Special Report: American Academy of Ophthalmology Task Force Recommendations for Specular Microscopy for Phakic Intraocular Lenses

Comparison of the Biometric Characteristics After Long-term Implantation of Iris-fixated Phakic Intraocular Lens in Explanted and Nonexplanted Groups of Eyes

PURPOSE

To evaluate and compare the biometric characteristics of the anterior chamber of a group of patients with significant endothelial cell loss (ECL) who required phakic intraocular lens (pIOL) explantation and a group of patients who did not fulfill the explantation criteria related to corneal decompensation.

DESIGN

Retrospective, consecutive, interventional case series.

METHODS

The study included all consecutive patients receiving a pIOL implantation at Oftalmosalud Instituto de Ojos, Lima, Peru, between 2001 and 2012. The explanted group (E group) consisted of eyes in which the pIOLs were explanted due to ECL, and the nonexplanted group (NE group) consisted of eyes randomly selected in which the pIOL was not explanted with a minimum follow-up time of 8 years. Slit-lamp biomicroscopy, visual acuity, refraction, endothelial cell count, and anterior segment optical coherence tomography were assessed at the preoperative evaluation for both groups and before explantation in the E group and 8 years post-implantation in the NE group.

RESULTS

pIOLs were implanted in 265 eyes. The annual percentage of ECL was 1.47% and 5.55% in the NE group and E group, respectively (P < .001). The mean minimum endothelial lens distance (ELD) was 1.44 ± 0.22 mm and 1.05 ± 0.23 mm in the NE group and E group, respectively (P < 0.001). The mean time for explantation was 12.58 ± 3.79 years for the E group. Annual ECL could accurately discriminate between the NE group and E group; a cutoff point of 3.5 (%/year) or 86.5 (cells/years) had a 100% sensitivity and specificity. A cutoff of 1.21 mm in the minimum ELD has a 91% sensitivity and 79% specificity to discriminate between the E group and NE group.

CONCLUSIONS

pIOL explantation due to ECL occurs in eyes with a significantly postoperative lower minimum ELD. Annual ECL and minimum ELC can effectively discriminate between the E and NE groups.

Endothelial Cell Loss in Patients with Phakic Intraocular Lenses

Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.

Spherical aberrations and their role in modern ophthalmology

Spherical aberration is an imperfection of the optical system of the human eye. The role of spherical aberration of the human eye in the quality of vision and pseudoaccommodation is reviewed. Spherical aberration is an imperfection of the optical system of the human eye. In most cases, due to well-developed neuroadaptation, it is insignificant for the perception of the image. Nevertheless, its role in modern ophthalmology is far from straightforward. On the one hand, there are clinical scenarios in which an excess of spherical aberration degrades the retinal image and leads to a high dissatisfaction rate among patients.©Recently, there is a growing interest in the modulation of spherical aberration in the clinical setting. Modern intraocular lenses as well as laser refractive procedures are aimed at interfering with spherical aberrations of the optical system in order to increase range of pseudoaccommodation. Here, we review the role of spherical aberration of the human eye in the quality of vision and pseudoaccommodation.

Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses

Preoperative and postoperative diagnostics play an important role in ensuring the safety of patients with phakic intraocular lenses (pIOLs). The risk of endothelial cell loss can be addressed by regularly measuring the endothelial cell density using specular microscopy and considering the endothelial cell loss rate and the endothelial reserve in accordance with the patient's age when deciding whether to explant a pIOL. The anterior chamber morphometrics, including the anterior chamber depth and the distance between the pIOL and the endothelium, measured using Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), can help to assess the risk of the endothelial cell loss. In patients undergoing posterior chamber pIOL implantation, accurate prediction of the vault and its postoperative measurements using AS-OCT or Scheimpflug tomography are important when assessing the risk of anterior subcapsular cataract and secondary glaucoma. Novel approaches based on ultrasound biomicroscopy and AS-OCT have been proposed to increase the vault prediction accuracy and to identify eyes in which prediction errors are more likely. Careful patient selection and regular postoperative follow-up visits can reduce the complication risk and enable early intervention if a complication occurs.

Depth of focus of four novel extended range of vision intraocular lenses

PURPOSE

To assess the depth of focus of four latest non-diffractive extended range of vision IOLs on the optical bench. Such comparison had not been done before.

