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".

Changes in cataract and refractive surgery practice patterns among JSCRS members over the past 20 years

PURPOSE

To evaluate changes in cataract and refractive surgery practice patterns among members of the Japanese Society of Cataract and Refractive Surgery (JSCRS) over the past 20 years.

STUDY DESIGN

Questionnaire survey study.

SUBJECTS AND METHODS

Clinical surveys were conducted annually between February and April from 2004 to 2023. Survey questions covered various areas, including cataract surgical techniques, anesthesia, endophthalmitis prophylaxis, toric and presbyopia-correcting intraocular lenses (IOLs), complications, and refractive surgery.

RESULTS

The highest (n=554 [36.8%]) and lowest (n=316 [19.1%]) numbers of responses were collected in 2012 and 2016, respectively. In perioperative management, the intraoperative use of polyvinyl alcohol-iodine solution and topical antibiotic prescription 3 days before surgery has increased. The use of intracameral injection at the end of surgery has also significantly increased, although it has not been established as common practice. In anesthesia, there is a clear polarization between the use of topical drops and tenon injection. The use of toric IOLs and presbyopia-correcting IOLs has significantly increased from 2010 to 2023. In the latter, the use of trifocal IOLs has particularly increased. Regarding IOL power calculations, the Barrett True K and the Barrett Universal II formulas are rapidly gaining popularity for application with and without post-laser vision correction, respectively. In refractive surgery, phakic IOLs and corneal refractive therapy have attracted considerable interest, followed by laser in situ keratomileusis.

CONCLUSIONS

Evaluation of annual clinical survey data over the past two decades provided valuable insights into the shifting practice patterns and clinical opinions among JSCRS members.

EVALUATION AND MANAGEMENT OF POST-OPERATIVE COMPLICATIONS FOLLOWING CATARACT EXTRACTION AND INTRAOCULAR LENS PLACEMENT

THIS REVIEW EXPLORES POST-OPERATIVE CHALLENGES ARISING FROM CATARACT SURGERY, INCLUDING INTRAOCULAR LENS (IOL) DECENTRATION OR DISLOCATION, REFRACTIVE SURPRISES, DYSPHOTOPSIAS, AND IOL OPACIFICATIONS. IOL DECENTRATION OR DISLOCATION IS RARE, HIGHLIGHTING THE NEED FOR CAREFUL MANAGEMENT WITH MONITORING, SURGICAL REPOSITIONING OR LENS EXCHANGE TO ACHIEVE OPTIMAL VISUAL OUTCOMES. REFRACTIVE SURPRISES, ATTRIBUTED TO ERRORS IN IOL CALCULATION AND SELECTION, MAY BE MANAGED CONSERVATIVELY OR SURGICALLY, WITH THE MOST ACCURATE RESULTS ACHIEVED BY LASER VISION CORRECTION. POSITIVE AND NEGATIVE DYSPHOTOPSIAS MAY CONTINUE TO BE INTOLERABLE FOR PATIENTS, AND MAY REQUIRE LENS EXCHANGE AS WELL. IOL OPACIFICATIONS VARY BY IOL MATERIAL AND MAY BE VISUALLY SIGNIFICANT, REQUIRING LENS EXCHANGE. WE UNDERSCORE THE IMPORTANCE OF NUANCED MANAGEMENT AND PROVIDING OPTIMAL PATIENT CARE IN THE ABOVE POST-CATARACT SURGERY AND IOL IMPLANTATION COMPLICATIONS.

The Preoperative Factors for the Undercorrection of Myopia in an Extend Depth-of-Focus Intraocular Lens: A Case-Control Study

We aim to investigate the potential risk factors for undercorrection in those who have received extend depth-of-focus (EDOF) intraocular lens (IOL) implantation. A retrospective case-control study was conducted in which patients who had received one type of EDOF IOL implantation were included. The patients were divided into the residual group and non-residual group according to the final postoperative sphere power. The preoperative data include the refractive, topographic, endothelial, and biometric parameters obtained. A generalized linear model was generated to yield the adjusted odds ratio (aOR) and 95% confidence interval (CI) of each parameter of the residual myopia. One month postoperatively, the UDVA was better in the non-residual group than in the residual group (p = 0.010), and the final SE was significantly higher in the residual group than in the non-residual group (p < 0.001). In the multivariable analysis, the high preoperative cycloplegia sphere power, higher TCRP, higher corneal cylinder power, and longer AXL significantly correlated to the presence of postoperative residual myopia (all p < 0.05). Furthermore, the higher preoperative cycloplegia sphere power, higher TCRP, higher corneal cylinder power, longer AXL, larger ACD, and larger WTW were significantly associated with postoperative residual myopia in the high-myopia population (all p < 0.001), while the higher preoperative cycloplegia sphere power, higher TCRP, and longer AXL were related to postoperative residual myopia in the low-myopia population (all p < 0.05). In conclusion, high preoperative myopia and corneal refractive power correlate to high risk of residual myopia after EDOF IOL implantation, especially in the high-myopia population.

Clinical outcomes and rotational stability after implantation of a monofocal toric intraocular lens with textured haptics in normal vs high axial lengths

PURPOSE

To compare the clinical outcomes and rotational stability after implantation of a toric intraocular lens (IOL) with textured haptics in eyes with normal vs high axial lengths (ALs).

