Comparison of Implantable Collamer Lens Visian ICL V4 and ICL V4c for high myopia: A cohort study

Bibliometric and visualized analysis of posterior chamber phakic intraocular lens research between 2003 and 2023

Introduction

Myopia is causing a major public health concern, with its prevalence increasing globally. This study aimed to discuss posterior chamber phakic intraocular lens (pIOL) research publication trends and hotspots over the past 20 years.

Methods

Bibliometric analysis was performed using the Web Science Core Collection to investigate posterior-chamber pIOL research publication trends. The extracted records were analyzed, and a knowledge map was built using VOSviewer v.1.6.20. The analysis included visualizing the annual publication count, countries/regions distribution, international and institutional collaborations, author productivity, and journal contribution, in addition to identifying knowledge bases and hotspots. Burst keywords were extracted using CiteSpace v.6.1.R.

Results

In total, 791 articles on posterior chamber pIOLs published between 2003 and 2023 were retrieved. China had the highest number of publications, whereas Japanese papers received the most citations. Fudan University had the highest number of publications, with articles from Kitasato University having the highest number of citations. Regarding individual research, Xingtao Zhou has published the most significant number of articles, and Shimizu Kimiya had the highest number of citations. The top productive/influential journal was 'Journal of Cataract & Refractive Surgery'. The top cited references primarily focused on reporting the clinical outcomes of implantable collamer lens (ICL) for individuals with moderate to high myopia. The keywords primarily formed four clusters: posterior chamber pIOL clinical outcomes for myopic astigmatism correction, posterior chamber pIOL implantation complications, ICL size selection and postoperative vault predictions, and postoperative visual quality following posterior chamber pIOL implantation.

Conclusion

This study presents the first bibliometric analysis of research trends in posterior chamber pIOL over the past two decades. We investigated the current state and emerging trends of global collaboration and research focal points in this field, offering fresh insights and guidance for researchers.

One-stage versus two-stage bilateral implantable collamer lens implantation: a comparison of efficacy and safety

Implantable collamer lens implantation (ICL) represents a safe and effective treatment for myopia and myopic astigmatism. To compare the outcomes of a bilateral one-stage same day approach to a two-stage approach, the databases of the University Eye Hospital Munich, Ludwig Maximilians-University and Smile Eyes Linz, Austria were screened for eyes that had undergone ICL implantation. Two-stage surgery was performed at an interval of 1 day (17 patients), 2 days (19 patients) and 1 week (2 patients). Variables analyzed were preoperative, 1-day and last follow-up uncorrected distance (UDVA) and corrected distance visual acuity (CDVA), manifest refraction, refractive spherical equivalent (SEQ), astigmatism, age, endothelial cell count (ECD), intraocular pressure (IOP) and ICL vaulting. In total, 178 eyes (100 eyes one-stage, 78 eyes two-stage) of 89 patients were included in this study. Mean follow-up was 1.1 ± 0.8 and 1.3 ± 0.5 years. Mean preoperative SEQ was - 7.9 ± 2.6 diopters (D) in the one-stage and - 8.0 ± 1.7 D in the two-stage group (p = 0.63) and improved to 0.00 ± 0.40 and - 0.20 ± 0.40 D at end of follow-up, showing slightly better stability in the one-stage group (p = 0.004). There was no difference in the efficacy (1.1 vs. 1.2, p = 0.06) and the safety index (1.2 vs. 1.2, p = 0.60) between the two groups. No eye (0%) in either group lost 2 lines or more of UDVA (p > 0.99). Refraction within ± 0.50 D and ± 1.00 D around target was achieved comparably often (89 vs. 86%, p = 0.65; 99 vs. 99%, p > 0.99). Endothelial cell loss was slightly higher in the two-stage group (1.3 vs. 4.3%). Vaulting at the final follow up was higher in the one-stage group (373.8 ± 205.4 µm vs. 260.3 ± 153.5 µm, p = 0.00007). There were no serious intraoperative complications in either group. In conclusion, this study demonstrates that both the one- and two-stage approaches are equally effective, predictable and safe. Regarding endothelial cell loss, vaulting and SEQ stability, the one-stage group showed slightly better outcomes, but these results are clinically questionable because they are so small. Larger studies are needed to quantitatively evaluate a potential benefit.

The influence of pupil diameter upon and subjective quality of vision following implantable collamer lens (ICL V4c) implantation: An observational study