METHODS

We assessed and compared the through focus modulation transfer function (MTF) of the following novel IOLs with a nominal power of 22 D: Acrysof Vivity, LuxSmart Crystal, RayOne EMV and Tecnis Eyhance. An ISO-2 model eye was applied with apertures of 3 and 4.5 mm with monochromatic light of 546 nm. Measurements were done on OptiSpheric IOL PRO 2 optical bench.

RESULTS

For the aperture of 3 mm, Eyhance and RayOne EMV showed the most pronounced peak in MTF with only little enlarged depth of power. Vivity and LuxSmart showed two peaks of about 1.7 D respectively 1.3 D depth of focus, yet reduced MTF and with maxima differently located. For 4.5 mm, MTF values for Eyhance and particularly for RayOne EMV dropped. For Vivity and LuxSmart, only the peak for the secondary focus decreased.

CONCLUSION

Vivity and LuxSmart showed a larger depth of focus for our measuring conditions than Eyhance and RayOne EMV. Correspondingly, the peak MTF was best for Eyhance and RayOne ERV with small aperture. With the larger aperture, RayOne EMV considerably lost performance.

Optimising curve fitting techniques to look for standardisation of the analysis of defocus curves derived from multifocal intraocular lenses

Introduction

To establish the most appropriate curve fitting method to allow accurate comparison of defocus curves derived from intraocular lenses (IOLs).

Methods

Defocus curves were plotted in five IOL groups (monofocal, extended depth of focus, refractive bifocal, diffractive bifocal and trifocal). Polynomial curves from 2nd to 11th order and cubic splines were fitted. Goodness of fit (GOF) was assessed using five methods: least squares, coefficient of determination (R²_adj), Akaike information criteria (AIC), visual inspection and Snedecor and Cochran. Additional defocus steps at −2.25 D and −2.75 D were measured and compared to the calculated visual acuity (VA) values. Area under the defocus curve and range of focus were also compared.

Results

Goodness of fit demonstrated variable results, with more lenient methods such as R²_adj leading to overfitting and conservative methods such as AIC resulting in underfitting. Furthermore, conservative methods diminished the inflection points resulting in an underestimation of VA. Polynomial of at least 8th order was required for comparison of area methods, but overfitted the EDoF and monofocal groups; the spline curve was consistent for all IOLs and methods.

Conclusions

This study demonstrates the inherent difficulty of selecting a single polynomial function. The R² method can be used cautiously along with visual inspection to guard against overfitting. Spline curves are suitable for all IOLs, guarding against the issues of overfitting. Therefore, for analysis of the defocus profile of IOLs, the fitting of a spline curves is advocated and should be used wherever possible.

Five-year clinical outcomes of rigid iris-fixated phakic intraocular lens in northern Chinese

PURPOSE

To investigate the 5-year clinic outcomes of rigid iris-fixated pIOL on the visual performance, complications and intraocular light scattering in northern Chinese.

METHODS

Thirty eyes implanted with iris-fixated phakic IOLs (pIOLs group) and 34 eyes with high myopia (myopia group) were involved in this study. At preoperatively, 6 months, 1, 3, and 5 years postoperatively, the uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), endothelial cell density (ECD), and intraocular pressure (IOP) were measured in pIOLs group. The objective scatter index (OSI), modulation transfer function cut off (MTF cut off), and Strehl ratio were measured by Optical Quality Analysis System and a pseudophakic dysphotopsia questionnaire (PDQ) was used to evaluate the subjects' satisfaction in pIOLs and myopia groups.

RESULTS

At 5 years postoperatively, an UCVA of 20/20 or better was found in 43.33% of eyes in pIOLs group. At 6 months, 1, 3, and 5 years postoperatively, the mean ECD decrease were 1.29% ± 0.45%, 2.59% ± 1.30%, 6.67% ± 2.26%, and 10.80% ± 3.48%. The value of OSI in pIOLs group was significantly higher than that in myopia group (P < 0.001). The PDQ results showed that the subjects in myopia group complained less with intolerance of bright lights than those in pIOLs group. The values of Strehl ratio and MTF cut off in pIOLs group were significantly lower than that in myopia group (P < 0.001).

CONCLUSIONS

Iris-fixated pIOL induce more intraocular light scattering. A significant decrease in ECD was observed at 5 years postoperatively. An annual evaluation of ECD is necessary for patients undergoing pIOL implantation.

