Phakic intraocular lens: Two-year results and comparison of endothelial cell loss with iris-fixated intraocular lenses

Long-term safety and efficacy of a foldable iris-fixated phakic intraocular lens for the correction of myopia

PURPOSE

To analyze and report the long-term outcomes in terms of efficacy and safety of eyes implanted with the spherical version of a foldable iris-fixated phakic intraocular lens (pIOL) for the correction of myopia.

METHODS

Retrospective analysis of the results of 56 eyes of 32 patients (age, 19-45 years) who underwent implantation of the spherical model of the Artiflex pIOL (Ophtec B.V., Groningen, The Netherlands) for the correction of myopia. Visual, refractive, biometric, intraocular pressure (IOP) and corneal endothelial changes were evaluated during a long-term follow-up: 2, 7, 10 and 12 years for more than 50, 30, 20 and 10 eyes, respectively.

RESULTS

At 4 weeks postoperatively, a significant reduction of manifest sphere and spherical equivalent (SE), with a significant improvement of uncorrected distance visual acuity were found (all p < 0.001). No significant changes were found during the rest of follow-up in sphere (p ≥ 0.072). The percentage of eyes with SE within ± 1.00 D was over 83% during the whole follow-up. A non-significant trend to IOP increase was observed at 4 weeks postoperatively (p = 0.530), with a significant reduction at 1 year after (p = 0.039) and no significant changes during the rest of follow-up (p = 0.180). There was a significant reduction of anterior chamber depth at 4 weeks after surgery (p < 0.001), with no significant changes during the following 9 years of follow-up (p = 0.118). However, an additional significant decrease of this parameter was observed between 10 and 13 years after surgery (p = 0.027). Mean endothelial cell loss changed from 2.01 ± 4.49% at 4 weeks after surgery to 9.11 ± 2.24% at the end of the follow-up. No complications were reported during the follow-up.

CONCLUSIONS

Myopia correction with the Artiflex pIOL is an effective and safe procedure in the long term.

Long-Term Follow-Up of Corneal Endothelial Cell Changes After Iris-Fixated Phakic Intraocular Lens Explantation

PURPOSE

The purpose of this study was to evaluate long-term corneal endothelial cell changes and visual outcomes after iris-fixated phakic intraocular lens (pIOL) explantation in patients with endothelial damage and to investigate potential predictors of endothelial injury.

METHODS

Consecutive patients undergoing pIOL explantation with corneal endothelial cell density (ECD) <2000 cells/mm 2 at the time of the procedure were retrospectively reviewed in a single tertiary center. All patients were treated between April 2016 and October 2020 at a high-volume referral-based tertiary hospital. The primary outcome was the change in corneal endothelial parameters, including ECD, over long-term follow-up. Secondary outcomes included changes in corrected distance visual acuity and analysis of prognostic factors.

RESULTS

This study included 44 eyes from 28 patients with an average age of 42.5 ± 7.8 years (range: 27-63). Mean ECD before explantation was 1375.4 ± 468.2 cells/mm 2 (range: 622-1996), and the average duration of follow-up after explantation was 20.5 months (6-58.2). Two years after explantation, ECD had significantly decreased by more than 25% to 1019.6 ± 368.6 (608-1689; P < 0.01). However, there was no significant change in corrected distance visual acuity (20/23-20/22, P = 0.59). Longer operation duration (odds ratio, 1.004; P = 0.04) was the only significant factor weakly associated with postoperative decreases in ECD.

CONCLUSIONS

Although ECD continuously decreased despite pIOL explantation on a long-term follow-up, patients did not experience any discomfort or showed decreases in visual acuity. Therefore, a careful follow-up is required for possible endothelial injury after pIOL explantation.

Long-term efficacy and safety results after iris-fixated foldable phakic intraocular lens for myopia and astigmatism: 6-year follow-up

PURPOSE

To evaluate the long-term efficacy and safety of iris-fixated foldable phakic intraocular lenses (pIOLs) for the management of myopia and astigmatism after 6-year follow-up.

SETTING

Ophthalmology Department, Hospital Braga, Portugal.

DESIGN

Retrospective cohort study.

METHODS

Patients included underwent iris-fixated foldable Artiflex pIOL implantation between January 2010 and December 2013. Follow-up evaluations were performed 6 months postoperatively and every 12 months until 72 months. Preoperative and follow-up data on uncorrected and corrected distance visual acuity (CDVA), manifest refraction, endothelial cell density (ECD), and anterior chamber depth (ACD) were analyzed.

