Posterior chamber phakic intraocular lens implantation: comparative, multicentre study in 351 eyes with low-to-moderate or high myopia

The comparison of white-to-white via triple person-times caliper measuring and machine-measuring in V4c implantable collamer lens implantation

This study aimed to compare the differences and characteristics of white-to-white (WTW) values obtained before V4c implantation using triple person-times caliper, IOL-Master 700, Pentacam HR, and UBM, and to assess their correlation with vaulting. A total of 930 myopia patients (1842 eyes) who were interested in undergoing ICL surgery were assessed before the procedure using various instruments. The WTW measurements were obtained using a triple person-times caliper, Pentacam HR, and IOL-Master 700, whereas the angle-to-angle (ATA) measurements were obtained using UBM. The size of the ICL was subsequently calculated using triple person-times caliper measurements. The vault of the ICL was assessed using Pentacam HR three months after the surgery. The WTW was determined to be 11.30 ± 0.29 mm, 11.43 ± 0.29 mm, and11.86 ± 0.38 mm, respectively, using the triple person-times caliper, Pentacam HR, and IOL-Master 700. The measurement of ATA was 11.57 ± 0.51 mm, as done by UBM. The ICL vault was measured to be 400.97 ± 198.46 µm when examined with Pentacam HR three monthsafter the procedure. The linear regression analyses of ICL size and WTW of triple person-times caliper, ICL vault and WTW were (R = 0.703, p < 0.001; R = 0.0969, p < 0.001) respectively. The highest correlation was found between IOL-Master and Pentacam HR (r = 0.766, p = 0.000). The lowest correlation was found between UBM and Pentacam HR (r = 0.358, p = 0.002). Bland-Altman analysis showed that the 95% limits of agreement (LoA) were the triple person-times caliper and Pentacam HR (- 0.573, 0.298) and the triple person-times caliper and UBM (- 1.15, - 0.605). This indicated a strong agreement between the triple person-times caliper and Pentacam HR and a lack of agreement between the triple person-times caliper and UBM. Triple person-times caliper measurements offer excellent maneuverability, practicality, and reliable outcomes for determining ICL vaults. Measurements obtained using the triple-person caliper were less differece than those obtained using the Pentacam HR.

A review of posterior chamber phakic intraocular lenses

PURPOSE OF REVIEW

Posterior chamber phakic intraocular lenses (pIOLs) are increasing in popularity as a viable alternative to laser refractive surgery. The purpose of this review is to evaluate the recent updates to pIOLs and to assess the advancements and safety of the procedure.

RECENT FINDINGS

Accurate lens sizing is the key determinant to suitable vault prediction, advancements to sizing formulae including the use of very high frequency (VHF) digital ultrasound and the application of artificial intelligence and machine learning has led to improved vault prediction and safety. The introduction of the central aquaport has been shown to reduce the formation of cataract and is now adopted in most myopic pIOLs. Recently published studies have demonstrated that pIOLs have an excellent safety profile with no increased risk of retinal detachment or endothelial cell loss. Advancements have led to the introduction of extended depth of focus pIOLs for the correction of presbyopia, further research is required to evaluate the efficacy of new lens designs.

SUMMARY

pIOL surgery is experiencing traction with improved lens design and increased lenses choices such as larger optical zone and presbyopic options. Accuracy of implantable collamer lens sizing is paramount to the safety and clinical outcomes, greater predictability is likely to encourage more posterior chamber pIOL users due to fewer sizing related complications.

The rate of vault changes after ICL V4c implantation and its correlation with anterior segment parameters

Purpose

To investigate the rate of vault changes after implantation of ICL V4c and the correlation with anterior segment parameters.

Methods

A total of 64 eyes were studied from the 37 myopic subjects recruited. CASIA2 was used to record the vault at 1 week, 1 month, 3 months and 6 months after the operation as well as the preoperative anterior segment parameters including pupil diameter, lens vault, anterior chamber depth, anterior chamber width, iris area (IA), iris thickness, angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle. The rates of vault change in different time intervals were compared and the correlations between the rates and anterior segment parameters were analyzed. P < 0.05 was considered statistically significant.

Results

The rate of vault decrease was -19.53 ± 111.28 μm/month between 1 week and 1 month, -19.90 ± 29.71 μm/month between 1 month and 3 months and -4.25 ± 18.10 μm/month between 3 months and 6 months; hence the rate was shown to slow down significantly from 3 months post-operation (P = 0.024). The average rate of vault changes showed a significant positive correlation with IA (R2 = 0.140, F = 4.980, P = 0.01). No significant correlation was found with other anterior segment parameters (all P > 0.05).

Conclusion

The rate of decreasing vault significantly slowed down from 3 months post-operation. A larger IA may imply a lower decreasing rate of vault change.

A Comprehensive Retrospective Analysis of EVO/EVO+ Implantable Collamer Lens: Evaluating Refractive Outcomes in the Largest Single Center Study of ICL Patients in the United States

Purpose

We evaluate visual outcomes in patients with EVO/EVO+™ (posterior chamber phakic intraocular lens with a central port) within approved United States (US) age and refractive range indications.

Patients and Methods

This single-center retrospective study evaluated one-month, single-center postoperative data for 225 eyes meeting inclusion criteria and undergoing EVO/EVO+ implantation from April to October 2022. Data included lens size (mm), lens power (diopters of spherical and cylindrical power), preoperative best corrected visual acuity, preoperative spherical equivalent from manifest refraction, achieved postoperative uncorrected visual acuity, postoperative refraction, intraocular pressure (mmHg), and adverse events.

Results

A total of 225 eyes underwent EVO/EVO+ Implantable Collamer Lens (ICL) implantation from April to October 2022, with 51.5% receiving toric lenses. The most common ICL size was 12.6mm (56.4%), followed by 13.2mm (27.5%), 12.1mm (15.1%), and 13.7mm (0.9%). Among patients with preoperative BCVA of 20/20 or better (149 eyes), 95.2% achieved postoperative UCVA of 20/20 or better, and 99.3% achieved UCVA of 20/25 or better at postoperative month one. About 75% of eyes were within a spherical equivalent target of ±0.50 D and 94% within ±1.00 D. Toric ICLs were implanted in 116 eyes (51.8%). Of these, anticipated residual cylinder >1 diopter was seen in 21 eyes (18.1%) resulting in three rotations, three explants, and three laser vision correction (LVC) enhancements. The postoperative adjustment rate (including rotations, exchanges, and LVC enhancement) was minimal (4.8%). Incidence of major adverse events was 0%.

Conclusion

Our study, the largest US single-center analysis of EVO/EVO+ ICL implantation, demonstrates strong early results and infrequent adverse events, supporting ICL safety and effectiveness. High predictability and favorable visual outcomes, including 20/20 or better, highlight the reliability of this technology. Despite study limitations, our findings underscore this technology's effectiveness. Future research should refine patient criteria and assess long-term outcomes in this evolving landscape.

Five-year follow-up of a posterior chamber phakic intraocular lens with a central hole for correction of myopia

PURPOSE

To evaluate intermediate and long-term visual outcomes and safety of a phakic intraocular posterior chamber lens with a central hole (ICL V4c) for myopic eyes.

METHODS

Retrospective, consecutive case study of patients that uneventfully received a ICL V4c for myopia correction, with a 5-year postoperative follow-up. Department of Ophthalmology, Goethe University Frankfurt, Germany.

RESULTS

From 241 eyes that underwent ICL implantation, we included 45 eyes with a mean age at surgery of 33 years ± 6 (18-48 years), with a 5 years follow-up. CDVA improved from 0.05logMAR ± 0.15 CDVA preoperatively to  - 0.00 ± 0,07 at 5 years and did not change significantly from 3 to 5 years' time (p = 0.266). The mean spherical equivalent (SE) improved from -10.13D ± 3.39 to  - 0.45D ± 0.69. The change in endothelial cell count showed a mean decrease of 1.9% per year throughout the follow-up. Safety and efficacy index were 1.16 and 0.78, respectively. Cataract formation was seen in 2 of 241 eyes (0.8%), but in none of the 45 eyes that finished the 5-year follow-up.

CONCLUSIONS

Our data show a good intermediate and long-term stability, efficiency, and safety of ICL V4c phakic lenses in myopic eyes comparable to other known literature.

The influence of iris -ciliary angle (ICA) on the vault after implantation of V4c implantable collamer lens: a chain mediation model of ICL haptic related factors

BACKGROUND

This study aims to identify the relationship between iris -ciliary angle (ICA) and the vault. Additionally, we also seek to investigate the chain mediating effects of the ICL haptic related factors on this relationship.

METHODS

The participants were categorized into three groups according to the ICA value as follows: low ICA group (< 35°); moderate ICA group (35°-70°); high ICA group (> 70°). We compared the preoperative ocular characteristics and postoperative examinations among the three groups. Multiple variable stepwise regression was performed to establish the vault prediction formula. The Process V4.0 in SPSS and Hayes's PROCESS model 6 was conducted to further elucidate the mediating effects of the final tip point of ICL haptic and the ICL arc-lens arc on the relationship between the ICA and vault.

RESULTS

There was a significant difference in the positions of the ICL haptic among three ICA groups. The regression vault equation was Vault = 679.42-7.26*TCA + 192.30*ACD-196.37*CLR + 73.21* STS(horizontal).A significant negative correlation was found between the ICA and vault (P < 0.01).The chain mediation model revealed that the final tip point of ICL haptic and the ICL arc-Lens arc were sequential mediators between ICA and vault (effect = -1.63, 95% CI = -2.72--0.73).

CONCLUSION

The ICA was associated with vault via the mediation effect of the final tip point of the ICL haptic and the ICL arc -lens arc. Assessment of ICL haptic related parameters adds significant information to interpret the vault after surgery.

Efficacy and Safety of Implantable Collamer Lens V4c Implantation in 1,834 Myopic Eyes for 1 Year of Follow-up

PURPOSE

To evaluate visual outcomes of patients with myopia after EVO Implantable Collamer Lens (ICL) (STAAR Surgical) implantation and predict risk factors of postoperative vault abnormalities.

METHODS

In this single-center, retrospective analysis, 1,834 eyes of 926 patients with myopia who underwent EVO ICL implantation were recruited between 2020 and 2021. Patients were followed up for 1 year, during which surgery outcomes were evaluated. In addition, 31 eyes with vault abnormalities who underwent secondary surgery were enrolled to form a generalized linear model, which aimed to predict risk factors contributing to vault abnormalities.