SETTING

Nethradhama Superspeciality Eye Hospital, Bangalore, India.

DESIGN

2-arm, retrospective comparative study.

METHODS

This retrospective study included 114 eyes of 114 patients who underwent femtolaser cataract surgery followed by implantation of the HOYA Vivinex Toric monofocal IOL (Model XY1A-SP), of which 62 and 52 eyes belonged to normal (≤23.9 mm) and high (≥24 mm) AL groups, respectively. 1 week and 3 months postoperatively, clinical outcomes and rotational stability of the toric IOL was evaluated.

RESULTS

3 months postoperatively, % eyes achieving refractive astigmatism accuracy within ≤0.50 diopter, was 100% (n = 62) in the normal vs 94% (n = 49) in the high AL group. All eyes that is, 100% (n = 62) in the normal and 96.15% (n = 50) eyes in the high myopia group were <5 degrees of the intended axis. The mean change in postoperative rotation from 1 week to 3 months was 0.28 ± 0.09 degrees in the normal, and 0.30 ± 1.11 degrees in the high AL group ( P = .80). No significant correlation was observed between AL and white-to-white diameter with 1-week postoperative rotation values. No eye required repositioning of toric IOL for significant misalignment.

CONCLUSIONS

No significant differences were observed for clinical outcomes and postoperative rotational stability between eyes with normal and high ALs, suggesting excellent rotational stability of the Vivinex Toric IOL with textured haptics in all eyes, irrespective of the preoperative AL measurements.

Toric intraocular lens: A literature review

Toric intraocular lenses (IOLs) are universally recommended in cataract cases with preoperative corneal astigmatism ≥1.5 D. An optimal surgical outcome depends on careful patient selection, complete preoperative evaluation, accurate IOL power calculation, precise marking of the axis, meticulous intraoperative approach, and methodical postoperative care. Understanding the importance of posterior corneal astigmatism, surgically induced astigmatism, and effective lens position in IOL power calculation and newer techniques to measure them directly have resulted in better postoperative refractive outcomes. We present a brief overview of toric IOLs along with the preoperative evaluation, IOL power calculation, different marking methods, intraoperative approach, and postoperative outcomes. Functional and anatomical outcomes, including uncorrected visual acuity, residual refractive astigmatism, and postoperative IOL misalignment, which have been reported for both toric IOLs and multifocal toric IOLs, are reviewed.

Insights into the rotational stability of toric intraocular lens implantation: diagnostic approaches, influencing factors and intervention strategies

Toric intraocular lenses (IOLs) have been developed to enhance visual acuity impaired by cataracts and correct corneal astigmatism. However, residual astigmatism caused by postoperative rotation of the toric IOL is an important factor affecting visual quality after implantation. To decrease the rotation of the toric IOL, significant advancements have been made in understanding the characteristics of toric IOL rotation, the factors influencing its postoperative rotation, as well as the development of various measurement techniques and interventions to address this issue. It has been established that factors such as the patient's preoperative refractive status, biological parameters, surgical techniques, postoperative care, and long-term management significantly impact the rotational stability of the toric IOL. Clinicians should adopt a personalized approach that considers these factors to minimize the risk of toric IOL rotation and ensure optimal outcomes for each patient. This article reviews the influence of various factors on toric IOL rotational stability. It discusses new challenges that may be encountered to reduce and intervene with rotation after toric IOL implantation in the foreseeable future.

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.

[Enhancement Options after Lens and Corneal Refractive Surgery]

BACKGROUND

 Modern preoperative diagnostics as well as current surgical techniques allow cataract and refractive surgery to deliver precise refractive results.Occasionally, unsatisfactory refractive and visual results occur despite all the care taken. In these cases, subsequent improvement is required to achieve the best final visual outcome. This article shows the therapeutic options for the treatment of residual refractive errors after lens and corneal refractive surgery.

KEY MESSAGES

 The causes of postoperative refractive errors after refractive laser- or lens-based procedures are very diverse and require extensive workup of the cause as well as an individual solution to achieve the desired result. Before any further surgical intervention, specific complications of the primary procedure as well as concomitant ocular diseases must be excluded or treated. The appropriate enhancement after keratorefractive surgery depends primarily on the type of primary surgery, residual stromal thickness, possible complications from the initial surgery, and the patient's personal preference. For enhancements using surface treatments, such as PRK, the use of mitomycin C is recommended for prophylaxis of haze formation. After lens surgery, for low-grade postoperative refractive errors (spherical and astigmatic), keratorefractive enhancements provide the most accurate results. For higher refractive errors, lens-based procedures can be used, with add-on IOLs being safer and more precise compared with one IOL exchange. Low astigmatisms can be successfully treated with LRI or keratorefractive surgery, but higher astigmatisms should be corrected with an IOL exchange in the early postoperative period and with an add-on IOL in the later postoperative period. IOL explantations should be performed very cautiously, especially in cases of pronounced capsular fibrosis, previous posterior capsulotomy, and existing weakness of the zonular apparatus.

