Outcomes of toric supplementary intraocular lenses for residual astigmatic refractive error in pseudophakic eyes

Polypseudophakia: from "Piggyback" to supplementary sulcus-fixated IOLs

Polypseudophakia, the concept of using a second intraocular lens (IOL) to supplement an IOL that has already been placed in the capsular bag, was first used as a corrective measure where the power requirement was higher than that of available single IOLs. Subsequently, the technique was modified to compensate for post-operative residual refractive errors. In these early cases, an IOL designed for the capsular bag would be implanted in the sulcus.  Although these approaches were less than ideal, alternative means of correcting residual refractive errors were not without their limitations: IOL exchange can be traumatic to the eye and is not easily carried out once fibrosis has occurred, while corneal refractive surgical techniques are not suitable for all patients. Piggyback implantation was the term first coined to describe the use of two IOLs, placed together in the capsular bag. The term was later extended to include the procedure where an IOL designed for the capsular bag was placed in the sulcus. Unfortunately, the term piggyback has persisted even though these two approaches have been largely discredited. Intraocular lenses are now available which have been specifically designed for placement in the ciliary sulcus. As these newer IOLs avoid the many unacceptable complications brought about by both types of earlier piggyback implantation, it is time to employ a new terminology, such as supplementary IOL or secondary enhancement to distinguish between the placement of an unsuitable capsular bag IOL in the sulcus and the implantation of an IOL specifically designed for ciliary sulcus implantation. In addition to minimising possible complications, supplementary IOLs designed for the sulcus have expanded the options available to the ophthalmic surgeon. With these new IOLs it is possible to correct presbyopia and residual astigmatism, and to provide temporary correction of refractive errors in growing, or unstable, eyes. This article aims to review the literature available on supplementary IOL implantation in the ciliary sulcus and to summarise the evidence for the efficacy and safety of this intervention. KEY MESSAGES: What is known Polypseudophakia has been used for over 30 years to correct hyperopia or residual refractive error, but early techniques were associated with significant complications. What is new The development of specially designed sulcus-fixated supplementary IOLs significantly reduces the risks associated with these procedures, and has also opened up new opportunities in patient care. The reversibility of the procedure allows patients to experience multifocality, and to provide temporary and adjustable correction in unstable or growing eyes. The terms "secondary enhancement" or "DUET" to describe supplementary IOL implantation are preferential to "piggyback".

Rotational stability of two different piggyback toric intraocular lenses for correction of high post-keratoplasty pseudophakic ametropia

We present the case of a 65-year-old man with bilateral keratoconus and history of bilateral penetrating keratoplasty (PK) who developed gradual visual decline in the left eye due to cataract formation. Following successful left eye cataract surgery and monofocal, non-toric intraocular lens (IOL) in-the-bag implantation, the patient experienced persistently low uncorrected distance visual acuity (UDVA) due to high residual refractive error and intolerance to contact lenses. A supplementary toric IOL was placed in the ciliary sulcus, but subsequent rotational instability of the lens required repeated realignment. Despite two attempts at IOL repositioning, the rotational instability persisted, necessitating the replacement of the original Sulcoflex IOL with a toric, implantable Collamer lens. Following the implantation of the toric ICL, the patient achieved excellent UDVA with no adverse events over a 4-year follow-up period. This case highlights the potential rotational instability associated with toric piggyback IOLs in keratoconic, post-PK, pseudophakic eyes and the special considerations on choosing the type of piggyback lens in these eyes.

Supplemental Toric Intraocular Lenses in the Ciliary Sulcus for Correction of Residual Refractive Astigmatism: A Review

PURPOSE

This study conducted a critical review of the peer-reviewed literature on the use of supplemental toric intraocular lenses (STIOL) in the ciliary sulcus to correct residual refractive astigmatism.

METHODS

This review used PubMed as a database from 1 January 2010 to 13 March 2023. According to the inclusion and exclusion criteria defined, 14 articles were selected for the current review.