RESULTS

At the final follow-up visit, safety and efficacy indexes were 1.12 ± 0.17 and 1.10 ± 0.19, respectively, and there was no statistical significance between the low and high myopia groups. Furthermore, 79.18% of eyes achieved a residual spherical equivalent within ±0.50 diopters. Except for the temporary elevation of intraocular pressure at 1 week postoperatively, IOP and endothelial cell density remained stable during follow-up visits. The rate of postoperative adverse events was 21.97% and most adverse events were transient. Vault abnormalities accounted for the majority of complications (9.54%). Results of generalized linear model showed that age was a risk factor for postoperative vault abnormalities, and the anterior chamber depth served as a protective factor (P < .05).

CONCLUSIONS

Visual outcomes of EVO ICL implantation were satisfactory in safety and efficacy indexes in both the low and high myopia groups for 1 year of follow-up, with acceptable stability in postoperative spherical equivalent, intraocular pressure, and endothelial cell density. This study emphasized cautious ICL size selection for older patients and those with shallow anterior chamber depth. [J Refract Surg. 2023;39(10):694-704.].

Vault Height Is a Key Predictive Factor for Anterior Segment Measurement Error by IOLMaster 700 in Eyes With Phakic Intraocular Lens

Purpose

To identify risk factors of ocular anterior segment measurement error by the IOLMaster 700 in eyes implanted with an implantable Collamer lens (ICL).

Methods

In total, 152 patients with clear lens (152 eyes, group 1) and another 32 cataract patients (57 eyes, group 2) who underwent ICL implantation were included, and the presence of measurement error by the IOLMaster 700 was determined based on B-scan images. The risk factors for measurement error were evaluated by logistic regression, and the optimal threshold was determined using receiver operating characteristic analysis.

Results

The ICL was misidentified as the anterior surface of the crystalline lens in 51.97% of eyes (79/152) in group 1 and 80.70% of eyes (46/57) in group 2. For every 100-µm decrease in the vault height, a 3.57- and 5.78-fold increase in the risk of measurement error was observed in group 1 and group 2, respectively. We identified an optimal threshold of the vault height at 389.47 µm for predicting biometric measurement error in eyes implanted with ICL, which showed an area under the curve of 0.93 (95% confidence interval, 0.90-0.97), a sensitivity of 0.87, and a specificity of 0.86.

Conclusions

Patients with ICL implantation, particularly those with a vault height less than 389.47 µm, are at a greater risk of anterior segment biometric measurement error by the IOLMaster 700.

Translational Relevance

The threshold of vault height can help to identify high-risk patients and further optimize biometric measurement.

Effect of long-term rotation on astigmatism following EVO-toric intraocular collamer lens implantation

Objective

To evaluate the effect of long-term rotation on astigmatism following Evolution-toric intraocular collamer lens (EVO-TICL) implantation.

Methods

Forty eyes of 22 patients were enrolled in this prospective study. Visual acuity, refractive parameters, and axial position of the EVO-TICL by OPD-Scan III aberrometer were measured preoperatively, 1 month and 3 years postoperatively.

Results

Last visit, the safety index was 1.32 ± 0.15 and the efficacy index was 1.01 ± 0.23. The best-fitting curve of the attempted versus achieved correction was y = 0.9751x + 0.001. The mean spherical equivalent (SE) decreased from -8.94 ± 2.72D preoperatively to 0.06 ± 0.24D and - 0.36 ± 0.46D 1 month and 3 years postoperatively, respectively. The mean target and surgical induced astigmatism were 1.55 ± 0.61D and 1.67 ± 0.94D 3 years postoperatively. The average expected axis of the TICL was-1.15 ± 9.07 (-21-19°). One month and 3 years postoperatively, the average actual axis was -0.70 ± 9.86 (-20-20°) and - 0.35 ± 11.72 (-25-30°), respectively. The absolute rotation of the TICL was 3.70 ± 4.42 (0-22°) and 6.00 ± 6.70 (0-32°) 1 month and 3 years postoperatively, respectively (p < 0.001). The expected astigmatism was -0.10 ± 0.12D, and the mean actual astigmatism was -0.21 ± 0.30D and - 0.44 ± 0.45D 1 month and 3 years postoperatively, respectively. The mean absolute rotation without postoperative astigmatism was 3.73 ± 2.69 (0-9°) and 1.67 ± 1.66 (0-5°) for low (<2D) and high (≥2D) astigmatic TICL, respectively (p < 0.05).

Conclusion

EVO-TICL implantation is safe and effective, with good predictability and stability. OPD-Scan is a fast device to detect the axial position of the TICL without mydriasis, and the axial position is relatively stable in the long term postoperatively. A slight rotation of low-astigmatic TICL may not cause postoperative astigmatism, whereas rotation of the high-astigmatic TICL may cause it.

Artificial intelligence-based refractive error prediction and EVO-implantable collamer lens power calculation for myopia correction

BACKGROUND

Implantable collamer lens (ICL) has been widely accepted for its excellent visual outcomes for myopia correction. It is a new challenge in phakic IOL power calculation, especially for those with low and moderate myopia. This study aimed to establish a novel stacking machine learning (ML) model for predicting postoperative refraction errors and calculating EVO-ICL lens power.

METHODS

We enrolled 2767 eyes of 1678 patients (age: 27.5 ± 6.33 years, 18-54 years) who underwent non-toric (NT)-ICL or toric-ICL (TICL) implantation during 2014 to 2021. The postoperative spherical equivalent (SE) and sphere were predicted using stacking ML models [support vector regression (SVR), LASSO, random forest, and XGBoost] and training based on ocular dimensional parameters from NT-ICL and TICL cases, respectively. The accuracy of the stacking ML models was compared with that of the modified vergence formula (MVF) based on the mean absolute error (MAE), median absolute error (MedAE), and percentages of eyes within ± 0.25, ± 0.50, and ± 0.75 diopters (D) and Bland-Altman analyses. In addition, the recommended spheric lens power was calculated with 0.25 D intervals and targeting emmetropia.

RESULTS

After NT-ICL implantation, the random forest model demonstrated the lowest MAE (0.339 D) for predicting SE. Contrarily, the SVR model showed the lowest MAE (0.386 D) for predicting the sphere. After TICL implantation, the XGBoost model showed the lowest MAE for predicting both SE (0.325 D) and sphere (0.308 D). Compared with MVF, ML models had numerically lower values of standard deviation, MAE, and MedAE and comparable percentages of eyes within ± 0.25 D, ± 0.50 D, and ± 0.75 D prediction errors. The difference between MVF and ML models was larger in eyes with low-to-moderate myopia (preoperative SE >  - 6.00 D). Our final optimal stacking ML models showed strong agreement between the predictive values of MVF by Bland-Altman plots.

CONCLUSION

With various ocular dimensional parameters, ML models demonstrate comparable accuracy than existing MVF models and potential advantages in low-to-moderate myopia, and thus provide a novel nomogram for postoperative refractive error prediction and lens power calculation.

Clinical outcomes of implantation of posterior chamber phakic intraocular lens for pathologic and non-pathologic myopia

BACKGROUND

To compare the clinical outcomes of posterior chamber phakic intraocular lens (pIOL) implantation for non-pathological myopia and pathological myopia.

METHODS

This retrospective case series study which were conducted in Beijing Tongren Eye Center between July 2017 and Oct 2021 comprised 192 eyes of 100 consecutive patients undergoing pIOL implantation. Eyes were divided into two groups based on having pathological myopia or not. Predictability, efficacy, safety, and adverse events were compared at 6 months after pIOL implantation.

RESULTS

Our study included 86 non-pathological myopes (171 eyes, group1) and 14 pathological myopes (21eyes, group2) to analysis. The average ages were 25.5 and 33.0, respectively, and the spherical equivalent (SE) were -9.31D and -17.50D pre-operation. Six months after pIOL implantation, the SE were 0.00 and -0.50, respectively, and the refraction changes were statistically significant (P ≤ 0.05). Six months after surgery, 76.92% and 80.41% were within ± 0.50 D of the target and 92.31% and 95.88% were within ± 1.00 D. All eyes had unchanged BCVA or gained 1 or more lines in both groups and mean BCVA both improved a line 6m after operation. The efficacy index in the two groups were 0.95 and 0.88 and the safety index were 1.20, 1.33, respectively which was significantly different (P ≤ 0.05). Over the 6-month follow-up, no cataract, pigment dispersion glaucoma, pupillary block, or other vision-threatening complications happened, either.

CONCLUSIONS

The pIOL performed well for the correction of both non-pathological and pathological myopia throughout the 6-month observation period. The clinical outcomes of pIOL implantation for non-pathological myopia are essentially equivalent to those for pathological myopia.

State of refractive surgery with Visian ICL posterior chamber phakic lens in Spain

OBJECTIVES

To analyse the state of refractive surgery with Visian ICL phakic lens implantation in Spain, indicating the mean ranges of implanted powers, visual and refractive outcomes obtained and safety and efficacy indices.

METHOD

This is a population-based, cross-sectional, descriptive, analytical, retrospective, multicentre study in which each co-author collected data from at least the last 10 patients (up to a maximum of 30) with Visian ICL phakic lens implantation. One eye from each subject was randomly selected for study inclusion, and the variables analysed were: age, gender, visual acuities with and without correction pre and post-surgery, preoperative and residualrefraction, keratometry, endothelial cellular density, anterior chamber depth from endothelium, central corneal pachymetry, intraocular pressure, white-white, implanted lens (power and size), expected and achieved spherical equivalent (SEQ) post-surgery at one month after surgery.

RESULTS

A sample of 140 eyes was obtained from 140 patients with a mean age of 31.35 ± 7.28 years. Mean preoperative SEQ was -6.33 ± 3.69D, mean CDVA was 0.96 ± 0.16, ACD was 3.30 ± 0.29 mm, WTW 12.02 ± 0.40 mm, CCT 535.03 ± 37.68 µm, ECD 2684.37 ± 313.74 cels/mm² and IOP 14.84 ± 2.59 mmHg. 66.4% of the implanted lenses were spherical ICLs and 33.6% toric, with a mean power of -7.81 ± 4.09D and a mean cylinder of 2.27 ± 1.23D. 5.7% of the implanted lenses were hypermetropic. The mean SEQ target selected was +0.04 ± 0.27D. 48.92% of the implanted lenses were of size 13.2 mm, with the remaining 36.69, 10.79 and 3.60% being of sizes 12.6, 12.1 and 13.7 mm, respectively. At one month after surgery a residual SEQ of -0.01 ± 0.31D was obtained. The efficacy and safety indices were 1.06 ± 0.18 and 1.10 ± 0.19, respectively. The mean central vault was 508.80 ± 201.04 µm. The accuracy between the calculated SEQ and the obtained SEQ was 99.3% for spherical lenses and 88.2% for Cyl correction. The mean ECD at 1 month after surgery was 2805.53±273.30céls/mm2, which was a difference from preoperative of 0.11% (p = 0.922), similarly, the mean IOP was 13.98 ± 2.57 mmHg, which was a difference of -0.92 ± 2.80 mmHg.

