Laser in situ keratomileusis versus lens-based surgery for correcting residual refractive error after cataract surgery

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".

Early intraocular lens explantations: 10-year database analysis

BACKGROUND

The aim of this study was to analyze the causes and characteristics of IOL explantation within the first year after primary implantation.

METHODS

In this retrospective, cross sectional database study, a database consisting of over 2500 IOL explants sent from 199 national and international doctors over the past 10 years was analyzed. All IOLs explanted within the first year after implantation were included in this analysis. Explants with insufficient information as well as phakic and Add-on IOLs were excluded. Main outcome measures were the reason for explantation, the time between implantation and explantation, as well as IOLs' and patients' characteristics. Additionally, the explanted IOLs were microscopically and histologically analyzed, as required.

RESULTS

Of all explanted IOLs from the database, 1.9% (n = 50) were explanted within the first year after implantation. The most frequent reasons for early IOL explantation were IOL dislocation (32%), visual intolerance (26%), opacification (20%), and intraoperative complications (16%). The time between implantation and explantation was the shortest in cases with intraoperative complications (1.5 ± 3.1 days), followed by IOL dislocation (90.9 ± 103.9 days), visual intolerance (98.3 ± 86.5 days), opacifications (253.5 ± 124.0 days) and other indications (249.7 ± 124.0 days). Calcification of hydrophilic IOLs was the main type of opacification (80%). Notably, seven IOLs required immediate intraoperative exchange due to an intraoperative crack in the optic or a torn off haptic.

CONCLUSION

Indications for early IOL explantation were IOL dislocation, visual intolerance, opacification, and intraoperative complications. Especially intraoperative damages to the IOL and early calcification show a potential for improvement of affected IOLs and implantation systems.

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.

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.

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.

The Effect of Lifitegrast on Refractive Accuracy and Symptoms in Dry Eye Patients Undergoing Cataract Surgery

Purpose

To determine the effect of lifitegrast ophthalmic solution 5% on improving the tear film, biometry/keratometry, and refractive accuracy for dry eye patients scheduled for cataract surgery.

Patients and Methods

Multicenter, prospective, open-label study of 100 eyes of 100 patients undergoing cataract surgery who had a confirmed diagnosis of dry eye. Patients underwent biometry at baseline and again after a 28-day course of lifitegrast 5% BID. Primary outcome was an improvement in the accuracy of preoperative anterior corneal power measurements at predicting postoperative spherical equivalent (SE) pre- and post-lifitegrast treatment. Secondary outcomes included changes in dry eye symptoms and corneal staining.

Results

The accuracy of the biometry readings for the achieved refractive SE: within 0.25 D in 47% and 50% of eyes before and after the initial lifitegrast treatment, respectively; within 0.5 D in 71% and 79% of eyes before and after the initial lifitegrast treatment; and within 0.75 D in 81% and 91% of eyes before and after the initial lifitegrast treatment (p < 0.04).

Conclusion

Lifitegrast 5% significantly improved preoperative corneal surface measurement accuracy in patients with confirmed dry eye who were scheduled for cataract surgery.

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Hyperopic laser keratorefractive surgery: Do steep corneas have worse outcomes?

PURPOSE

To report the visual and refractive outcomes of hyperopic patients undergoing laser keratorefractive surgery in preoperatively steep corneas versus a matched control group.

METHODS

Retrospective cohort study. All patients underwent photorefractive keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK) at Care-Vision Laser Centers, Tel-Aviv, Israel, between 1/2000 and 11/2016. Patients were divided into two groups: steep corneas (mean keratometry ≥ 44.00 D) and control group (mean keratometry < 44.00 D). The two study groups were matched by age, gender, sphere and cylinder. Only the right eye of each patient was included. Outcomes included postoperative uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (CDVA), safety and efficacy indexes, refractive outcomes and retreatment rates.

RESULTS

Five hundred and two patients were included. Both groups were similar in demographic data, visual acuity and refraction. Postoperatively, the steep corneas group had a significantly higher mean keratometry as compared to the control group (46.52 ± 1.43 D vs 44.58 ± 1.68 D, p < 0.001), K_min (46.04 ± 1.50 D vs 44.12 ± 1.76 D, p < 0.001) and K_max (46.99 ± 1.51 D vs 45.03 ± 1.77 D, p < 0.001). Both groups had similar postoperative UDVA and CDVA and achieved a similar final sphere (0.64 ± 0.19 vs 0.54 ± 1.19, p = 0.44) and cylinder (- 0.89 ± 0.59 vs - 0.86 ± 0.72, p = 0.67). Both groups had a similar efficacy index (0.92 ± 0.22 vs 0.90 ± 0.25, p = 0.33) and similar retreatment rates (4.2% vs 3.5%, p = 0.74). None of the patients in either group underwent more than one retreatment throughout the follow-up period.