Five Years Follow-Up of Acrysof Cachet® Angle-Supported Phakic Intraocular Lens Implantation for Myopia Correction

Purpose

The Acrysof Cachet® angle-supported phakic intraocular lens (pIOL) (Alcon Laboratories, Inc., Fort Worth, TX) is designed to correct high refractive errors in human eyes. The aim of this study was to evaluate the outcome of AcrySof Cachet® angle-supported pIOL implantation with particular regard to efficacy and safety of the implant over a 60-month follow-up period.

Design

Retrospective consecutive clinical case study.

Methods

Prior to pIOL implantation, patients had a complete ophthalmologic examination including objective and subjective refraction, uncorrected visual acuity (UCVA) and corrected distance visual acuity (CDVA), endothelial cells density (ECD), slit lamp photography, optical coherence tomography (OCT), Scheimpflug digital videokeratoscopy, optical biometry, slit lamp examination, intraocular pressure (IOP) measurement, and pupillometry. Postoperatively, patients received yearly a complete eye examination.

Results

Thirty-one eyes of 16 patients were included in this study. The mean age was 36.2 ± 8.1 years. UCVA (logMAR) improved from 1.33 ± 0.20 before surgery to 0.08 ± 0.14 one year after surgery and was 0.20 ± 0.20 five years after surgery. CDVA (logMAR) improved from 0.10 ± 0.10 before surgery to 0.05 ± 0.13 one year after surgery and was 0.04 ± 0.14 five years postoperatively. The mean percentage of endothelial cells loss (ECL) was 11.51% over the first year and 15.95% five years after surgery. There were no intraoperative complications in any of the eyes.

Conclusions

Our results up to five years after implantation of the AcrySof Cachet® angle-supported pIOL demonstrated very good outcomes in all above shown measurements, including CDVA, UCVA, and ECD. However, since major endothelial cell loss may occur in some patients with this type of pIOL, regular follow-up visits are required.

Long-term results in patients with iris-fixated foldable phakic intraocular lens for myopia and astigmatism

PURPOSE

To evaluate the long-term results of iris-fixated foldable phakic intraocular lenses (pIOLs) implantation for the management of myopia and astigmatism.

SETTING

Centro Hospitalar Universitário do Porto, Oporto, Portugal.

DESIGN

Prospective, clinical study.

METHODS

Patients who underwent Artiflex Myopia or Artiflex Toric (Ophtec B.V., Groningen, The Netherlands) iris-fixed pIOLs implantation for the treatment of myopia or astigmatism between 2003 and 2011 were included. Refractive stability, refractive predictability, safety, efficacy, and cumulative probability of success were evaluated at five, 10, and 15 years of follow-up.

RESULTS

Five-, 10- and 15-year follow-ups were completed by 199 of 217 (91.7%), 187 of 217 (86.2%), and 43 of 45 (95.6%) eyes implanted with pIOLs, respectively. The mean spherical equivalent was -8.36±2.75, -0.11±0.31, -0.33±0.62, and -0.80±1.32 dioptres (D) preoperatively and after five, 10 and 15 years after surgery. At 5, 10, and 15 years after surgery, 100%, 95.6%, and 81.6% were within ±1.00D. The safety and efficacy indexes were 1.07 and 1.06 at five, 1.04 and 0.99 at 10, and 1.05 and 1.00 at 15 years of follow-up, respectively. Kaplan-Meier analysis showed survival rates of 97% at five years, 73% at 10 years, and 43% at 15 years of follow-up.

CONCLUSION

Long-term results demonstrate that the implantation of Artiflex pIOLs is a stable, predictable, and effective procedure at five, 10, and 15 years of follow-up. We recommend annual follow-up visits to evaluate endothelium cell density and anterior chamber depth decrease, alerting patients to this need in the preoperative evaluation.

DETERMINATION OF FACTORS ASSOCIATED WITH LONG-TERM ENDOTHELIAL LOSS AND REFRACTIVE RESULT IN PATIENTS WITH ARTISAN PHAKIC LENS

PURPOSE

To determine the changes in endothelial cell density, refractive results, and risk factors associated with endothelial loss in patients with irisclaw phakic intraocular lenses for myopia/myopic astigmatism (Artisan).

METHODOLOGY

Data collection was obtained from an existing database with information on patients with a phakic Artisan lens implant between 1998 and 2011 at the Virgilio Galvis Ophthalmology Centre, with at least 5 years of follow-up. As a second stage, an analysis was carried out to identify the change in endothelial cell density and its potential associated factors.