CONCLUSIONS

ICL phakic lens surgery is an effective, safe and predictable procedure. There were no significant changes in endothelial cell count or intraocular pressure measurement one month after surgery.

EVO/EVO+ Visian Implantable Collamer Lenses for the correction of myopia and myopia with astigmatism

INTRODUCTION

Intraocular lens implantation in phakic eyes for the correction of refractive error is currently a widespread procedure. The EVO and EVO+ Visian Implantable Collamer Lenses (ICL) are two of the most prevalent lenses implanted. They incorporate a central orifice to avoid the need for iridotomy. The main difference between both ICL is the higher optical diameter zone provided by the EVO+, allowing a better quality of vision at night. This review aims to provide an overview of the current ICL models available for correcting myopia and myopic astigmatism.

AREAS COVERED

During the last decade, more than 100 scientific papers analyzing the performance of EVO and EVO+ lenses have been published. This review describes the objective visual performance achieved with the implantation of central hole ICL lenses and the subjective perception of the patients implanted with these lenses. In addition, the safety and the potential complications associated with undergoing an EVO and EVO+ ICL implantation have been addressed.

EXPERT OPINION

Refractive surgeons and candidates to undergo ICL implantation should be aware of the excellent safety and visual outcomes provided by the implantation of central hole ICL lenses. However, future research could address minor issues currently not resolved.

Prospective clinical study of retinal microvascular alteration after ICL implantation

Purpose: To evaluate the retinal microvascular alteration after implantable collamer lens (ICL) implantation in moderate to high myopia patients using quantitative optical coherence tomography angiography (OCTA). Methods: This prospective cohort study included 50 eyes of 25 patients with preoperative spherical equivalent ≥ -3.00 D. Patients underwent bilateral ICL implantation at the Department of Ophthalmology, Peking University Third Hospital, from November 2018 to July 2019. OCTA was used to image the superficial and deep retinal capillary plexuses before ICL implantation surgery and at 3 months follow-up. Results: There was no significant difference in the microvascular density within each annular zone and all quadrantal zones of the superficial and deep layers found in myopia patients before and after ICL surgery. Conclusion: Levels of microvascular density in retinal capillary plexuses were stable, as detected by the OCTA, showing the high security of ICL implantation, which would not leave adverse effects on retinal microvasculature in myopia patients.

A quantitative study of the effect of ICL orientation selection on post-operative vault and model-assisted vault prediction

Background

Appropriate vault height of implantable collamer lens (ICL) implantation matters for it has risks of corneal endothelial cell loss, cataract formation and intraocular pressure elevation, which could lead to irreversible damage to optic nerve. Therefore, pre-operative prediction for an ideal vault height is a hotspot. However, few data exist regarding quantitative effect of ICL orientation on vault height. This study is aimed to quantitatively investigate the effect of ICL implantation orientation on vault height, and built a machine-learning (ML)-based vault prediction model taking implantation orientation into account.

Methods

473 consecutive case series treated with ICL implantation were retrospectively analyzed (408 were horizontally implanted, and 65 were vertically implanted). Multivariable logistic regression analysis was performed to determine the association between ICL orientation and achieved vault. ML was performed to develop a new vault height prediction model taking ICL orientation into account. Receiver operating characteristic curve (ROC) and net reclassification index (NRI) were obtained to assess the prediction ability.

Results

95% of all the patients achieved 20/20 uncorrected distance visual acuity (UDVA) or better. No complications including cataract formation, dispersion or optic nerve injury were observed in any cases. Sex, sphere power, cylinder power, axis, ICL size and ICL orientation were all significant risk factors associated to vault height, and age was positively co-related. Of note, ICL size and ICL orientation were the top-ranking risk factors. Comparing to conventional horizontal implantation, vertical implantation could reduce the achieved vault by 81.187 μm (p < 0.001). In regarding to different ICL sizes, vertical implantation had no good to vault reduction when using ICL of 12.1 mm. However, it could reduce the vault by 59.351 μm and 160.992 μm respectively when ICL of 12.6mm and 13.2 mm were implanted (p = 0.0097 and p = 0.0124). For prediction of vault height, ML based model significantly outperformed traditional multivariable regression model.

Conclusion

We provide quantitative evidence that vertical implantation of ICL could effectively reduce the achieved vault height, especially when large size ICL was implanted, comparing to traditional horizontal implantation. ML is extremely applicable in development of vault prediction model.

The best choice for low and moderate myopia patients incapable for corneal refractive surgery: implantation of a posterior chamber phakic intraocular lens

PURPOSE

This study aims to evaluate the early clinical outcomes of central hole phakic posterior chamber intraocular lens(ICLV4c) implantation for low and moderate myopia correction.

METHODS

This retrospective clinical study included 27 patients(47 eyes)who underwent ICLV4c implantation to correct myopia with spherical equivalent (SE) between - 1.75D and -6.0D. The uncorrected visual acuity (UCVA), intraocular pressure(IOP), central anterior chamber depth (ACD), vault, and endothelial cell density (ECD) were evaluated after surgery.

RESULTS

At one year follow-up, the postoperative UCVA of patients was higher than the preoperative CDVA and showed a stable trend. There was no significant difference in ECD (p > 0.05) one month after the surgery, the vault was 0.77 ± 0.32 mm, which decreased to 0.63 ± 0.26 mm after one year of surgery. Similarly, ACD was 3.24 ± 0.25 mm in the preoperative, which decreased significantly to 2.05 ± 0.39 mm at one month, while rose to 2.2 ± 0.39 mm at one year after surgery. There was no significant correlation between IOP and ACD and vault at one month and one year after surgery. The correlation coefficient between ACD and vault was found to be - 0.72 at one month after surgery, while the same -0.71 after one year. One patient developed visual fatigue, one with glare, and while no other complications were observed with the rest of the patients.

CONCLUSION

The ICL implantation is a safe, effective and stable method to correct low and moderate myopia, and may be a good alternative for patients with low and moderate myopia who cannot undergo corneal refractive surgery.

Evaluation of Higher Order Aberrations and Anterior Segment Parameters Changes After Implantable Collamer Lens Implantation for High Myopia

Purpose

To evaluate changes in higher order aberrations (HOAs) induced by implantable collamer lens (ICL) implantation in correction of high myopia and to compare the anterior segment parameters before and after surgery. Also, to correlate these parameters with HOAs, the best corrected visual acuity (BCVA) and intraocular pressure (IOP).

Methods

This prospective interventional cohort case series study included 40 eyes with high myopia that underwent ICL V4c implantation. They were evaluated pre-operatively and post-operatively at 1^st and 3^rd month HOAs using Scheimpflug Sirius Camera. The anterior segment parameters were evaluated by optical biometry. Correlations between HOAs, BCVA and anterior segment parameters were evaluated.

Results

The mean pre-operative BCVA was 0.67 ± 0.17, while post-operative BCVA was 0.74 ± 0.16 (p-value < 0.001). The spherical equivalent was -13.66 ± 2.23 pre-operatively, while post-operatively it was -0.77 ± 0.65 (p-value < 0.001). The mean pre-operative root mean square (RMS) of HOAs was 0.62 ± 0.11 µm, while mean post-operative RMS in the 1st month was 0.82 ± 0.29 µm (p-value < 0.001). At 3rd month, it was 0.63 ± 0.17 µm (p-value = 0.685). The mean pre-operative anterior chamber depth (ACD) was 3.66 ± 0.26 mm. It decreased in the post-operative 1^st month to 3.46 ± 0.30 mm, while in 3^rd month 3.45 ± 0.24 mm (p-value < 0.001, < 0.001) respectively. The mean pre-operative anterior chamber angle (ACA) 45.98 ± 8.39 ^o while, the mean ACA was 31.65 ± 4.14, 31.03 ± 3.74 post-operatively (p-value < 0.001, < 0.001) respectively. There was significant increase in IOP (p-value < 0.001).

Conclusion

ICL implantation is safe and effective in correction of high myopia, as HOAs increase at first month post-operatively then, return to the pre-operative level by 3^rd month. However, anterior segment parameters show significant changes which may need longer follow up.

Intraocular Implantable Collamer Lens with a Central Hole Implantation: Safety, Efficacy, and Patient Outcomes

This review summarizes the available literature and provides updates on the efficacy, safety, and patient outcomes of phakic intraocular lens implantation using implantable collamer lens (ICL), with a focus on newer models with a central port (EVO/EVO+ Visian Implantable Collamer Lens, STAAR Surgical Inc.). All studies included in this review were identified from the PubMed database and were reviewed for relevancy of their topic. Data on hole-ICL implantation performed between October 2018 and October 2022 in 3399 eyes showed a weighted average efficacy index of 1.03 and a weighted average safety index of 1.19 within an average follow-up of 24.7 months. The incidence of complications such as elevated intraocular pressure, cataract, and corneal endothelial cell loss was low. Moreover, both quality of vision and quality of life improved after ICL implantation, confirming the benefits of this procedure. In conclusion, ICL implantation is a promising refractive surgery alternative to laser vision correction with excellent efficacy, safety, and patient outcomes.

Visual Acuity Improvement in Low, Moderate and High Myopia After Posterior-Chamber Phakic Implantable Collamer Lens Surgery in a Large Patient Cohort

Purpose

To compare best-corrected visual acuity (BCVA) before and after implantable collamer lens (ICL) surgery in patients with low, moderate and high myopia.

Methods

A single-centre, prospective, registry-based study involving patients with myopia who received ICLs between October 2018 and August 2020. The study population was divided into three groups of subjects with low (from 0 to -6 D), moderate (-6 to -10 D) and high myopia (more than -10 D). We analysed uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent (SE), differences between BCVA pre- and 1-month postoperative, and line gain in BCVA 1 month after surgery.