Enhancement-Optionen nach Linsen- und refraktiver Hornhautchirurgie

Gelegentlich kommt es trotz aller Sorgfalt und präziser Operationstechnik in der Katarakt- und Refraktivchirurgie zu unbefriedigenden refraktiven und visuellen Ergebnissen. In diesen Fällen ist eine nachträgliche Korrektur erforderlich, um das beste endgültige visuelle Ergebnis zu erzielen. Dieser Beitrag zeigt die Möglichkeiten zur Behandlung residualer Refraktionsfehler nach Linsen- und refraktiver Hornhautchirurgie auf.

Combining primary and sulcus piggyback IOLs for the correction of a spherical-cylindrical defect in an eye with abnormal cornea

INTRODUCTION

Piggyback IntraOcular Lenses (IOLs), or supplementary secondary implant lenses, have been developed to provide a sufficient dioptric power in eyes with high refractive defects, which are not fully correctable after cataract surgery with single IOL in the range of powers available. These lenses can also be used for the correction of refractive errors that occurred for a wrong choice of the IOL power after cataract surgery.

CASE DESCRIPTION

We report the case of a complete refractive success obtained in a patient with an abnormal cornea, with a central stable ectasia, with thinning, high myopic astigmatism and cataract, obtained with the implant of a primary posterior chamber IOL at the time of cataract surgery and a subsequent implant of a secondary piggyback, sulcus-based customized toric IOL (Camellens FIL 622-2 Toric Monofocal IOL, Soleko, Rome, Italy).

CONCLUSIONS

This brief report demonstrates the utility of combining primary and piggyback IOLs implant for the correction of a complex spherical-cylindrical refractive defect in a case of abnormal cornea and cataract.

Outcomes of LASIK vs PRK enhancement in eyes with prior cataract surgery

PURPOSE

To compare postenhancement visual acuity between patients who underwent postcataract laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK).

SETTING

A private, tertiary referral practice in Sioux Falls, South Dakota.

DESIGN

3-year, retrospective chart review.

METHODS

Patients who underwent postcataract extraction excimer laser enhancement surgery targeted for emmetropia (±0.50 diopter). Postenhancement uncorrected distance visual acuity (UDVA) and manifest refraction spherical equivalent (MRSE) was recorded for all available follow-ups and compared for both groups.

RESULTS

822 postcataract enhanced eyes (491 LASIK; 331 PRK). For patients with at least 6-month follow-up, mean UDVA was 0.05 ± 0.13 logMAR in LASIK-enhanced patients and 0.15 ± 0.20 in PRK-enhanced patients ( P < .001). Mean absolute value MRSE was 0.22 ± 0.36 and 0.48 ± 0.62 for LASIK-enhanced and PRK-enhanced patients at or beyond 6 months, respectively ( P < .001). 330 (67%) LASIK-enhanced patients achieved 20/20 or better postenhancement UDVA, compared with 142 (43%) PRK-enhanced patients ( P < .001). Controlling for pre-enhancement UDVA, LASIK-enhanced patients showed significantly better postenhancement UDVA than PRK-enhanced patients, except in those with pre-enhancement vision of 20/20 or better, or those worse than 20/50. LASIK-enhanced virgin corneas had mean postenhancement of 0.05 ± 0.14 UDVA compared with 0.13 ± 0.19 UDVA in PRK-enhanced virgin cornea patients ( P < .001).

CONCLUSIONS

LASIK provides better and more predictable outcomes in UDVA than PRK in postcataract enhancement patients, even when controlling for pre-enhancement visual acuity and prior ocular procedures.

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).

Correction of pre-existing astigmatism with phacoemulsification using toric intraocular lens versus spherical intraocular lens and wave front guided surface ablation

BACKGROUND

This study aimed to evaluate toric intraocular lens to correct of pre-existing astigmatism at the time of phacoemulsification compared to using of spherical intraocular lens followed by wavefront guided surface ablation.

RESULTS

The patients were classified into three groups: Group A with 20 eyes of 19 patients having phacoemulsification with spherical intraocular lens only as a control group, group B with 20 eyes of 14 patients had phacoemulsification with toric intraocular lens and group C with 20 eyes of 16 patients had phacoemulsification with spherical intraocular lens and wavefront guided PRK three months later. Comparison pre-operative data for all groups showed no statistically significant difference regarding UCVA, BCVA, MRSE, and refractive astigmatism (P>0.05). Post operatively, there was a statistically significant difference for UCVA, BCVA, MRSE, and refractive astigmatism for group A compared to group B (P<0.05) and group A compared to group C but there was no statistically significant difference for group B compared to C regarding all these parameters (P>0.05).

CONCLUSION

In this study, we found similar effects for both techniques in astigmatism corrected groups while both differed from the control group that was not corrected. Correcting preexisting astigmatism during cataract surgery should be in mind in every case to improve visual outcomes. Longer period of follow up are required to evaluate stability of these techniques and possibility of regression.

Multifocal Femto-PresbyLASIK in Pseudophakic Eyes

BACKGROUND

Presbyopia treatment in pseudophakic patients with a monofocal IOL is challenging. This study investigates the refractive results of femto-PresbyLASIK and analyzes presbyopia treatment in pseudophakic eyes.

METHODS

14 patients with 28 pseudophakic eyes were treated with femto-PresbyLASIK. The dominant eye was targeted at a distance and the non-dominant eye at -0.5 D. The presbyopic algorithm creates a steepness in the cornea center by using an excimer laser that leads to corneal multifocality.