RESULTS

A total of 177 eyes of 98 patients with a mean age of 32.33 ± 7.13 years were analyzed. There was a statistically significant improvement in CDVA from 0.09 ± 0.02 logMAR preoperatively to 0.04 ± 0.02 logMAR (P < .0001) at 6 years postoperatively. The spherical equivalent demonstrated a statistically significant improvement from -9.50 ± 2.93 diopters (D) to -0.41 ± 0.45 D at 6 years. At 72 months, the efficacy and safety indexes were 0.94 and 1.15, respectively. A mean loss of 31.77 cells/mm2 (1.19%) was observed each year until the sixth year. The overall mean ECD loss after correction for the physiological loss was 3.02% after 6 years. No correlations were observed between the mean ECD loss and the preoperative ACD.

CONCLUSIONS

The Artiflex pIOL was a safe, effective, and a stable option to correct myopia. A mean ECD loss of 3.02% was observed over 6 years. No pIOL was explanted due to corneal decompensation.

Artisan versus Artiflex phakic intraocular lens implantation in the treatment of moderate to high myopia: meta-analysis

Background

To compare the postoperative safety, efficacy, predictability, visual quality and biomechanics after implantation of Artisan vs. Artiflex phakic intraocular lenses (PIOLs).

Methods

Pubmed, Embase, Cochrane Library were conducted up from January 2000 to February 2020. Comparative clinical studies reporting in accordance with the eligibility criteria were included in this meta-analysis. The pooled weighted mean differences (WMDs) and odds ratios (ORs) with corresponding 95% confidence intervals were calculated.

Results

Comparative trials with myopia patients were selected in this review. The pooled WMD and OR estimates statistical significance in terms of postoperative best corrected visual acuity (BCVA), efficacy, postoperative spherical equivalence (SE), predictability, contrast sensitivity and mean intraocular higher-order aberrations (HOA) (mm) for a 6-mm pupil, manifesting that Artiflex PIOL showed evident beneficial effect for correcting myopia compared to Artisan PIOL. There was no significant difference in the incidence of complications between the two groups.

Conclusion

Both of two techniques were safe and effective for myopia and compared to Artisan PIOL, Artiflex PIOL had significant improvement in efficacy, predictability, contrast sensitivityand HOA, except safety and complications in the treatment of moderate to high myopia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01930-6.

Reasons for explantation of phakic intraocular lenses and associated perioperative complications: cross-sectional explant registry analysis

Background

We discuss the safety, since their introduction, of phakic intraocular lenses (pIOLs) to correct refractive errors in healthy eyes. We investigated the reasons for pIOL explantation and the associated perioperative complications.

Methods

This retrospective, cross-sectional study included 69 pIOLs, explanted at a single tertiary center between July 2005 and March 2020: 34 angle-supported (G1), 28 iris-fixated (G2) and seven posterior chamber (G3) pIOLs. Case data including the reason for explantation was taken from the patient records. Intra- and postoperative complications were evaluated for an association with the pIOL.

Results

The mean duration in the eye was 10.4 (0.2–28) years. Cataractogenesis and subsequent surgery that required pIOL explantation was the reason in 42% of all cases. In 22%, cataract in combination with endothelial damage prompted explantation, with 26, 18 and 14% for G1, G2 and G3 respectively. The second most common reasons were corneal damage alone in the angle-supported group (26%), IOL subluxation in the iris-fixated group (18%), and photopic disturbance in the posterior chamber group (29%). In 68% of all explantations, the surgical course was unremarkable, while in the remaining cases perioperative complications were associated with the lens in 45.7%.

Conclusion

Overall, the need for cataract surgery was the most common reason for pIOL explantation. Corneal complications were more frequent in the angle-supported pIOLs and their removal was associated with higher rates of complication compared to the other groups.

Middle- and long-term results after iris-fixated phakic intraocular lens implantation in myopic and hyperopic patients: a meta-analysis

The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects. The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects of iris-fixated pIOLs on myopic and hyperopic eyes with a follow-up of at least 2 to 4 years. Visual and refractive results after implantation for correction of myopia are positive and the complication rate is low. Endothelial cell loss appears to be at an acceptable rate, although the range of endothelial cell change is too wide to draw firm conclusions. Care should be taken when considering an iris-fixated pIOL for hyperopic eyes because complication rates, particularly pigment dispersion, might be higher than those in myopic eyes. More well-designed, long-term studies are needed, especially in hyperopic eyes. The authors advocate for standardized reporting of refractive surgery data. Initiatives proposed by journal authors and editors to achieve uniformity should be supported.