Results

A total of 770 eyes belonging to 473 patients were surgically intervened during the study period, of which 692 eyes completed 1 month of postoperative follow-up and were included in the study population. At 1-month follow-up, 478 eyes (69%) achieved a BCVA of 20/20, 599 (87%) obtained 20/25 or better, and 663 (96%) had a BCVA of 20/40 or better. We identified a significant improvement in BCVA (baseline 0.15±0.2 logMAR vs follow-up 0.07±0.2 logMAR, p<0.0001) and a significant reduction in SE (baseline -9.23±4.1 D, vs follow-up -0.21±0.8 D, p<0.0001), with a significant relationship between preoperative SE and line gain (r = -0.46, p<0.0001). We identified a significantly higher line gain among eyes with higher degrees of myopia (low myopia 0.22±0.69 lines compared to moderate myopia 0.56±1.1 lines and high myopia 1.51±1.9 lines, p<0.0001). Notably, 99.6% of eyes with a high grade of myopia achieved improvement to a low degree (less than -6 D) at follow-up. The safety and efficacy indexes were 0.083±0.1 and -0.001±0.1, respectively.

Conclusion

In this large patient cohort, ICL surgery was related to a significant line gain in BCVA, particularly among eyes with higher degrees of myopia.

Corneal endothelial ring following the implantation of toric implantable collamer lenses with a central hole: a case report

BACKGROUND

To report a case of a corneal endothelial ring after toric implantable collamer lens (TICL, V4C) implantation in the right eye of a patient.

CASE PRESENTATION

A 36-year-old woman with refractive errors of -8.00 DS/-2.00 DC * 8° in the right eye and - 6.50 DS/-1.75 DC * 177° in the left eye developed a corneal endothelial ring in the right eye on the first day after receiving TICLs implantation for treatment of high myopic astigmatism, which has not been previously reported as a complication of ICLs implantation. At 1 day postoperatively, the uncorrected distance visual acuity (UDVA) was 20/16, the intraocular pressure as measured by non-contact tonometry was 16.9 mmHg, and the vault as measured by anterior segment optical coherence tomography was 1238 μm. The eye was quiet and there was no unusual anterior chamber reaction. However, slit-lamp examination revealed an endothelial annular lesion of approximately 0.4 mm in diameter in the central part of the cornea, which was gray-white in color. The shape of the ring was the same as that of the central hole of the TICL. Specular microscopy showed that the mean endothelial cell density (ECD) of the ring significantly decreased to 1442 ± 263 cells/mm², while the other part was still normal (2852 ± 103 cells/mm²). After 9 days of corticosteroid treatment and intense lubrication, the patient had a clear cornea, increased ECD (1532 ± 653 cells/mm²), and a good UDVA (20/16).

CONCLUSION

This case suggests that a few hours after ICL V4C implantation, with a large vault, corneal displacement caused by an air puff would make the endothelium close to or even contact the ICL, producing a corneal endothelial ring. After ruling out various possible factors, we speculated that the endothelial ring was developed due to the non-contact tonometer air puff before slit-lamp evaluation, and this phenomenon was recorded by Corvis, which confirmed that the cornea could come in contact with the ICL due to gas shock. This "contact" may cause transient corneal endothelial damage.

Short-term clinic observation of misalignment and rotational stability after implantable collamer lens implantation

PURPOSE

We aimed to investigate misalignment (tilt and decentration) and rotational stability of the implantable collamer lens V4c 6 months after implantation and to explore the potential risk factors associated with postoperative misalignment and rotation.

METHODS

A total of 36 eyes of 36 patients with high myopia and myopic astigmatism who underwent implantable collamer lens V4c implantation were included in this study. Tilt, decentration, and rotation of the implantable collamer lens were assessed postoperatively at l week, 1 month, 3 months, and 6 months. Correlation analysis was used to identify the potential risk factors for implantable collamer lens tilt, decentration, and rotation at 6 months postoperatively. Higher-order aberration was measured to evaluate the effect of implantable collamer lens misalignment on visual quality at pupil diameters of 4.0 mm and 6.0 mm.

RESULTS

The tilt and decentration at the last follow-up were 2.43 ± 1.35° and 0.278 ± 0.160 mm, respectively. There was a significant positive correlation between tilt and decentration (r = 0.31, P = 0.046). No significant correlation was detected between implantable collamer lens decentration and internal higher-order aberrations (P > 0.05). The degree of implantable collamer lens rotation (3.11 ± 2.00°) was significantly associated with the vault (r =  - 0.422, P = 0.01), while it was positively associated with the preoperative anterior chamber depth (r = 0.36, P = 0.034). No significant correlation was found between postoperative astigmatism and rotation (r =  - 0.07, P = 0.351).

CONCLUSIONS

The implantable collamer lens V4c provides relatively stable misalignment and rotation after implantation. The ICL lens vault is a potential risk factor for postoperative implantable collamer lens rotation. The absolute value of decentration and tilt was relatively small, which showed no correlation with internal higher-order aberration in short-term observation.

The EVO ICL for Moderate Myopia: Results from the US FDA Clinical Trial

Purpose

To evaluate the safety and effectiveness of collamer posterior chamber phakic refractive lenses with a central port design (EVO and EVO+ Sphere and Toric implantable collamer lenses [ICLs]) for correction of moderate myopia with or without astigmatism.

Patients and Methods

Six-month results of a multicenter clinical trial were performed under United States FDA Investigational Device Exemption. Subjects 21 through 45 years of age with manifest refraction spherical equivalent ranging from -3.00 D to -6.00 D and astigmatism up to 4.00 D underwent implantation of EVO or EVO+ Sphere or Toric ICLs. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, intraocular pressure (IOP), endothelial cell density, and adverse events were evaluated over 6 months.

Results

This report includes a retrospective review of 200 eyes of 114 subjects with mean age 35.1 ± 5.1 years that completed the 6-month visit. Mean preoperative spherical equivalent (SE) measured -4.61 ± 0.87 D (range: -3.00 to -6.00 D). At 6 months, mean SE was -0.085 ± 0.26 D, with 91.5% within ± 0.50 D of target and 100.0% within ±1.00 D of target. Mean postoperative UDVA and CDVA were -0.065 ± 0.08 logMAR and -0.14 ± 0.07 logMAR, respectively. About 98.0% of eyes maintained or gained lines of CDVA, and no eye lost more than 1 line CDVA. Efficacy and safety indices were 1.03 and 1.21, respectively. No eye experienced pupillary block, required preoperative or postoperative peripheral iridotomy or iridectomy, developed anterior subcapsular cataract or had elevated IOP due to angle narrowing or pigment dispersion. Mean endothelial cell density declined by 2.2%.

Conclusion

EVO ICL lenses demonstrated accuracy, predictability and stability of refractive correction with achievement of high levels of UDVA and an excellent safety profile for patients with moderate myopia with or without astigmatism.

Vault differences in eyes implanted with spherical and toric implantable collamer lenses: an inter-eye analysis

Purpose

To determine the influence of implantable collamer lenses (ICL) geometry, i.e. spherical and toric on the vault, and report the refractive and visual outcomes of patients bilaterally implanted with the two ICL geometries.

Methods

This retrospective case series analysed 41 patients implanted with a spherical ICL (sICL) in one eye and an equal sized toric ICL (tICL) in the fellow eye. The anatomical and ICL-related parameters were assessed using anterior-segment optical coherence tomography (AS-OCT Visante, Zeiss Meditec AG) and optical tomography (Pentacam, OCULUS). The influence of the anatomical and ICL-related parameters on the vault was determined using generalised estimating equations (GEE) to incorporate inter-eye correlations.

Results

Postoperative spherical equivalent was within ± 0.50D in 66% and 83% of the eyes, respectively implanted with sICL and tICL. The efficacy index in the sICL group was 1.06 and 1.14 in the tICL group. The mean inter-eye vault difference was -1.46 µm, anatomical and ICL-related parameters showed similar associations with the vault for sICL and tICL. The GEE identified the ICL size minus the anterior chamber width, the ICL spherical power and ICL central thickness as significant factors influencing the vault.

Conclusions

Spherical and toric ICL showed good efficacy for the correction of myopia and astigmatism. Patients implanted bilaterally with sICL and tICL tend to present similar vaults. The vault produced by both types of ICL was mainly regulated by the oversizing of the ICL. This suggests that the ICL geometry (spherical vs toric) is a factor with limited influence on the vault, thus the sizing method of a sICL and tICL should be similar.

Early Assessment of Circumferential Anterior Segment Structures Following Implantable Collamer Lens V4c Implantation Via SS-OCT

Purpose

To explore early changes in circumferential anterior segment structures following Implantable Collamer Lens (ICL) V4c implantation via swept-source optical coherence tomography (SS-OCT).

Methods

In 103 eyes of 56 myopic patients undergoing ICL V4c surgery, anterior segments were measured via SS-OCT to compute local anterior chamber angle (ACA) parameters on the nasal–temporal (0°–180°), superior–inferior (90°–270°), and superior nasal–inferior temporal (80°–260°) meridians, including angle-opening distance at 500 µm (AOD500), trabecular–iris space area at 500 µm (TISA500), trabecular–iris angle at 500 µm (TIA500), and circumferential ACA parameters, including AOD area at 500 µm (AODA500), trabecular–iris circumference volume at 500 µm (TICV500), and the index and area of iris–trabecular contact (ITC). ACA parameters were compared preoperatively and at 1 week, 1 month, and 3 months postoperatively and compared among quadrants. Mixed-effects model was used to evaluate the parameters correlated with the post-ITC parameters.

Results

The mean AOD500, TISA500, TIA500, AODA500, and TICV500 were decreased by 65.4% to 71%, 64.1% to 69.3%, 53.8% to 61.5%, 69.9%, and 69.2%, respectively, at 1 week postoperatively. The ITC index and area values rose from 1.436% ± 4.427% and 0.070 ± 0.254 mm² to 12.343% ± 13.216% and 0.903 ± 1.304 mm² (all P < 0.05). No further decreases in ACA parameters were observed beyond 1 week postoperatively (all P > 0.05). Significant differences were observed among quadrants, with the narrowest in the superior–nasal quadrant, followed by the superior quadrant. The 3-month vault was significantly correlated with the ITC index and area at 3 months postoperatively.