RESULTS

6 months after surgery a refraction of -0.11 ± 0.13 D (p = 0.001), an uncorrected distance visual acuity of 0.05 ± 1.0 logMAR (p < 0.001) and an uncorrected near visual acuity of 0.15 ± 0.89 logMAR (p = 0.001) were achieved in the dominant eye. For the non-dominant eye, the refraction was -0.28 ± 0.22 D (p = 0.002), the uncorrected distance of visual acuity was 0.1 ± 1.49 logMAR, and the uncorrected near visual acuity was 0.11 ± 0.80 logMAR (p < 0.001). Spherical aberrations (Z400) were reduced by 0.21-0.3 µm in 32% of eyes, and by 0.31-0.4 µm in 26% of eyes.

CONCLUSION

By steepening the central cornea while maintaining spherical aberrations within acceptable limits, PresbyLASIK created a corneal multifocality that safely improved near vision in both eyes. Thus, femto-PresbyLASIK can be used to treat presbyopia in pseudophakic eyes without performing intraocular surgery.

The incidence and results of laser enhancement after cataract and refractive surgery with trifocal lens implantation

PURPOSE

To evaluate the incidence of laser enhancement following cataract surgery and refractive lens exchange (RLE) with FineVision Micro F trifocal lens implantation (PhysIOL, Liège, Belgium).

METHODS

Retrospective study of patients who had undergone cataract or RLE surgery and had received a FineVision Micro F intraocular lens. Laser enhancement of residual refractive error was determined. Visual acuity (VA) assessments were performed before and after surgery: uncorrected distance VA (UCDVA), best-corrected distance VA (BCDVA), uncorrected near VA (UCNVA), plus preoperative and postoperative spherical equivalent (SE) assessments.

RESULTS

Of the 1129 eyes from 596 patients, 61 (5.4%) required laser enhancement to correct residual refractive error (by group: 30/679 eyes [4.4%] cataract; 31/450 eyes [6.9%] RLE). Eleven eyes received FemtoLASIK; 50 eyes received PRK. Mean UCDVA before laser enhancement was 0.26±0.19 logMAR and 0.24±0.14 in the FemtoLASIK and PRK groups, respectively. After laser enhancement, these were 0.04±0.05 logMAR and 0.13±0.19, respectively; BCDVA values were 0.00±0.00 logMAR in the FemtoLASIK group and 0.06±0.11 in the PRK group. Laser enhancement improved UCNVA (Jaeger) from 2-3 to 1-2 in both groups. Enhancement reduced preoperative SE of -0.39±0.99 D and -0.53±0.58 D (FemtoLASIK and PRK groups, respectively) to 0.24±0.36 D and 0.04±0.47 D.

CONCLUSIONS

The FineVision Micro F trifocal lens is an effective solution for gaining increased spectacle independence. The incidence of residual refractive error requiring laser enhancement is low, and laser procedures are a safe and effective solution for improving the quality of vision and patient satisfaction.

SYNOPSIS

Laser enhancement rates and outcomes were determined following cataract / refractive lens exchange surgery that used a trifocal IOL. Enhancement was safe and effective and rates were low (5.4%).

Secondary Piggyback Intraocular Lens for Management of Residual Ametropia after Cataract Surgery

Purpose

To investigate the indications, clinical outcomes, and complications of secondary piggyback intraocular lens (IOL) implantation for correcting residual refractive error after cataract surgery.

Methods

In this prospective interventional case series, patients who had residual refractive error after cataract surgery and were candidates for secondary piggyback IOL implantation between June 2015 and September 2018 were included. All eyes underwent secondary IOL implantation with the piggyback technique in the ciliary sulcus. The types of IOLs included Sulcoflex and three-piece foldable acrylic lenses. Patients were followed-up for at least one year.

Results

Eleven patients were included. Seven patients had hyperopic ametropia, and four patients had residual myopia after cataract surgery. The preoperative mean of absolute residual refractive error was 7.20 ± 7.92, which reached 0.42 ± 1.26 postoperatively (P< 0.001). The postoperative spherical equivalent was within ±1 diopter of target refraction in all patients. The average preoperative uncorrected distance visual acuity was 1.13 ± 0.35 LogMAR, which significantly improved to 0.41 ± 0.24 LogMAR postoperatively (P = 0.008). There were no intra- or postoperative complications during the 22.4 ± 9.5 months of follow-up.

Conclusion

Secondary piggyback IOL implantation is an effective and safe technique for the correction of residual ametropia following cataract surgery. Three-piece IOLs can be safely placed as secondary piggyback IOLs in situations where specifically designed IOLs are not available.

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.

[Evolution of IOL exchange. Part 1. Development of methods for IOL exchange]

The review presents the history of development and improvement of methods for intraocular lens (IOL) exchange. Existing techniques of IOL exchange are comparatively analyzed.

A pinhole implant to correct postoperative residual refractive error in an RK cataract patient

Purpose

To report the clinical outcomes after implantation of a pinhole supplementary implant (Xtrafocus, Morcher GmbH, Stuttgart, Germany) to correct fluctuating residual refraction after cataract surgery in a patient with a history of radial keratotomy (RK).