RESULTS

A total of 80 eyes with myopic errors were included with a follow-up of 11.9 + 3.48 years. The percentage of total loss of endothelial cells was greater than 25% of the preoperative density in 43.8% of the eyes. A postoperative annual loss &gt; 1.6% was found in 47.0% of the eyes with that information available. 41 eyes (51%) had final endothelial density &lt; 2000 cells/mm2, and 7 (8.8%) eyes had endothelial cell density &lt; 1000 cells/mm2. Among the variables studied, no associated factors for long-term endothelial loss were found. During the course of the study, 8 (10%) phakic intraocular lenses were explanted, including 3 with accelerated endothelial loss, and another 2 with cataract associated and a significantly low endothelial density. The last mean spherical equivalent was -0.81 (±1.01 D), and the final uncorrected distance visual acuity was 0.45 logMar (Snellen 20/56).

CONCLUSION

Artisan-type phakic lenses are a good alternative for the correction of high myopic defects, with predictable refractive results in the long term. However, there is an increased loss of endothelial cells in the long term in a high percentage of patients. Strict postoperative follow-up, including endothelial evaluation, is required, and further studies are warranted.

Myopic Correction with Iris-Fixated Phakic Intraocular Lenses: Twelve-Year Results

PURPOSE

To evaluate a 12-year follow-up of myopic patients after iris-fixated phakic intraocular lenses (IF pIOLs) implantation. Setting. Ophthalmology Department, Military University Hospital in Prague (Czech Republic).

DESIGN

Single-center retrospective cohort study.

METHODS

We describe the results of a cohort study that included 85 eyes of 46 myopic patients who underwent implantation of Verisyse myopia, Veriflex, and Verisyse myopia toric (all Abbott Medical Optics, Inc.) intraocular lenses. Refractive functions and adverse events were assessed preoperatively, at 6 months, and 1, 2, 5, and 12 years after IF pIOL implantation.

RESULTS

Mean spherical equivalent was measured as -9.37 ± 2.87 D, 0.14 ± 0.61 D, and -0.42 ± 1.08 D, preoperatively, at 6 months and 12 years postoperatively, respectively. There was a significant reduction in the cylinder after surgery. At 12 years postoperatively, 90% of eyes had uncorrected distance visual acuity (UDVA) of 20/40 and 64% of 20/20. The safety index was 1.10 for the whole postoperative follow-up period. We found cataract formation in 3 eyes (3.5%). The endothelial cells loss (EC loss) directly caused by IF pIOL implantation was 6.0%, 8.10%, 12.8%, and 11.9%, at 1, 2, 5, and 12 years, respectively. In our cohort, 95% of eyes lost a higher percentage of EC than would be expected from a physiological loss at 12 years postoperatively. We found a significant negative interaction between preoperative pachymetry and EC loss, indicating that the lower pachymetry leads to a faster decline in endothelial cells density (ECD). IF pIOL re-enclavation was found in 28% of eyes. 7% of subluxations were caused by trauma. The mean time of nontraumatic re-enclavation was 6 years postoperatively.

CONCLUSIONS

The study confirmed the advantages of IF pIOL implantation due to rapid visual recovery and stable visual function over the 12-year follow-up and also showed the influence of lower corneal pachymetry regarding EC loss.

Analysis of higher order aberrations in recently developed wavefront-shaped IOLs

PURPOSE

A new class of enhanced range of vision intraocular lenses (IOLs) has been introduced recently to cope with compromises of diffractive optics in patients aiming for spectacle independence. Few information is available about their optical function. We aimed to analyze higher order aberrations of four of these new wavefront-shaped IOLs under standardized conditions.

METHODS

Two recently developed enhanced monofocal and two recently developed enhanced depth of focus IOLs (power 22 D) were analyzed by a Shack-Hartmann sensor in an in-situ model eye according to ISO 11,979 in NaCl with 546 nm. We determined the Zernike polynomials up to the 10th order.

RESULTS

Only spherical aberration (SA) of different orders was considerably modified. Whereas RaySof EMV showed a moderate increase in Z 4-0, Eyhance and Vivity produced a considerable increase of negative Z 4-0. A combination of Z 4-0 and Z 6-0 with an opposite sign was found in LuxSmart.

CONCLUSION

SAs of different orders are the only relevant Zernike polynomials in this new class of wavefront-shaped IOLs. RaySof EMV proved to be a monofocal IOL with increased positive SA. The central change in radial power and the resulting increase in negative SA in Eyhance IOL might produce some depth of field. The magnitude of SA modification of Vivity and LuxSmart is expected to extend the depth of focus considerably. Surgeons can select among these novel IOLs depending on corneal asphericity and the patient's wish for spectacle independence.