This study aimed to assess the change in pupil size and its influence on subjective quality of vision (QoV) in subjects with implanted collamer lenses (ICLs). This retrospective study assessed 53 participants (53 eyes) implanted with ICL (V4c) and categorized them into incremental groups according to pupil diameter. Preoperative and postoperative photopic and mesopic pupil diameter, uncorrected distance visual acuity (UDVA), and QoV questionnaire scores were assessed and compared. Postoperatively, at 3 months, UDVA was -0.10 ± 0.06 logarithm of the minimum angle of resolution (LogMAR), and mean QoV for day and night was 9.34 ± 0.76 and 8.58 ± 1.29, respectively. The mean mesopic and photopic pupil diameters were 6.59 ± 0.79 mm and 4.61 ± 0.74 mm, respectively. Photopic pupil diameter negatively correlated with "QoV day" (Rs = -0.413, P = .001), positively correlated with "haloes" (Rs = 0.568*, P < .001) and "blurred vision" (Rs = 0.243, P = .04) respectively. Mesopic pupil diameter negatively correlated with "QoV night" (Rs = -0.426, P = .001), positively correlated with "haloes" (Rs = 0.624*, P < .001), "starburst" (Rs = 0.233, P = .046) and "difficulty focusing" (Rs = 0.27, P = .025), respectively. Participants had excellent VA at 3-month follow-up. Photopic and mesonic pupil diameter negatively correlated with QoV day and QoV night scores, respectively. Pupil diameter was found to have a more significant effect on visual symptoms at night, and lower QoV due to larger pupil size was more noticeable at night. Further investigation is needed to explore the importance of pupil diameter and its impact on the QoV in ICL implanted patients.

Comparison of higher-order aberrations between implantable collamer lens V4c implantation and simulated spectacle correction in patients with high myopia

PURPOSE

To investigate the differences in higher-order aberrations between non-toric or toric implantable collamer lens (ICL or TICL) V4c implantation and simulated spectacle correction.

METHODS

Patients with high myopia who underwent ICL/TICL V4c implantation were enrolled. The "total no defocus" pattern of iTrace aberrometry to simulate the condition of spectacle correction was measured before ICL/TICL implantation, and higher-order aberrations in this condition were compared to those 3 months after surgery. Related factors with changes in coma were comprehensively analyzed.

RESULTS

A total of 89 right eyes of 89 patients were included. Compared to simulated spectacle correction, total-eye coma (P<0.0001 ICL, P<0.0001 TICL) and internal coma (P<0.0001 ICL, P<0.001 TICL) decreased in the ICL- and TICL-treated groups after surgery. Total-eye secondary astigmatism (P<0.0001 ICL, P=0.007 TICL) and internal secondary astigmatism (P<0.0001 ICL, P=0.009 TICL) were also decreased in both groups postoperatively. Spherical error showed positive correlations with variation in total-eye coma (r=0.37, P=0.004 ICL; r=0.56, P=0.001 TICL) and internal coma (r=0.30, P=0.02 ICL and r=0.45, P=0.01 TICL). Axial length revealed negative correlations with changes in total-eye coma (r=-0.45, P<0.001 ICL; r=-0.39, P=0.03 TICL) and internal coma (r=-0.28, P=0.03 ICL and r=-0.42, P=0.02 TICL).

CONCLUSIONS

Both ICL- and TICL-treated groups demonstrated a decrease in coma and secondary astigmatism after 3 months, postoperatively. ICL/TICL may confer a compensatory effect on coma aberration and secondary astigmatism. Patients with a higher myopia achieved a greater improvement in coma and may benefit more from ICL/TICL implantation than from spectacle correction implantation than from spectacle correction.

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.

Posterior-Chamber Phakic Implantable Collamer Lenses with and without a Central Hole: A Comparative Study

Purpose

 This study aimed to compare the short-term outcome of implanting the Visian implantable collamer lens V4 ICL versus the Visian V4c ICL in patients with moderate and high myopia.

Patients and Methods

 This is a retrospective that was conducted on patients with moderate or high myopia who were scheduled for ICL implantation at our institution, Patients who underwent V4 ICL implantation with peripheral iridectomy were assigned to group A, and those who underwent V4c ICL implantation without peripheral iridectomy were assigned to group B. In group A, a preoperative peripheral iridectomy was performed. In group B, the patients received cycloplegic and dilating agents. The patients underwent a complete ocular examination preoperatively and during the follow-up visits that were conducted at 3, 6, and 12 months postoperatively.

Results

This study included 214 eyes from 107 patients; group A included 110 eyes, and group B included 104 eyes. Postoperatively, the UCVA and BCVA showed statistically significant improvement across the follow-up time points (p<0.001), with no significant difference between the two groups. No statistically significant difference was found between the two groups in the mean achieved correction or the residual refraction. Both groups showed a strong correlation between the target and the achieved correction, with R2 = 0.99 in the two groups. No significant difference was found between the two groups in the IOP across all time measures. However, the intraocular pressure showed a statistically significant postoperative increase in group A (p=0.004), and no significant change in group B (p=0.817). There was a downward slope in the vaults of both groups across time, with significant variation in the last follow-up measure compared to the 3-month measure in the two groups (p<0.001). No significant difference was found between the two groups across all time measures.

Conclusion

The current study adds new evidence concerning the feasibility, safety, and efficacy of ICL V4c implantation for the treatment of moderate and high myopia, with safer postoperative IOP.

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.

Clinical Outcomes of Toric Implantable Collamer Lens (T-ICL) and Toric Implantable Phakic Contact Lens (IPCL) for High Myopia with Astigmatism: A Comparative Study

Background:

Our study aimed to compare the clinical, visual outcomes, and efficacy of toric Implantable Collamer Lens (T-ICL) and toric implantable phakic contact lens (IPCL) in patients with high myopia and astigmatism over a follow-up period of 6 months.