Conclusions

Anterior segment structures were significantly shallow at 1 week with no further decreases thereafter. In light of anatomical variability, we recommend circumferential meridian scan to assess angle status, with special attention to the superior–nasal and superior quadrants.

Translational Relevance

We investigated the early changes in circumferential anterior segment structures following ICL V4c implantation, thus providing a better perspective for understanding anterior segment structural characteristics after ICL V4c surgery.

Corneal diameter measurements by 3 optical biometers and their effect on phakic intraocular lens sizing

PURPOSE

To compare phakic intraocular lens size calculations based on corneal diameter (CD) measurements by 3 instruments.

SETTING

G.B. Bietti Foundation I.R.C.C.S., Rome, Italy.

DESIGN

Retrospective interventional case series.

METHODS

Preoperatively, CD was measured with the Aladdin, IOLMaster 700, and Pentacam AXL Wave. The simulated ICL size was computed by entering CD measurements into the manufacturer's calculator. Postoperatively, vaulting was measured by anterior segment optical coherence tomography. The optimal ICL size (OIS) was calculated and compared with the commercially available OIS (CAOIS).

RESULTS

54 eyes (29 patients) with the implantable collamer lens (ICL) were enrolled. The mean CD was 12.02 ± 0.36 mm with the Aladdin, 12.35 ± 0.39 mm with the IOLMaster 700, and 12.22 ± 0.41 mm with the Pentacam AXL Wave ( P &amp;lt; .0001), with the closest agreement between the Pentacam AXL Wave and IOLMaster 700 (95% limits of agreement: -0.43 to +0.17 mm). Vaulting (mean: 558 ± 261 μm) was within 251 and 1000 μm in 49 eyes (83.3%). The mean difference between the simulated ICL size and OIS ranged between -0.11 ± 0.35 mm and 0.10 ± 0.30 mm ( P &amp;lt; .0001), with no statistically significant difference between the IOLMaster 700 and Pentacam AXL Wave. The simulated ICL size was equal to CAOIS in 38 eyes (70.37%) with the Aladdin, 37 eyes (68.52%) with the IOLMaster 700, and 39 eyes (72.22%) with the Pentacam AXL Wave, without any statistically significant difference.

CONCLUSIONS

CD measurements by the 3 devices lead to similar percentages of eyes with an ICL size equal to the OIS. Agreement is closer between the IOLMaster 700 and Pentacam AXL Wave.

Analysis of perioperative problems related to intraocular Implantable Collamer Lens (ICL) implantation

PURPOSE

To introduce a modified procedure of ICL implantation, to summarize the perioperative problems and their corresponding treatment after myopia correction with Implantable Collamer Lens (ICL), and to compare the difference of complications between the no-hole ICL and hole ICL.

METHODS

We searched all articles on ICL-related perioperative problems and their corresponding treatment in Scopus, Embase, PubMed and Web of Science databases for the last 22 years.

RESULTS

ICL implantation is safe, effective, stable and predictable in the correction of myopia, hyperopia and astigmatism, but can also cause a series of perioperative problems, including intraoperative and postoperative complications.

CONCLUSION

There are many kinds of complications related to ICL, but the common intraoperative and postoperative complications mainly include abnormality of arch height, abnormal position of ICL, loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma, cataract and night vision symptoms. Compared with ICL without central pore, the incidence of complications such as loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma and cataract was relatively lower in central hole ICL, while postoperative complications such as night vision symptoms were obvious.

Implantable collamer lens implantation (ICL) versus small incision lenticule extraction (SMILE) in low to moderate myopia: study protocol for a randomized, non-inferiority trial

BACKGROUND

Implantable collamer lens implantation (ICL) is a form of 'foldable' posterior chamber phakic intraocular lens refractive surgery that generally does not impair cornea and natural accommodation. The potential advantages of the ICL over keratorefractive laser procedures include less induction of higher-order aberrations (HOAs) and enhanced retinal image magnification. On the other hand, small incision lenticule extraction (SMILE), currently, one of the most popular refractive surgery procedures, also offers excellent visual outcomes, particularly for eyes with low to moderate amounts of myopia. The aim of this study is to evaluate whether ICL/TICL (toric ICL) is comparable to SMILE for low to moderate myopia in terms of refractive outcomes at 3 and 18 months post-operatively.

METHODS/DESIGN

This is a prospective randomized study. A total of 300 participants will be randomized into two groups, the ICL/TICL group and SMILE group. Eligible participants with spherical equivalent (SE) less than - 6.0 diopter (D) will be recruited. Following randomization, participants will be followed at 1, 3, 6, 12, and 18 months. The primary outcome is the refractive predictability at every postoperative point after surgery, which is the proportion of the number of eyes achieving a postoperative SE within ± 0.5 D and ± 1.0 D of the intended target. Secondary outcome parameters include visual acuity, refraction, adverse events, and quality of vision measurements.

DISCUSSION

This trial will provide information on whether ICL has comparable, if not superior, refractive outcomes compared to the established SMILE for low to moderate myopia, thus providing evidence for translation into clinical practice.

TRIAL REGISTRATION

Chinese clinical trial registry (ChiCTR) 2200055372. Registered on 08 January 2022.

Factors leading to realignment or exchange after implantable collamer lens implantation in 10 258 eyes

PURPOSE

To evaluate the incidence, causes, and outcomes of implantable collamer lens (ICL) realignment or exchange after implantation of the EVO-ICL.

SETTING

Eye and ENT Hospital of Fudan University, China.

DESIGN

Retrospective study.

METHODS

The study included 10 258 consecutive eyes after ICL implantation. Preoperative refractive and biometric measurements were compared between eyes with and without realignment or exchange. For eyes with ICL realignment or exchange, visual and biometric outcomes were also compared before and after ICL realignment or exchange.

RESULTS

The overall incidence of ICL realignment or exchange was 0.21% 22 eyes. 12 eyes (0.12%) underwent ICL realignment by axis rotation (10 eyes) or ICL exchange (2 eyes) due to toric ICL (TICL) misalignment. After realignment, uncorrected distance visual acuity improved, and residual cylinder decreased from -1.75 ± 0.48 diopters (D) to -0.87 ± 0.59 D ( P = .01). 10 eyes (0.10%) underwent vertical rotation of ICL (3 eyes) or ICL exchange (7 eyes) due to excessive vault. After either vertical rotation or ICL exchange, vault decreased significantly ( P < .05).

CONCLUSIONS

The incidence of ICL realignment or exchange after ICL implantation is low. TICL misalignment and excessive vault are 2 main causes. Implant exchange may be performed for excessive vault or misalignment with an insufficient vault. In addition, vertical rotation of an ICL may be a less invasive method to treat excessive vault in certain cases.

Determinants of Subjective Quality of Vision After Phakic Intraocular Lens Implantation

PURPOSE

To evaluate postoperative subjective quality of vision in patients who underwent Implantable Collamer Lens (ICL) (STAAR Surgical) implantation for correction of myopia and to identify potential predictive parameters.

METHODS

In this single-center cross-sectional study, a total of 162 eyes of 81 patients (58 women, 23 men) who underwent ICL implantation were analyzed. The Quality of Vision (QOV) questionnaire was used to assess patient-reported outcomes. Baseline characteristics (eg, age), treatment parameters (eg, surgical corrected refraction), and refractive (eg, residual refraction) and visual (eg, uncorrected distance visual acuity) outcomes were analyzed regarding their effect on QOV.

RESULTS

Mean age was 33.3 ± 7.0 years (range: 21 to 51 years) and mean preoperative spherical equivalent was -8.42 ± 2.49 diopters (D) (range: -3.25 to -14.38 D). After a mean postoperative follow-up period of 19 ± 14 months (range: 6 to 54 months), the safety index score was 1.23 ± 0.21 and the efficacy index score was 1.17 ± 0.22. The mean QOV scores were 35.5 ± 11.3, 32.2 ± 11.1, and 23.3 ± 16.1 for frequency, severity, and bothersomeness, respectively. The most frequently experienced symptoms were halos (90.1%) and glare (66.7%). Halos appeared in 66.7% of the patients "occasionally" and 5 of them (6.2%) experienced them "very often." Only 1 patient (1.2%) classified halos as "very bothersome." Patients older than 36 years reported visual symptoms more frequently (P < .05) and showed higher bothersomeness scores (P = .01).

CONCLUSIONS

Halos are the most commonly perceived long-term visual disturbance after myopic ICL implantation with a central hole. Visual symptoms can persist more than 6 months postoperatively, causing only minor disturbances in most cases. Older patients seem more prone to experiencing these symptoms. [J Refract Surg. 2022;38(5):280-287.].

A Nationwide Multicenter Study on 1-Year Outcomes of Posterior Chamber Phakic Intraocular Lens Implantation for Low Myopia

Purpose

To assess the nationwide multicenter outcomes of posterior chamber phakic intraocular lens implantation with a central hole (EVO-ICL, STAAR Surgical) for patients with low myopia.

Methods

This multicenter study comprised 172 eyes of 111 consecutive patients undergoing hole ICL implantation to correct low myopia and myopic astigmatism [manifest spherical equivalent (MSE);-3 diopters (D) or less] at seven nationwide major surgical facilities. We retrospectively determined safety, efficacy, predictability, stability, and adverse events at 1 week, 1, 3, 6, and 12 months postoperatively, and at the final visit.

Results

The mean follow-up period was 1.4 ± 1.0 years. Uncorrected and corrected visual acuities at 1 year postoperatively were -0.17 ± 0.12 and -0.24 ± 0.07 logarithm of the minimal angle of resolution (logMAR), respectively. At 1 year postoperatively, 91% and 100% of eyes were within 0.5 and 1.0 D of the target correction, respectively. No significant manifest refraction changes of -0.07 ± 0.26 D occurred from 1 week to 1 year. No vision-threatening complications occurred at any time in this series.

Conclusions

According to our experience, the EVO-ICL performed well without significant complications throughout the 1-year observation period, even for the correction of low myopia. It is suggested that current ICL implantation is one of the viable surgical options for correcting low myopia.

Posterior chamber phakic intraocular lens implantation after laser in situ keratomileusis

BACKGROUND

To assess the multicenter outcomes of posterior chamber phakic intraocular lens implantation with a central hole (EVO-ICL, STAAR Surgical) for patients undergoing previous laser in situ keratomileusis (LASIK).