Eight-year follow-up of Artiflex and Artiflex Toric phakic intraocular lens

PURPOSE

To analyse long-term efficacy, safety, visual and refractive stability and physiological changes of Artiflex Myopia and Toric phakic intraocular lenses (pIOL) separately throughout an 8-year follow-up.

DESIGN

Retrospective cohort study.

METHODS

A total of 67 eyes of 37 patients underwent Artiflex Myopia (47 eyes) or Artiflex Toric (20 eyes) implantation for correcting myopia and/or astigmatism. Follow-up evaluations were performed 1, 3, 5 and 8 years after surgery. Preoperative and postoperative data included corrected (CDVA) and uncorrected distance visual acuity (UDVA), manifest refraction, endothelial cell density (ECD) and intraocular pressure (IOP) assessments. Efficacy and safety indexes were analysed. The vectorial analysis was performed using the Thibos method.

RESULTS

Mean CDVA and UDVA of both pIOLs significantly improved from preoperative to 1 year after implantation, and then it remained stable over the 8-year follow-up. The efficacy and safety indexes after 8 years were 0.94 ± 0.16 and 1.07 ± 0.18 for Artiflex Myopia and 1.00 ± 0.11 and 1.10 ± 0.15 for Artiflex Toric, respectively. The spherical equivalent (SE) significantly improved after surgery. J0, J45 and SE refractive components showed no changes between postoperative visits. A total ECD loss of 4.8% (p < 0.001) and 10.4% (p = 0.005) was found after 8 years for Artiflex Myopia and Toric, respectively.

CONCLUSIONS

Artiflex Myopia and Toric pIOLs are a safe, efficient and predictable option for the correction of myopia and/or astigmatism. The vectorial analysis showed excellent rotation stability for the toric version.

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.

Implantation of an iris-fixated phakic intraocular lens for the correction of hyperopia: 15-year follow-up

PURPOSE

To assess the predictability, efficacy, stability, and safety of implantation of an Artisan iris-fixated phakic intraocular lens (IF-pIOL) for the correction of hyperopia with a follow-up of up to 15 years.

SETTING

Leiden University Medical Center, the Netherlands.

METHODS

Patients operated by a single surgeon up to 2007 were identified, and data on refraction, corrected distance visual acuity (CDVA), uncorrected distance visual acuity, endothelial cell (EC) density, and complications were collected.

RESULTS

A total of 61 eyes (32 patients) were analysed. The mean spherical equivalent decreased from +6.43 ± 1.78 diopters (D) preimplantation to -0.22 ± 0.57 D at 1 year postimplantation and remained stable throughout follow-up. A stable CDVA with safety indices ranging from 0.91 to 1.10 and efficacy indices between 0.43 and 0.86 were observed. Follow-up time had a significant effect on EC density with an estimated annual decline of 58 cells/mm2 after IF-pIOL implantation. IF-pIOL explantation was performed in a 10 eyes (16.4%) after 8.13 ± 5.11 years. The main reason for IF-pIOL explantation was EC loss (4 eyes [6.6%]). Pigment dispersion was the most encountered complication, observed in 9 eyes (14.8%).

CONCLUSIONS

Visual and refractive results after implantation of an IF-pIOL to correct hyperopia show favorable and stable results with long-term follow-up. Lifelong monitoring of EC counts is mandatory. Pigment dispersion might be a problem in hyperopic eyes implanted with an IF-pIOL; a shallower anterior chamber depth and a convex iris configuration might be predisposing factors.

Posterior chamber phakic intraocular lens for the correction of presbyopia in highly myopic patients

PURPOSE

To report the initial experience with a new presbyopic phakic intraocular lens (pIOL) in the correction of high myopia and presbyopia.

SETTING

Gemini Eye Clinic, Zlin, Czech Republic.

DESIGN

Prospective cohort study.

METHODS

Presbyopic eyes with moderate to high myopia were implanted with a presbyopic posterior chamber pIOL (IPCL). The visual acuities at near and distance, endothelial cell density, and ocular condition were examined 1 week, 3 months, 1 year and 2 years postoperatively.