CONCLUSIONS

Hyperopic patients with steep corneas undergoing laser keratorefractive surgery can achieve adequate visual and refractive outcomes, similar to control group.

Unilateral Refractive Lens Exchange with a Multifocal Intraocular Lens in Emmetropic Presbyopic Patients

Purpose: To evaluate the visual outcome and patient satisfaction after a unilateral multifocal IOL implantation in the non-dominant eye of emmetropic patients with presbyopia. Methods: An interventional case series of consecutive patients who underwent unilateral phacoemulsification with femto-laser assisted cataract surgery (FLACS) and refractive lens exchange (RLE), followed by an implantation of a trifocal diffractive IOL (FineVision Micro F), was performed in the non-dominant eyes of emmetropic patients with presbyopia. After 6 months of follow-up, the main outcome measures were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), and uncorrected near visual acuity (UNVA). Secondary outcomes included spherical equivalent (SE), refraction, contrast sensitivity, patient questionnaire and presence of visual side effects. Results: A total of 26 eyes of 26 patients, with an average age of 53.8 ± 4.1 years, were included in this study. Preoperative mean UDVA was 0.13 ± 0.04 logMAR (Snellen 20/27), UIVA was 0.46 ± 0.12 logMAR (Snellen 20/58), and UNVA was 0.66 ± 0.17 logMAR (Snellen 20/91), in comparison to postoperative mean UDVA of 0.18 ± 0.32 logMAR (Snellen 20/30) (p = 0.32), UIVA of 0.17 ± 0.21 logMAR (Snellen 20/30) (p < 0.005), and UNVA of 0.02 ± 0.10 logMAR (Snellen 20/21) (p < 0.005). Monocular UNVA of 20/25 or better in the operated eye was achieved in 23 (88%) patients. Twenty-four (96%) patients said they would recommend this procedure to family and friends. There were no intraoperative complications and no IOL exchange was required. Conclusions: A unilateral RLE of the non-dominant eye with FLACS and a trifocal diffractive IOL (FineVision Micro F) implantation in emmetropic, presbyopic patients is provides satisfactory distance, intermediate, and near visual outcomes with no complications reported in this preliminary case series.

Consensus on the management of astigmatism in cataract surgery

This project was aimed at achieving consensus on the management of astigmatism during cataract surgery by ophthalmologists from Latin America using modified Delphi technique. Relevant peer-reviewed literature was identified, and 21 clinical research questions associated with the definition, classification, measurement, and treatment of astigmatism during cataract surgery were formulated. Twenty participants were divided into seven groups, and each group was assigned three questions to which they had to respond in written form, after thoroughly reviewing the literature. The assigned questions with corresponding responses by each group were discussed with other participants in round 4 – presentation of findings. The consensus was achieved if approval was obtained from at least 80% of participants. The present paper provides several agreements and recommendations for management of astigmatism during cataract surgery, which could potentially minimize the variability in practice patterns and help ophthalmologists adopt optimal practices for cataract patients with astigmatism and improve patient satisfaction.

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

PURPOSE

To evaluate rotational stability and visual and refractive outcomes of supplementary toric IOLs (Sulcoflex Toric 653T, Rayner Intraocular Lenses Ltd) for residual astigmatic refractive error in pseudophakic eyes.

METHODS

A retrospective interventional case series was conducted in a single surgeon practice. Charts of patients who had Sulcoflex Toric supplementary IOLs inserted between June 2009 and September 2015 were reviewed. Outcomes were compared between eyes with and without prior corneal transplant. Patients with at least 3-months follow-up were included.