Methods:

A prospective interventional randomized comparative study included 60 myopic eyes divided into 2 groups, group A including 30 eyes that were implanted with T-ICL, and group B, including 30 eyes that were implanted with toric IPCL. The refractive results, visual acuity, central corneal endothelial cell count, and intraocular pressure (IOP) were evaluated at baseline and at 1 and 6 months post-surgery. Any complications either during or after surgery were assessed.

Results:

In both study groups, the mean central corneal endothelial cell count was significantly decreased after 1 month and improved to reach near pre-operative values after 6 months postoperatively, indicating good lens biocompatibility. A statistically significant increase in IOP was found in both groups during the early follow-up, and a significant decrease after 6 months postoperatively (p=0.036) was reported in group A. A significant reduction in both spherical and cylindrical refractive errors with good predictability was reported in both groups compared with pre-operative values. Regarding the predictability, In T-ICL group (A), the median spherical and cylindrical errors were significantly improved from (-10 D & -4.5 D) pre-operatively to (-0.3 D & - 0.3 D) at the end of 6 months follow up period. Similarly, in the toric IPCL group (B), the median spherical and cylindrical errors were significantly improved from (-11 D & -4.5 D) pre-operatively to (-0.3 D & - 0.3 D) by the end of follow up period. A statistically significant improvement of UCDVA at 6 months postoperatively was found in both groups, as median preoperative LogMAR UCDVA was 1.1 and 1.3 in groups A and B respectively, which was improved to 0.3 in both groups at the end of follow-up period. There were no reported intra- or postoperative complications such as cataract, keratitis, or lens decentration.

Conclusion:

Toric IPCL is a suitable alternative to T-ICL for the management of high myopia with astigmatism, especially in developing countries, as it is cheaper and easier to implant than T-ICL. However, data over longer follow-up periods are needed to confirm its safety and stability.

Predictive factors for postoperative visual acuity improvement with ICL-V4c for ultrahigh myopia above - 10 D

PURPOSE

The purpose of this study is to evaluate the predictive factors for postoperative visual acuity improvement (PVAI) in subjects who underwent phakic intraocular lens implantation with a central hole (ICL-V4c) for ultrahigh myopia above - 10 D.

METHODS

This was a retrospective study. Eyes with ultrahigh myopia above - 10 D undergoing ICL-V4c implantation were studied. Univariable linear regression models were used to assess the association between PVAI and preoperative parameters. Myopic maculopathy was classified into 5 categories by fundus photography. After the 1-month follow-up, the PVAI was compared within different age and preoperative spherical degree groups.

RESULTS

This study included 726 eyes from 419 patients (111 men and 308 women), and the mean age, spherical refraction, and axial length were 28.67 ± 7.93 years, - 13.61 ± 3.44 D, and 28.59 ± 1.50 mm, respectively. At baseline, myopic maculopathy was classified (grades C0-C4) as follows: C0 was observed in 200 eyes (27.5%), C1 in 297 eyes (40.9%), C2 in 147 eyes (20.2%), C3 in 22 eyes (3.0%), and C4 in 60 eyes (8.3%). The PVAI was significantly negatively associated with age and positively associated with SD-pre(-Sph), but no significant association between myopic maculopathy classification and axial length was found. After 1 month, 417 eyes (57.4%) gained more than 1 line at BCVA, 250 eyes (34.4%) remained the same, and 59 eyes (8.13%) lost 1 line. The postoperative visual acuity of 52 eyes was improved by more than 3 lines, and 42.3% were grade C4.

CONCLUSIONS

The ICL performed well for the correction of ultrahigh myopia above - 10 D. Younger patients and those with a higher preoperative spherical degree had greater postoperative satisfaction.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2000036335). Date of registration: 2020/8/22.

Indications for exchange or explantation of phakic implantable collamer lens with central port in patients with and without keratoconus

AIM

To evaluate the causes of phakic implantable collamer lens (ICL) exchange/explantation in patients with and without keratoconus (KC) at two tertiary hospitals in Riyadh, Saudi Arabia.

METHODS

A retrospective chart review of all patients who underwent ICL (model V4c with central port) exchange/explantation was performed using the electronic medical record systems. All available preoperative and postoperative data were documented for each patient.

RESULTS

Over 7y, 2283 ICL implantation procedures were performed; 46 implants (2%) required exchange (21 implants)/explantation (25 implants), of which 14 cases (30.4%) were patients with KC. Indications for ICL exchange/explantation in non-KC group were vault measurement, cataract formation, increased intraocular pressure, inaccurate refraction, and patient dissatisfaction in 22 (68.75%), 4 (12.5%), 3 (9.37%), 2 (6.25%), and 1 (3.12%) case, respectively. The most common indication for ICL exchange/explantation in the KC group was inaccurate vault sizing in 11 patients (78.57%), inaccurate refraction in 2 patients (14.28%), and patient dissatisfaction postoperatively in 1 (7.14%) case.

