Posterior Chamber Phakic Intraocular Lens Implantation for the Correction of Myopia and Myopic Astigmatism: A Retrospective 10-Year Follow-up Study

Seven-Year clinical outcomes after implantation of Eyecryl posterior chamber phakic intraocular lenses for high myopia

PURPOSE

To evaluate the long-term clinical outcomes, safety and efficacy of Eyecryl posterior-chamber phakic intraocular lens implantation (pIOL) implantation in patients with high myopia.

METHODS

Patients with myopia between -6.00 and -20.00 dioptres and with endothelial cell density (ECD) was ≥2300 cells/mm2 were included. Preoperative and postoperative first, fourth, and seventh years of refraction, uncorrected/corrected distance visual acuity (UDVA/CDVA), ECD, central vault were detected.

RESULTS

Thirty-six eyes were analyzed. The mean UDVA and CDVA in postoperative seventh years were 0.25 ± 0.31 and 0.13 ± 0.24 logMAR, respectively. The safety and efficacy indices were 1.55 ± 0.54 and 1.24 ± 0.53, respectively. The mean cumulative ECD loss was 6.96% (p < 0.001). The central vault at the 1st and the 7th year were 0.52 ± 0.14 and 0.49 ± 0.14 mm, respectively (p = 0.25).

CONCLUSIONS

These findings supported the long-term stability, efficacy, safety of the Eyecryl pIOL for high myopia. Eyecryl posterior chamber pIOL is one of the effective refractive options in correcting high myopia.

Lens height paraments comparison according to ciliary sulcus width (CSW): a pilot study of the predictive role of CLR and STSL for vault after ICL implantation

BACKGROUND

To assess the relationship between postoperative implantable collamer lens (ICL) vault and lens height obtained from two different measurements.

METHODS

A retrospective case series study enrolled eyes with horizontally implanted ICL. Crystal lens rise (CLR) and the distance between STS plane and anterior crystalline lens surface (STSL) were measured in the horizontal and vertical directions using ultrasound biomicroscopy (UBM). We compared the differences in the parameters measured in both horizontal and vertical directions. The participants were categorized into three groups according to ciliary sulcus width (CSW) which is defined as the distance between the posterior angle of the iris and the anterior angle of the ciliary process: narrow CSW group (NSG); medium CSW group (MSG); and wide CSW group (WSG). The correlations between CLR/STSL and vault were examined in each of the three groups. Biased correlation analysis was used further to contrast the correlation between CLR/STSL and vault.

RESULTS

This retrospective study included 223 myopic eyes. Vertical STSL (VSTSL) and vertical CLR (VCLR) exhibited significantly greater values compared to their horizontal counterparts (both P < 0.05). None of the indicators were statistically different between the three groups. In both NSG and MSG, STSL/CLR correlated with vault, while in WSG, only STSL correlated with vault (r=-0.316, P = 0.013). In contrast to HCLR, the correlation between HSTSL and vault remained after controlling for HCLR (r=-0.162, P = 0.015).

CONCLUSIONS

STSL should deserve more attention in the preoperative evaluation of ICL compared to CLR especially when CSW is large.

Accuracy of intraocular lens calculation formulas based on swept-source OCT biometer in cataract patients with phakic intraocular lens

PURPOSE

To research the accuracy of intraocular lens (IOL) calculation formulas and investigate the effect of anterior chamber depth (ACD) and lens thickness (LT) measured by swept-source optical coherence tomography biometer (IOLMaster 700) in patients with posterior chamber phakic IOL (PC-pIOL).

METHODS

Retrospective case series. The IOLMaster 700 biometer was used to measure axial length (AL) and anterior segment parameters. The traditional formulas (SRK/T, Holladay 1 and Haigis) with or without Wang-Koch (WK) AL adjustment, and new-generation formulas (Barret Universal II [BUII], Emmetropia Verifying Optical [EVO] v2.0, Kane, Pearl-DGS) were utilized in IOL power calculation.