RESULTS

In 51 eyes, mean UDVA improved from 20/86 to 20/43 (p = 0.002), though UDVA was better in eyes without corneal grafts (20/31) than eyes with (20/62). The proportion of eyes achieving 20/20 UDVA was 43%, 61% and 17% overall, in eyes with prior graft and in eyes with no prior graft, respectively. Sixty-four percentage achieved a spherical equivalent of within 0.5D of target (84% no graft, 34% prior graft). Fifty-three percentage of eyes achieved a cylinder of within 0.5D of target (no graft: 73%, prior graft: 0%). Mean lens rotation was 8.23° on day 1, and mean maximal rotation during follow-up was 17.63°. Sixty-two percentage of IOLs required repositioning. Of those that required repositioning, this was conducted a mean of 2.3 times. The mean final IOL rotation (following repositioning if required) was 6.17°.

CONCLUSION

Sulcoflex Toric supplementary IOLs result in good visual and refractive outcomes in eyes with no prior corneal graft. However, outcomes are sub-optimal in eyes with prior corneal transplantation, and the majority of lenses require repositioning.

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.

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.

Supplementary IOLs: Monofocal and Multifocal, Their Applications and Limitations

Supplemental intraocular lenses (IOLs) have been developed to replace IOLs designed for in-the-bag placement being used as "piggy-back" IOLs in the sulcus due to unacceptable complications. The new IOLs have unique platform designs to avoid these complications. As a result, a new nomenclature is needed to describe the 4 scenarios when supplemental IOL use is now indicated.

Pseudophakic ametropia management with toric implantable collamer lens with a central hole (case report)

BACKGROUND

To report the clinical outcomes of correcting pseudophakic ametropia using toric implantable collamer lens with a 360 um central hole (TICL V4c).

CASE PRESENTATION

The right eye of a 22-year-old male patient developed high myopia after unilateral phacoemulsification and intraocular lens (IOL) implantation following traumatic cataract 16 years ago. The manifest refraction was -11.50 DS/-2.50 DC × 175 with an uncorrected distance visual acuity (UDVA) of 20/2000 and a corrected distance visual acuity (CDVA) of 20/20. The manifest refraction of left eye was -6.25 DS/-3.75 DC × 180 with UDVA 20/200 and CDVA 20/20. Both eyes were implanted posterior chamber TICL V4c lens. Postoperatively, the refractive errors were +1.00 DS/-0.50 DC × 50 with UDVA 20/16 and CDVA 20/16 in the right eye and +0.75 DS/-0.75 DC × 45 with UDVA 20/16 and CDVA 20/13 in the left eye, respectively. No complications were observed.

CONCLUSIONS

TICL V4c is safe, effective and predictable in managing pseudophakic ametropia.

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.

Clinical results with a supplementary toric intraocular lens for the correction of astigmatism in pseudophakic patients

PURPOSE

To evaluate the visual outcomes of pseudophakic patients who underwent supplementary toric intraocular lens (IOL) implantation to correct astigmatic refractive errors.

METHODS

Pseudophakic patients referred for the implantation of a supplementary toric IOL (Sulcoflex Toric 653T) were evaluated. Uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively), spherical equivalent (SE) refraction, rotational stability, higher order aberrations (HOA), and photopic glare and no-glare contrast sensitivity (CSV-1000, VectorVision) were evaluated.

RESULTS

A total of 10 eyes of 10 patients were included. The mean age was 56.42 ± 5.9 years (range 45-65 years). Mean follow-up was 6.99 ± 5.1 months (6-18 months). Postoperatively, UDVA improved to 0.10 ± 0.12 (0.3 to -0.1) (p = 0.004) and CDVA to 0.07 ± 0.12 (0.3 to -0.1) (p = 0.021). Mean SE was -0.30 ± 0.56 D (-1.00 to +0.75) (p = 0.001). Mean toric IOL axis rotation at 6-month follow-up was 3.0° ± 2.45° (0-6). Ocular aberrometry values decreased after surgery (for average HOA root mean square, p = 0.008). Photopic contrast sensitivity (for all spatial frequencies) showed a trend for improvement after surgery; however, this was not borne out from the analysis (p&gt;0.05).

CONCLUSIONS

The implantation of the Sulcoflex Toric IOL to correct astigmatism in pseudophakic patients provided excellent visual outcomes, predictability of refractive results, rotational stability, and optical performance. The implantation of this IOL is a safe and effective technique to correct pseudophakic cylindrical refractive errors and reduce spectacle dependence in these patients.

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.