CONCLUSION

ICL implantation results in predictable refractive outcomes over the long term with exchange/explantation rates comparable to previous literature. Improper vault size is the most common cause of ICL exchange/explantation among patients with or without KC.

In vivo optical quality of posterior-chamber phakic implantable collamer lenses with a central port

BACKGROUND

The aim of this review is to summarize the optical quality results in patients following the implantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc.).

MAIN TEXT

A literature search in several databases was carried out to identify those publications, both prospective, retrospective and/or comparative with other refractive surgery procedures, reporting optical outcomes of patients who were implanted with the V4c ICL model. A total of 17 clinical studies published between 2012 and 2021 were included in this review. A detailed analysis of the available data was performed including number of eyes, follow-up and preoperative spherical equivalent. Specifically, the review focused on several optical parameters including higher-order aberrations (HOAs), modulation transfer function (MTF) cut-off frequency and Strehl ratio. This review encompassed a total of 817 eyes measured using different optical devices based on Hartmann-Shack, retinal image quality measurement and ray-tracing technologies at different follow-ups.

CONCLUSIONS

The outcomes found in this review lead us to conclude that the ICL V4c model provides good optical quality, by means of different metrics, when implanted.

Comparison of the optical quality after SMILE and FS-LASIK for high myopia by OQAS and iTrace analyzer: a one-year retrospective study

BACKGROUND

To compare the correction effect and optical quality after small-incision lenticule extraction (SMILE) and femtosecond laser assisted laser in situ keratomileusis (FS-LASIK) for high myopia.

METHODS

51 high myopia eyes after SMILE and 49 high myopia eyes after FS-LASIK were enrolled and divided into two groups retrospectively. The OQAS and iTrace analyzer were used for optical quality inspection. Between the two groups the spherical equivalent (SE), astigmatism, uncorrected distant visual acuity (UDVA), strehl ratio (SR), modulation transfer function cutoff frequency (MTF cutoff), objective scatter index (OSI) and wavefront aberrations were analyzed and compared before surgery and at 1, 6 and 12 months after surgery.

RESULTS

After the operation: (1) SE and astigmatism declined and UDVA increased significantly in both groups, and UDVA was better after SMILE than FS-LASIK. (2) SR and MTF cutoff reduced and OSI increased significantly after SMILE and FS-LASIK. SR and MTF cutoff were significantly higher after SMILE than FS-LASIK. OSI was significantly lower after SMILE than FS-LASIK. (3) The total wavefront aberration, total low-order wavefront aberration, defocus and astigmatism aberration as well as trefoil aberration reduced significantly in both groups. The total high-order wavefront aberration increased significantly after FS-LASIK. The spherical and coma aberration increased significantly in both groups. The total high-order wavefront aberration and coma aberration at 1 month were higher after FS-LASIK than SMILE.

CONCLUSION

The optical quality descended after SMILE and FS-LASIK. SMILE was superior to FS-LASIK at the correction effect and optical quality for high myopia. The combination of OQAS and iTrace analyzer is a valuable complementary measurement in evaluating the optical quality after the refractive surgery.

TRIAL REGISTRATION

This is a retrospective study. This research was approved by the ethics committee of Xiangya Hospital and the IRB approval number is 201612074.

Detection of Static and Dynamic Stereopsis after Femtosecond Laser Small Incision Lenticule Extraction for High Myopia

Purpose

The purpose of this study is to test binocular visual function after femtosecond laser small incision lenticule extraction (SMILE) for high myopia. The traditional Titmus stereotest and dynamic stereotest based on the visual perception biological model were used for comparative analysis.

Methods

A total of 43 patients were enrolled in this prospective study. At Week 1, Month 1, and Month 3 after surgery, the Titmus stereotest and dynamic stereotest generated by MATLAB were conducted. Dynamic stereopsis consists of randomly flickering Gabor spots and is divided into two models of high energy and low energy according to flicker frequency.

Results

The preoperative manifest refraction spherical equivalent was −7.21 ± 0.70 D. The preoperative anisometropia was 0.52 ± 0.54D. The quartiles of static stereoacuity in preoperation and 3 follow-ups were as follows: 50.00 (25.00, 100.00) in preoperation, 63.00 (40.00, 63.00) at Week 1, 40.00 (32.00, 63.00) at Month 1, and 40.00 (25.00, 50.00) at Month 3. Static stereopsis improved at Month 1 and Month 3 compared with preoperation and Week 1 (P < 0.05). There were statistically significant differences in high energy dynamic stereopsis at Week 1 and Month 1 compared to preoperation (P < 0.05). In addition, significant differences in low energy dynamic stereopsis were detected between Month 1 and preoperation and also at Month 3 compared to Month 1 (P < 0.05).

Conclusion

Most high myopia patients have a dynamic stereopsis deficiency before refractive correction. SMILE surgery can improve both static and dynamic stereopsis early in the postoperation period. However, in the long term, there is no significant difference or even a decrease in dynamic stereopsis.