RESULTS

The mean uncorrected distance visual acuity improved significantly from 1.25 logarithm of the minimum angle of resolution (logMAR) (1.15 to 1.35 95% confidence interval [CI]) to 0.11 logMAR (95% CI, 0.03 to 0.17) (P < .0001). No eye lost 1 or more lines of corrected distance visual acuity. The mean distance refraction improved significantly from -6.9 diopters (D) (range -8.6 to -5.3 D) preoperatively to -0.35 D (range -0.55 to -0.15 D, P < .0001) with less than -0.5 D residual refraction in 11 of 17 eyes. Fifteen of 17 eyes had improved uncorrected near visual acuity to J1 (Jaeger chart) at the 2-year follow-up. The near addition at the 2-year follow-up decreased from preoperatively +1.26 D (range 0.19 to 2.34 D) to +0.39 D (range 0.18 to 0.60 D). The mean endothelial cell density was reduced from 2552 cells/mm (range 2421 to 2682 cells/mm) to 2299 cells/mm (range 2108 to 2490 cells/mm) after 2 years. All patients were subjectively satisfied with the outcomes.

CONCLUSIONS

The new pIOL provided good visual outcomes in near and far distances in an initial case series of patients.

Long-Term Destiny of Corneal Endothelial Cells in Anterior Chamber Intraocular Lens-Implanted Eyes

Purpose

To investigate the long-term changes of corneal endothelial cells (EC) in anterior chamber intraocular lens- (AC-IOL-) implanted eyes.

Methods

Retrospective study. We included 37 eyes (25 patients) that received AC-IOL implantation previously in the Eye and ENT Hospital of Fudan University between 1995 and 2016. Follow-up outcomes included the best-corrected visual acuity (BCVA), endothelial cell density, hexagonality, coefficient of variance, and central corneal thickness.

Results

In total, 23 eyes (62.16%) with phakic and 14 eyes (37.84%) with aphakic AC-IOLs were included. Among these, 3 eyes (8.11%) were angle-supported AC-IOLs and 34 eyes (91.89%) were Artisan iris-fixated AC-IOLs. The mean age of patients was 41.40 ± 17.17 years, and the mean follow-up time was 12.12 ± 4.71 years in our study. At the follow-up time, corneal decompensation existed in 3 angle-supported AC-IOL eyes with a rate of 100% and 15 iris-fixated AC-IOL eyes with a rate of 44.12%. AC-IOL displacement occurred in 14 (41.18%) iris-fixated AC-IOL eyes. In the 19 iris-fixated AC-IOL eyes without corneal decompensation, significant changes also took place in corneal endothelial cells. The endothelial cell density decreased from 2843.26 ± 300.76 to 2015.58 ± 567.99 cells/mm² (29.1% loss, P < 0.001) and hexagonality decreased from 51.21 ± 7.83 to 42.53 ± 9.17 (%) (16.9% loss, P < 0.001). The Kaplan–Meier survival curve also demonstrated the accumulated expectation rates of corneal endothelial cell decomposition for AC-IOLs with a median survival time of 12 years.

Conclusion

We reported a significant chronic loss and long-term decompensation destiny of corneal endothelial cells in AC-IOL eyes. Semiannual or annual follow-up and evaluation of endothelial cells should be conducted in AC-IOL-implanted patients.

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.

Safety and Efficacy of a New Posterior Chamber Phakic Intraocular Lens in Cases of High Myopia: Early Results

Purpose

To demonstrate the visual outcomes of a foldable, hydroxy ethyl-methacrylate, single-piece, posterior chamber phakic intraocular lens (pIOL).

Study Type

Retrospective study.

Materials and Methods

Patients presenting with moderate to high myopia who underwent surgical correction with a posterior chamber phakic IOL (refractive intraocular lens, phakic intraocular lens, Appasamy Associates, Chennai, India) were retrospectively reviewed. Only patients with at least one-year follow-up were included. Manifest refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), endothelial cell density (ECD), and pIOL vault were analyzed 1, 3, 6, and 12 months after surgery. Intraoperative and postoperative events were recorded in all cases.

Results

The study included 30 eyes from 15 patients. The mean patient age was 25.8 ± 3 years. The spherical equivalent of manifest refraction was −11.47 ± 4.38 D preoperatively and −0.44 ± 0.55 D postoperatively. The preoperative CDVA was 0.17 ± 0.12 logMAR. The postoperative UDVA was 0.053 ± 0.11 logMAR (min: −0.17 and max: 0.2) and 0.019 ± 0.091 logMAR (min: −0.17 and max: 0.2) at the end of 1 month and 6 months, respectively. At the end of the 12-month visit, the postoperative UDVA was 0.032 ± 0.094, and the safety index was 2.42. The mean ECD was 2639 cells/mm² (min: 2389 and max: 2993 with SD: 139.53) at the preoperative visit and 2445 cells/mm² (min: 2050 and max: 2701) at the 12-month visit (5.8% loss, p less than 0.001). ECD loss from 6 months to 12 months was not statistically significant. No significant cataract formation, significant endothelial cell loss, glaucoma, uveitis, or any other vision-threatening complication were observed.