Outcomes of small aperture corneal inlay implantation in patients with pseudophakia

PURPOSE

To evaluate the improvement in near visual acuity after KAMRA corneal inlay (AcuFocus, Inc., Irvine, CA) implantation in patients with pseudophakia.

METHODS

A retrospective study analysis of patients with pseudophakia undergoing monocular corneal inlay implantation in the non-dominant eye was performed. The inlay was implanted monocularly in the non-dominant eye of patients. Manifest refractive spherical equivalent, uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, and corrected near visual acuity were evaluated. The follow-up period was 3 months.

RESULTS

Thirteen eyes from 13 patients were evaluated. Four patients underwent LASIK for improved distance acuity at the time of inlay implantation. Mean uncorrected near visual acuity improved five lines (from J10 to J4) postoperatively. Mean uncorrected distance visual acuity, corrected distance visual acuity, and corrected near visual acuity remained stable and were 20/20, 20/16, and J1, respectively, before and after KAMRA implantation. Three eyes lost two lines and 1 eye lost one line of uncorrected distance visual acuity. Two eyes lost two lines and 1 eye lost 1 line of corrected distance visual acuity. Mean manifest refractive spherical equivalent changed before and after KAMRA implantation from -0.01 ± 1.07 diopters (D) (range: 2.25 to -1.88 D) to -1.12 ± 0.87 D (range: 0.25 to -2.75 D), respectively.

CONCLUSIONS

Implantation of a small aperture corneal inlay improved uncorrected near visual acuity while maintaining uncorrected and corrected distance visual acuity in monofocal patients with pseudophakia.

Intraocular lens confusions: a preventable "never event" - The Royal Victorian Eye and Ear Hospital protocol

Intraocular lens (IOL) confusions and errors are among the most common postoperative adverse events. Errors may occur at any stage from the decision to operate to the insertion of the IOL. The most common errors occur during IOL selection pre-operative preparation (anaesthesia given before recognition that the intended IOL is not available), or intraoperatively (wrong IOL implanted because of confusion in the operating room). We review the mechanisms of errors reported in the literature and describe the experience at The Royal Victorian Eye and Ear Hospital. We also describe the implementation of an error-detection protocol and provide qualitative data on its performance.

Internal spherical aberration by ray tracing-type aberrometry in multifocal pseudophakic eyes

PURPOSE

To demonstrate the results of the ray tracing-type aberrometer in measuring spherical aberration (SA) in pseudophakic eyes with monofocal intraocular lens (IOL), aspheric monofocal IOL, or aspheric diffractive multifocal IOL.

METHODS

Total, corneal, and internal SA were measured using iTrace at a 6-mm pupil size in 27 eyes of 27 patients implanted with a monofocal spherical IOL (group 1: Natural, SN60AT), 30 eyes of 30 patients implanted with a monofocal aspheric IOL (group 2: IQ, SN60WF), and 30 eyes of 30 patients implanted with a multifocal aspheric IOL (group 3: ReSTOR, SN6AD1) at 3 months after cataract surgery. We compared the internal SAs of these IOLs in pupil sizes of 3, 4, 5, and 6 mm.

RESULTS

There were no demographic statistically significant differences among the groups. The internal SA of group 1 had a positive value. The internal SA of group 2 was -0.175 ± 0.135 μm in 5-mm pupils and -0.227 ± 0.253 μm in 6-mm pupils. The internal SA of group 3 was -0.072 ± 0.128 μm in 5-mm pupils and -0.173 ± 0.231 μm in 6-mm pupils.

CONCLUSION

Measuring internal SA with iTrace yields relatively accurate results in all types of IOLs with adequate pupil sizes.

[Refractive precision and objective quality of vision after toric lens implantation in cataract surgery]

PURPOSE

To study efficacy and predictability of toric IOL implantation for correction of preoperative corneal astigmatism by analysing spherocylindrical refractive precision and objective quality of vision.

PATIENTS AND METHODS

Prospective study of 13 eyes undergoing micro-incisional cataract surgery through a 1.8mm corneal incision with toric IOL implantation (Lentis L313T(®), Oculentis) to treat over one D of preoperative corneal astigmatism. Preoperative evaluation included keratometry, subjective refraction, and total and corneal aberrometry (KR-1(®), Topcon). Six months postoperatively, measurements included slit lamp photography, documenting IOL rotation, tilt or decentration, uncorrected visual acuity, best-corrected visual acuity and objective quality of vision measurement (OQAS(®) Visiometrics, Spain).

