Figures 1 and 2JOURNAL/jcrs/04.03/02158034-202308000-00021/figure1/v/2023-07-21T030437Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202308000-00021/figure2/v/2023-07-21T030437Z/r/image-tiff). Of note, the patient was interested in returning to the spectacle independence he enjoyed in the past. Ocular examination revealed a corrected distance visual acuity (CDVA) of 20/30 in the right eye and 20/60 in the left eye, with a manifest refraction of +4.50 -0.50 × 177 in the right eye and +5.75 -1.75 × 14 in the left eye. Glare testing was 20/50 in the right eye and 20/100 in the left eye, with retinal acuity meter testing of 20/25 in each eye. Pupils, confrontation visual fields, and intraocular pressures were normal. Pertinent slitlamp examination revealed corneal findings of 8-cut RK with nasal-gaping arcuate incisions in both eyes and lens findings of 2+ nuclear sclerosis with 2+ cortical changes in the right eye and 3+ nuclear sclerosis with 3+ cortical changes in the left eye. Cup-to-disc ratios of the optic nerves measured 0.5 with temporal sloping in the right eye and 0.6 with temporal sloping in the left eye. The dilated fundus examination was unremarkable. What intraocular lens (IOL) options would you offer this patient and how would you counsel regarding realistic expectations? What additional diagnostic testing would be helpful in your assessment? How would you calculate the 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.

Small Aperture IC-8 Extended-Depth-of-Focus Intraocular Lens in Cataract Surgery: A Systematic Review

The aim of this paper is to evaluate the visual outcomes and patient satisfaction of small aperture IC-8 IOLs in cataract patients with or without prior ocular events. A systematic review of full-length original English studies reporting the visual results of small aperture IC-8 IOL implantation after cataract surgery in three databases, PubMed, Web of Science and Scopus, was performed according to the PRISMA statement. The Quality Assessment Tool for case series studies from the National Heart, Lung, and Blood Institute was used to analyze the quality of the studies selected. The search provided 543 articles, of which 22 were included in this systematic review. Significant improvements in uncorrected distance visual acuity (UDVA); uncorrected intermediate visual acuity (UIVA); uncorrected near visual acuity (UNVA); perception of photic phenomena; and patient satisfaction have been reported. Unilateral and bilateral small aperture IC-8 IOL implantation reduces photic phenomena and provides good vision for all distances with high patient satisfaction and minimal postoperative complications. Therefore, the implantation of this IOL may be recommended for patients with cataracts, corneal irregularities and ocular trauma with partial aniridia.

Presbyopia correction after previous Intracor treatment: Combined implantation of a small-aperture and a non-diffractive extended-depth-of-focus lens

PURPOSE

We present the case of implantation of two different Extended depth of focus intraocular lenses (EDoF IOLs) in a patient with a history of unilateral intrastromal femtosecond laser treatment for presbyopia correction (Intracor).

OBSERVATIONS

The patient reported decreasing visual acuity at near distance and increasing spectacle dependence. Ten years earlier, he had Intracor treatment for presbyopia correction in his left eye. Corrected distance visual acuity (CDVA) was 0.08 logMAR for the right eye and 0.16 logMAR for the left eye. Apart from dysfunctional lens syndrome, the examination results were unremarkable. Phacoemulsification and subsequent IOL implantation was performed in both eyes. The left eye was implanted with an IC-8 (AcuFocus, Irvine, CA, USA), whereas the fellow eye was implanted with an AcrySof IQ Vivity IOL (Alcon, Fort Worth, TX, USA). Postoperatively, CDVA improved to 0.02 and 0.04 logMAR for the right and left eye. Uncorrected intermediate visual acuity (UIVA) was 0.24 logMAR for the right eye and -0.04 logMAR for the left eye, binocular UIVA was -0.04 logMAR. The patient reported a low level of photic phenomena and spectacle independence for far and intermediate distance.

CONCLUSIONS AND IMPORTANCE

Combined implantation of a non-diffractive and a small-aperture EDoF lens after previous unilateral Intracor treatment could successfully improve visual acuity at far and intermediate distance.