RESULTS

This study enrolled 24 eyes of 24 patients undergoing combined PC-pIOL removal and cataract surgery at Xiamen Eye Center of Xiamen University, Xiamen, Fujian, China. The median absolute prediction error in ascending order was EVO 2.0 (0.33), Kane (0.35), SRK/T-WKmodified (0.42), Holladay 1-WKmodified (0.44), Haigis-WKC1 (0.46), Pearl-DGS (0.47), BUII (0.58), Haigis (0.75), SRK/T (0.79), and Holladay 1 (1.32). The root-mean-square absolute error in ascending order was Haigis-WKC1 (0.591), Holladay 1-WKmodified (0.622), SRK/T-WKmodified (0.623), EVO (0.673), Kane (0.678), Pearl-DGS (0.753), BUII (0.863), Haigis (1.061), SRK/T (1.188), and Holladay 1 (1.513). A detailed analysis of ACD and LT measurement error revealed negligible impact on refractive outcomes in BUII and EVO 2.0 when these parameters were incorporated or omitted in the formula calculation.

CONCLUSION

The Kane, EVO 2.0, and traditional formulas with WK AL adjustment displayed high prediction accuracy. Furthermore, the ACD and LT measurement error does not exert a significant influence on the accuracy of IOL power calculation formulas in highly myopic eyes implanted with PC-pIOL.

Analysis after posterior chamber phakic intraocular lens implantation: 17- to 19-year follow-up study

PURPOSE

To evaluate the clinical outcomes of the Visian implantable collamer lens (ICL) in eyes with ≥17 years of follow-up.

SETTING

Single-center.

DESIGN

Retrospective observational study.

METHODS

70 eyes from 38 patients who underwent surgery between 2002 and 2006 with V4 ICL implantation were analyzed. Preintervention data included corrected distance visual acuity (CDVA), refraction, and intraocular pressure (IOP). At the 19-year mark, CDVA, refraction, IOP, endothelial count, and vault were measured using Tomey Casia 2 anterior pole tomography, along with recording long-term events.

RESULTS

The operated patients had a spherical correction between -4 diopters (D) and -21 D and a cylinder up to 7.5 D. The mean CDVA (decimal) at the 17-year check-up was 0.89 ± 0.18, with a spherical equivalent of -1.05 ± 1.36 D. IOP has remained stable because mean measurements before surgery and currently were 15.16 ± 2.54 mm Hg and 16.19 ± 3.29 mm Hg, respectively. The endothelial cell count showed values of 2191 ± 386 cells/mm2, with a maximum of 2804 cells and a minimum of 1125 cells. Finally, the vault obtained was 348.53 ± 234.58 mm. Over the years, 2 eyes developed angle-closure glaucoma and 9 eyes were operated on for the development of anterior subcapsular cataracts.

CONCLUSIONS

Visian ICL implantation demonstrated long-term visual and refractive stability, indicating it as a low-risk procedure. The ICL V4 model yielded satisfactory results for myopia and astigmatism correction after 17 years.

Endothelial Cell Loss in Patients with Phakic Intraocular Lenses

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

Reverse pupillary block with pigment dispersion and elevated intraocular pressure following bilateral phakic intraocular lens implantation

The authors describe a case of reverse pupillary block with pigment dispersion following sequential phakic intraocular lens (pIOL) implantation for high myopia, in a young female patient. The intraocular pressure (IOP) elevation began 3 weeks postoperatively, for which Nd-YAG laser peripheral iridotomies (PIs) were attempted elsewhere. Despite maximum medical therapy, the IOP was uncontrolled. She was referred to our institute for further management. Examination showed anteriorly displaced iris-pIOL diaphragm, iris pigment dispersion and raised IOP. The PIs were incomplete. Based on clinical evaluation and investigations, we concluded that the excess area of contact of the posterior iris over the pIOL caused a reverse pupillary block and pigment dispersion. The IOPs were controlled by repeating laser iridotomies and with medical therapy. Subsequently, the patient developed a low lens vault leading to bilateral cataract. Sequential explantation of the pIOL along with cataract extraction was performed and her vision was restored.

Ten-year follow-up of posterior chamber phakic intraocular lens with central port design in patients with low and normal vault

PURPOSE

To assess the clinical outcomes and postoperative complications of the implantable collamer lens (ICL) with a central port throughout 10 years of follow-up in patients with low and normal vault.

SETTING

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

DESIGN

Retrospective and comparative case series.

METHODS

This study included eyes that underwent a V4c ICL implantation with 10 years of follow-up. The eyes were divided into 2 groups according to the vault at 1 year postoperatively: vault <250 μm and between 250 μm and 800 μm. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), vault, complications, and secondary surgeries were analyzed.

