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

Comparison of Vault Measurements Using a Swept-Source OCT-Based Optical Biometer and Anterior Segment OCT

Background

To newly describe the vault measurement by using a widely used swept-source OCT-based optical biometer (IOLMaster700) and accessd the accuracy of vault measurement.

Methods

This was a retrospective, cross-sectional study. All patients underwent implantable Collamer lens (ICL) implantation surgery without complications. IOLMaster700 and AS-OCT analyses were conducted for each eye on the same day in the same condition. Measurements of anterior chamber depth (ACD), corneal-ICL (C-ICL), and vault values were made and recorded. The repeatability of the IOL Master700 measurements was quantified based upon intraclass correlation coefficient (ICC) values. Correlations between IOL Master700 and AS-OCT measurements made with these different analytical approaches were assessed. The agreement of instruments was evaluated using Bland-Altman plots.

Results

The IOLMaster700 instrument yielded highly reliable measurements of vault, C-ICL, and ACD (ICC = 0.996, 0.995, 0.995, respectively). Vault, C-ICL and ACD values as measured using the IOLMaster700, was slightly smaller than that measured via AS-OCT, but these differences were not significant (p = 0.652, p = 0.121 and p = 0.091, respectively). The vault, C-ICL, and ACD measurements by these two instruments were strongly correlated (r = 0.971, r = 0.944, and r = 0.963, respectively; all p < 0.001). The 95% limits of agreement for vault, C-ICL, and ACD measurements between the two devices were−0.08 to 0.08 mm,−0.14 to 0.11 mm, and−0.13 to 0.10 mm, respectively.

Conclusions

The IOLMasrer700 can measure implanted ICL vault with a high degree of accuracy and repeatability. Good correlations and agreement were observed between IOLMaster700 and AS-OCT in measuring vault, C-ICL, and ACD measurements.

Evaluation of the EVO/EVO+ Sphere and Toric Visian ICL: Six Month Results from the United States Food and Drug Administration 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 Visian ICLs) for correction of moderate-to-high myopia with or without astigmatism.

Patients and Methods

Six-month results of a multicenter clinical trial performed under United States FDA Investigational Device Exemption. Subjects 21 through 45 years of age with myopia ranging from -3.00 D to -20.00 D and astigmatism up to 4.00 D underwent implantation of EVO or EVO+ Sphere or Toric Visian 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 clinical trial enrolled 629 eyes of 327 subjects with mean age 35.6 ± 5.09 years. Mean preoperative spherical equivalent (SE) measured -7.62 ± 2.75 D (range: -3.00 to -15.62 D). At 6 months, mean SE was -0.079 ± 0.33 D, with 90.5% within ± 0.50 D of target and 98.9% within ±1.00 D of target. Mean postoperative UDVA and CDVA were -0.059 ± 0.10 logMAR and -0.13 ± 0.08 logMAR, respectively. 52.3% of eyes gained lines of CDVA. Efficacy and safety indices were 1.06 and 1.24, respectively. No eye experienced pupillary block, required 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 2.3%.

Conclusion

EVO ICL lenses demonstrated accuracy of refractive correction and achievement of high levels of UDVA. This clinical trial confirmed that the central port design of EVO and EVO+ Sphere and Toric Visian ICL lenses functions effectively to allow physiologic flow of aqueous humor, thus eliminating the requirement for preoperative peripheral iridotomies. The results of this clinical trial resulted in FDA approval on March 25, 2022.

U.S. military implantable collamer lens surgical outcomes: 11-year retrospective review

PURPOSE

To examine the long-term efficacy and safety of myopic implantable collamer lens (ICL) implantation in active duty personnel of U.S. military.

SETTING

Hospital practice.

DESIGN

Retrospective longitudinal observational study.

METHODS

1485 patients (median age 25, interquartile range 22 to 29) underwent ICL surgery. Patients received a preoperative examination including uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), manifest refraction measuring corrected distance visual acuity (CDVA), corneal topography and tomography, qualitative grading of perceived ectatic risk, ophthalmic biometry, and baseline endothelial cell counts (ECCs). Outcome measures included UDVA, IOP, vault size, manifest refraction, CDVA, and ECCs. The long-term follow-up data ware drawn from the U.S. military medical record system.

RESULTS

A total of 3105 eyes were evaluated. Patients received ICLs because of either abnormal topography (2111 eyes [68%]) or high myopia (994 eyes [32%]). 94 eyes (80%) maintained UDVA of 20/25 or better up to 8 years postoperatively. The rate of achieving the desired refractive correction was 97% (503 eyes) at 1 year and 90% (81 eyes) at 8 years. Stability of these outcomes was also shown by minimal change in manifest refraction. Documented mean ECC loss was 22% at postoperative year 5. The overall rate of adverse events was 1.2% (36 eyes) including visually significant cataract formation, glaucoma, retinal detachment, and traumatic incision opening. A removal or replacement rate of 4.5% (135 eyes) was observed.

CONCLUSIONS

ICL implantation was found to be effective and safe. Vault sizes decreased over time, suggesting an increased risk of cataract formation after 7 years. Further study is necessary to assess long-term clinical significance of ECC decline.

Efficacy and Safety After Toric Posterior Chamber Implantable Collamer Lens and Toric Iris-Fixated Foldable Phakic Intraocular Lens for Myopic Astigmatism

PURPOSE

To compare visual, refractive, and safety outcomes of toric posterior chamber Implantable Collamer Lens (T-ICL) (STAAR Surgical) and toric iris-fixated foldable phakic intraocular lens (IOL) (T-Artiflex; Ophtec BV) implantation for the correction of myopic astigmatism.

METHODS

This retrospective cohort study included 312 eyes of 312 patients who had phakic IOL implantation for myopic astigmatism. Two groups were defined: 205 eyes that underwent T-ICL implantation and 107 eyes that underwent T-Artiflex implantation. Safety, efficacy, and predictability outcomes were evaluated preoperatively and at 12 months postoperatively. Refractive and corneal astigmatic vector analysis were performed using the Alpins method.