Observations

A 62-year-old patient who had radial keratotomy 22 years earlier, underwent uneventful bilateral cataract surgery using the ASCRS IOL-Calculator for post-RK. Postoperatively, the patient showed fluctuating subjective manifest refraction (MR) on both eyes. To correct the large fluctuating residual refractive error and subjectively worse visual acuity, Xtrafocus IOL was implanted in the right eye. One week later, the uncorrected distance visual acuity (UDVA) was already 0.1 logMAR and the patient stated to have stable vision. Three months after Xtrafocus implantation, the UDVA was −0.04 logMAR which did not improve with MR and the patient expressed high satisfaction, good subjective binocular contrast sensitivity, comparable visual field outcomes, and an elongated depth of focus.

Conclusions and Importance

The pinhole sulcus implant not only helped eliminate the fluctuation in residual refraction after cataract surgery, but also provided an elongated depth of focus without greatly affecting the visual field. The supplementary implantation of the Xtrafocus lens can offer an effective option for the treatment of instable refractive errors after cataract surgery in patients with a history of corneal surgery.

[Causes, prevention and correction of refractive errors after phacoemulsification with intraocular lens implantation]

PURPOSE

To evaluate the influence of dry eye disease (DED) in cataract patients on refractive results of phacoemulsification with implantation of intraocular lenses (IOLs).

MATERIAL AND METHODS

The study included 24 patients (24 eyes) with early cataract or phacosclerosis who planned to undergo phacoemulsification with implantation of multifocal IOL. Inclusion criteria was preoperative presence of DED. During the initial visit, all patients first had IOL power calculated, received comprehensive treatment to address DED, and then repeated the IOL power calculation. Accuracy of achieving target refraction was evaluated by the amount of residual spherical equivalent one months after the surgery.

RESULTS

In patients with cataract and DED, the following statistically significant changes were noted after ocular surface normalization: reduction of the cylindrical component of refraction, reduction of corneal irregularity and its asymmetry, as well as normalization of eye surface. The average difference in the calculation of IOL power before and after DED treatment was 0.87±0.11 D, maximum error was 2.25 D. Control examination one month after the operation showed high visual functions in all operated patients. Deviation from the planned refraction was minimal (41.2% of cases were within in ±0.25 D of the planned refraction, 76.5% of cases in ±0.5 D, 100% of cases in ±1.0 D).

CONCLUSION

Preoperative detection of DED and its correction in patients with cataract increases calculation precision of IOL power and improves clinical and functional results.

Multifocal Intraocular Lenses Implantation in Presbyopia Correction. Literature Review

Reduced dependence on glasses is an increasingly common expectation among those who want to take advantage of new surgical opportunities, especially for patients who lead an active lifestyle. Currently, due to the increase in the duration of active life in people over 40, there is a need for effective correction of presbyopia. Multifocal intraocular lenses are increasingly used in the treatment of presbyopia. After implantation of multifocal intraocular lenses most patients have no need for spectacle or contact vision. However, complications can affect the patient’s quality of life and level of satisfaction. The most common complications of multifocal correction are blurred vision and the presence of optical phenomena (“halo” and “glare”), associated with residual ametropia, clouding of the posterior capsule, large pupil size, anomalies of the wave front, dry eye and lens decentration. The main reasons for this are the failure to attempt to neuroadapt a patient, the dislocation of the lens, the residual refractive error and the clouding of the lens. The review presents the main features of various models of multifocal intraocular lenses, their implantation techniques, associated complications and methods for their correction. The development of multifocal correction of presbyopia and ametropia seems to be a promising direction in ophthalmic surgery.

Enhancement-procedure outcomes in patients implanted with the Precisight multicomponent intraocular lens

Purpose

Eyes that have undergone phacoemulsification with implantation of a multicomponent intraocular lens (MCIOL) may further undergo an enhancement procedure for correction of residual refractive errors. The enhancement procedure is accomplished by exchanging the front lens used in the primary surgery with another lens containing the correct dioptric power. We evaluated the efficacy and safety of enhancement procedures among eyes that received an MCIOL.

Methods

A total of 25 eyes that had undergone phacoemulsification with implantation of an MCIOL were found to have a residual error of refraction (spherical equivalent ≥0.75 D) 3 months after primary cataract surgery, and underwent further enhancement surgery. The main study outcomes were uncorrected and corrected distance visual acuity, subjective refraction, anterior-chamber depth, pachymetry, and endothelial cell count.

Results

There was a statistically significant improvement in uncorrected distance visual acuity of approximately two lines after enhancement surgery (0.20±0.20-0.02±0.08 logMAR, P<0.001) and a significant decrease in residual spherical equivalent from 1.3±1.1 D to 0±0.38 D (P<0.001). There were no statistically significant changes in pre- and postenhancement corrected distance visual acuity, anterior-chamber depth, pachymetry, or keratometry. There was a statistically significant decrease (2.6%) in endothelial cell count (P<0.01), which could have been endothelial equilibration from the primary procedure. All enhancement surgeries were uneventful, and no major complications were observed.

Conclusion

The MCIOL-enhancement procedure demonstrates statistical and clinical improvement in uncorrected distance visual acuity and correction of postoperative refractive errors. The Precisight IOL may be a useful choice for patients with high risk of having significant residual refractive errors after primary cataract surgery.