Effect of the EVO+ Visian Phakic Implantable Collamer Lens on Visual Performance and Quality of Vision and Life

PURPOSE

To assess the effect of EVO+ (V5) Visian implantable collamer lens implantation on mesopic visual performance, quality of vision (QoV), and quality of life (QoL).

DESIGN

Prospective interventional case series.

METHODS

Thirty-six eyes of 36 participants who underwent EVO+ implantation for myopia were evaluated preoperatively and at postoperative visits at 1 week and 1, 3, and 6 months. Visual acuity (VA) and mesopic contrast sensitivity (CS) with and without halogen- and xenon-type glare sources were evaluated at each visit. Subjective QoV was assessed with the QoV questionnaire and QoL assessed with the Quality of Life Impact of Refractive Correction (QIRC) questionnaire at each visit. Ring-shaped dysphotopsia was also assessed at each postoperative visit. Linear, cumulative link and logit mixed models were fitted to analyze the effect of the EVO+.

RESULTS

Following EVO+ implantation, VA significantly (P ≤ .012) improved at the 4 postoperative visits. Mesopic CS progressively improved at 1, 3, and 6 months postoperatively (P ≤ .012). Halogen glare CS decreased at 1 week and halogen and xenon glare CS improved at 6 months (P ≤ .016). Photostress recovery time after halogen glare improved at 3 and 6 months (P ≤ .004). QoV scores improved at 1 week and 3 and 6 months (P ≤ .001). QIRC scores improved postoperatively (P < .001). Ring-shaped dysphotopsia decreased at 3 and 6 months (P ≤ .007).

CONCLUSIONS

EVO+ implantation provides good mesopic visual performance, QoV, and QoL during up to 6 months follow-up. Some activities performed under mesopic conditions with glare sources may be affected during the first postoperative week. Ring-shaped dysphotopsia is negligibly bothersome 6 months after surgery.

Visian® ICLV4c™ and Artiflex®: Comparative Analysis with the HD AnalyserTM and Integration with Subjective Performance and Anatomical Parameters

Purpose

To analyze and compare the mid-term objective and subjective performance of two phakic intraocular lenses (PIOLs) – Visian^® ICL™ V4c and Artiflex^® and to correlate those results with anatomical parameters.

Patients and Methods

Observational retrospective study including thirty patients (15 for each PIOL) randomly selected from those who underwent bilateral implantation of one of the PIOLs (60 eyes were analysed). Uncorrected and corrected distance visual acuities (UDVA and CDVA), anterior chamber structural parameters, and corneal endothelial cells density and morphology were evaluated. Quality of vision was assessed both subjectively with a questionnaire, and objectively using a double-pass technology optical quality analysis system.

Results

At the end of follow-up the Artiflex^® group showed better UDVA (0.95±0.11 vs 0.99±0.05, p=0.027) and higher proportion of eyes reaching at least 20/20 (28/30 vs 18/30, p=0.005). Excellent and similar objective scatter index (1.79±0.9 vs 2.14±1.6, p=0.306) and modular transfer function cutoff frequency (26.91±9.2 vs 26.51±11.9, p=0.784) results were achieved in the HD Analyzer^® and the questionnaire showed comparable high Satisfaction (55.7±3.5 vs 54.3±5.4, p=0.386) and low Dysphotopsia Scores (3.1±1.8 vs 2.1±2.2, p=0.213). The ICL group showed inferior anterior chamber volume (p<0.001), and angle (p<0.001) and superior pupillary diameter (p=0.007). Minimum follow-up was 24 months.

Conclusion

Both the Visian^® ICLV4c™ and the Artiflex^® showed excellent optical performance through the HD Analyzer^TM technology, translated in high patient satisfaction. Overall, both PIOLs showed similar safety, predictability, stability and effectiveness of for the reduction of high sphero-cylindrical refractive errors, despite better UDVA results with the Artiflex^®.

Long-Term Outcomes of Retinal Detachment in Phakic Eyes After Implantation of Implantable Collamer Lens V4c for High Myopia Correction

Aim: To estimate whether implantable collamer lens (V4c ICL) implantation increases the risk of retinal detachment in high myopia comparing with myopes with Rigid Gas-Permeable (RGP) correction.

Methods: This prospective study was comprised of an ICL group (704 eyes) and an RGP group (628 eyes). Patients were enrolled according to the inclusion criteria and exclusion criteria, then divided into the ICL group and RGP group. Patients in the ICL and RGP groups received V4c ICL implantation and RGP fitting respectively. Retinal details, spherical equivalent refraction (SE), uncorrected distance visual acuity (UDVA), corrected distance vision acutivity (CDVA), axis length (AL), anterior chamber depth (ACD) and other relevant parameters were recorded at different time points. Rhegmatogenous retinal detachment (RRD) morbidity and incidence, RRD morphology and relevant parameters were analyzed.

Results: All enrolled patients were followed for 3–6 years. Patients characteristics before the refractive procedure did not show a statistical difference. At the end of the follow up, all the RD cases were RRD. The RRD morbidity of the ICL group and RGP group was 1.99% (14 eyes) and 0.96% (6 eyes) respectively, which did not show statistical difference (P = 0.12). During the first year after refractive procedure, the RRD incidence of the ICL group was 0.85% (6/704), while this number of the RGP group was 0.16% (1/628). It did not show statistical difference (P = 0.08).