RESULTS

The data of 155 eyes were analyzed. Most of the studies reviewed had a short follow-up and poor or limited design, including case reports, case series, and retrospective cohorts. The follow-up period ranged from 43 days to 4.5 years. STIOL rotation was the most frequently described complication in the literature, with a mean rotation of 30.48 ± 19.90°. These patients required repositioning in 50 of 155 eyes (32.25%). Moreover, four eyes (2.58%) required scleral fixation sutures and two eyes (1.29%) iris fixation. Other complications were high intraocular pressure (3 eyes, 1.93%), transient corneal edema (2 eyes, 1.29%), corneal decompensation (2 eyes, 1.29%), and pigment dispersion (1 eye, 0.64%). From the total, 57.41% of eyes (89 eyes from 155) achieved within ± 0.50D of target refractive astigmatism. It is important to highlight that at least 52 eyes out of the 155 (33.54%) had an abnormal cornea with irregular astigmatism.

CONCLUSION

STIOL seem to offer good visual and refractive outcomes. However, STIOL showed variable rotational stability, especially in some platforms. Further studies with a more robust design, methodology, and standardized analysis methods are needed to confirm these trends.

Reversible Multifocality Achieved Through Polypseudophakia

Simultaneous implantation of a monofocal or monofocal toric intraocular lens (IOL) into the capsular bag and a multifocal IOL into the ciliary sulcus, referred to as duet procedure, allows us to create multifocality that is more easily reversible than the implantation of a capsular bag-fixated multifocal IOL. The optical quality and results after the duet procedure are equivalent to those of a capsular bag-fixated multifocal IOL. Patients who cannot tolerate the side effects of multifocal optics or who develop an ocular condition leading to loss of function such as age-related macular degeneration (AMD) or glaucoma in the course of their lives may benefit from the reversibility of the procedure.

Novel custom designed toric piggyback intraocular lens for the correction of residual postoperative astigmatism

We report the outcomes of a custom-designed toric piggyback intraocular lens in a patient with high postoperative residual astigmatism. A 60-year-old male patient underwent customized toric piggyback IOL for postoperative residual astigmatism of 13 D, with follow-up examinations for IOL stability and refractive outcomes. The refractive error stabilized at two months and remained stable at one year, with a correction of nearly 9 D of astigmatism. The IOP remained within normal limits, and there were no postoperative complications. The IOL remained stable in the horizontal position. To our knowledge, this is the first case report of correction of unusually high astigmatism by a novel smart toric design of piggyback IOL.

Management of post-keratoplasty ametropia

Even after a successful corneal transplant, patients experience severe refractive errors, impeding their rehabilitation and satisfaction. Refractive errors can be caused by recipient pathology and corneal thickness, as well as intraoperative factors such as donor-host discrepancy, recipient's eccentric trephination, vitreous length, wound apposition, technique of suturing, and suture material. Also, wound healing and the interim between keratoplasty and suture removal contribute to astigmatism. Lamellar keratoplasty outperforms penetrating keratoplasty in terms of endothelial cell loss and endothelial graft rejection, yet the risk of developing refractive errors is comparable. Nonsurgical interventions such as spectacles and lenses fail to provide desirable vision in cases with high astigmatism and corneal irregularity. When these limitations are encountered, surgical interventions including incisional keratotomy, wedge resection, laser refractive surgeries, intracorneal segments, and intraocular lens implantation are employed. However, occasionally, none of these approaches deliver the desired effects, leading to the need for a repeat keratoplasty.

Refractive and Visual Outcomes After Implantation of a Secondary Sulcus Intraocular Lens with an Extended Depth of Focus

Purpose

To evaluate the range of vision, visual function, and quality of vision after implantation of a secondary extended depth of focus intraocular lens (EDOF IOL) implanted in the sulcus.

Setting

One clinical practice in Haugesund, Norway.

Design

Prospective single arm non-interventional study.

Methods

Eligible subjects presenting for surgery, or who had previous successful primary cataract or refractive lens exchange surgery in both eyes were subsequently implanted with the AddOn® secondary EDOF IOL in the sulcus. Manifest refraction and visual acuity at distance, intermediate and near were measured 3 months after surgery, along with the monocular defocus curve. Subjects also completed a visual function and a quality of vision questionnaire.