Photorefractive keratectomy after cataract surgery in uncommon cases: long-term results

AIM

To evaluate the efficacy and safety of the excimer laser correction of the residual refractive errors after cataract extraction with intraocular lens (IOL) implantation in uncommon cases.

METHODS

Totally 24 patients with high residual refractive error after cataract surgery with IOL implantation were examined. Twenty-two patients had a history of phacoemulsification and IOL implantation, and two had extra-capsular cataract extraction with IOL implantation. Detailed examination of preoperative medical records was done to explain the origin of the post-cataract refractive errors. All patients underwent photorefractire keratectomy (PRK) enhancement. The mean outcome measures were refraction, uncorretted visual acuity (UCVA), best corrected visual acuity (BCVA) and corneal transparency and follow up ranged from 1 to 8y.

RESULTS

The principal causes of residual ametropia was inexact IOL calculation in abnormal eyes with high myopia and congenital lens abnormalities, followed by corneal astigmatism both suture induced and preexisting. After cataract surgery and before the laser enhancement the mean spherical equivalent (SE) was -0.56±3 D ranging from -4.62 to +2.25 D in high myopic patients, instead it was -1±1.73 D ranging from -3.25 to +3.75 D in the astigmatic eyes, with a mean cylinder of -3.75±0 ranging from -3 to +5.50 D. After laser refractive surgery the mean SE was 0.1±0.73, ranging from -0.50 to +1.50 in the myopic group, and it was -0.50±0.57 ranging from -1.25 to +0.50 in astigmatic patients, with a mean cylinder of -0.25±0.75. In myopic patients the mean UCVA and BCVA were 0.038±0.072 logMAR and 0.018±0.04 respectively, both ranging from 0.10 to 0.0. In astigmatic patients, the mean UCVA and BCVA were 0.213±0.132 and 0.00±0.0 respectively, UCVA ranging from 0.50 to 0.22 and BCVA was 0.00. All patients presented normal corneal transparency. No ocular hypertension was detected and no corneal haze was observed. All registered values remained stable also at the end line evaluation.

CONCLUSION

The excimer laser treatment of residual refractive errors after cataract surgery with IOL implantation in abnormal eyes resulted in satisfactory and stable visual outcome with good safety and efficacy.

Photorefractive keratectomy for correcting residual refractive error following cataract surgery with premium intraocular lens implantation

PURPOSE:

The aim of this study is to evaluate the effectiveness and predictability of photorefractive keratectomy (PRK) for correcting residual refractive error following cataract surgery with premium intraocular lens (IOL) implantation.

METHODS:

We conducted a retrospective review of the medical records of patients who received PRK for correcting residual hyperopia, myopia, and/or astigmatism due to unsatisfied uncorrected distance visual acuity (UDVA) after cataract extraction with implantation of aspheric, diffractive multifocal, or toric IOL from September 2011 to December 2017. Pre-cataract surgery, pre- and post-PRK data including UDVA, best-corrected distance visual acuity, and refractive status were analyzed.

RESULTS:

A total of 18 consecutive eyes in 17 patients were included in this study. The UDVA after PRK improved 1 line or more in 10 eyes, remained unchanged in five eyes, and decreased in three eyes. The overall improvement in the logarithm of minimal angle of resolution (logMAR) UDVA after PRK was significant (P < 0.05). While dividing patients into subgroups based on IOL type, significant improvement in logMAR UDVA was found in patients with aspheric IOL or diffractive multifocal IOL implantation (P < 0.05). No significant improvement of UDVA was found in patients with toric IOL implantation. All eyes achieved ± 1.00 D of the attempted spherical correction, demonstrating good predictability of PRK.

CONCLUSIONS:

PRK was a safe and effective procedure to correct residual refractive error following cataract extraction with premium IOL implantation. Although satisfactory for all patients, the outcome is better and more predictable in patients with aspheric and diffractive multifocal IOL implantation and is less satisfactory and unpredictable in patients with toric IOL implantation.

Optimizing outcomes with toric intraocular lenses

Toric intraocular lenses (IOLs) are the procedure of choice to correct corneal astigmatism of 1 D or more in cases undergoing cataract surgery. Comprehensive literature search was performed in MEDLINE using “toric intraocular lenses,” “astigmatism,” and “cataract surgery” as keywords. The outcomes after toric IOL implantation are influenced by numerous factors, right from the preoperative case selection and investigations to accurate intraoperative alignment and postoperative care. Enhanced accuracy of keratometry estimation may be achieved by taking multiple measurements and employing at least two separate devices based on different principles. The importance of posterior corneal curvature is increasingly being recognized in various studies, and newer investigative modalities that account for both the anterior and posterior corneal power are becoming the standard of care. An ideal IOL power calculation formula should take into account the surgically induced astigmatism, the posterior corneal curvature as well as the effective lens position. Conventional manual marking has given way to image-guided systems and intraoperative aberrometry, which provide a mark-less IOL alignment and also aid in planning the incisions, capsulorhexis size, and optimal IOL centration. Postoperative toric IOL misalignment is the major factor responsible for suboptimal visual outcomes after toric IOL implantation. Realignment of the toric IOL is needed in 0.65%–3.3% cases, with more than 10° of rotation from the target axis. Newer toric IOLs have enhanced rotational stability and provide precise visual outcomes with minimal higher order aberrations.