Conclusion: Compared with RGP fitting, V4c ICL implantation for high myopia correction does not add RRD risk in the long term. V4c ICL implantation is a safe method for high myopia correction.

Clinical observations of iridociliary cysts and their changes after implantable collamer lens implantation in myopic patients

AIM

To observe the characteristics of iridociliary cysts in myopic patients and evaluate the influences on the position and safety of implantable collamer lens (ICL) after surgery.

METHODS

Totally 270 eyes of 135 patients who underwent ICL surgery for the corrections of myopia were included in this study. Preoperative and postoperative morphology of iridociliary cysts were observed in ultrasonic biomicroscopy (UBM) image.

RESULTS

A total of 138 iridociliary cysts were found in 88 eyes of 50 patients among 270 eyes of 135 patients before surgery (37%). Twenty-five patients had cysts in one eye (50%) and 25 had cysts in both eyes (50%). The prevalence of iridociliary cysts was negatively correlated with age, but no gender difference (P>0.05). The incidence of iridociliary cysts was much less in eyes with myopia greater than -9.00 D (P<0.05). The diameter of the largest cyst was 1.96 mm and the smallest cyst was 0.24 mm, with a majority within the range of 0.5 to 1.0 mm. Most of the cysts were located in the inferior temporal quadrant. One year after ICL implantation, 51 iridociliary cysts (37%) remained unchanged, 47 cysts (34%) decreased in size, and 40 cysts (29%) disappeared. Most of cysts that changed after surgery were smaller than 1.0 mm (P<0.05) and located in the nasal and temporal sides around the haptics of implantable lens. All the ICL were in their original position.

CONCLUSION

Iridociliary cysts are commonly seen in myopic eyes. The cysts have no impact on the safety of ICL surgery. Some cysts may decrease in size or disappear after ICL implantation.

One-year natural course of corneal densitometry in high myopic patients after implantation of an implantable collamer lens (model V4c)

BACKGROUND

Corneal densitometry, which is also known as corneal backscattering, is a surrogate measure of corneal clarity. The purpose of the study was to investigate the changes in corneal densitometry (CD) after implanting an implantable collamer lens (ICL-V4c).

METHOD

Twenty-six high myopic patients (aged 29.3 ± 6.6 years, 6 males and 20 females) who underwent ICL-V4c implantation were enrolled. Intraocular pressure (IOP), corneal topography, corneal densitometry, uncorrected distance visual acuity (UCDVA), manifest refraction, and best corrected distance visual acuity (BCDVA) were evaluated pre-operatively and at 1 day, 1 week, and 1, 3, 6, and 12 months post-operatively. Endothelial cell density (ECD) was measured pre-operatively and at 3, 6, and 12 months post-operatively. The efficacy index (mean post-operative UCDVA / mean pre-operative BCDVA) and the safety index (mean post-operative BCDVA / mean pre-operative BCDVA) were evaluated at 1 month, 3 months, 6 months and 12 months post-operatively.

RESULTS

Over the annular diameters of 0-2 mm, the pre-operative densitometry values of the anterior layer, central layer, posterior layer, and total layer were 20.1 ± 2.8, 11.8 ± 1.1, 10.5 ± 0.9 and 14.1 ± 1.5, respectively. From pre-operatively to post-operative Month 12, the values changed insignificantly (P = 0.177, P = 0.153, P = 0.543 and P = 0.207, respectively). Over the annular diameters of 2-6 mm, the pre-operative mean densitometry values were 17.9 ± 2.2, 10.5 ± 0.9, and 12.6 ± 1.2, respectively. From pre-operatively to post-operative Month 12, the values decreased to 16.5 ± 2.1, 10.0 ± 0.9, and 11.9 ± 1.2, respectively, which were similar to the pre-operative values (all P > 0.05) but significantly lower than the values obtained at post-operative Day 1 (P = 0.013, P = 0.002 and P = 0.010, respectively). The densitometry value of the posterior layer over the annular diameters of 2 to 6 mm remained unchanged (from 9.4 ± 0.7 to 9.1 ± 0.7) over time (P = 0.372). The efficacy and safety indices assessed at 12 months post-operatively were 1.04 ± 0.27 and 1.19 ± 0.23, respectively. The changes in IOP and ECD values were statistically insignificant (P = 0.896 and P = 0.968, respectively).

CONCLUSION

ICL-V4c implantation may be safe and efficient for high ametropia correction. The corneal densitometry values obtained over the annulus of 0-6 mm increased slightly from before the operation to post-operative Day 1 and then decreased gradually, which indicates that ICL-V4c implantation may not compromise corneal clarity.

Phakic Posterior Chamber Intraocular Lens with a Central Hole in Treating Patients with Moderate to High Myopia: A Meta-Analysis

Purpose

To evaluate the efficacy of phakic posterior chamber intraocular lens with a central hole (ICL V4c) in treating patients with moderate to high myopia.