METHODS

This case series enrolled 31 eyes of 21 consecutive patients undergoing EVO-ICL implantation to correct residual refractive errors after LASIK at 7 nationwide major surgical sites. We investigated safety, efficacy, predictability, stability, and adverse events at 1 week, 1, 3, and 6 months postoperatively, and at the final visit.

RESULTS

The mean observation period was 1.6 ± 1.8 years. Uncorrected and corrected visual acuities were - 0.14 ± 0.11 and - 0.22 ± 0.09 logMAR at 6 months postoperatively. At 6 months postoperatively, 81% and 100% of eyes were within ± 0.5 D and ± 1.0 D, respectively, of the targeted correction. We found neither significant manifest refraction changes of 0.05 ± 0.38 D from 1 week to 6 months nor apparent intraoperative or postoperative complications in any case.

CONCLUSIONS

Our multicenter study confirmed that the EVO-ICL provided good outcomes in safety, efficacy, predictability, and stability, even in post-LASIK eyes. Therefore, EVO-ICL implantation may be a viable surgical option, even for correcting residual refractive errors after LASIK. Trial registration University Hospital Medical Information Network Clinical Trial Registry (000045295).

Multicenter survey on implantable collamer lens dislocation

This study aimed to investigate the incidence, patient background, and postoperative prognosis of implantable collamer lens (ICL) dislocation. We retrospectively reviewed all cases of ICL dislocation at four major refractive surgery centers in Japan until December 2019. The incidence, patient background, cause of dislocation, complications of repositioning surgery, and postoperative visual function were investigated. Seven ICL dislocations [0.072% of total ICL-implanted eyes (9775 eyes)] occurred at an average of 28.6 months (11–82 months) postoperatively. All patients were male. Five eyes were injured during sports activities, one due to a fall from a bicycle, and another due to ocular blunt trauma caused by a mortuary tablet. Two patients had re-dislocation in the same eye. Retinal detachment occurred after repositioning surgery in one patient, and scleral buckling surgery was performed without ICL removal. ICL dislocation is a rare complication of ICL surgery; repositioning surgery is effective, but retinal complications may occur.

One-year Observation of Safety of Implantable Collamer Lens V4c Implantation Without Using an Ophthalmic Viscosurgical Device

Purpose

To investigate the feasibility and safety of the implantable collamer lens V4c (ICL V4c) implantation without using an ophthalmic viscosurgical device (OVD-free technique).

Methods

This prospective consecutive case study enrolled 118 eyes of 60 patients (15 eyes were of male patients, 103 eyes were of female patients, age 26.19 ± 5.03 years, spherical equivalent −10.05 ± 2.73 D). Eyes were considered for OVD-free or OVD-using ICL V4c implantation based on the maintenance of the anterior segment during the surgery. The follow-up lasted for 12 months. The main measurements were visual acuity and changes in endothelial cell density (ECD) at 12 months.

Results

A total of 75 eyes were included in the OVD-free group and 43 in the OVD group. No infection or other complications were observed in any eye. In the OVD-free group, the safety and efficacy indices were 1.19 ± 0.15 and 1.05 ± 0.20, respectively. 74.5% of the eyes gained one or two lines of corrected distance visual acuity (CDVA), and 25.5% were stable. In the OVD group, the safety and efficacy indices were 1.17 ± 0.17 and 1.03 ± 0.15, respectively; 65.7% of the eyes gained one or two lines of CDVA, and 34.3% were stable. The mean change of ECD was 65.34 cell/ mm² compared to the baseline in the OVD-free group and 25.94 cell/ mm² compared to baseline in the OVD group (P = 0.038).

Conclusions

The ICL V4c implantation with an OVD-free technique is a safe and feasible method in eyes with good maintenance of the anterior segment.

Vertically Fixated Posterior Chamber Phakic Intraocular Lens Implantation Through a Superior Corneal Incision

Introduction

To assess the 1-year outcomes of vertically fixated posterior chamber phakic intraocular lens implantation through a superior corneal incision.

Methods

This pilot study comprised 78 eyes of 53 consecutive patients undergoing vertically fixated implantable collamer lens (ICL) implantation through a superior corneal incision to correct moderate to high myopia and myopic astigmatism. We prospectively determined the safety, efficacy, predictability, stability, and adverse events preoperatively, and at 1 week and 1, 3, and 12 months postoperatively.

Results

The mean follow-up period was 10.4 ± 5.4 months. Uncorrected and corrected visual acuity were −0.20 ± 0.10 and −0.25 ± 0.07 logMAR, respectively, at 1 year postoperatively. At 1 year postoperatively, 98% and 100% of eyes were within 0.5 and 1.0 D, respectively, of the targeted correction. A nonsignificant change in manifest refraction of −0.01 ± 0.08 D occurred from 1 week to 1 year. The manifest astigmatism decreased significantly, from 0.69 ± 0.73 D preoperatively to 0.21 ± 0.27 D at 1 year postoperatively (Mann–Whitney U test, p < 0.001). No vision-threatening complications occurred at any time in this series.

Conclusions

According to our experience, the vertically fixated ICL through a superior incision achieved good results, without significant complications. Considering that younger patients requiring ICL surgery tend to have with-the-rule astigmatism, this surgical technique may be a viable option for reducing astigmatism without using toric ICLs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00470-6.

Accuracy of Intraocular Lens Calculation Formulas in Patients Undergoing Combined Phakic Intraocular Lens Removal and Cataract Surgery

PURPOSE

To investigate the prediction accuracy of intraocular lens (IOL) calculation formulas, and the impact of anterior chamber depth (ACD) and lens thickness (LT) measurement errors on IOL power calculation in patients undergoing combined phakic IOL (PIOL) removal and cataract surgery.

DESIGN

Retrospective, consecutive case series study.

METHODS

Thirty-six PIOL implanted eyes (12 anterior chamber PIOLs and 24 posterior chamber PIOLs [PC-PIOL]) undergoing cataract surgery were included. The prediction accuracy of new formulas (Barrett universal II, Emmetropia verifying optical, Kane, and Ladas super formula) and traditional formulas (Haigis, Hoffer Q, Holladay 1 and SRK/T) with or without Wang-Koch (WK) axial length (AL) adjustment was evaluated. The influence of ACD and LT measurement errors of IOLMaster 700 on refractive outcomes was also investigated.

RESULTS

The Kane and traditional formulas with WK AL adjustment had no significant systematic prediction error and displayed a smaller median absolute error, whereas the other formulas showed significant hyperopia shift (P < .05) and relatively lower prediction accuracy. The accuracy rate of IOLMaster 700 in measuring the ACD and LT was 100% in eyes with anterior chamber PIOL implantation, and 37.50% in the PC-PIOL subgroup. No significant difference was observed in refractive outcomes of formulas using correct and wrong parameters in the PC-PIOL subgroup (P > .05).

CONCLUSIONS

The Kane and traditional formulas with WK AL adjustment exhibited relatively higher prediction accuracy in patients who underwent combined PIOL removal and cataract surgery. The IOLMaster 700 displayed low accuracy in ACD and LT measurements for PC-PIOL implanted eyes, but showed negligible impact on IOL prediction accuracy.

Changes of ocular biometry in eyes with posterior chamber phakic intraocular lens implantation

OBJECTIVE

To evaluate changes in biometric variables and intraocular lens (IOL) calculation results after posterior chamber phakic IOL (PCPIOL) implantation.

METHODS

This retrospective, observational study included 65 eyes of 38 patients who underwent PCPIOL (EVO Visian ICL) implantation for correction of myopia. Prior to and a minimum of one year (mean 14.9 months) after EVO Visian ICL implantation, biometric variables and IOL calculation results were compared. Optical biometry, including anterior chamber depth, axial length, flat, steep, and mean keratometry values and IOL calculation results for the Holladay 2, Hoffer Q, Haigis, and SRK/T formulas were measured using the IOLMaster 700 SWEPT Source OCT biometer.

MAIN RESULTS

The mean anterior chamber depth decreased from 3.70±0.22mm to 3.34±0.39mm, the mean axial length increased from 26.61±1.61mm to 26.71±1.66mm, and the mean flat keratometry changed from 42.82±1.86 D to 42.73±1.83 D. These changes were statistically significant. The mean IOL power calculation also revealed a statistically significant decrease with all four formulas (ranging from 0.19 D to 0.30 D) after PCPIOL implantation.

CONCLUSIONS

Biometric variables and IOL calculation results showed statistically significant changes one year after EVO Visian ICL implantations. However, IOL power calculations yielded a decrease of less than 0.50 D, inducing much less refractive deviation in the spectacle plane; and the change was primarily related to an increase in AL measurements. IOL power calculations in eyes with EVO Visian ICL in situ provided satisfactory and reliable results.

Eight-Year Outcomes of Implantation of Posterior Chamber Phakic Intraocular Lens With a Central Port for Moderate to High Ametropia

Purpose: To assess the 8-year clinical outcomes of implantation of an implantable collamer lens (ICL) with a central port (KS-Aquaport; EVO-ICL) for moderate to high myopia and myopic astigmatism. Methods: This retrospective study comprised a total of 177 eyes of 106 patients with spherical equivalents of -7.99 ± 3.33 D [mean ± standard deviation], who underwent EVO-ICL implantation. We evaluated the safety, efficacy, predictability, stability, and adverse events of the surgery, at 1 month, and 1, 2, 4, 6, and 8 years postoperatively. Results: The logarithm of the minimal angle of resolution (LogMAR) uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were -0.07 ± 0.17 and -0.20 ± 0.09, respectively, at 8 years postoperatively. The safety and efficacy indices were 1.18 ± 0.24 and 0.89 ± 0.28, respectively. At 8 years, 83 and 93% eyes were within ± 0.5 D and ± 1.0 D of the targeted correction, respectively. Change in manifest refraction from 1 month to 8 years postoperatively was -0.13 ± 0.30 D. Three eyes (1.7%) that developed cataracts had a slight pre-existing peripheral anterior subcapsular cataract formation required simultaneous ICL extraction and cataract surgery at 2 or 3 years or ICL size change (1 size up) at 7 years postoperatively. We found that neither significant intraocular pressure (IOP) rise (including pupillary block) nor significant endothelial cell loss occurred in any case throughout the 8-year observation period. Conclusions: Current ICL implantation with central port technology offered good continuous outcomes for all measures of safety, efficacy, predictability, and stability for correcting moderate to high myopic errors over a long period, thereby suggesting its long-term viability as a surgical approach for the treatment of such eyes.