Results

The study included 32 eyes of 16 subjects. At 3 months postoperative, the mean refraction spherical equivalent (MRSE) was −0.16 ± 0.30 D, with a residual cylinder of 0.29 ± 0.27 D. The mean monocular uncorrected VA was 0.1 logMAR (20/25) or better at all test distances. The monocular defocus curves showed a depth of focus of 2.0 D. For every category except reading fine print, all but one subject (94%) had no difficulty or little difficulty with near tasks. Glare and halos were the most common visual disturbances, with no reports of starbursts. There was no evidence of any intralenticular opacification in any of the eyes, and no evidence of iris chafing/depigmentation.

Conclusion

This secondary EDOF IOL provided excellent distance and intermediate vision, and very good near vision to subjects. Subject reported near visual function was also very good and visual disturbances were limited. This lens appears to be a good option for patients who would like to improve their range of vision. Results appear as good or better than those reported for primary EDOF lenses.

Toric intraocular lens for astigmatism correction following keratoplasty in phakic and pseudophakic eyes

ABSTRACT

Residual astigmatism and anisometropia significantly impact patients' vision and quality of life even in clear grafts after corneal transplant. We reviewed and summarized the role of toric intraocular lens (IOL) in phakic and pseudophakic eyes after penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK) in correcting residual astigmatism. We included 342 eyes from 20 studies with iris-clipped toric IOL, ciliary sulcus toric implantable collamer lens, piggyback sulcus toric IOL, or posterior chamber toric IOL implantations for phakic, pseudophakic, or eyes undergoing cataract surgery after keratoplasty. Visual, refractive, and predictability outcomes were encouraging. Secondary re-alignment rate and complications were low. Endothelial cell loss secondary to phakic toric IOL might be a concern over the long-term, particularly in iris-clipped IOL in PKP eyes. Toric IOL represent a viable option in the treatment of residual astigmatism in post-keratoplasty eyes, resulting in improved visual acuity and reduced anisometropia.

Outcomes of a Toric Monofocal Piggyback Intraocular Lens for Residual Astigmatic Refractive Error in Pseudophakic Eyes

PURPOSE/AIM

To evaluate the visual outcomes, refractive outcomes and rotational stability of a toric piggyback intraocular lens (1stQ AddOn, GmbH, Mannheim, Germany) for astigmatic refractive error in pseudophakic eyes.

MATERIALS AND METHODS

Visual and refractive outcomes were assessed based on the standard graphs for reporting refractive surgery outcomes. Rotational stability was assessed according to the Intraocular Lens (IOL) standards of the International Organisation for Standards.

RESULTS

Twenty-two eyes of 17 patients (age: 65.1 ± 9.3 years) underwent toric piggyback IOL insertion. After a minimum follow-up of 3 months, 18 eyes (82%) achieved an uncorrected distance visual acuity (UDVA) of 0.00 logMAR (20/20) or better and all eyes achieved 0.1 logMAR (20/25). Mean UDVA improved from 0.27 ± 0.03 to 0.12 ± 0.03 and 0.04 ± 0.04 at one and 3 months (all p < .05). Nineteen eyes (86%) achieved an UDVA at least equal to the pre-operative corrected distance visual acuity (CDVA). No eyes lost more than one line of CDVA. All eyes achieved within 0.5D of target spherical equivalent (SE). In 18 eyes (82%), the residual astigmatism magnitude was 0.5D or less. The mean absolute difference between the target axis and the achieved axis 1 and 3 months postoperatively was 2.5° ± 2.7° and 3.2° ± 3.3°, respectively. The final IOL orientation was within 10 degrees of target axis in 19 of 22 (86.4%) eyes, within 20 degrees in 21 of 22 (95.2%) eyes and within 30 degrees in 22 of 22 (100%) eyes. IOL rotational repositioning was required in two eyes (9.1%).

CONCLUSIONS

In this cohort of patients, the 1stQ AddOn toric monofocal piggyback IOL resulted in very good visual and refractive outcomes and showed reasonable rotational stability. This IOL appears to be an effective treatment option for residual astigmatic refractive error in pseudophakic eyes.

Refractive enhancements for residual refractive error after cataract surgery

PURPOSE OF REVIEW

Advances in cataract surgery have allowed surgeons to achieve superior refractive outcomes but have also led to higher patient expectations. Despite ever-evolving technology, residual refractive errors still occur. Postcataract refractive enhancements may be required to deliver satisfactory visual outcomes. This review aims to discuss the potential causes of residual refractive errors and the various enhancement modalities to correct them.