RESULTS

37 and 90 eyes were enrolled in the low and normal-vault groups, respectively. No differences in UDVA, CDVA, and refraction were found between the groups over 10 years of follow-up. No cases developed ICL-induced anterior subcapsular opacity over the follow-up period. 2 (5.4%) and 8 (8.9%) eyes in the low and normal-vault groups, respectively, required ICL exchange. 1 (2.8%) and 2 (2.2%) eyes in the low and normal-vault groups, respectively, required excimer laser to correct residual refractive error. The IOP remained stable throughout the 10-year follow-up. The loss in ECD from that preoperatively to 10 years postoperatively was 3.8% and 4.5% in the low and normal-vault groups, respectively ( P = .4). No pigment dispersion glaucoma or other vision-threatening complications were reported.

CONCLUSIONS

This study shows good long-term outcomes of the V4c ICL, supporting that the central hole provides safety to the procedure and prevents the potential risk associated with low vault.

Implantable Collamer Lens Procedure Planning: A Review of Global Approaches

More than 2 million implantable collamer lenses (ICLs) have been implanted worldwide. With a central port to improve aqueous flow through the ICL, the latest iteration of this phakic intraocular lens (pIOL) has been shown to have stable outcomes with very low rates of adverse events. However, correct planning and ICL size selection continue to be important to achieve an optimal vault. Shallow or excessive vaults are not complications in and of themselves but may increase the risk of complications. Historically, surgeons have relied on measurements of anterior chamber depth (ACD) and manual, caliper-measured white-to-white (WTW) distance to select the ICL size. New diagnostic and imaging technologies such as optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) provide additional opportunities for visualization and measurement of the intraocular dimensions involved in phakic intraocular lens implantation, including sulcus-to-sulcus (STS) and angle-to-angle (ATA) diameters. This paper reviews various approaches to ICL planning and sizing that have been published in the peer-reviewed literature, all of which produce acceptable results for predicting vault and size selection. Surgeons may also want to identify a methodology for patient evaluation and ICL size selection that best aligns with their personal preferences, diagnostic technology, and familiarity with analytical optimization tools.

Effect of vault on predicting postoperative refractive error for posterior chamber phakic intraocular lens based on a machine learning model

PURPOSE

To investigate how vault and other biometric variations affect postoperative refractive error of implantable collamer lenses (ICLs) by integrating artificial intelligence and modified vergence formula.

SETTING

Eye and ENT Hospital of Fudan University, Shanghai, China.

DESIGN

Artificial intelligence and big data-based prediction model.

METHODS

2845 eyes that underwent uneventful spherical ICL or toric ICL implantation and with manifest refraction results 1 month postoperatively were included. 1 eye of each patient was randomly included. Random forest was used to calculate the postoperative sphere, cylinder, and spherical equivalent by inputting variable ocular parameters. The influence of predicted vault and modified Holladay formula on predicting postoperative refractive error was analyzed. Subgroup analysis of ideal vault (0.25 to 0.75 mm) and extreme vault (<0.25 mm or >0.75 mm) was performed.

RESULTS

In the test set of both ICLs, all the random forest-based models significantly improved the accuracy of predicting postoperative sphere compared with the Online Calculation & Ordering System calculator ( P < .001). For ideal vault, the combination of modified Holladay formula in spherical ICL exhibited highest accuracy ( R = 0.606). For extreme vault, the combination of predicted vault in spherical ICL enhanced R values ( R = 0.864). The combination of predicted vault and modified Holladay formula was most optimal for toric ICL in all ranges of vault (ideal vault: R = 0.516, extreme vault: R = 0.334).

CONCLUSIONS

The random forest-based calculator, considering vault and variable ocular parameters, illustrated superiority over the existing calculator on the study datasets. Choosing an appropriate lens size to control the vault within the ideal range was helpful to avoid refractive surprises.

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.

Clinical decision support system based on deep learning for evaluating implantable collamer lens size and vault after implantable collamer lens surgery: a retrospective study

OBJECTIVES

To aid doctors in selecting the optimal preoperative implantable collamer lens (ICL) size and to enhance the safety and surgical outcomes of ICL procedures, a clinical decision support system (CDSS) is proposed in our study.

DESIGN

A retrospective study of patients after ICL surgery.

SETTING

China Tertiary Myopia Prevention and Control Center.

PARTICIPANTS

2772 eyes belonging to 1512 patients after ICL surgery. Data were collected between 2018 and 2022.