A Comparative Study of Two Types of Implantation Surgery Methods for Implantable Collamer Lenses

Purpose

To investigate the effects of two different surgical methods of implantable collamer lens (ICL) implantation on the operation time, visual outcomes, corneal endothelial cell count, and intraocular pressure (IOP).

Methods

This was a contralateral eye comparison study, a total of 192 eyes from 96 patients were included, and the two eyes from the same patient were randomly assigned to two groups (group 1 and group 2, with 96 eyes in each group). In group 1, after making the corneal incision, ophthalmic viscosurgical devices (OVDs) were first injected into the anterior chamber followed by ICL implantation. In group 2, the ICL was first implanted into the anterior chamber followed by OVDs injection. The operation time, uncorrected distance visual acuity, corrected distance visual acuity, spherical equivalent, corneal endothelial cell count, and IOP were recorded and analyzed.

Results

The operative time in group 1 was significantly longer than that in group 2 (P = 0.002 < 0.05). There were significant differences between IOP measured 2 hours following surgery of the two groups (P = 0.026 < 0.05), Furthermore, the rate of IOP change 2 hours following the operation was significantly higher in group 1 than in group 2 (P = 0.019 < 0.05). There were significant differences in the anterior chamber angle 2 hours after surgery compared with that before surgery in both groups (P = 0.014 < 0.05 and P = 0.029 < 0.05, respectively). No significant differences were observed in the other parameters measured (all P > 0.05).

Conclusion

The two ICL implantation methods had similar clinical outcomes and effects on the corneal endothelial cell count. Additionally, the implantation of an intraocular lens prior to injecting OVDs reduces the operation time and lowers the rate of IOP rise in the early postoperative period, making it safe and effective for ICL implantation.

Influence of tomographic and biomechanical corneal indexes on myopic refractive surgery indications: A multicenter study

PURPOSE

To evaluate the influence of corneal tomographic and biomechanical indexes on the refractive technique indication.

METHODS

A total of 251 eyes from 251 patients interested in refractive surgery were enrolled in this cross-sectional and multicenter study. Previous to the surgeon decision, a preoperative protocol was performed by refractive optometrists, containing four sections: refraction, biometry, corneal tomography and biomechanics. The refractive surgeons made a first decision based only on refraction, biometric and tomographic information. Biomechanical indexes were revealed, and refractive surgeons made a second indication. Additionally, for Laser-Assisted in-situ Keratomileusis cases, the percent tissue altered were calculated. Possible indications were no refractive surgery, photorefractive keratectomy, Laser-Assisted in-situ Keratomileusis or intraocular Collamer lens.

RESULTS

After the first surgery indication, the distribution was photorefractive keratectomy (47.4%), Laser-Assisted in-situ Keratomileusis (48.2%) while intraocular Collamer lens achieved 2.8%. This proportion changed significantly after the second indication regarding corneal biomechanics and photorefractive keratectomy and Laser-Assisted in-situ Keratomileusis decreased by 24% while intraocular Collamer lens increased 19%. A total of 69 eyes changed the indication (27.5%) and 182 eyes (72.5%) remained unchanged. All indications changes were from photorefractive keratectomy or Laser-Assisted in-situ Keratomileusis to intraocular Collamer lens or no surgery. Indication changes to intraocular Collamer lens were observed in 49 eyes (71%). Tomographic, biomechanical indexes, ablation depth and percent tissue altered achieved statistically significant differences between eyes without and with indication changes (all, P < .01).

CONCLUSION

New corneal biomechanical indexes could change the indication decision regarding biometric and tomographic data alone. Intraocular Collamer len was the preferred indication for eyes at risk of ectasia or with subclinical keratoconus due to corneal biomechanical parameters.

Five-year outcomes of EVO implantable collamer lens implantation for the correction of high myopia and super high myopia

Background

To evaluate the long-term safety, efficacy, predictability, and stability of implantable collamer lens with a central hole (EVO ICL) implantation for correcting high myopia (HM) and super high myopia (SHM).

Methods

This prospective study evaluated 83 eyes of 46 patients who were divided into groups based on their spherical equivalent refractive error (SE): HM group (− 12 D ≤ SE < − 6 D) and SHM group (SE < − 12 D). They were followed up for 5 years after ICL implantation; assessments of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive error, axial length, intraocular pressure, corneal endothelial cell density, and vault were conducted, and a questionnaire was administered.

ResuIts

At 5 years postoperatively, the safety indices of the HM and SHM groups were 1.03 ± 0.10 and 1.32 ± 0.39, and the efficacy indices were 0.83 ± 0.25 and 0.86 ± 0.32, respectively. In the HM group, 60.47% and 79.07% of the eyes were within ± 0.50 D and ± 1.00 D of the attempted correction, while it was achieved for 22.50% and 47.50% of the eyes in the SHM group, respectively. The SE of the HM group decreased from  − 9.72 ± 1.41 D preoperatively to 0.04 ± 0.39 D 1 month postoperatively and − 0.67 ± 0.57 D 5 years postoperatively, while in the SHM group, it decreased from − 15.78 ± 3.06 D preoperatively to  − 0.69 ± 0.97 D 1 month postoperatively and − 1.74 ± 1.19 D 5 years postoperatively.

Conclusion

EVO ICL implantation is safe, effective, and predictable for correcting HM and SHM. CDVA improved more after surgery for SHM, but the growth of axial length still needs attention.

A critical evaluation of longitudinal changes of astigmatism following implantation of toric implantable collamer lens (TICL): a comparison between treated and untreated cases over 4 years

PURPOSE

To evaluate residual astigmatism following correction with toric implantable collamer lens (TICL) (group I) over a period of 4 years and compare with the change of astigmatism in spectacle wearers (group II).

METHODS

Groups I (86 cases implanted with TICL [EVO + Visian ICL, Staar Surgical, Nidau, Switzeland], preop refractive error [sphere and cylinder] - 22.25 DS to - 1.00 DS and - 5.50 DC to - 1.00 DC) and II (80 cases initial refractive error [sphere and cylinder] - 18.00 DS to 0.00 DS and - 7.00 DC to - 1.00 DC) were reviewed annually. Refractive and tomography data were subjected to vector analysis to determine surgically induced astigmatism (SIA), angle of error [Δθ° = angle of target-induced astigmatism (TIA) - angle of SIA], and ΔC [TIA-SIA powers] and total corneal astigmatism (TCA) in group I and induced change in astigmatism (ICA) in group II.

RESULTS

In group I, on all occasions, SIA correlated with TIA (p < 0.05); differences between SIA and TIA means were insignificant and changes in TCA were not correlated with ΔC. Mean (± sd, 95% CI) residual astigmatic powers (RA) in attending group I cases (1-4 years) were - 0.40 DC (0.58, - 0.52 to - 0.28), - 0.40 DC (0.59, - 0.52 to - 0.27), - 0.41 DC (0.58, - 0.54 to - 0.28), and - 0.61 DC (0.74, - 0.82 to - 0.40). In group II, the corresponding ICA powers were - 0.47 DC (0.53, - 0.61 to - 0.32), - 0.49 DC (0.48, - 0.69 to - 0.29), - 0.60 DC (0.40, - 0.76 to - 0.44), and - 0.86 DC (0.71, - 1.19 to - 0.52). Differences between RA and ICA were not significant. Of the group I cases presenting at 1-4 years postop, 23, 18, 16, and 28 had RA powers ≤  - 0.75 DC. Of these 12, 10, 6, and 16 were associated with Δθ° > 5° (ΔC - 0.50 to 0 DC) and 5, 1, 4, and 4 were related to ΔC (Δθ° < 5°).

CONCLUSION

The development of astigmatism after TICL implantation is on par with the natural change in astigmatism in untreated cases. In about 50% of TICL cases presenting with astigmatism ≤  - 0.75 DC, the residual astigmatism could be neutralized by realigning the TICL.

Pure ICL Implantation: A Novel Ophthalmic Viscosurgical Device-Free Method

PURPOSE

To assess the clinical efficiency of a novel ophthalmic viscosurgical device-free (OVD-free) method for intraocular collamer lens (EVO-ICL) implantation in myopic eyes.

METHODS

In this study, 40 patients underwent ICL implantation for both eyes: one eye underwent traditional ICL implantation, and the other eye underwent OVD-free (pure) ICL implantation. Preoperative and postoperative UDVA, BCVA, equivalent spherical degree (SE), IOP, visual quality index, subjective visual quality scale, corneal endothelial cell density (ECD), operation time, and complications were compared between and within the traditional and pure ICL implantation groups.

RESULTS

Increased IOP >22 mmHg 2 h after surgery was noted in 8 eyes (20%) in the traditional group, but not in the pure group (0%, P < 0.001). Increased IOP relative to baseline was significantly higher at 2 h after surgery for the traditional group compared with the pure group (P < 0.001). UDVA, BCVA, and SE were significantly improved in the pure group compared with those in the traditional group 1 day (P < 0.001, P=0.003) after implantation, but not 1 week or 3 months after. Modulation transfer function cut-off frequency (MTF cut-off), Strehl ratio (SR), and OV20% were significantly better in the pure group than in the traditional group 1 day after implantation (P=0.013, P=0.009, and P=0.004). No significant difference in ECD changes within or between groups was observed (P > 0.05). The operation time for the pure group (2.897 ± 0.346 min) was significantly shorter than that for the traditional group (4.444 ± 0.656 min; P < 0.001). No complications were reported for either group during the observation period, except early IOP elevation in the traditional group.

CONCLUSIONS

The pure ICL implantation method was associated with faster visual acuity recovery, shorter operation time, and more stable intraocular pressure. Pure ICL represents a safe and convenient method for ICL implantation compared with the traditional method, completely eliminating OVD-related complications without causing additional complications.

One-step viscoelastic agent technique for ICL V4c implantation for myopia

AIM

To investigate the safety and efficacy of using a one-step viscoelastic agent technique for posterior chamber phakic implantable collamer lens with a central hole (ICL V4c) implantation for myopia correction.

METHODS

The one-step viscoelastic agent technique for ICL V4c implantation was used in 100 eyes of 52 patients. Refractive outcomes, intraocular pressure (IOP), corneal endothelial cell, and corneal densitometry values were evaluated at 1d, 1wk, 1 and 3mo postoperatively.