Phakic intraocular lenses: An overview

Phakic intraocular lenses (pIOLs) are a common solution for the surgical correction of high myopia and myopia in thin corneas. Global trends result in increasing rates of patients with high myopia which will result in increased rates of pIOL implantation. Three types of lenses can be distinguished: anterior chamber angle-supported, anterior chamber iris-fixated, and posterior chamber phakic IOLs. The efficacy of phakic intraocular lenses is generally very good, but pIOLs have undergone many changes over the years to improve the safety profile and decrease pIOL-related complications such as endothelial cell loss, corneal decompensation and cataract formation. This article describes the efficacy and safety profiles of the most recent pIOLs, as well as suggests gaps of knowledge that are deserve additional research to optimize the results of pIOLs.

Explantation of phakic intraocular lenses: causes and outcomes

PURPOSE

To describe reasons for explantation of anterior and posterior chamber phakic intraocular lenses (pIOLs), as well as outcomes of the surgery.

METHODS

The medical files of patients who underwent pIOL explantation due to complications were reviewed. All patients were divided into three groups based on the type of explanted pIOL: anterior chamber angle-supported (AS pIOL), anterior chamber iris-fixated (IF pIOL), and posterior chamber (PC pIOL).

RESULTS

Sixty-two eyes of 41 patients were evaluated. There were 26 (41.9%), 16 (25.8%), and 20 (32.2%) eyes in the AS pIOL, IF pIOL, and PC pIOL groups, respectively. The mean interval between the implantation and removal of the pIOL (i.e., survival time) was 13.6 ± 8.1 years (range 0.01-21.22 years). The mean follow-up after the explantation was 22.5 ± 4.0 months (range 11.3-28.7 months). The main causes of explantation were cataract in the PC pIOL group (60%) and chronic endothelial cell loss in the AS pIOL group (53.8%) and IF pIOL group (56.2%). Overall, the procedure most often combined with pIOL explantation was phacoemulsification and implantation of a posterior chamber IOL (40.3%), followed by keratoplasty (9.6%). Intraoperative complications were significantly more common in the AS pIOL group than the other groups (p < 0.001).

CONCLUSIONS

Explantation of anterior chamber pIOLs due to severe endothelial cell loss and the proportion of keratoplasty was more common in patients with a relatively long survival time. Therefore, patients with pIOL implantation should be monitored regularly after surgery.

Artiflex foldable lens for myopia correction results of 10 years of follow-up

PURPOSE

The aim of this study was to evaluate the long-term efficacy and safety of the Artiflex® lens implant and to follow the evolution of the number of corneal endothelial cells over time.

DESIGN

It was a retrospective study of an observational case series of patients who underwent surgery at "The INVISION Ophthalmic Hospital" (Almería, Spain) in 2007 and who were followed for 10 years.

METHODS

Setting: Clinical practice. Study population included 53 eyes of 30 patients who underwent an Artiflex® lens implant for the correction of myopia from -4 to -14 D. Each patient included in this study had stable myopia for at least 2 years and a contraindication for corneal refractive surgery. The efficacy index was defined as the quotient between uncorrected distance visual acuity postoperative and best-corrected distance visual acuity (BCDVA) preoperative. The safety index was calculated as the quotient between BCDVA postop and BCDVA preop.

RESULTS

The average efficacy and safety indices of the lenses implanted were 1.1 (SD 0.30) and 1.06 (SD 0.2) at 10 years of follow-up. In this period of time there has been a loss of 12% of the corneal endothelial cells. The postoperative complications were pigment dispersion in four eyes (7%) of four patients and decentration of phakic intraocular lens in two eyes (4%) of another two patients.

CONCLUSIONS

The Artiflex® foldable phakic lens could be a safe and effective long-term alternative for myopic patients in whom laser surgery was contraindicated.

Five-Year Endothelial Cell Loss After Implantation With Artiflex Myopia and Artiflex Toric Phakic Intraocular Lenses

PURPOSE

To evaluate the long-term changes in endothelial cell density (ECD) after the implantation of 2 types of foldable iris-fixated phakic intraocular lenses (pIOLs) for the treatment of myopia and astigmatism.

DESIGN

Prospective clinical cohort study.