OUTCOME MEASURES

A CDSS is constructed and used to predict vault at 1 month postoperatively and preoperative ICL dimensions using various artificial intelligence methods. Accuracy metrics as well as area under curve (AUC) parameters are used to determine the CDSS prediction methods.

RESULTS

Among the ICL size prediction models, conventional neural networks (CNNs) achieve the best prediction accuracy at 91.37% and exhibit the highest AUC of 0.842. Regarding the prediction model for vault values 1 month after surgery, CNN surpasses the other methods with an accuracy of 85.27%, which has the uppermost AUC of 0.815. Thus, we select CNN as the prediction algorithm for the CDSS.

CONCLUSIONS

This study introduces a CDSS to assist doctors in selecting the optimal ICL size for patients while improving the safety and postoperative outcomes of ICL surgery.

Smurf1 Modulates Smad Signaling Pathway in Fibrotic Cataract Formation

Purpose

TGF-β/BMP signaling pathway plays a significant role in fibrotic cataract. Smurf1, a ubiquitin protein ligase, regulates the TGF-β/BMP signaling pathway through the ubiquitin-proteasome system (UPS). This study aims to investigate the role of Smurf1 in the progression of fibrotic cataract and its underlying mechanism.

Methods

We used a mouse model of injury-induced anterior subcapsular cataract (ASC) and administered the Smurf1 inhibitor A01 for in vivo investigations. RNA sequencing was performed to examine global gene expression changes. Protein levels were assessed by Simple Western analysis. The volume of subcapsular opacity was determined using whole-mount immunofluorescence of lens anterior capsules. Lentivirus was utilized to establish cell lines with Smurf1 knockdown or overexpression in SRA01/04. Lens epithelial cell (LEC) proliferation was evaluated by CCK8 and EdU assays. Cell cycle profile was determined by flow cytometry. LEC migration was measured using Transwell and wound healing assays.

Results

The mRNA levels of genes associated with cell proliferation, migration, epithelial-mesenchymal transition (EMT), TGF-β/BMP pathway, and UPS were upregulated in mouse ASC model. Smurf1 mRNA and protein levels were upregulated in lens capsules of patients and mice with ASC. Anterior chamber injection of A01 inhibited ASC formation and EMT. In vitro, Smurf1 knockdown reduced proliferation, migration and TGF-β2-induced EMT of LECs, concomitant with the upregulation of Smad1, Smad5, and pSmad1/5. Conversely, overexpression of Smurf1 showed opposite phenotypes.

Conclusions

Smurf1 regulates fibrotic cataract progression by influencing LEC proliferation, migration, and EMT through the modulation of the Smad signaling pathway, offering a novel target for the fibrotic cataract treatment.

Development and Validation of Data-Level Innovation Data-Balancing Machine Learning Models for Predicting Optimal Implantable Collamer Lens Size and Postoperative Vault

INTRODUCTION

There are only four sizes of implantable collamer lens (ICL) available for selection, which cannot completely fit all patients as a result of the discontinuity of ICL sizes. Sizing an optimal ICL and predicting postoperative vault are still unresolved problems. This study aimed to develop and validate innovative data-level data-balancing machine learning-based models for predicting ICL size and postoperative vault.

METHODS

The patients were randomly assigned to training and internal validation sets in a 4:1 ratio. Feature selection was performed using analysis of variance (ANOVA) and Kruskal-Wallis feature importance methods. Traditional linear regression model and machine learning-based models were used. The accuracy of models was assessed using the area under the curve (AUC) and confusion matrix.

RESULTS

A total of 564 patients (1127 eyes) were eligible for this study, consisting of 808 eyes in the training set, 202 eyes in the internal validation set, and 117 eyes in the external validation set. Compared with the traditional linear regression method, the machine learning model bagging tree showed the best performance for ICL size selection, with an accuracy of 84.5% (95% confidence interval (CI) 83.2-85.8%), and the AUC ranged from 0.88 to 0.99; the prediction accuracy of 12.1 mm and 13.7 mm ICL sizes was improved by 49% and 59%, respectively. The bagging tree model achieved the best accuracy [90.2%, (95% CI 88.9-91.5%)] for predicting the postoperative vault, and the AUC ranged from 0.90 to 0.94. The prediction accuracies of internal and external validation dataset for ICL sizing were 82.2% (95% CI 81.1-83.3%) and 82.1% (95% CI 81.1-83.1%), respectively.