A review of results after implantation of a secondary intraocular lens to correct residual refractive error after cataract surgery

PURPOSE

The purpose of this study was to provide clinical outcomes data related to secondary intraocular lens (IOL) implantation for the correction of residual refractive error after cataract surgery.

PATIENTS AND METHODS

A chart review was conducted to identify all eyes implanted with the monofocal spherical or toric AddOn^® secondary IOL. Data were collated from charts where uncomplicated initial cataract surgery was completed. Measures of interest included the original IOL implanted, the postoperative refractive error (before secondary IOL implantation) and the associated corrected and uncorrected visual acuities (VAs). Postoperative data of interest included the residual refractive error, the best-corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA).

RESULTS

Refractive and VA data from 1 week to 3 months post-surgery were available for 46 of 70 eyes implanted with a secondary IOL by one surgeon at one practice between 4/15 and 3/17. There was a statistically significant improvement in UCVA of about 2 lines after surgery (p<0.01), with no change in BCVA (p=0.94). No eyes lost a line of BCVA. There was a statistically significant reduction in the absolute magnitude of the residual spherical equivalent refractive error (p<0.01). In the 10 cases with a toric secondary IOL, there was a statistically significant reduction in refractive cylinder (p<0.01).

CONCLUSION

The secondary IOL studied here appears to be a viable surgical option to correct residual refractive error after primary IOL implantation.

Predictability and Vector Analysis of Laser In Situ Keratomileusis for Residual Errors in Eyes Implanted With Different Multifocal Intraocular Lenses

PURPOSE

To investigate potential differences in predictability, efficacy, and safety of corneal excimer laser to correct residual myopia, hyperopia, and astigmatism in eyes previously implanted with multifocal intraocular lenses using distinct optical surfaces and platforms for multifocality.

METHODS

This prospective comparative study included 37 eyes submitted to laser in situ keratomileusis correction for residual errors after implantation of either an apodized diffractive-refractive (Restor) or a full-diffractive (Tecnis) multifocal intraocular lens. Data analysis included investigation of predictability, efficacy, and safety of excimer laser surgery to correct residual errors. A double-angle plot, using vector analysis, was also created to evaluate predictability of astigmatism correction.

RESULTS

At 6-month follow-up, statistical analyses revealed a significant improvement when comparing preoperative (0.51 ± 0.25 and 0.44 ± 0.18) and postoperative values (0.17 ± 0.10 and 0.09 ± 0.07) of uncorrected distance visual acuity (P < 0.0001 and <0.0001), preoperative (0.92 ± 0.61 and 1.02 ± 0.45) and postoperative values (0.33 ± 0.23 and 0.19 ± 0.17) of manifest refractive spherical equivalent (P = 0.0006 and <0.0001), and preoperative (-1.08 ± 0.70 and -0.65 ± 0.42) and postoperative values (-0.25 ± 0.28 and -0.14 ± 0.21) of astigmatism (P < 0.0001 and <0.0001) in eyes implanted with Restor and Tecnis, respectively. Vector analysis revealed a predictable correction of astigmatism in all groups. Ninety-two percent of total eyes achieved a manifest refractive spherical equivalent within ±0.5 of emmetropia.

CONCLUSIONS

Corneal excimer laser refractive surgery seems to be equally effective to correct different residual errors, including astigmatism, in eyes implanted with intraocular lenses with various platforms for multifocality.

Visual Performance after Bilateral Implantation of a Four-Haptic Diffractive Toric Multifocal Intraocular Lens in High Myopes

Background. The vision with diffractive toric multifocal intraocular lenses after cataract surgery in long eyes has not been studied previously. Objectives. To report visual performance after bilateral implantation of a diffractive toric multifocal intraocular lens in high myopes. Methods. Prospective, observational case series to include patients with axial length of ≥26 mm and corneal astigmatism of >1 dioptre who underwent bilateral AT LISA 909M implantation. Postoperative examinations included photopic and mesopic distance, intermediate, and near visual acuity; photopic contrast sensitivity; visual symptoms (0–5); satisfaction (1–5); and spectacle independence rate. Results. Twenty-eight eyes (14 patients) were included. Postoperatively, mean photopic monocular uncorrected distance, intermediate, and near visual acuities (logMAR) were 0.12 ± 0.20 (standard deviation), 0.24 ± 0.16, and 0.29 ± 0.21, respectively. Corresponding binocular values were −0.01 ± 0.14, 0.13 ± 0.12, and 0.20 ± 0.19, respectively. One eye (4%) had one-line loss in vision. Under mesopic condition, intermediate vision and near vision decreased significantly (all P ≤ 0.001). Contrast sensitivity at all spatial frequencies did not improve significantly under binocular condition (all P > 0.05). Median scores for halos, night glare, starbursts, and satisfaction were 0.50, 0.00, 0.00, and 4.25, respectively. Ten patients (71%) reported complete spectacle independence. Conclusions. Bilateral implantation of the intraocular lens in high myopes appeared to be safe and achieved good visual performance and high satisfaction.