RESULTS

All the surgeries were uneventful. No corrected distance visual acuity was lost after 3mo. IOP was 16.12±3.18 mm Hg before surgery, and 14.74±3.08 mm Hg at 1d and 14.50±2.56 mm Hg at 3mo after surgery (P<0.05). Corneal endothelial cell density was 2580±242 cell/mm², the coefficient of variation in cell size was 42.11%±7.92%, and the percentage of hexagonal cells was 40.98%±9.46% before surgery. No significant difference was found when these outcomes were compared between the studied time points (P>0.05). The corneal densitometry values of the central 2 mm and 2 to 6 mm areas showed similar regularities. After surgery, the values significantly increased at 1d, then decreased to the preoperative values at 1wk, and then continued to decrease at 3mo (P<0.05).

CONCLUSION

The one-step viscoelastic agent technique for ICL V4c implantation is found to be safe and effective for myopia correction and causes little disturbance to the cornea.

Assessment of the Vault After Implantable Collamer Lens Implantation Using the KS Formula

PURPOSE

To examine the vault size after Implantable Collamer Lens (ICL) (KS-AquaPORT; STAAR Surgical) surgery using the KS formula.

METHODS

In this prospective study, the postoperative vault was examined using the KS formula in 121 eyes of 65 patients (28 men and 37 women) who underwent ICL implantation for myopia and myopic astigmatism. The mean horizontal angle-to-angle (ATA), anterior chamber depth, and axial length before surgery were 11.83 ± 0.40, 3.25 ± 0.34, and 26.52 ± 1.17, respectively. Anterior segment optical coherence tomography (CASIA2; Tomey Corporation) was used for ATA measurement.

RESULTS

Multiple regression analysis of the potential factors influencing the predicted vault error (postoperative vault - predicted vault by KS formula) showed that only ICL size was a significant factor (P < .001, r = 0.36). At an ICL size of 12.1 mm, the postoperative vault was smaller than the predicted vault, and the postoperative vault tended to be larger than the predicted vault at ICL sizes of 13.2 and 13.7 mm.

CONCLUSIONS

Vault prediction by the KS formula was generally good, but the ICL size influenced the vault prediction error; therefore, a modified KS formula was created to reduce the error in measurements of the postoperative vault. [J Refract Surg. 2021;37(9):636-641.].

Comparison of magnitude and summated vector mean of surgically induced astigmatism vector according to incision site after phakic intraocular lens implantation

Background

To compare the arithmetic mean (M-SIA) and the summated vector mean of surgically induced astigmatism (SVM-SIA) according to the incision site after phakic intraocular lens (Visian implantable collamer lens (ICL), STAAR Surgical) implantation.

Methods

This study comprised 121 eyes of 121 consecutive patients undergoing ICL surgery through a 3.0-mm temporal or superior clear corneal incision. The magnitude and the axis of corneal astigmatism preoperatively and 3 months postoperatively were measured using an automated keratometer. The M-SIA and the SVM-SIA were determined according to the incision site.

Results

The magnitude of corneal astigmatism significantly increased from 1.23 ± 0.59 D preoperatively to 1.46 ± 0.72 D postoperatively in the temporal incision group (Wilcoxon signed-rank test, P < 0.001), but it significantly decreased from 1.09 ± 0.36 D preoperatively to 0.86 ± 0.41 D postoperatively in the superior incision group (P < 0.001). The M-SIA was 0.48 ± 0.30 D, and the SVM-SIA was 0.23 ± 0.52 D at a meridian of 82° in the temporal incision group. The M-SIA was 0.57 ± 0.30 D, and the SVM-SIA was 0.47 ± 0.45 D at a meridian of 1° in the superior incision group.

Conclusions

ICL implantation induces the M-SIA by approximately 0.5 D, but the SVM-SIA decreased to 50% and 80% of the M-SIA in magnitude through temporal and superior incisions, respectively. The direction of the SVM-SIA showed a tendency toward corneal flattening to the incisional site. It should be noted that the M-SIA is somewhat different from the SVM-SIA according to the incision site.

Trial registration University Hospital Medical Information Network Clinical Trial Registry (000044269)

Changes in ocular parameters the crystalline lens after implantation of a collamer lens

CLINICAL RELEVANCE

Understanding changes in ocular anatomical parameters after intraocular lens implantation will allow a more accurate determination of dioptric power prior to surgery.

BACKGROUND

The crystalline lens position might change due to the implantation and removal of an implantable collamer lens (ICL) or toric implantable collamer lens (TICL). This study aimed to assess the effect of ICL implantation on position of the crystalline lens.

METHODS

This retrospective study was conducted on patients who underwent V4c ICL or V4c TICL implantation between March and September, 2018. Preoperative and post-operative (2 weeks, 3 months and 6 months) axial length, central corneal thickness, crystalline lens position, crystalline lens thickness and vault height were analysed. Multivariable linear regression was used to determine the variables associated with 6-month changes in lens position.

RESULTS

This study included 117 eyes of 117 patients. There were decreases in all vertical distance measures from the central corneal endothelium to the anterior and posterior crystalline lens capsule (all p > 0.05). The amount of reduction was related to the crystalline lens position before the operation and crystalline lens thickness after the operation (all p < 0.01). An error in anterior chamber depth and lens thickness may appear when the ICL/TICL is close to the crystalline lens.

CONCLUSION

Phakic intraocular lens implantation resulted in lens thickening and forward movement on day 1 post-operatively, which becomes stable within 6 months. Preoperative lens position and post-operative lens thickness were related to the amount of movement.

Comparison of visual outcomes after non-toric and toric implantable collamer lens V4c for myopia and astigmatism

PURPOSE

To evaluate the visual quality of myopic patients after non-toric versus toric implantable collamer lens (ICL and TICL, respectively) V4c, and to investigate the potential risk factors of postoperative night vision disturbances.

METHODS

This prospective cohort study included 42 eyes of 21 patients treated with ICL and 46 eyes of 23 patients treated with TICL. Refractive parameters and ocular aberrations were examined before and 6 months after surgery. Subjective quality of vision was scored by a validated questionnaire.

RESULTS

The efficacy index at 6 months was 1.14 ± 0.20 for ICL and 1.17 ± 0.16 for TICL; the safety index was 1.20 ± 0.17 for ICL and 1.20 ± 0.19 for TICL. The root mean square of total higher-order aberrations (HOAs) and trefoil was significantly increased, and no statistical differences between groups were detected in HOA changes. Many patients reported haloes (85.7% for ICL and 100% for TICL) and glare (76.2% for ICL and 65.2% for TICL), but most (94.4% for ICL and 95.5% for TICL) were satisfied or very satisfied with visual outcomes. Implantable collamer lens (ICL) toricity was the risk factor for frequency (OR = 2.81, p = 0.01), severity (OR = 3.85, p = 0.003) and bothering effect (OR = 2.89, p = 0.01) of haloes.

CONCLUSIONS

Implantable collamer lens and TICL provided comparable efficacy, safety and predictability, induced acceptable level of HOAs and achieved high satisfaction in correcting myopia and myopic astigmatism. Although not severe, haloes and glare have a non-negligible prevalence and ICL toricity is a potential risk factor of haloes.

Posterior chamber phakic intraocular lens with central-port design in 45- to 55-year-old patients: 1-year follow-up

PURPOSE

To assess the efficacy, safety, and predictability of the Visian implantable collamer lens with a central port in patients aged between 45 and 55 years.

SETTING

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

DESIGN

Retrospective case series.

METHODS

Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure (IOP), endothelial cell density (ECD), vault, and adverse events over a 1-year period were evaluated retrospectively.

RESULTS

A total of 87 eyes (49 patients) were evaluated. The mean postoperative UDVA and CDVA were 0.82 ± 0.24 and 0.93 ± 0.12, respectively. Seventy-eight eyes (approximately 90%) achieved a CDVA of 20/25 or greater. No eye lost 1 or more lines, 53 eyes (60.92%) did not change, 15 eyes (17.24%) gained 1 line, and 19 eyes (21.84%) gained 2 lines or more of CDVA. The efficacy and safety indexes were 0.95 and 1.08, respectively. Seventy-eight eyes (89.65%) were within ±0.50 diopter (D) of the desired sphere refraction, and all eyes (100%) were within ±1.00 D. Fifty eyes (57.7%) showed a spherical equivalent within ±0.13 D. The mean postoperative IOP was 13.58 ± 1.79 mm Hg, and no significant rise (>18 mm Hg) occurred during the follow-up. The largest proportion of eyes (35.63%) reported a reduction in IOP by 1 to 2 mm Hg. Postoperative mean ECD was 2574 ± 362 cells/mm2 (0.41% loss from the preoperative baseline). The mean postoperative vault was 398 ± 187 μm, being the most prevalent range from 201 to 300 μm (22.89% of eyes). No adverse events were reported during the study.

CONCLUSIONS

The outcomes reported in this study support the use of this lens in older patients.

Long-term assessment of crystalline lens transparency in eyes implanted with a central-hole phakic collamer lens developing low postoperative vault

PURPOSE

To assess long-term crystalline lens transparency in eyes implanted with phakic collamer intraocular lens (pIOL) with a central port and low postoperative vault for correction of myopia.

SETTING

Clinica Baviera, Madrid, Spain.

DESIGN

Retrospective cross-sectional single-center study.

METHODS

Using a noninvasive Fourier-domain swept-source anterior segment optical coherence tomography system, shifts in myopic and astigmatic myopic eyes implanted with a pIOL with vaulting lower than 100 μm in miosis and more than 4 years of follow-up were dynamically evaluated. Main outcome measures were pIOL dynamic vault (vault interval and vault range [VR]), crystalline lens density, and anterior subcapsular lens opacities. Crystalline lenses were examined under slitlamp microscopy, and lens density was evaluated using quantitative Scheimpflug images. Scheimpflug images were compared with those of a control group comprising eyes that were candidates for pIOL implantation.

RESULTS

The study population comprised 24 eyes from 16 patients previously implanted with a pIOL (5.82 ± 0.9 years) with central vault lower than 100 μm under photopically induced miosis. The mean vault value was 52 ± 19 µm under photopic light conditions and 113 ± 37 µm under scotopic conditions. The mean VR was 58 ± 24 μm. Anterior subcapsular lens opacities were found in only 1 eye (4.17%). The mean lens density was 7.94 ± 0.43, and no statistically significant differences were observed compared with the control group.

CONCLUSIONS

Long-term low vaulting in eyes implanted with a pIOL with a central port for correction of myopia was associated with a low risk for developing anterior crystalline lens opacities.