Methods

PubMed, Embase, Cochrane Library, Clinical Trial, China Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), and China Science Periodical Database (CSPD) were searched online. The search included publications from the building of the library until December 2018. All randomized controlled trials containing moderate to high myopia treated by phakic posterior chamber intraocular lens with a central hole were collected. Literature search, screening literature, data extraction, and quality evaluation were independently performed by two reviewers. Meta-analysis was performed using RevMan 5.3 software.

Results

Meta-analysis results based on five randomized controlled trials showed that ICL V4c and ICL without a central hole had similar UCVA results (SMD = 0.08, 95% CI (−0.71, 0.88), P=0.84), SE (SMD = −0.18, 95% CI (−0.52, 0.15), P=0.29), BCVA (SMD = −0.27, 95% CI (−0.93, 0.40), P=0.43), and IOP (SMD = 0.03, 95% CI (−0.24, 0.30), P=0.84), and the difference was not statistically significant. In addition, no complications that could jeopardize vision occurred.

Conclusions

Implanting ICL V4c in patients with moderate to high myopia is safe and effective.

Accommodation changes after visian implantable collamer lens with central hole for high myopia: A STROBE-compliant article

To characterize the accommodative changes in high-myopic patients after the implantation of the Visian implantable collamer lens with a central hole (ICL V4c).This prospective study enrolled 30 patients (60 eyes) with uneventful surgery of ICL V4c implantation. Parameters including amplitude of accommodation (AA), monocular and binocular facility of accommodation (FA), positive relative accommodation (PRA), negative relative accommodation (NRA), near point convergence (NPC), accommodative response, and accommodation convergence/accommodation (AC/A) ratio were assessed before surgery, at 1 and 3 months postoperatively.Mean preoperative SE was -10.86 ± 3.87 diopter (D) (range, -6.5D to -22D), which improved to 0.27 ± 0.51D at 1 month and 0.09 ± 0.47D at 3 months after surgery (P <.001). Significant improvements in AA, NRA, PRA, NPC, monocular, and binocular FA were seen at 1 month and 3 months postoperatively compared to the values before surgery (P <.05), but the difference between 1 month and 3 months were not obvious (P >.05) except for binocular FA (P = .002). However, no significant changes were seen in either AC/A ratio or accommodative response at any postoperative follow-ups in contrast to those before surgery (P >.05). Similar changes in accommodative function were found in patients with less myopia (> -10.00D) and those with more myopia (≤10.00D) (P >.05).The accommodative function of eyes after the implantation of ICL V4c is enhanced and stabilizes at 1 month, except for the AC/A ratio and accommodative response. The clearer vision and increased amount of accommodation for near target account for the majority of the improvement.

Altered whole-brain gray matter volume in high myopia patients: a voxel-based morphometry study

High myopia (HM) was associated with impaired long-distance vision. Previous neuroimaging studies showed that abnormal visual experience leads to dysfunction in brain activity in HM even corrected. However, whether alterations in brain structure occur in HM remains unknown. In this study, we analyzed the difference in the whole-brain gray matter volume (GMV) and white matter volume between HM patients and healthy controls (HCs) using a voxel-based morphology method. A total of 82 HM patients (52 men and 30 women) and 58 HCs (28 men and 30 women), matched closely in terms of age and education, were enrolled in this study. All participants underwent MRI scans. The MRI data were processed using the SPM8 software. The relationship between the mean GMV values of the brain regions and clinical features, including refractive diopter and the mean retinal nerve fiber layer thickness, in the HM group were analyzed using Pearson’s correlation. Compared with HCs, HM patients showed significantly decreased GMV values in the right cuneus/lingual gyrus and the right thalamus. In contrast, HM groups showed higher GMV values in the brain stem, right parahippocampal gyrus/thalamus, left parahippocampal gyrus/thalamus, as well as the right and the left putamen. No significantly different white matter volume values were found between the two groups. Moreover, in the HM group, the mean retinal nerve fiber layer of the left eye showed a negative correlation with the mean GMV values of the brain stem (r=−0.218; P=0.049), right parahippocampal gyrus/thalamus (r=−0.262; P=0.017), left parahippocampal gyrus/thalamus (r=−0.249; P=0.024), and left putamen (r=−0.232; P=0.036). We found that HM patients showed an altered brain structure in the visual pathway regions and the limbic system, which may provide useful information to explore the neural mechanisms of impaired long-distance vision in HM.

The Implantable Collamer Lens with a central port: review of the literature

The purpose of this review is to summarize preclinical and clinical data from publications appearing in the peer-reviewed scientific literature relevant to the safety and effectiveness of the EVO Implantable Collamer Lens (ICL) posterior chamber phakic refractive lens with a central port (V4c Visian ICL with KS Aquaport, STAAR Surgical, Inc.). A literature search was conducted using PubMed.gov to identify all articles relating to the EVO ICL. Articles were examined for their relevance, and the references cited in each article were also searched for additional relevant publications. On the basis of a total of 67 preclinical studies and clinical reports, including effectiveness data on 1,905 eyes with average weighted follow-up of 12.5 months and safety data on 4,196 eyes with weighted average follow up of 14.0 months, the EVO ICL is safe and effective for the correction of a broad range of refractive errors. High levels of postoperative uncorrected visual acuity, refractive predictability, and stability demonstrate the effectiveness of the EVO ICL. Safety data suggest reduced rates of anterior subcapsular cataract and pupillary block compared with earlier models. Improved safety and proven effectiveness make EVO an attractive option for surgeons and patients.