RESULTS

One year postoperatively, uncorrected distance visual acuity was 0.05 ± 0.18 (T-ICL) and 0.10 ± 0.16 (T-Artiflex) logMAR, with efficacy indexes of 1.16 ± 0.27 and 1.05 ± 0.31, respectively (P < .001). Safety indexes were 1.28 ± 0.30 and 1.21 ± 0.31, respectively (P = .04). Spherical equivalent was within ±0.50 diopters (D) of emmetropia in 165 (80.5%) and 88 (82.2%) eyes, respectively. Refractive astigmatic analysis showed an index of success of 0.28 ± 0.33 (T-ICL) and 0.31 ± 0.26 (T-Artiflex) (P = .07). Surgically induced corneal astigmatism was 0.48 ± 0.74 and 0.81 ± 0.61 D, respectively (P < .001). Mean endothelial loss was 1.11% and 2.05%, respectively (P = .42). Six (2.9%) eyes in the T-ICL group and 1 (0.9%) eye in the T-Artiflex group had phakic IOL repositioning due to significant misalignment. No vision-threatening complications occurred.

CONCLUSIONS

Both the T-ICL and T-Artiflex groups showed high visual and refractive efficacy with a good safety profile for the correction of myopic astigmatism. T-ICL implantation demonstrated significantly better efficacy and safety indexes after 12 months. Vector analysis showed similar refractive astigmatic correction in both groups, but T-Artiflex implantation revealed higher surgically induced corneal astigmatism. [J Refract Surg. 2022;38(6):339-347.].

Analysis of Microcirculation Changes in the Macular Area and Para-Optic Disk Region After Implantable Collamer Lens Implantation in Patients With High Myopia

Myopia has become an important public health problem to be solved urgently. Posterior chamber phakic implantable Collamer lens (ICL) implantation is one of the latest and safest products for myopia correction worldwide. This prospective cross-sectional case series aimed to observe changes in the macular retinal thickness, retinal nerve fiber layer (RNFL) thickness of para-optic disk region, and blood flow density after posterior ICL implantation in patients with high myopia using optical coherence tomography angiography (OCTA). A total of 67 eyes of 67 patients with high myopia, who underwent ICL implantation at The Affiliated Eye Hospital of Nanjing Medical University from January 2020 and December 2020, were included. The spherical equivalent (SE) of the operative eyes was &gt;−6.00 D. The changes in vision, intraocular pressure (IOP), SE, and vault were observed pre-operatively, and follow-up were performed 1 week, 1 month, and 3 months. OCTA was used to observe the changes in the CRT, retinal thickness of paracentral fovea, FAZ, superficial and deep retinal blood flow density in the macular area, RNFL thickness of para-optic disk region, and blood flow density before and after ICL implantation. The uncorrected distance visual acuity (UDVA) and best corrected distance visual acuity (CDVA) of the patients post-operation were significantly improved (P &lt; 0.001). The IOP increased in comparison with other time points at 1 week post-operation (P &lt; 0.05). There were no significant changes in CRT post-operation. The retinal thickness in the upper, lower, nasal, and temporal quadrants of the paracentral fovea increased significantly at 1 month and 3 months post-operation (P &lt; 0.05). The FAZ area at all postoperative time points were decreased (P &lt; 0.001). At 3 months post-operation, the blood flow density of the superficial and deep retinal layers in the upper, lower, and nasal macular area were significantly reduced (P &lt; 0.05). At 1 month post-operation, the RNFL thickness in the temporal para-optic disk region and blood flow density were significantly reduced (P = 0.001 and P &lt; 0.05, respectively). ICL implantation for highly myopic eyes led to an increase of the retinal thickness in the upper, lower, nasal, and temporal regions of the paracentral fovea; reduction of RNFL thickness in the temporal area of para-optic disk; decrease in FAZ area; and decrease in the blood flow density of some deep and superficial retinal layers as well as that of the temporal para-optic disk region.

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).

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.

Multicenter clinical outcomes of hole implantable collamer lens implantation in middle-aged patients

To assess the multicenter clinical outcomes of the implantation of hole implantable collamer lens (Hole ICL, ICL KS-AquaPORTTM; STAAR Surgical, Nidau, Switzerland) in patients of 45 years or more. We retrospectively assessed the surgery’s safety, efficacy, predictability, stability, and adverse events before surgery and after the surgery at 1 week; 1, 3, and 6 months; and 1 year, followed by once every year for approximately 2.2 years. A total of 118 eyes of 65 patients aged 45–65 years with myopic refractive errors ranging from − 2.13 to − 18.75 diopters (D) underwent hole ICL implantation and routine postoperative examinations. The average observation period was 2.2 ± 1.0 years. The safety and efficacy indices were 1.08 ±  0.21 and 0.87 ± 0.25, respectively. Manifest refraction changes of − 0.20 ± 0.43 D occurred from 1 month to the final visit after ICL implantation. Eight eyes (6.8%) developed asymptomatic anterior subcapsular cataract (ASC) immediately after surgery, and three eyes (2.5%) developed clinically significant symptomatic nuclear cataracts during the follow-up period. According to our experience, hole ICL implantation offered favorable outcomes in all measures of safety, efficacy, predictability, and stability, even in middle-aged patients, during the 2.2-year observation period.

Agreement of implantable collamer lens sizes using parameters from different devices

Objective

To assess agreement and repeatability of white-to-white (WTW) and anterior chamber depth (ACD), and agreement of implantable collamer lens (ICL) size using these measurements from different devices.

Methods and analysis

A retrospective review of 83 eyes with ICL implantation (42 patients) was conducted. The agreement of WTW (measured with WaveLight Topolyzer and Orbscan IIz) and ACD (measured with WaveLight Oculyzer and Orbscan IIz) was analysed. Correlation of ICL sizes and difference of eyes with unacceptable vaults between two data sets (WaveLight platform; Topolyzer and Oculyzer and Orbscan IIz) were assessed.

Results

Average WTW measured by Orbscan IIz and Topolyzer demonstrated good agreement (Ρ 0.884) with low systematic bias (−0.03±0.1 mm) and narrow 95% limits of agreement (LoA) of −0.28 to 0.22. Average ACD measured by Orbscan IIz and Oculyzer also showed good agreement (Ρ 0.903) with low systematic bias (−0.04±0.1 mm) and relatively narrow 95% LoA (0.2 to 0.12). ICL size selected according to two data sets showed moderate to strong level of agreement (Kappa=0.81). There was a statistically significant difference (p<0.001) in the proportion of eyes with unacceptable postoperative vaults when using the Wavelight platform data set (five eyes, 6.02%) and the Orbscan IIz data set (12 eyes, 14.46%).