Conclusion

Based on postoperative experience, we found that RIL phakic IOLs are safe and effective for treating high myopia at short-term follow-up.

Ten-year safety follow-up and post-explant analysis of an anterior chamber phakic IOL

PURPOSE

To assess endothelial cell loss (ECL) rate and collect safety data in patients with AcrySof L-series Cachet phakic intraocular lens (pIOL) up to 10 years post-implantation.

SETTING

Clinical settings in the United States, European Union, and Canada.

DESIGN

Nonrandomized, observational, open-label safety study.

METHODS

Central and peripheral endothelial cell density was evaluated and compared with 6-month post-implantation baseline. Nonlinear analysis was performed to identify factors affecting post-explantation ECL. Additional evaluations included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), adverse device effects (ADEs), and serious adverse events (SAEs).

RESULTS

The study included 1123 implanted eyes (mean age, 37.5 years). At 10 years, mean central and peripheral ECL was 16% (1.7% annualized). Explantations were performed in 10% of eyes (n = 136/1323). For eyes with pIOL explantation because of ECL (7%), annualized ECL rate post-explantation was numerically lower compared with the overall rate in eyes that underwent explantation for any reason (annualized rate, -1.65% vs -2.03%, respectively; n = 96) and compared with pre-explantation ECL. Mean ± SD CDVA and UCVA were -0.12 ± 0.11 and 0.03 ± 0.22 logarithm of the minimum angle of resolution, respectively. Common ocular ADEs included ECL (10%), pIOL extraction (9%), iris adhesion (7%), and pupillary deformity (2%). Common SAEs included pIOL extraction (11%), ECL (9%), and iris adhesions (8%).

CONCLUSIONS

Cachet pIOLs were associated with long-term ECL in some cases. Overall, only 10% of all implanted eyes underwent explantation during 10-year follow-up. In patients requiring explantation because of ECL, the annualized ECL rates decreased post-explantation in some eyes. Continued monitoring of patients regardless of explantation is recommended.

Phakic intraocular lens implantation for the correction of hyperopia

The prevalence of myopia is much higher than hyperopia. Hence, there are relatively few studies investigating phakic intraocular lens (pIOL) implantation for the correction of hyperopia. This review aimed to summarize the available relevant literature on the efficacy and safety of pIOL implantation for the correction of hyperopia and hyperopic astigmatism. At present, two types of pIOLs are used to correct hyperopia and hyperopic astigmatism: anterior chamber iris-fixated pIOLs and posterior chamber implantable collamer lenses. Both have been found to be safe and effective. No serious events (eg, retinal or choroidal detachment, endophthalmitis) were reported in the reviewed articles. Implantation of pIOLs might be the optimal refractive surgery for the correction of high hyperopia.

Long-term results of Descemet-stripping automated endothelial keratoplasty for endothelial failure caused by phakic intraocular lenses

PURPOSE

To describe the surgical approach and long-term outcomes of Descemet-stripping automated endothelial keratoplasty (DSAEK) for endothelial failure secondary to phakic intraocular lenses (pIOL).

METHODS

Retrospective, interventional case series of 18 eyes of 13 patients who developed endothelial failure secondary to pIOL implant. Patients were submitted to pIOL explant and DSAEK for visual rehabilitation, with or without phacoemulsification plus posterior-chamber intraocular lens implant. The minimum follow-up time was 3 years and the main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD) and percentage of endothelial cell loss (ECL), intraoperative and postoperative complications.

RESULTS

Patients' mean age was 47.44 (7.86) years with a mean follow-up time of 55.61 (14.13) months. Sixteen eyes (88.9%) had an angle-supported pIOL. The mean pIOL implant-to explant time was 8.17 (2.73) years. BCVA improved from 1.00 (0.36) logMAR preoperatively to 0.29 (0.36) logMAR at 1 year of follow-up (p < 0.001), remaining stable over the entire follow-up period (p > 0.05). At the last visit, all corneas were clear, with a mean ECD of 724.74 (325.57) cells/mm². During the follow-up, two eyes (11.1%) required a re-DSAEK due to early graft failure (<3 months).