RESULTS

Postoperatively, mean uncorrected distance visual acuity was 8.33/10 ± 1.91 (0.09 ± 0.11 LogMar). Mean postoperative refractive sphere was 0.13 ± 0.73 diopters. Mean refractive astigmatism was -0.66 ± 0.56 diopters with corneal astigmatism of 2.17 ± 0.68 diopters. Mean IOL rotation was 4.4° ± 3.6° (range 0° to 10°).

DISCUSSION

Mean rotation of this IOL at 6 months was less than 5°, demonstrating stability of the optic within the capsular bag. Objective quality of vision measurements were consistent with subjective uncorrected visual acuity.

CONCLUSION

Implantation of the L313T(®) IOL is safe and effective for correction of corneal astigmatism in 1.8mm micro-incisional cataract surgery.

The use of a supplemental sulcus fixated IOL (HumanOptics Add-On IOL) to correct pseudophakic refractive errors

Purpose.

To evaluate the safety and efficacy of piggybacking with the HumanOptics Add-On intraocular lens (IOL) to correct pseudophakic refractive errors.

Materials and Methods.

Ten eyes of 10 patients with pseudophakic refractive errors were included in this study. All patients were targeted for a range of refraction −0.50 to +0.50 D. Uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively), endothelial cell count (ECC), anterior chamber depth (ACD), the distance between intraocular lenses, and contrast sensitivity measurements under mesopic, scotopic, and scotopic with glare conditions were evaluated preoperatively and postoperatively.

Results.

The mean age of the patients was 54±27 years (range 4-78). Mean follow-up time was 10.5±1.36 months (range 6-15 months). Mean diopters of implanted Add-On IOLs were −1.4±6.9 (range −12 to +9 D). Mean preoperative and postoperative UDVA was 0.133±0.12 and 0.73±0.27, respectively (p=0.0001); mean preoperative and postoperative CDVA were 0.77±0.26 and 0.79±0.27, respectively (p=0.066). Mean preoperative and postoperative ACD were 3.87±0.91 mm vs 3.58±1.05 mm, respectively (p=0.343); mean inter-IOL distance was 0.53±0.08 mm. Mean preoperative and postoperative ECC were 2455±302 and 2426±294, respectively (p=0.55). All patients were within the targeted refractive range of −0.50 D to +0.50 D. No complications were observed during the operations or postoperative follow-up period.

Conclusions

Piggybacking with the Add-On IOL is a safe, efficient, and reliable technique to correct pseudophakic refractive errors.

[Post-operative residual astigmatism after cataract surgery: Current surgical methods of treatment]

Residual astigmatism after cataract surgery can be corrected by three different techniques: classic limbal relaxing incisions, easy to perform but with limited precision; laser refractive surgery (PRK or Lasik), additionally allowing for correction of spherical equivalent; and more recently the use of a piggyback toric intraocular lens in the ciliary sulcus.

Clinical outcomes of photoastigmatic refractive keratectomy for the correction of residual refractive errors following cataract surgery

PURPOSE

To assess the clinical outcomes of photoastigmatic refractive keratectomy (PARK) for the correction of residual refractive errors after cataract surgery.

METHODS

This study evaluated 88 eyes of 66 consecutive patients with mean spherical equivalent refraction of -3.16±1.71 diopters (D) who underwent PARK to correct refractive errors after phacoemulsification with intraocular lens (IOL) implantation. Patient age at the time of surgery was 65.2±12.7 years. Safety, efficacy, predictability, stability, and adverse events of the surgery were assessed 1, 3, 6, and 12 months postoperatively.

RESULTS

At 1 year postoperatively, uncorrected distance visual acuity and corrected distance visual acuity were 0.08±0.16 logMAR (Snellen 20/25) and -0.08±0.11 logMAR (Snellen 20/16), respectively. Safety and efficacy indices were 1.08±0.25 and 0.76±0.28, respectively. At 1 year, 68% of eyes were within ±0.50 D and 88% were within ±1.00 D of targeted correction. Manifest refraction changes of -0.06±1.06 D occurred from 1 week to 1 year. No vision-threatening complications occurred during the observation period.

CONCLUSIONS

Photoastigmatic refractive keratectomy is safe and moderately effective in the correction of residual refractive errors in pseudophakic eyes, suggesting its viability as a surgical option for the treatment of such eyes.