Conclusion

Although the agreement of WTW and ACD between devices was good, there was a significant difference in proportion of eyes with unacceptable postoperative vaults when using two data sets. Therefore, Topolyzer and Oculyzer might not be suitable for operating interchangeably with Orbscan IIz for ICL size selection.

Evaluation of the anterior chamber angle by anterior segment optical coherence tomography after implantable phakic contact lens implantation in myopic eyes

PURPOSE

To evaluate the changes in the angle of the AC and lens vault after IPCL implantation by AS-OCT in myopic patients.

METHODS

This was a prospective observational study involving 30 myopic eyes implanted with IPCL. AS-OCT was used to evaluate lens vault and AC angle parameters including anterior chamber angle, angle opening distance and trabecular-iris space area (TISA) at 1, 3 and 6 months postoperatively.

RESULTS

All 3 AC angle parameters were significantly reduced at the 1st postoperative month compared to preoperative values, but remained stable thereafter with no significant change at the 3rd or 6th postoperative months. The lens vault showed no significant change over the entire follow-up period.

CONCLUSION

IPCL implantation is a safe method for correction of myopia with stable AC angle narrowing over the course of 6 months postoperatively as monitored using AS-OCT.

[Correction of ametropia with posterior chamber phakic intraocular lens]

Posterior chamber phakic intraocular lens (PIOL) implantation is a widely accepted and performed refractive surgery for correction of moderate and high myopia used when corneal laser ablation procedures are not suitable. This paper analyzes literature data to reveal the advantages and limitations of the technology.

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.

Phaco with ICL in situ in a case of high hyperopia

Purpose

To describe a unique method of biometric calculation and surgical technique of phacoemulsification and posterior chamber intraocular lens (PCIOL) implantation with an implantable collamer lens (ICL) in situ; for a high hyperope with post – ICL cataract.

Observations

A patient with high hyperopia who underwent bilateral ICL implantation later developed cataract in both eyes. He underwent phacoaspiration of the cataract with ICL in situ and a standard power PCIOL implantation in the left eye. A unique method of PCIOL power calculation was later devised for the right eye by accounting for the residual refractive error of the eye and implanted by a similar surgical technique.

Conclusion and importance

Following cataract surgery with the ICL in situ, the patient had a residual refractive error of +3.00D in the left eye however had a minimal residual refractive error in the right eye. A new surgical method of PCIOL implantation after cataract extraction with an ICL in situ as well as the biometric calculation for a PICOL to be implanted with an ICL in situ was devised.

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.

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.

Correlation between intraoperative and postoperative vaulting of the EVO implantable Collamer lens: a retrospective study of real-time observations of vaulting using the RESCAN 700 system

Background

Implantable Collamer lens (ICL) vaulting is one of the most important parameters for the safety, aqueous humor circulation, and lens transparency after ICL implantation. This study aimed to investigate the factors associated with the actual vaulting after refractive EVO-ICL surgery.

Methods

This retrospective study included patients who underwent EVO-ICL surgery at a tertiary eye hospital between October and December 2019. A RESCAN 700 was used for the intraoperative and CIRRUS HD-OCT was used for postoperative observation of vaulting. Subjective and objective refractions, anterior ocular segment, corneal morphology, intraocular pressure (IOP), anterior chamber volume (ACV), crystalline lens rise (CLR), white-to-white distance (WTW), anterior chamber depth (ACD), axial length, corneal endothelial cell density (ECD), and fundoscopy were examined. A multivariable analysis was performed to determine the factors independently associated with 1-month postoperative vaulting.

Results

Fifty-one patients (102 eyes) were included. Compared with the eyes with normal vaulting, those with high vaulting had higher preoperative diopter values (P = 0.039), lower preoperative corrected visual acuity (P = 0.006), lower preoperative IOP (P = 0.029), higher preoperative ACD (P = 0.004), lower preoperative CLR (P = 0.046), higher ICL spherical equivalent (P = 0.030), higher intraoperative vaulting (P < 0.001), and lower IOP at 1 month (P = 0.045). The multivariable analysis showed that the only factor independently associated with high vaulting at 1 month after surgery was the intraoperative vaulting value (odds ratio = 1.005, 95% confidence interval: 1.002–1.007, P < 0.001). The intraoperative and 1-month postoperative vaulting values were positively correlated (R² = 0.562).

Conclusions

The RESCAN700 system can be used to perform intraoperative optical coherence tomography to predict the vaulting value of ICL at 1 month.

First Experiences with Implantation of Phakic Lenses in Correction of Myopia in R. N. Macedonia

Objective: Analysis of visual acuity parameters in patients with moderate to high myopia and myopic astigmatism 1 year after treatment with phakic intraocular lenses. Material and methods: This was a retrospective study on 35 patients (52 eyes) with moderate to high myopia who were implanted with the Visian V4c phakic implantable Collamer lens (Staar Surgical, Nidau, Switzerland). Examined parameters were: uncorrected distance visual acuity (UDVA) and best corrected visual acuity (CDVA), manifest and cycloplegic refraction, intraocular pressure, and endothelial cell count. The investigated parameters were measured preoperatively, 1, 3, 6 and 12 months postoperatively. Results: In 17 patients, phakic lenses were implanted binocularly and in 18 patients monocularly. Preoperatively 34.62% of patients had CDVA from 0.9 to 1.0. One year after the surgery 48.08% of patients had UDVA from 0.9 to 1.0. Preoperatively 80.77% of patients had diopter range from -6.00 Dsph to -10.00 Dsph. At 1 year postoperatively 78.85% of patients were within 0.00 Dsph to -1.00 Dsph. Preoperatively, in patients with astigmatism -4 Dcyl to -2 Dcyl dominated, as opposed to significant improvement postoperatively when 94.23% had astigmatism ranging from -1.0 Dcyl to 0 Dcyl. Conclusion: The implantation of phakic lenses demonstrated a successful postoperative outcome in the treatment of myopia and myopic astigmatism. Visual acuity and refraction show a gradual and significant improvement in visual function parameters within 1 year of lens implantation.