CONCLUSIONS

The innovative data-level data balancing-based machine learning model can be used to predict ICL size and postoperative vault more accurately, which can assist surgeons in choosing optimal ICL size, thus reducing risks of postoperative complications and secondary surgery.

Evaluation of long-term clinical outcomes after toric implantable collamer lens implantation

PURPOSE

To evaluate the long-term (8-10 years) outcomes of toric implantable collamer lens (TICL) surgery.

SETTING

Nagoya Eye Clinic, Nagoya, Aichi, Japan.

DESIGN

Retrospective observational study.

METHODS

Patients who underwent TICL surgery from 2005 to 2009 to correct myopia and myopic astigmatism were enrolled. The safety, efficacy, predictability, astigmatism correction efficacy, and complications were evaluated using preoperative, 1-year postoperative, and final examination data.

RESULTS

133 eyes of 77 patients were included. At the final visit, the mean uncorrected and corrected visual acuities were -0.01 ± 0.2 and -0.17 ± 0.05, respectively. The mean safety and efficacy indices were 0.91 ± 0.26 and 0.68 ± 0.21, respectively. The manifest astigmatism was -0.45 ± 0.43 diopters (D). The mean corneal astigmatism change from 1 year postoperatively to the final visit was 0.40 ± 0.26 D. Of the 38 eyes with a change in corneal astigmatism ≥0.5 D, 30 eyes (78.9%) changed to against-the-rule (ATR) astigmatism, 1 (2.6%) changed to oblique astigmatism, and 7 (18.4%) changed to with-the-rule (WTR) astigmatism. The mean manifest astigmatism change from 1 year postoperatively to the final visit was 0.43 ± 0.52 D. Of the 60 eyes with a change in manifest astigmatism ≥0.5 D, 25 (41.7%) changed to ATR astigmatism, 18 (30.0%) changed to oblique astigmatism, and 17 (28.3%) changed to WTR astigmatism. During follow-up, 8 (6.0%) of 133 eyes developed anterior subcapsular cataracts, among which 4 (3.0%) underwent TICL removal and phacoemulsification and aspiration. No vision-threatening complications occurred.

CONCLUSIONS

TICL surgery showed good long-term astigmatism-correcting effects, although the long-term uncorrected visual acuity decreased. The procedure was effective in correcting myopia and astigmatism.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Translational Relevance

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

Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses

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

Long-term results of a new posterior chamber phakic intraocular lens in patients with high myopia: 5-year results

PURPOSE

To evaluate the long-term refractive outcomes of Eyecryl posterior chamber spherical phakic intraocular lens (pIOL) implantation in high myopia and endothelial cell density (ECD) change.

SETTING

Beyoglu Eye Training and Research Hospital, Istanbul, Turkey.

DESIGN

Retrospective.

METHODS

Eyes that were not suitable for corneal refractive surgery, had high myopia between -6.00 diopters (D) and -20.00 D, had Eyecryl posterior chamber spherical pIOL implantation, and had at least 5 years of follow-up were included. Preoperative ECD was ≥2300 cells/mm 2 and cylindrical value was ≤2.0 D in all cases. Preoperative and postoperative first, third, and fifth years of refraction, uncorrected and corrected distance visual acuity (UDVA/CDVA), and ECD were recorded.

RESULTS

36 eyes of 18 patients were examined. The mean UDVA and CDVA in postoperative fifth years were 0.24 ± 0.19 logMAR and 0.12 ± 0.18 logMAR, respectively. The safety and efficacy indices were 1.52 ± 0.54 and 1.14 ± 0.38, respectively. At 5 years, the spherical equivalent was ±0.50 D in 75% of eyes and ±1.00 D in 92% of eyes. After 5 years, the mean cumulative ECD loss was 6.91% ( P = .07). The annual ECD loss was 1.57% in the first year, 0.26% between 1 year and 3 years, and 2.38% between 3 years and 5 years. Asymptomatic anterior capsule opacity developed in 1 eye 4 years after surgery. Rhegmatogenous retinal detachment developed in 1, and myopic choroidal neovascular membrane occurred in 1 eye.

CONCLUSIONS

Eyecryl posterior chamber spherical pIOL implantation is one of the effective and safe refractive surgical methods in correcting high myopia with predictable and stable refractive results over a 5-year period. Longer-term studies are needed for complications such as decreased ECD, retinal complications, and lens opacity.