Cataract surgery on the previous corneal refractive surgery patient

Cataract surgery in cases with previous corneal refractive surgery may be a major challenge for the ophthalmologist. The refractive outcome of the case deserves special attention in the preoperative planning process, which should be tailored for the type of prior refractive procedure: incisional, ablative under a flap, or on the corneal surface. Avoiding refractive surprise after cataract surgery in these cases is principally dependent on the accuracy of the intraocular lens calculation, together with the selection of the appropriate biometric formula for each case. Modern techniques for cataract surgery help surgeons to move toward the goal of cataract surgery as a refractive procedure free from refractive error. We give practical guidelines for the cataract surgeon in the management of these challenging cases.

Outcomes of excimer laser enhancements in pseudophakic patients with multifocal intraocular lens

Purpose

The aim of this study was to assess visual and refractive outcomes of laser vision correction (LVC) to correct residual refraction after multifocal intraocular lens (IOL) implantation.

Patients and methods

In this retrospective study, 782 eyes that underwent LVC to correct unintended ametropia after multifocal IOL implantation were evaluated. Of all multifocal lenses implanted during primary procedure, 98.7% were refractive and 1.3% had a diffractive design. All eyes were treated with VISX STAR S4 IR excimer laser using a convectional ablation profile. Refractive outcomes, visual acuities, patient satisfaction, and quality of life were evaluated at the last available visit.

Results

The mean time between enhancement and last visit was 6.3±4.4 months. Manifest spherical equivalent changed from −0.02±0.83 D (−3.38 D to +2.25 D) pre-enhancement to 0.00±0.34 D (−1.38 D to +1.25 D) post-enhancement. At the last follow-up, the percentage of eyes within 0.50 D and 1.00 D of emmetropia was 90.4% and 99.5%, respectively. Of all eyes, 74.9% achieved monocular uncorrected distance visual acuity 20/20 or better. The mean corrected distance visual acuity remained the same before (−0.04±0.06 logMAR [logarithm of the minimum angle of resolution]) and after LVC procedure (−0.04±0.07 logMAR; P=0.70). There was a slight improvement in visual phenomena (starburst, halo, glare, ghosting/double vision) following the enhancement. No sight-threatening complications related to LVC occurred in this study.

Conclusion

LVC in pseudophakic patients with multifocal IOL was safe, effective, and predictable in a large cohort of patients.

Intraocular lens alignment methods

PURPOSE OF REVIEW

This article reviews current concepts in intraocular lens alignment strategies to maximize intraocular lens (IOL) positioning.

RECENT FINDINGS

A variety of strategies has been developed to maximize toric IOL position, including preoperative calculators to determine the appropriate IOL power and orientation, intraoperative alignment devices, and postoperative software to determine if IOL rotation would be beneficial for refractive outcomes.

SUMMARY

The combination of using multiple toric IOL calculators and intraoperative alignment devices has improved toric IOL outcomes. The relationship of the posterior corneal power and its effect on outcomes remains to be fully elucidated. Postoperative IOL rotation may be necessary even when the IOL is aligned as planned because of surgically induced astigmatism.

Surgical options for correction of refractive error following cataract surgery

Refractive errors are frequently found following cataract surgery and refractive lens exchange. Accurate biometric analysis, selection and calculation of the adequate intraocular lens (IOL) and modern techniques for cataract surgery all contribute to achieving the goal of cataract surgery as a refractive procedure with no refractive error. However, in spite of all these advances, residual refractive error still occasionally occurs after cataract surgery and laser in situ keratomileusis (LASIK) can be considered the most accurate method for its correction. Lens-based procedures, such as IOL exchange or piggyback lens implantation are also possible alternatives especially in cases with extreme ametropia, corneal abnormalities, or in situations where excimer laser is unavailable. In our review, we have found that piggyback IOL is safer and more accurate than IOL exchange. Our aim is to provide a review of the recent literature regarding target refraction and residual refractive error in cataract surgery.

Corrective Techniques and Future Directions for Treatment of Residual Refractive Error Following Cataract Surgery

Postoperative residual refractive error following cataract surgery is not an uncommon occurrence for a large proportion of modern-day patients. Residual refractive errors can be broadly classified into 3 main categories: myopic, hyperopic, and astigmatic. The degree to which a residual refractive error adversely affects a patient is dependent on the magnitude of the error, as well as the specific type of intraocular lens the patient possesses. There are a variety of strategies for resolving residual refractive errors that must be individualized for each specific patient scenario. In this review, the authors discuss contemporary methods for rectification of residual refractive error, along with their respective indications/contraindications, and efficacies.

Management of residual refractive error after cataract surgery

PURPOSE OF REVIEW

To provide a review of the recent literature on the management of residual refractive error after cataract surgery.

RECENT FINDINGS

Laser in-situ keratomileusis (LASIK) is the most accurate procedure to correct residual refractive error after cataract surgery. Lens-based procedures, such as intraocular lens (IOL) exchange or piggyback lens implantation, are also possible alternatives in cases with extreme ametropia, corneal abnormalities, or in situations where excimer laser is not available. In this review, we found that Piggyback IOL were safer and more accurate than IOL exchange.

SUMMARY

Emmetropia is our main target today in modern cataract surgery. Accurate biometric analysis, selection and calculation of the adequate IOL, and modern techniques for cataract surgery all help surgeons to move toward the goal of cataract surgery as a refractive procedure free from refractive error. However, in spite of all these inputs, residual refractive error still occasionally occurs after cataract surgery and LASIK seems to be the most accurate method for its correction.