Long-term Comparison of Vault and Complications of Implantable Collamer Lens with and without a Central Hole for High Myopia Correction: 5 Years

PURPOSE

To investigate the long-term safety, efficacy, stability, vault, and complications of implantable collamer lens with (ICL V4c) and without (ICL V4) a central hole for correcting high myopia.

METHODS

78 eyes (40 patients) underwent ICL V4c implantation and 78 eyes (48 patients) underwent ICL V4 implantation were enrolled. They were followed up for 5 years of the uncorrected and corrected distance visual acuity, spherical equivalent (SE), axial length, intraocular pressure, endothelial cell density and vault.

RESUITS

The safety indices of the ICL V4c and V4 groups at 5 years were 1.25 ± 0.40 and 1.31 ± 0.40, respectively (P = .353). The efficacy indices were 0.90 ± 0.29 and 1.00 ± 0.44, respectively (P = .098). The preoperative, 1 month and 5 year postoperative logMAR UDVAs were respectively 1.54 ± 0.48, 0.11 ± 0.17, and 0.20 ± 0.26 in the V4c group and 1.56 ± 0.44, 0.14 ± 0.19, and 0.22 ± 0.26 in the V4 group (P = .703, 0.329, 0.585). The logMAR CDVAs were resepectively 0.13 ± 0.18, 0.02 ± 0.11, and 0.05 ± 0.16 in the V4c group and 0.18 ± 0.22, 0.05 ± 0.14, and 0.09 ± 0.21 in the V4 group (P = .128, 0.169, 0.229). The SE were resepectively -15.10 ± 4.32 D, -0.71 ± 1.31 D and -1.65 ± 1.30 D in the V4c group and -15.44 ± 3.51 D, -0.61 ± 1.12 D and -1.40 ± 1.30 D in the V4 group (P = .585, 0.637, 0.296). The mean vault reduced by 97.31 ± 136.61 μm in the V4c group and by 99.74 ± 245.83 μm in the V4 group. Three eyes (3.85%) with mid-periphery anterior subcapsular opacification in the V4c group and two (2.56%) with cataract, one (1.28%) with central anterior subcapsular opacification in the V4 group were observed. The CDVA of 20/40 was obtained in the two cataract eyes after phacoemulcification and intraocular lens implantation.

CONCLUSION

Long-term ICL V4c and ICL V4 implantations are safe, effective, and stable for high myopia correction. ICL V4c can potentially reduce the risk of lens opacification and may be more tolerant to low vault than ICL V4.

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.

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.

Initial clinical outcomes of two different phakic posterior chamber IOLs for the correction of myopia and myopic astigmatism

PURPOSE

The purpose of this study is to document clinical outcomes of 2 posterior chamber phakic intraocular lenses with a central hole, the implantable contact lens (IPCL V2.0) and the Visian implantable collamer lens V4c (ICL), in myopic and myopic-astigmatic patients.

METHODS

Retrospective study comprising 111 IPCL (60 toric) and 106 ICL implantations (59 toric) with a follow-up of 3 months to 2 years. Primary outcome was uncorrected distance visual acuity (UDVA) improvement; secondary outcomes were changes in corrected distance visual acuity (CDVA), and complications.

RESULTS

At 3 months postoperatively, 76% of plano targeted eyes in the IPCL group and 83% of eyes in the ICL group had a UDVA of 20/20 or better. Ninety-six percent of IPCL implanted eyes and 94% of ICL implanted eyes had a postoperative UDVA within 1 line of preoperative CDVA. One eye lost one line of CDVA after IPCL implantation, and no lines were lost after ICL implantation; 33.7% of IPCL eyes and 40.6% of ICL eyes gained at least 1 line of CDVA. Cataract extraction (none because of anterior subcapsular opacification) was performed after 4 ICL implantations, none after IPCL implantation. Endothelial cell loss was mild with both pIOLs. Mean IOP was not clinically significantly affected at 3 months or thereafter.

CONCLUSIONS

We observed equally excellent (statistically not different) results with the IPCL and ICL for the correction of myopia and myopic astigmatism, at least up to 2 years post implantation. Longer follow-up is needed to determine the stability of these results especially with the IPCL.

Dynamic assessment of variations in pupil diameter using swept-source anterior segment optical coherence tomography after phakic collamer lens implantation

Purpose

To dynamically assess variations in pupil diameter induced by changes in brightness in myopic eyes implanted with an implantable collamer lens (ICL, STAAR Surgical) with a central port.

Methods

This prospective, observational single-center case series study comprised 65 eyes from 65 consecutive patients undergoing ICL implant. A modified commercially available swept-source Fourier-domain anterior segment optical coherence tomography (AS-OCT) device was used for imaging and performing dynamic pupillometry under changing light conditions before and after a mean follow-up interval of four months after surgery.

Results

Preoperative mean pupil size under photopic conditions was 3.38 ± 0.64 mm; after surgery, this increased to 3.48 ± 0.61 mm. Mean pupil size under scotopic light conditions was 5.72 ± 0.79 mm before surgery and 5.84 ± 0.77 mm postoperatively. The differences between preoperative and postoperative pupil diameter in miosis and mydriasis were 0.10 ± 0.44 mm (P = 0.078) and 0.12 ± 0.58 mm (P = 0.098), respectively. The scotopic pupil exceeded the optic zone of the implanted lens in 39 eyes (60%). The mean central vault value was 412 ± 177 μm under maximum miosis and 506 ± 190 μm under maximum mydriasis. We found a positive correlation between vault and differences in pupil diameter under all light conditions (P < 0.05).

Conclusion

Dynamic AS-OCT enables a very precise determination of the pupillary diameter in the iris plane. The changes in the pupil diameter under different light conditions after the implantation of an ICL are related to the postoperative vault.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40662-021-00262-2.

Vault changes and pupillary responses to light in myopic and toric implantable collamer lens

BACKGROUND

Achieving an appropriate vault is the main concern after the implantation of Implantable Collamer Lens (ICLs) for surgical correction of high myopia. The vault will vary with time and optical parameters, such as accommodation and pupil size. This research is to evaluate the vault change in Myopic and Toric ICLs under different lighting conditions; and to analyze the relationship between vault changes and pupillary responses to light.