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

Background

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

Methods

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

Results

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

Conclusion

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

Validation of the vault prediction model based on the sulcus-to-sulcus diameter and lens thickness: a 925-eye prospective study

BACKGROUND

To verify the accuracy and stability of the prediction formula based on the ciliary sulcus diameter and lens thickness and to analyse factors influencing the prediction results.

METHODS

In total, 925 eyes from 506 subjects were enrolled in this prospective study between July 1, 2020, and June 30, 2021. Subjects were divided into four seasons, each spanning three months. The target vault was set to be between 300 μm and 700 μm according the prediction formula. The actual vault was measured one month postoperatively. The Bland-Altman test, 95% confidence intervals (95% CI) and 95% limits of agreement (95% LoA) were used to evaluate the agreement between the predicted vault and the actual vault. Eyes with absolute prediction errors greater than 300 μm were further analysed.

RESULTS

The mean predicted vaults for the four seasons were 503 ± 99, 494 ± 96, 481 ± 92 and 502 ± 93 μm, while the mean actual vaults were 531 ± 189, 491 ± 179, 464 ± 179 and 529 ± 162 μm, respectively. The predicted and actual vaults of the overall subjects were 493 ± 95 and 500 ± 180 μm, respectively. Of the 925 eyes, 861 eyes (93.08%), 42 eyes (4.54%), and 22 eyes (2.38%) showed a normal vault, high vault, and low vault, respectively. Bland-Altman plots showed that the mean difference between the actual vault and predicted vault overall (± 95% LoA) was 6.43 ± 176.2 μm (-339 to 352 μm). Three UBM features may lead to large prediction errors (more than 300 μm): wide iris-ciliary angle (ICA), iris concavity and anteriorly positioned ciliary body.

CONCLUSIONS

This study demonstrated the accuracy and stability of the prediction formula through the validation of a large sample size and a long time span. Wide ICA, iris concavity and anteriorly positioned ciliary body may have an effect on vault.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Inter-eye and postoperative prediction of vault after implantation of EVO + Visian phakic implantable collamer lens

PURPOSE

To assess whether the postoperative outcomes of the implantation of an EVO + implantable collamer lens (ICL) in one eye can be used as a predictor of the vault of the fellow eye, and to evaluate the vault changes of the implantation in both eyes during the postoperative period.

METHODS

A prospective study including 40 eyes of 20 patients with a bilateral EVO + ICL implantation was performed. Subjects were evaluated before the surgery and 1 day, 1 week and 1, 3 and 6 months postoperatively. Central vault was assessed using spectral-domain optical coherence tomography. The inter-eye and follow-up analyses were performed using lineal models and the Bland-Altman method.

RESULTS

The vault of the first implanted eye at the 1-day visit highly predicts the vault of the second eye (R² = .87; P < .001); the mean inter-eye difference was - 0.95 μm, and the superior and inferior limits of agreement were -50.27 μm and 148.37 μm, respectively. This relationship was maintained during the medium-term follow-up, not finding differences in the slopes among visits (P ≥ .09). A progressive decrease of vault was found during the follow-up (P < .001). Larger vault change 6 months after the surgery was associated with higher vault 1 day after the ICL implantation (R² = .19;P = .005).

CONCLUSION

One-day postoperative vault in the first eye can help to predict the optimal ICL sizing in the second eye. Vault tends to decrease during the first 6 months after EVO + ICL implantation. Eyes with higher initial vaults will also show larger reductions during the medium-term follow-up.

Clinical observations of EVO-ICL implantation and changes in corneal astigmatism using a modified technique

Background

Implantable collamer lens (ICL) surgery techniques are constantly progressing. The purpose of this study was to investigate the application effect of the modified technique and its impact on the change in corneal astigmatism in EVO-ICL surgery.

Methods

The analysis of retrospective cohort data included 153 eyes of 81 patients with myopia from July 2018 to May 2020. An EVO-ICL was inserted by modified surgical skills, including a single 3.0 mm corneal incision and no ophthalmic viscosurgical device (OVD) before the insertion of the ICL (modified technique group: 41 cases, 80 eyes) and standard procedure (standard technique group: 40 cases, 73 eyes). Early postoperative intraocular pressure (IOP) was monitored at 2 and 24 h. IOP, corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), vault, and anterior chamber depth (ACD) were measured 1, 6, and 12 months following the initial examination. The corneal endothelial cell density (ECD) was monitored at 6 and 12 months after the operation. Surgically induced astigmatism (SIA) in the total, anterior, and posterior corneal surfaces was analysed 1 month after the operation.