Posterior Chamber Phakic Intraocular Lens Implantation in Eyes with an Anterior Chamber Depth of Less Than 3 mm: A Multicenter Study

This study was aimed to assess the clinical outcomes of Visian ICL (hole ICL; STAAR Surgical, Inc.) implantation for the correction of myopic refractive errors in eyes having an anterior chamber depth (ACD) below the current manufacturer's recommendation (<3.0 mm). We comprised 365 eyes of 201 consecutive patients (mean age ± standard deviation, 35.7 ± 7.5 years) with spherical equivalents of -8.66 ± 3.54 D. We evaluated the safety, efficacy, predictability, stability, intraocular pressure (IOP), endothelial cell density (ECD), and complications. The safety and efficacy indices were 1.12 ± 0.22 and 0.98 ± 0.22. At 1 year, 90% and 98% of eyes were within ± 0.5 and 1.0 D of the attempted correction, respectively. Changes in the manifest refraction from 1 week to 1 year postoperatively were -0.08 ± 0.34 D. The mean ECD loss was 0.2 ± 8.7%. No eyes showed a significant ECD loss (≥30%). We found no significant correlation between the ACD and the change in ECD (Pearson correlation coefficient r = -0.048, p = 0.360). No significant IOP rise or vision-threatening complication occurred at any time. These findings indicate that the surgical indication of ICL implantation should be reconsidered in terms of ACD.

Long-Term Clinical Observation of Posterior Chamber Phakic Intraocular Lens Implantation in Young Population

OBJECTIVES

To compare the clinical outcomes and vision-related quality of life after implantable collamer lens (ICL) implantation for younger patients (17 years ≤ age ≤21 years) and for older patients (age >21 years).

METHODS

Design: Retrospective observational study. This study-enrolled patients underwent ICL implantation and finished 5-year follow-up who were divided into two groups based on age. Uncorrected distance visual acuity and corrected distance visual acuity (CDVA), refractions for the evaluation of efficacy, safety, stability, and predictability, intraocular pressure, corneal endothelial cell, ICL vaults, higher-order aberration (HOA), contrast sensitivity (CS) functions, adverse events, and quality of life were evaluated on 1, 3, 7, 14 days, 1, 3, 6 months and 1, 3, 5 years after surgery.

RESULTS

The study enrolled 164 eyes (82 patients), 84 in younger group (17 years ≤ age ≤21 years) and 80 in older group (age >21 years). The mean postoperative log of minimal angle of resolution CDVA of younger group was better than those of older group. The mean spherical equivalent values were more myopic in younger group than older group. As for CS and HOA, the younger and older groups showed similar data. The NEI-RQL scores of dependence on correction, worry, suboptimal correction, appearance, and satisfaction of older group were higher, whereas the score of symptom and near vision was worse. Both groups showed similar results in vaults, endothelial cell density and adverse events.

CONCLUSIONS

The ICL performed well for the ametropia correction of both younger and older patients throughout the 5-year period. In the younger group, the visual quality was even better, but the myopic shift was quicker.

Refractive outcomes and optical quality after implantation of posterior chamber phakic implantable collamer lens with a central hole (ICL V4c)

Background

To investigate refractive outcomes and optical quality after implantation of posterior chamber phakic implantable collamer lens with a central hole (ICL V4c) to correct high myopia.

Methods

Sixty seven eyes of 38 patients who underwent ICL V4c implantation were enrolled. The mean preoperative spherical equivalent (SE) was − 12.44 ± 3.15 D (range: − 6.63 to − 20.50 D). The refractive outcomes and optical quality of the eyes at postoperative 1 and 3 months were evaluated and compared.

Results

At 3 months postoperatively, the mean safety and efficacy indexes were 1.33 ± 0.22 and 1.14 ± 0.23, respectively. The mean SE was − 0.32 ± 0.52 D; no patient lost 1 or more lines of corrected distance visual acuity (CDVA), 13% remained unchanged, 45% gained 1 line and 42% gained 2 or more lines. The mean modulation transfer function cutoff frequency (MTF_cutoff), Strehl in two dimensions ratio, and objective scatter index (OSI) were 38.20 ± 9.96 cycles per degree, 0.21 ± 0.06, and 1.00 ± 0.73, respectively. No significant difference was found in any of the above parameters (P > 0.05) between 1 and 3 months. The postoperative intraocular pressure (IOP) did not change when compared with preoperative values (P > 0.05).

Conclusions

ICL V4c implantation is a safe, effective, and stable solution for high myopia. Patients will acquire high and stable postoperative optical quality. ICL V4c implantation has little influence on IOP.