METHODS

We enrolled and analyzed 68 eyes from 68 patients who were implanted with Myopic EVO ICLs; we also included 60 eyes from 60 patients who were implanted with Toric EVO ICLs. The anterior chamber depth, pupil size and the post-operative vault were evaluated, 1 week after the operation, using a Visante Optical Coherence Tomography (OCT) under different lighting conditions. For each eye that was assessed, we calculated the vault change, which is defined as the difference between vault under mesopic condition and photopic condition; and the rate of vault change, which is defined as the vault change divided by mesopic vault.

RESULTS

No significant difference was noted with the anterior chamber depth between mesopic and photopic conditions in either group. A significant decrease in vault and pupil size was detected under photopic condition in both groups. We found no difference in vault change between Myopic and Toric EVO ICLs under different lighting conditions. Moreover, the rate of vault change had a significant decrease with increased mesopic vault (baseline value).

CONCLUSIONS

Too low a mesopic vault has a big rate of vault change, which may cause the contact of ICL with crystalline lens in photopic state; Too high a mesopic vault would constrict the posterior movement of pupil. The findings of the study suggest that, for patients with high or low vault, we should be more careful and must perform checks in different lighting conditions.

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.

Evaluation of the efficacy, safety, and stability of posterior chamber phakic intraocular lenses for correcting intractable myopic anisometropic amblyopia in a pediatric cohort

BACKGROUND

Myopic anisometropic amblyopia in pediatrics is one of the most challenging clinical situations that can face an ophthalmologist. Conventional correction modalities for myopic anisometropia, using spectacles, contact lenses, and/or occlusion therapy, may not be suitable for some pediatric patients or for some ocular conditions. This may lead to the development of anisometropic amblyopia. The aim of the present study was to evaluate the visual and the refractive efficacy, safety, and stability of Posterior Chamber Phakic Intraocular Lenses (PC-pIOLs) for correcting myopic anisometropic amblyopia in a pediatric cohort.

METHODS

This case series, prospective, interventional study was conducted at Watany Eye Hospital, Cairo, Egypt. It comprised children and teenagers with myopic anisometropic amblyopia and unsuccessful conventional therapy. After implantation of Intraocular Collamer Lenses "ICLs" (Visian ICL, Model V4c, STAAR Surgical, Monrovia, California, USA), postoperative follow-up visits were scheduled, with automated refraction and Pentacam imaging performed.

RESULTS

The study enrolled 42 eyes of 42 patients. The age range was 3 to 18 years (mean ± SD = 10.74 years ±4.16). The mean preoperative spherical equivalent (SE) was - 12.85 D ± 2.74. The results declared a significant improvement in the postoperative Corrected Distance Visual Acuity "CDVA" (P value < 0.01) and SE (P value < 0.01). The efficacy index had a value of 1.18 ± 0.3 and the safety index was 1.09 ± 0.24. The follow-up visits had a mean ± SD of 14.67 months ±16.56 (range of 1 to 54 months). The results showed a refractive stability, with statistically insignificant improvements in the patients' visual acuity and refractive status on evaluating the enrolled pediatrics during the follow-up visits compared to the first postoperative visits. No postoperative complications were encountered. Worthy of mention is that there was a significant (80%) non-compliance with the prescribed postoperative occlusion therapy.

CONCLUSIONS

The present study, with the longest reported follow-up range, declared the long-term efficacy, safety, and stability of Visian ICLs for correcting myopic anisometropic amblyopia in pediatrics. The reported non-compliance with occlusion therapy validates the early implantation of Visian ICLs in cases with failed conventional therapy to guard against anisometropic amblyopia.

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.

Visian Implantable Collamer Lens Behavior in Descemet Membrane Endothelial Keratoplasty Surgery

Endothelial damage is one of the leading causes for anterior chamber phakic intraocular lens (AC-pIOL) explantation. In young patients, where the pIOL is explanted alone without lensectomy, an important anisometropia is left, unless an exchange with a posterior chamber (PC) pIOL is performed. However, in the event of corneal decompensation, there is no published evidence about the potential influence of a collamer-based PC-pIOL [implantable collamer lens (ICL)] on endothelial keratoplasty surgery. We report a case of severe endothelial damage after AC-pIOL implantation managed by the exchange of the AC-pIOL by an ICL, followed by Descemet membrane endothelial keratoplasty. Collamer-based PC-pIOLs seem to not affect Descemet membrane endothelial keratoplasty outcomes. ICL did not show any transparency loss. These results cannot be extrapolated to other non-collamer-based PC-pIOLs. Further studies with larger samples are necessary to confirm these outcomes.

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.

Agreement between optical coherence and Scheimpflug tomography: Vault measurements and reproducibility after implantable collamer lens implantation

PURPOSE

To evaluate the agreement between Scheimpflug tomography (Pentacam, Oculus) and anterior segment optical coherence tomography (AS-OCT, RTVue 100, Optovue) as well as the reproducibility of each technique in assessing the lens-ICL distance (vault) after implantable collamer lens (ICL) implantation.

METHODS

The vault was measured manually with Scheimpflug tomography and AS-OCT. Intraclass correlation coefficients (ICC) and Bland-Altman plots were used to determine the reproducibility of measurements and the agreement between them. Multivariate regression analysis was performed to identify predictors of differences in vault measurements between devices.

RESULTS

80 eyes of 46 ICL patients were analyzed. Mean patient age was 33.8±7.4 years (range, 21 to 51), and 27 (59%) were women. The preoperative spherical equivalent refraction ranged from -26 to 8.5 diopters (D). The mean vault measured by AS-OCT was 558.8±240.2μm (range, 162 - 1220) vs. 430.1±215.3μm (range, 0 to 1070) by Pentacam. AS-OCT yielded vault values, on average, 128.1±64.6μm higher than the Pentacam (range, -22 to 293μm). The ICC values for consistency and absolute agreement were 0.960 and 0.928, respectively. Reproducibility of vault measurements was excellent for both devices (ICC≥0.946). Four parameters-vault, pupil diameter (PD), PD differences between devices, and preoperative spherical equivalent refraction-were significant predictors of differences in vault measurements (adjusted-R²=0.412; P<0.001).