Results

No serious complications were detected. The two groups had no difference in visual outcomes, ICL vaults, or ACD at any time point (P > 0.05). Two hours postoperatively, IOP was significantly lower in the modified technique group (16.22 ± 2.22 vs. 18.37 ± 1.92 mmHg, P < 0.05) than in the standard technique group. IOP decreased gradually after 24 h to preoperative levels. The postoperative IOP remained stable over a 12-month period. The ECD at 6 and 12 months was not significantly different between the groups (P > 0.05). SIA in the total, anterior, and posterior corneal surfaces were assumed to have no clinically meaningful differences between groups at one month after operation (P > 0.05).

Conclusions

The modified technique is efficient and safe, producing comparable visual and structural outcomes without adversely affecting ECD, and reduces fluctuations in IOP at the early postoperative stages. The auxiliary incision in the standard technique does not increase corneal SIA, which is also a factor to consider for inexperienced surgeons.

Three-year follow-up of posterior chamber phakic intraocular lens with a central port design after deep anterior lamellar keratoplasty

Background

To evaluate clinical outcomes of the Visian implantable collamer lens (ICL) with a central port to correct myopia and astigmatism after deep anterior lamellar keratoplasty (DALK) for keratoconus throughout 3 years of follow-up.

Methods

This study included 20 eyes of 20 patients that underwent V4c ICL (13 eyes with a spherical ICL and 7 eyes with a toric ICL) implantation after DALK. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure (IOP), endothelial cell density (ECD), and vault were analyzed.

Results

The mean UDVA improved from the preoperative 1.18 ± 0.33 logMAR to 0.25 ± 0.14 logMAR at 6 months after surgery (P < 0.0001) and remained unchanged throughout the whole follow-up (P = 0.4). All eyes gained lines of CDVA compared to preoperative values. At the last follow-up visit, all eyes achieved CDVA of 0.2 logMAR or better and 13 eyes (65%) 0.1 logMAR or better. At 6 months post-surgery, all eyes (100%) had a spherical equivalent within ± 1.50 D, and 19 (95%) within ± 1.00 D. The mean manifest spherical equivalent was stable over the postoperative follow-up (P = 0.25). No significant increase in IOP occurred in any case throughout the 3 years of follow-up. The loss in ECD from the preoperative baseline at the last follow-up visit was 2.27%.

Conclusions

The clinical outcomes suggest that the V4c ICL implantation for correction of myopia and regular astigmatism in post-DALK eyes was satisfactory in terms of effectiveness, safety, and stability during 3 years of follow-up.

A prediction model for sulcus-to-sulcus diameter in myopic eyes: a 1466-sample retrospective study

Background

To establish and verify the accuracy and reliability of a sulcus-to-sulcus diameter (STS) prediction model.

Methods

In this retrospective study, the prediction formula was established with the data from 1466 eyes from 733 subjects from July 2020 to April 2021 and verified with the data from 278 eyes from 139 subjects between May 2021 and June 2021. Each subject was measured with a Pentacam, IOLMaster 700, OPD-Scan III, and ultrasound biomicroscope. The prediction formulas were established with multiple linear regression, and intergroup correlation coefficients (ICCs) and Bland–Altman tests were used to assess the agreement between the predicted and actual STS (actual STS was measured by UBM).

Results

The explanatory variables relevant to the horizontal STS (STSH) were the Pentacam white-to-white diameter (WTWP; standardized partial regression coefficient [β] = 0.330; p < 0.001), the flat K value (β = -0.211; p < 0.001), and the anterior corneal diameter (ACD) (β = 0.178; p < 0.001). The corresponding multiple regression equation was : STSH (mm) = 8.061 + 0.510 × WTWP − 0.090 × Flat K value + 0.430 × ACD. The explanatory variables relevant to the vertical STS (STSV) were the WTWP (β = 0.435; p < 0.001), the steep K value (β = -0.271; p < 0.001), and the ACD (β = 0.187; p < 0.001). The corresponding multiple regression equation was : STSV (mm) = 8.540 + 0.492 × WTWP − 0.075 × Steep K value + 0.329 × ACD. The bias of the predicted to the actual STSH was − 0.021, with 95% limits of agreement (95% LoA) from − 0.499 to 0.457. The bias of the predicted to the actual STSV was 0.057, with 95% LoA from − 0.462 to 0.575. The ICC was 0.883 between the predicted and actual STSH and 0.859 between the predicted and actual STSV.