Correction of residual refractive error in pseudophakic eyes with the use of a secondary piggyback toricImplantable Collamer Lens

PURPOSE

To evaluate the feasibility of piggyback insertion with a toric Implantable Collamer Lens (ICL, STAAR Surgical).

METHODS

This study investigated eight pseudophakic eyes of five patients who underwent piggyback insertion of a toric ICL to correct residual refractive error. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refractive sphere and astigmatism were measured before and 6 months after surgery.

RESULTS

Pre- and 6-month postoperative logMAR UDVA were 0.759±0.430 and 0.201±0.458, respectively. All eyes were corrected within ±0.50 diopters (D) of intended spherical equivalent refraction. The manifest refractive astigmatism was within ±0.50 D in five (62.5%) eyes and ±1.00 D in seven (87.5%) eyes. No eyes lost more than one line of CDVA. Pupillary block occurred in one eye on postoperative day 1.

CONCLUSIONS

Piggyback insertion of a toric ICL appears to be effective and predictable in correcting refractive error in pseudophakic eyes.

Wavefront-guided photorefractive keratectomy to correct ametropia following aspheric ReSTOR implantation

PURPOSE

To describe the clinical course of three eyes of two patients who underwent wavefront-guided photorefractive keratectomy to correct ametropia following cataract extraction and aspheric ReSTOR lens (SN6AD3; +4.00-diopter model) implantation.

METHODS

Pre-and postoperative uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA), manifest refraction, and WaveScans based on the Hartmann-Shack analyzer were evaluated. The VISX STAR S4 excimer with eye tracking and iris registration was used in all cases.

RESULTS

Good quality WaveScans were obtained; UCVA improved in all cases and BSCVA improved or remained unchanged.

CONCLUSIONS

These cases demonstrate that it is possible to obtain good quality wavefront data in patients with the ReSTOR lens and to use such data to design wavefront-guided treatment to maximize uncorrected distance and near visual acuities after ReSTOR implantation.

Comparison of intraocular lens power calculation by the IOLMaster in phakic and eyes with hydrophobic acrylic lenses

PURPOSE

To compare the optical biometry measurements and intraocular lens (IOL) power estimation using the IOLMaster (Carl Zeiss Meditec, Dublin, CA) in phakic eyes and eyes with hydrophobic acrylic lenses.

DESIGN

Observational cross-sectional study.

PARTICIPANTS

A total of 156 patients (226 eyes).

METHODS

The IOLMaster measurements (IOLM-1) were performed before phacoemulsification and reexamined 3 months postoperatively (IOLM-2). One of the foldable acrylic IOLs (AcrySof SA60AT, SN60WF, or SN60D3, Alcon Laboratories Inc., Dallas, TX) was implanted.

MAIN OUTCOME MEASURES

The expected refraction and estimation error calculated from IOLM-1 using the SRK II, SRK/T, and Haigis formulae were compared with the residual refraction 3 months postoperatively. The power of the implanted IOL and IOLM-2 measurement data were used to re-estimate the postoperative expected refraction in pseudophakic eyes. The difference in expected refraction and estimation error between phakic and pseudophakic eyes was studied. Differences in the anterior chamber depth and axial length measured by IOLM-1 and IOLM-2 were analyzed and correlated with the estimation error.

RESULTS

The IOLMaster measured an axial length 0.10+/-0.15 mm shorter in pseudophakic eyes (P<0.001). Calculations from IOLM-2 gave a significantly more hyperopic expected refraction than IOLM-1, with an averaged 0.20+/-0.46 diopters (D), 0.18+/-0.45 D, and 0.65+/-0.59 D calculated by the SRK II, SRK/T, and Haigis formulae, respectively. There was no significant difference among the 3 IOLs. The difference in estimation error correlated with the difference in axial length and anterior chamber depth (P<0.001 for the SRK II, SRK/T, and Haigis formulae). However, the correlation was strongest when the Haigis formula was used for the calculation.

CONCLUSIONS

The expected refraction in pseudophakic eyes differed significantly from that in phakic eyes by the IOLMaster depending on the IOL formulae used for the calculation rather than the type of IOL. An adjustment of target refraction by 0.20 to 0.65 D toward the hyperopic side of the desired refraction could be considered when using optical biometry data in pseudophakic eyes to achieve postoperative emmetropia.