METHODS

Two-hundred and ninety-three and 188 eyes implanted with, respectively, the Artiflex Myopia and Artiflex Toric (Ophtec B.V., Groningen, The Netherlands) iris-fixated pIOL for the treatment of myopia or astigmatism at the University Eye Clinic Maastricht as of January 2004. One-hundred and forty-six eyes from the myopic and 64 eyes from the toric groups completed a 5-year follow-up. Main outcome measures were chronic endothelial cell (EC) loss, percentage of eyes with a ≥25% decrease in ECD, and the percentage of eyes with an ECD < 1500 cells/mm².

RESULTS

Chronic EC loss showed an annual decline of 64 cells/mm² in the myopic (P < .001, standard error 3.58) and 62 cells/mm² in the toric (P < .001, standard error 3.77) groups. Total chronic EC loss from 6 months to 5 years postoperatively was 10.5% in the myopic and 10.2% in the toric groups. After 5 years, an ECD decrease of ≥25% occurred in 4.4% and 4.3% of eyes, and an ECD < 1500 cells/mm² was reported in 3.0% and 0.0% of eyes, respectively. Explantation of a pIOL owing to EC loss was required in 3.1% and 0% of eyes.

CONCLUSION

Chronic EC loss was around 10% over a 5-year period in eyes implanted with the foldable myopic (toric) pIOL. In up to 3.1% of eyes significant EC loss resulted in subsequent pIOL explantation.

Complications and outcomes of descemet stripping automated endothelial keratoplasty with artisan aphakia intraocular lens implantation

AIM

To evaluate the complications and outcomes of descemet stripping automated endothelial keratoplasty (DSAEK) combined with artisan aphakia intraocular lens (IOL) implantation in severely damaged eyes without capsular support.

METHODS

DSAEK combined with artisan iris claw IOL implantation was performed on 29 eyes. All eyes were of abnormal structure due to complications from prior intraocular surgeries and ocular trauma. Ocular complications observed included graft dislocations, high intraocular pressure (IOP), IOL dislocations, macular edema and hyphema. Best corrected visual acuity (BCVA), IOP and mean central endothelial cell density (ECD) were recorded.

RESULTS

Thirteen eyes had a history of ocular trauma, 10 eyes had an anterior chamber IOL, 16 eyes had prior vitrectomy. The iris was abnormal in 22 cases. Graft dislocation occurred in 5 (17.2%) of 29 eyes. IOL dislocation occurred in 2 eyes (6.9%). High IOP was found in 9 eyes and was controlled with treatment. The preoperative mean BCVA was 20/286. The 6mo postoperative mean BCVA was 20/42. The average center ECD was 1965.3 cells/mm² at 6mo, and the rate of the donor cell loss was 34.7%.

CONCLUSION

DSAEK combined with artisan aphakia IOL implantation is an alternative option for resolving endothelial and lens disorders in aphakic eyes without capsular support. However, it should be performed cautiously for eyes with severe iris defects.

Visual acuity, endothelial cell density and polymegathism after iris-fixated lens implantation

PURPOSE

The purpose of this study was to evaluate the visual acuity as well as endothelial cell density (ECD) and polymegathism after iris-fixated lens (Artiflex® AC 401) implantation for correction of moderate to high myopia.

PATIENTS AND METHODS

In this retrospective cross-sectional study, 55 eyes from 29 patients undergoing iris-fixated lens implantation for correction of myopia (-5.00 to -15.00 D) from 2007 to 2014 were evaluated. Uncorrected visual acuity, best spectacle-corrected visual acuity, refraction, ECD and polymegathism (coefficient of variation [CV] in the sizes of endothelial cells) were measured preoperatively and 6 months postoperatively.

RESULTS

In the sixth month of follow-up, the uncorrected vision acuity was 20/25 or better in 81.5% of the eyes. The best-corrected visual acuity was 20/30 or better in 96.3% of the eyes, and more than 92% of the eyes had a refraction score of ±1 D from the target refraction. The mean corneal ECD of patients before surgery was 2,803±339 cells/mm2, which changed to 2,744±369 cells/mm2 six months after surgery (p=0.142). CV in the sizes of endothelial cells before the surgery was 25.7%±7.1% and six months after surgery it was 25.9%±5.4% (p=0.857).

CONCLUSION

Artiflex iris-fixated lens implantation is a suitable and predictable method for correction of moderate to high myopia. There was no statistically significant change in ECD and polymegathism (CV in the sizes of endothelial cells) after 6 months of follow-up.