CONCLUSION

Our outcomes reveal that an individualized and careful approach may result in a stable visual rehabilitation in young patients with corneal decompensation following pIOL implant.

Changes in Endothelial Cell Count Up to Three Years After Implantation of Toric Implantable Collamer Lenses

PURPOSE

To determine the temporal effect of toric implantable collamer lens (TICL) implantation and location on corneal endothelial cell density (ECD) over a period of 36 months after surgery.

METHODS

ECD [number of cells per square millimeter estimated using the Specular Microscope SP-1P (Topcon Europe Medical B.V., Netherlands)] data were collected from cases deemed suitable for the TICL (VTICMO, VTICM5; STAAR Surgical, Nidau, Switzerland). The preoperative refractive error (sphere and cylinder) ranged from -1.00 to -22.25 diopter sphere and from -0.50 to -5.50 diopter cylinder. ECD was evaluated at preoperative and all postoperative sessions.

RESULTS

Key findings were as follows: the mean ECD (±SD, 95% confidence interval) was 2720 cells/mm (±272, 2620-2820 cells/mm) preoperatively, which was reduced to 2372 cells/mm (±325, 2250-2490 cells/mm) at 36 months postoperatively (P < 0.001). Linear regression revealed the following significant correlations between the (1) log of the change in ECD (y1) and log of preoperative ECD (x1) at 2 years postoperatively, y1 = 2.513x1-6.2816 (n = 62, r= 0.3503, P = 0.005); (2) mean ECD (y2) and log time (in months, x2), y2= 2543.7-36.997x2-38.99x2 (r=-0.9654, n = 7, P = 0.0004); and (3) mean axial distance between the front surface of the crystalline lens and the TICL back surface (y3) and time postoperatively (in months, x3), y3 = 0.1035x3-5.2808x3 +473.18 (r = 0.8512, n = 7, P = 0.015).

CONCLUSIONS

Expected ECD loss after TICL implantation by 2 years postoperatively is predictable. On average, over 3 years after implantation, there is (1) an initial rapid decline in ECD, followed by a gradual fall in the rate of cell loss, and (2) a gradual fall in the distance between the TICL and the crystalline lens by 2 years postoperatively, followed by a reversal by the third year.

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.

Long-Term Endothelial Cell Loss in Patients with Artisan Myopia and Artisan Toric Phakic Intraocular Lenses: 5- and 10-Year Results

PURPOSE

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

DESIGN

Prospective, clinical cohort study.

PARTICIPANTS

A total of 507 eyes of 289 patients receiving the Artisan Myopia or Artisan 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 1998.

METHODS

A total of 381 myopic and 126 toric pIOLs were implanted. Five- and 10-year follow-ups were completed by 193 and 127 eyes implanted with the myopic pIOL and by 40 and 20 eyes implanted with the toric pIOL, respectively.

MAIN OUTCOME MEASURES

Chronic endothelial cell (EC) loss, percentage of eyes with a decrease of ≥25% in ECD, and percentage of eyes with an ECD <1500 cells/mm².

RESULTS

Chronic EC loss was calculated from 6 months postoperatively to the end of follow-up and showed an annual ECD decline of 48 cells/mm² (standard error, 3.14) and 61 cells/mm² (standard error, 6.30) in the myopic (P < 0.001) and toric (P < 0.001) groups, respectively, resulting in a total EC loss of 16.6% and 21.5% from 6 months to 10 years postoperatively, respectively. Ten years after implantation, ECD had decreased by ≥25% in 7.9% and 6.3%, whereas ECD was <1500 cells/mm² in 3.9% and 4.0% in the myopic and toric groups, respectively. Explantation of the pIOL occurred in 6.0% in the myopic group and 4.8% in the toric group. Risk factors for increased EC loss were a shallow anterior chamber depth (ACD) (P ≤ 0.005) and a smaller distance between the central and peripheral pIOL edge to the endothelium (P ≤ 0.005).

CONCLUSIONS

A significant linear chronic EC loss was reported after implantation with myopic or toric iris-fixated pIOLs. A smaller ACD and smaller distance between pIOL edge and endothelium were risk factors for EC loss. Modification of preoperative age-related ECD thresholds is indicated to maintain an ECD that warrants safe future combined pIOL explantation and cataract surgery.