RECENT FINDINGS

A thorough preoperative workup to detect and address underlying pathologic causes of impaired vision should be performed prior to enhancement or corrective procedures. Corneal-based procedures are the safest and most accurate methods of correcting mild cases of residual refractive error. Hyperopic, high myopic, and high astigmatic errors are best managed with lens-based enhancements. Piggyback intraocular lenses (IOLs) are safer and more effective compared with IOL exchange. Toric IOL rotation and IOL exchange are ideally performed in the early postoperative period.

SUMMARY

A multitude of options exist for effective correction of residual refractive errors. The choice on how to best manage these patients depends on many factors such as the cause of refractive error, type of IOL used, ocular comorbidities, and patient preference.

Refractive and Visual Outcomes After Implantation of a Secondary Toric Sulcus Intraocular Lenses

Purpose

To evaluate the rotational stability, visual acuity and refractive error after sulcus implantation of a secondary toric IOL.

Setting

One clinical practice in Haugesund, Norway.

Design

Non-interventional single-arm diagnostic study.

Methods

Eligible subjects who had previous successful primary cataract or refractive lens exchange surgery in one or both eyes and the AddOn^® secondary toric IOL implanted in the sulcus were evaluated at a single postoperative diagnostic visit to measure visual outcomes. Subjects with surgical complications (either primary or secondary) or pathology that would affect best-corrected visual acuity (eg, amblyopia) were excluded. Clinical evaluations at the diagnostic visit included measurement of visual acuity, manifest refraction and IOL orientation.

Results

Eighteen eyes were evaluated. After secondary IOL implantation, mean residual refractive astigmatism was significantly reduced (1.66 ± 0.92 to 0.32 ± 0.25 D). There was no appreciable change in the spherical equivalent refraction. Sixteen of 18 eyes (89%) had residual refractive astigmatism ≤0.50D, and no eye had more than 0.75D after secondary IOL implantation. Mean UCVA was 0.00 ± 0.03 logMAR, with no eyes worse than 0.10. Mean BCVA was −0.05 ± 0.03 logMAR (20/20+2), with all eyes having BCVA of 0.00 logMAR. The mean change in orientation was near zero, with a mean absolute change of 4.9 ± 3.7 degrees. Sixteen of 18 eyes (89%) had a lens orientation ≤10 degrees from intended, with no eye oriented more than 13 degrees from intended.

Conclusion

The AddOn^® toric sulcus IOL significantly reduced postoperative refractive astigmatism in patients with high astigmatism after their primary cataract or RLE surgery, providing very good uncorrected distance vision.

Spectacle Independence for Pseudophakic Patients - Experience with a Trifocal Supplementary Add-on Intraocular Lens

Purpose

To evaluate the refractive and functional outcomes of the trifocal 1stQ AddOn^® (Medicontur) supplementary intraocular lenses (IOLs) designed for implantation into the ciliary sulcus.

Patients and Methods

The study included 18 eyes of 11 pseudophakic patients with uncomplicated previous implantation of monofocal capsular bag IOLs. These patients had a desire for spectacle independence. Distance, intermediate and near visual acuities were measured, and defocus curves were plotted over a period of 6 months following implantation of the add-on IOLs. Intraocular pressure (IOP), endothelial cell density measurements and biomicroscopic evaluation were also performed.

Results

In this study, 83.3% of eyes had spherical refractions within ±0.5 D from emetropia and 100% of eyes had spherical equivalent refractions that were within ±1.0 D of the target refraction. Visual acuities and defocus curves clearly confirmed trifocal optical performance (UDVA=0.03 ±0.05; UIVA=0.21 ±0.04; UNVA=0.12 ±0.04 logMAR; expressed as mean ±SD). Depth of focus showed identical results (DOF=0.486 D) compared to a trifocal capsular bag IOL, while the defocus curve was found to be superior in the intermediate and near ranges when compared to a trifocal capsular bag IOL. All patients achieved spectacle independence at all distances. All add-on IOLs were well positioned in the ciliary sulcus. No negative changes were noted in connection with endothelial cell counts, IOPs, the angle structure during surgery and during the follow-up period.

Conclusion

The supplementary trifocal add-on IOL seems to be a safe, efficient and stable solution for achieving spectacle independence in pseudophakic patients with monofocal primary IOLs.