CONCLUSIONS

Agreement between AS-OCT and Pentacam for vault measurement was good. Vaults were higher when measured by AS-OCT. These differences are clinically relevant, and therefore these devices cannot be used interchangeably to measure vault.

Comparison of the visual performance of iris-fixated phakic lens and implantable collamer lens to correct high myopia

Background

To compare visual performance between the iris-fixated phakic intraocular len (pIOL) and implantable collamer len (ICL) to correct high myopia.

Methods

Twenty-four eyes underwent iris-fixated pIOL implantation and 24 eyes underwent ICL implantation. At the 6-month follow-up, the best-corrected visual acuity (BCVA) and uncorrected distance visual acuity (UDVA) were compared between the iris-fixated pIOL and ICL groups. The objective scatter index (OSI), modulation transfer function (MTF) cutoff, and ocular aberrations were performed to evaluate postoperative visual quality between the two groups.

Results

No significant difference was found in UDVA, BCVA, and spherical equivalent between the iris-fixated pIOL and ICL groups (P > 0.05). Six months after surgery, the following values were significantly higher in the ICL group than in the iris-fixated pIOL group: MTF cutoff, strehl ratio and optical quality analysis system values at contrasts of 9 %, 20 %, and 100 % (P < 0.01). The OSI in the iris-fixated pIOL group was higher than in the ICL group 6 months after surgery (P < 0.01). All high-order aberrations were slightly more severe in the iris-fixated pIOL group than in the ICL group 6 months after surgery, although only trefoil (P = 0.023) differed significantly in this regard.

Conclusions

Both iris-fixated lenses and ICLs can provide good visual acuity. ICLs confer better visual performance in MTF-associated parameters and induce less intraocular light scattering than iris-fixated pIOLs.

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

PURPOSE

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

SETTING

Leiden University Medical Center, the Netherlands.

METHODS

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

RESULTS

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

CONCLUSIONS

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

An anterior segment optical coherence tomography study of the anterior chamber angle after implantable collamer lens-V4c implantation in Asian Indian Eyes

Purpose:

To quantitatively assess anterior chamber and angle parameters by anterior segment optical coherence tomography (AS-OCT) in myopic eyes undergoing Implantable Collamer Lens (ICL V4c) implantation.

Methods:

Prospective noncomparative observational case series. Pre and postoperative (1^st and 3^rd month) AS-OCT angle parameters (anterior chamber depth [ACD], anterior chamber angle [ACA], Angle opening distance [AOD], trabecular iris space area [TISA], scleral spur angle [SSA]) were evaluated in 32 eyes (16 patients). SPSS version 20 with paired t-test for intragroup and Mann-Whitney U value test for intergroup comparisons.

Results:

It included 6 (37.5%) males and 10 (62.5%) females. Preoperative ACA of 34.6 ± 2.3° reduced to 32.2 ± 2.4°, 31.9 ± 2.5° at 1 and 3 months postoperatively (P = 0.001). Preoperative mean AOD500, AOD750, TISA500, TISA750, SSA of 0.34 ± 0.06 mm, 0.52 ± 0.15 mm, 0.09 ± 0.02 mm², 0.20 ± 0.04 mm², 34.27 ± 4.6° decreased to 0.32 ± 0.06 mm, 0.48 ± 0.15 mm, 0.08 ± 0.02 mm², 0.17 ± 0.05 mm², 32.5 ± 4.3° at 1-month (P = 0.001); 0.32 ± 0.06 mm, 0.47 ± 0.13 mm, 0.08 ± 0.02 mm², 0.17 ± 0.05 mm² and 32.4 ± 4.6° (P = 0.001) at 3-months, respectively. Correlation analysis between preoperative ACD/intraocular pressure (IOP) was − 0.62 (P = 0.0002) [1^st month], −0.40 (0.024) [third month]; between IOP/postoperative ACA, AOD500, AOD750, TISA500, TISA750, SSA was − 0.04 (0.81), −0.03 (0.85), −0.08 (0.64), −0.12 (0.48), −0.10 (0.57), −0.06 (0.73) at 1 month; −0.09 (0.58), 0.04 (0.78), 0.12 (0.48), −0.02 (0.9), −0.04 (0.79), 0.02 (0.88) at 3 months; between ICL vault/ACA, AOD500, AOD750, TISA500, TISA750, SSA was 0.38 (0.02), 0.24 (0.17), 0.21 (0.25), 0.05 (0.75), 0.15 (0.41), 0.27 (0.13) at 1^st month; 0.19 (0.28), 0.06 (0.71), −0.03 (0.85), 0.005 (0.97), 0.05 (0.78), 0.07 (0.68) at 3^rd month.

Conclusion:

Postoperatively significant angle narrowing was noted. There was a negative correlation between IOP and preoperative ACD. There was no significant correlation between IOP and ICL vault with postoperative AS-OCT angle parameters.

Posterior-chamber phakic implantable collamer lenses with a central port: a review

We aimed to summarize the outcomes reported following the implantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc) for myopia correction. A literature search in PubMed, Web of Science and Scopus was carried out to identify publications reporting clinical outcomes of patients who were implanted with the V4c ICL model and had a follow‐up period of at least 6 months. A total of 35 clinical studies published between 2012 and 2020 were included in the present review. A comprehensive analysis of the available data was performed, focusing on visual and refractive outcomes at different time‐points post‐surgery. In addition, adverse events and other parameters such as endothelial cell density, intraocular pressure and vault measurements—which were evaluated in some of the studies—were also compared. This review encompassed a total of 2904 eyes. The outcomes reported in this review lead us to conclude that ICL V4c implantation for myopia correction is a safe and efficient procedure, with stable visual and refractive outcomes and low adverse event rates. The patient’s anterior segment should be thoroughly characterized, and the ICL parameters should be carefully selected so as to achieve good outcomes and avoid complications.

Changes in anterior lens density after Implantable Collamer Lens V4c implantation: a 4-year prospective observational study

PURPOSE

To investigate the changes in anterior lens density with a Pentacam after Implantable Collamer Lens (ICL) V4c implantation in patients with myopia.