Intraocular lens power calculations in eyes with previous corneal refractive surgery: Challenges, approaches, and outcomes

In eyes with previous corneal refractive surgery, difficulties in accurately determining corneal refractive power and in predicting the effective lens position create challenges in intraocular lens (IOL) power calculations. There are three categories of methods proposed based on the use of historical data acquired prior to the corneal refractive surgery. The American Society of Cataract and Refractive Surgery postrefractive IOL calculator incorporates many commonly used methods. Accuracy of refractive prediction errors within ± 0.5 D is achieved in 0% to 85% of eyes with previous myopic LASIK/photorefractive keratectomy (PRK), 38.1% to 71.9% of eyes with prior hyperopic LASIK/PRK, and 29% to 87.5% of eyes with previous radial keratotomy. IOLs with negative spherical aberration (SA) may reduce the positive corneal SA induced by myopic correction, and IOLs with zero SA best match corneal SA in eyes with prior hyperopic correction. Toric, extended-depth-of-focus, and multifocal IOLs may provide excellent outcomes in selected cases that meet certain corneal topographic criteria. Further advances are needed to improve the accuracy of IOL power calculation in eyes with previous corneal refractive surgery.

Review of surgical devices using small aperture optics

Small aperture optics work by blocking unfocused peripheral light rays while allowing central light rays to focus on the retina. This pinhole effect creates an extended depth of focus and has been used in presbyopia correction, improving intermediate and near vision without markedly affecting distance vision. Another beneficial effect of small aperture optics is reducing aberrations caused by irregular corneas or irregular pupils. The first small aperture surgical device was the Kamra corneal inlay used on the nondominant eyes of presbyopic emmetropes. The pinhole concept was also adapted into the IC-8 intraocular lens (IOL) for presbyopia correction during cataract surgery and by the XtraFocus piggyback device to lessen unwanted aberrations in eyes with irregular corneas or pupils. The IC-8 IOL can be placed monocularly or binocularly with mini-monovision for further near vision improvement. The XtraFocus piggyback device can be placed either in the sulcus or capsular bag. The aim of this literature review is to synthesize evidence on the efficacy, safety, and patient-reported outcomes on surgical devices utilizing small aperture optics. A comprehensive search on PubMed was conducted with the keywords “small aperture optics,” “small aperture corneal inlay,” “small aperture IOL,” “Kamra corneal inlay,” “IC-8 IOL,” and “XtraFocus.” In this review, we describe the progression of small aperture surgical devices, patient criteria, visual outcomes, complications, satisfaction, and recommendations for surgical success.

Bilateral implantation of a supplementary intraocular pinhole

PURPOSE

To evaluate the safety and efficacy of bilateral implantation of a supplementary small-aperture device to treat irregular corneal astigmatism.

SETTING

Private practice.

DESIGN

Retrospective consecutive case series.

METHODS

Patients with bilateral irregular corneal astigmatism secondary to multiple causes and consented for implantation of the XtraFocus intraocular pinhole (IOPH) were enrolled. The mean follow-up was 27 months (range 5 to 66 months). Patients were assessed in their scheduled follow-up visits and monocular and binocular uncorrected and corrected distance and near visual acuities were recorded. Assessment of darkening vision complaints was also performed after implantation in the first eye and repeated after second-eye surgery.

RESULTS

Thirty-two eyes of 16 patients were analyzed. The mean monocular and binocular uncorrected distance visual acuities improved from logMAR 1.091 ± 0.208 and 1.078 ± 0.259 preoperatively to 0.342 ± 0.091 (P < .001) and 0.342 ± 0.147 (P = .001) 1 year postoperatively. Three patients were excluded because of darkening vision complaints after surgery in the first eye. No major complications were noted after implantation of the IOPH.

CONCLUSIONS

Bilateral implantation of the XtraFocus IOPH is a safe technique in a selected group of patients. There was improvement in visual acuity sustained over the analyzed period. Postoperative darkening vision complaints vary between individuals and can limit the application of this approach in certain patients.

Lens-based surgical correction of presbyopia. Where are we in 2020?

INTRODUCTION

Presbyopia is the progressive and irreversible loss of accommodation due to aging. It is one of the main causes of loss of quality of life in people from 45 years of age, due to the, often novel, dependence on spectacles. The eagerness to correct it by ophthalmologists impulsed by the desire of millions of people who suffer from it, has become one of the main drivers for the development of intraocular lens (IOL) technology over the last twenty years.

MATERIAL AND METHODS

This review briefly presents the different alternatives that have allowed us to improve the crystalline lens surgical approach of presbyopia; from monofocal lenses and monovision technique, accommodative, refractive, and diffractive multifocal lenses, and finally the most recent extended depth of focus/field lenses known as EDOFs.

RESULTS

Each IOL has its advantages, limitations and disadvantages. Furthermore, there is no single lens that suits the needs of all patients.

CONCLUSIONS

It is necessary to know the variety of lenses available, and to have an in-depth understanding of their optical properties, as well as the impact that these will have later on their clinical performance and on the visual quality of the patients. This should help us to select the best alternative for each of them.

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."