METHODS

This prospective case series examined 62 eyes of 32 patients (mean age, 28.5 ± 5.73 years) with myopia or myopic astigmatism after ICL V4c implantation. Uncorrected distance vision acuity, corrected distance vision acuity (CDVA), manifest refraction, intraocular pressure, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), endothelial cell density and Pentacam images of lens density were obtained pre- and postoperatively. The vault was obtained during the follow-ups.

RESULTS

Patients were followed up for an average of 51 ± 2.7 months (range, 48-57 months). All surgeries were uneventful, without any complication. The efficacy and safety indices at the last follow-up were 1.03 ± 0.2 and 1.22 ± 0.22, respectively. No eye had decreased CDVA, and 66% eyes gained ≥1 line. Furthermore, refractive error in 90% eyes was within ±0.50 D and that of 100% was within ±1.0 D of the attempted refraction. Anterior average lens density (a-ALD) in the 0.5-, 1.0- and 1.5-mm depth zones increased by 10.41 ± 11.51%, 17.1 ± 11.09% and 16.76 ± 10.4%, respectively, compared to preoperative values (all p < 0.05). The change in a-ALD between two different age groups was not significant. Moreover, there were no significant correlations between the change in a-ALD and age, preoperative spherical equivalent, ACD, ACA, ACV or vault.

CONCLUSIONS

Implantable Collamer Lens (ICL) V4c implantation demonstrates safety and efficacy for myopia correction. Although a-ALD increased slightly at 4 years postoperatively, no cataract developed during the follow-up. Further studies should investigate the reason for the postoperative increase in a-ALD.

Posterior chamber collamer phakic intraocular lens implantation: Comparison of efficacy and safety for low and moderate-to-high myopia

PURPOSE

To compare visual, refractive and safety outcomes of central-hole posterior chamber collamer phakic intraocular lens implantation for low and moderate-to-high myopia.

SUBJECTS/METHODS

This retrospective cohort study included 338 eyes submitted to posterior chamber collamer phakic intraocular lens implantation that completed a 12-month postoperative follow-up. Two groups were defined depending on preoperative spherical equivalent: group 1 comprised 106 eyes with manifest spherical equivalent of -6.00 D or less; group 2 comprised 232 eyes with manifest spherical equivalent higher than -6.00 D. Effectiveness, predictability, stability and safety outcomes were compared preoperatively and at 1, 6 and 12 months postoperatively.

RESULTS

At 1-year postoperative, uncorrected and corrected visual acuities were 0.02 ± 0.17 and -0.01 ± 0.12 logMAR (group 1) and 0.04 ± 0.20 and 0.01 ± 0.16 logMAR (group 2), with an efficacy index of 1.05 ± 0.17 and 1.17 ± 0.28. Respectively, 92 (86.8%) and 199 (85.8%) eyes were within ±0.50 D of targeted refraction, and postoperative manifest refraction changes were -0.07 ± 0.25 D and -0.07 ± 0.35 D. Intraocular pressure did not change significantly. The mean rate of endothelial cell loss was 1.12% and 1.10%, respectively. One case of anterior subcapsular cataract (group 2) was observed. ICL exchange occurred in one case (group 1) and three cases (group 2). No vision-threatening complications were reported.

CONCLUSION

The posterior chamber collamer phakic intraocular lens implantation demonstrated high visual and refractive efficacy with an excellent safety profile for the correction of both low and moderate-to-high myopia, revealing equivalent 1-year outcomes regardless of the degree of preoperative myopia.

Trends in research related to high myopia from 2010 to 2019: a bibliometric and knowledge mapping analysis

AIM

To evaluate the global trends in and explore hotspots of high myopia (HM) research.

METHODS

This bibliometric analysis was used to reveal the publication trends in HM research field based on the Web of Science Core Collection (WoSCC). VOSviewer version 1.6.13 software was used to analyze the data and construct a knowledge map including the yearly publication number, journals, countries, international collaborations, authors, research hotspots, and intellectual base in HM.

RESULTS

The search engine found 3544 peer-reviewed publications on HM between 2010 and 2019, and the yearly research output substantially elevated over the past decade. China is the top publishing country, and Sun Yat-sen University was the most active academic institution. Jonas JB is the top publishing scientist, and Investigative Ophthalmology and Visual Science (IOVS) was the most productive journal. The highest cited references mainly focused on epidemiology and management. The keywords formed 6 clusters: 1) refractive surgery; 2) etiology and clinical characteristics; 3) the mechanism of eye growth; 4) management for myopic maculopathy; 5) vitrectomy surgical treatment; 6) myopia-associated glaucoma-like optic neuropathy.

CONCLUSION

The evaluation of development trends based on the data extracted from WoSCC can provide valuable information and guidance for ophthalmologists and public health researchers to improve management procedures in HM field.

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^®.

Etiology and outcomes of current posterior chamber phakic intraocular lens extraction

This study was aimed to review the etiology and the outcomes of current posterior chamber phakic intraocular lens (Visian ICL, STAAR Surgical) extraction. This review comprised 770 eyes of 403 consecutive patients undergoing ICL extraction. We evaluated prevalence, etiology, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), predictability, and patient satisfaction. ICL extraction was required in 8 of 770 (1.0%) eyes. The most common reason was the progression of the pre-existing cataract formation in 5 eyes (63%), followed by residual refractive errors in 3 eyes (38%). Of the 7 eyes targeted for emmetropia, 7 (100%) and 6 (86%) achieved UDVAs of 20/40 and 20/20 or better, respectively. Three eyes (38%) showed no change in CDVA, 3 eyes (38%) gained 1 line, 2 eyes (25%) gained 3 or more lines. 88% and 100% were within ± 0.5 and 1.0 diopter (D), respectively, of the targeted correction. Patient satisfaction improved significantly, from 3.0 ± 1.4 preoperatively, to 8.0 ± 2.4 postoperatively. No vision-threatening complications occurred. ICL extraction was required in approximately 1% of ICL-implanted eyes. Visual and refractive outcomes were good, and patient satisfaction was overall high, even in ICL-extracted eyes.

Phakic intraocular lenses: An overview

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

Performance and Safety of the Extended Depth of Focus Implantable Collamer® Lens (EDOF ICL) in Phakic Subjects with Presbyopia

Purpose

To evaluate the performance and safety of the Extended Depth of Focus Implantable Collamer^® Lens (EDOF ICL) for improvement of uncorrected near, intermediate and distance visual acuity in phakic subjects with myopia and presbyopia.

Design

Prospective multicenter study.

Methods

Presbyopic subjects who required an EDOF ICL in the range of −0.50 D to −18.00 D, exhibited ≤ 0.75 D refractive astigmatism and required from +1.00 to +2.50 D reading add were implanted bilaterally. Assessments at 6 months included uncorrected near, intermediate and distance visual acuities, defocus curves, contrast sensitivity, responses to the National Eye Institute Refractive Error Quality of Life Questionnaire and a Task Assessment Questionnaire.

Results

A total of 34 subjects completed the study. Investigators targeted emmetropia in all eyes. Mean binocular uncorrected near, intermediate and distance visual acuities measured logMAR −0.01 ± 0.05 (20/20), −0.02 ± 0.08 (20/19) and 0.07 ± 0.10 (20/23), respectively. Mean monocular uncorrected near, intermediate and distance visual acuities measured logMAR 0.068 ± 0.09 (20/23), 0.062 ± 0.10 (20/23) and 0.16 ± 0.12 (20/29). There were no clinically or statistically significant differences in contrast sensitivity between baseline and 6 months under any testing conditions. Subjects reported significant improvements in measures of vision-related quality of life and ability to perform tasks at all distances without glasses or contact lenses. Overall, satisfaction with the EDOF ICL was high: postoperatively, 91.2% of subjects were satisfied with their vision.

Conclusion

This multicenter, prospective clinical investigation demonstrated the ability of the EDOF ICL to correct myopia and presbyopia, resulting in improvement of uncorrected near, intermediate and distance visual acuity without compromising the quality of vision. The EDOF ICL allowed subjects to perform tasks of daily living without glasses or contact lenses. Subjects reported significant improvements in quality of life with high levels of spectacle independence and satisfaction.

Effect of central hole location in phakic intraocular lenses on visual function under progressive headlight glare sources

PURPOSE

To analyze the effect of the central hole location in the V4c implantable collamer lens (ICL) on the quality of vision, including progressive headlight glare simulation and quality of life.

SETTING

IOBA-Eye Institute, Valladolid, Spain.

DESIGN

Case series.

METHODS

The central hole location was determined by slitlamp and dual Scheimpflug imaging for 6 months or more postoperatively. The visual acuity, mesopic contrast sensitivity, halogen glare contrast sensitivity, xenon glare contrast sensitivity, photostress recovery time after glare, de Boer scale, and Quality of Life Impact of Refractive Correction (QIRC) questionnaire results were evaluated. Multiple regression models were used to analyze the effect of the central hole location on parameters using the pupil center and visual axis as references based on Cartesian and polar coordinates.

RESULTS

The safety index was 1.13 and the efficacy index, 1.12. Under all testing circumstances, central hole decentration did not affect the visual acuity or contrast sensitivity. With the visual axis as a reference, worse QIRC values were associated with greater upward central hole displacement (P = .03) and a lower polar angle value (P = .008); also, halogen glare discomfort was greater with a higher radius (P = .04). Using the pupil center as a reference, greater nasal central hole decentration was associated with longer xenon glare photostress recovery time (P = .002).

CONCLUSIONS

Implantation of the ICL with a central hole yielded excellent visual outcomes, even under increasing glare sources, regardless of the hole's location. However, hole decentration might affect patient-perceived quality of life, bothersome halogen glare, and longer xenon glare photostress recovery time. Such complaints after the early postoperative period might be managed with discrete ICL centration if the central hole is decentered upward or nasally.

Application of a Partial Least Squares Regression Algorithm for Posterior Chamber Phakic Intraocular Lens Sizing and Postoperative Vault Prediction

PURPOSE

To develop and validate a new algorithm for predicting the postoperative vault of the myopic EVO Visian Implantable Collamer Lens (ICL) V4c (STAAR Surgical AG).

METHODS

This study included 81 eyes of 43 patients who had undergone ICL implantation. Preoperative data obtained by swept-source optical coherence tomography, Scheimpflug camera, and anterior segment optical coherence tomography were applied to develop a new partial least squares (PLS) regression algorithm. ICL sizing was performed using the standard white-to-white method with the online calculation and ordering system. The postoperative vault was assessed based on anterior segment optical coherence tomography. The PLS approach was applied to create the calibration model for predicting the postoperative vault. The new PLS model was cross-validated using the leave-one-out method and compared to a recently published linear regression model. Agreement between the actual and predicted vault values for the two methods was assessed by the Bland-Altman method.

RESULTS

There was a statistically significant correlation (P < .001, r = 0.73) between the postoperative vault values and those predicted by the PLS algorithm. Validation of the PLS model yielded lower mean differences and limits of agreement (0 and 410 µm, respectively) than the linear regression method (400 and 750 µm, respectively).

CONCLUSIONS

The PLS algorithm increases the precision of ICL vault prediction. However, it shows a tendency to overestimate small vault values and underestimate high vaults. [J Refract Surg. 2020;36(9):606-612.].

Spontaneous rotation of a toric implantable collamer lens related to abnormal ciliary body morphology: a case report

BACKGROUND

This is a case of spontaneous toric implantable collamer lens (TICL) rotation that occurred twice in the left eye of a patient.

CASE PRESENTATION

A 24-year-old gentleman received TICL implantation for treatment of myopic astigmatism encountered with spontaneous rotation of approximately 90° from its original position. TICL reposition procedure was performed with visual outcome of 20/16. Surprisingly, a re-rotation of TICL occurred. The patient underwent a replacement of non-toric ICL with a larger size after careful re-evaluation with final visual outcome of 20/20. A short and small ciliary process with shallow ciliary sulcus and posteriorly positioned ciliary body was found by Ultrasound Biomicroscopy (UBM).

CONCLUSIONS

The unique morphology of the ciliary body may have a potential association with the vault and instability of implanted ICL. Careful examination of the ciliary body morphology is essential in preoperative evaluation.