Conclusions

The Pentacam-measured WTW, the K value and the ACD are important for predicting the STS diameter. The prediction model has good accuracy and reliability.

Trial registration

Not applicable.

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.

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.

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.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

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.

Safety of EVO ICL Implantation With an Ophthalmic Viscosurgical Device-Free Technique in the Early 24 h After Surgery

Purpose: To compare the safety of the non-ophthalmic viscosurgical device (OVD) technique with that of the minimum OVD technique in EVO Implantable Collamer Lens (EVO-ICL) implantation.

Methods: A total of 180 eyes of 90 consecutive patients were enrolled in the study, of which 100 eyes of 50 patients were treated with non-OVD technique, with a 55% success rate. The remaining 80 eyes of 40 patients were treated with min-OVD technique, so they were classified into the min-OVD group. Preoperative and postoperative intraocular pressure (IOP) measurements were collected and analyzed at 1, 2, 3, and 24 h. Visual acuity, corneal endothelial cell density (ECD), and corneal densitometry 24 h postoperatively were evaluated.

Results: No significant difference was found in visual outcomes (P = 0.54) or ECD (P = 0.78) between the two groups. The operation time was significantly shorter in the non-OVD group (P < 0.0001). The IOP was significantly higher at 1 h (P < 0.0001), 2 h (P < 0.0001) and 3 h (P = 0.0045) postoperatively in the min-OVD group. The non-OVD group had significantly lower IOP than the min-OVD group at 1 h (P = 0.01) and 2 h (P = 0.013) postoperatively. The temporal corneal densitometry in the non-OVD group were significantly lower than those in the minimum group (P = 0.0063) 1 day after surgery.

Conclusion: The non-OVD technique is safe and efficient for ICL implantation. It can be a safer method of ICL implantation in that it completely eliminates ophthalmic viscoelastic devices related complications without causing additional complications in short term.

Visual Outcomes, Footplate Position and Vault Achieved with the Visian Implantable Collamer Lens for Myopic Astigmatism

Purpose

Report the outcomes of the implantable collamer lens (ICL) in myopic astigmatism using very high-frequency (VHF) digital ultrasound sizing.

Methods

Analysis of 42 consecutive ICL procedures using EVO and EVO+ (Visian V4c) lenses (STAAR Surgical) was done. ICL size was chosen using the ultrasound-based Kojima Formula with Insight 100 VHF digital ultrasound (VHFDU). Standard visual outcomes analysis was performed using 3-month data, also including contrast sensitivity, refractive and corneal vector analysis, and ECC. Postoperative lens position was evaluated using VHF digital ultrasound.

Results

Attempted SEQ was −10.83±3.39D (−4.40 to −16.98D). Cylinder was −1.46±1.15D (0.00 to −4.25D). One-year follow-up was available in 86% of the eyes and 3 months in 96%. Postoperative UDVA was 20/20 or better in 89% of the eyes, relative to 71% preoperatively. Postoperative SEQ refraction was ±0.50 D in 74% and ±1.00 D in 98% of the eyes. There was a gain of one line of CDVA in 43% of the eyes, 2 or more lines in 10% of the eyes, while there was a one line loss in 7% and no eyes lost 2 or more lines. The vector mean for the corneal SIA was 0.24 D Ax 100. Contrast sensitivity showed a statistically significant increase with a mean of 0.14 log units at 6, 12, and 18 cycles per degree (P<0.01). The mean change in ECC was −153±353 cells/mm². Lens vault was 506±233 µm (114–924 µm). Footplate insertion was in zonular position in 48.3%, ciliary body in 49.2%, and sulcus in 2.5% of locations.

Conclusion

ICL implantation resulted in high safety and efficacy but with an implantation vault range that ideally would be improved upon. VHF digital ultrasound of the lens footplate and posterior anatomical relations may provide essential information for evaluating postoperative vault outliers.

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.

3-month surgical outcomes of Implantable Collamer Lens implantation for myopic regression after laser vision correction surgeries: a retrospective case series

Background

To investigate the surgical outcomes of implantable collamer lens (ICL) implantation in eyes with residual myopia after primary laser vision correction (LVC) surgeries.

Methods

This study included patients who underwent ICL implantation and had a history of LVC surgery, including photorefractive keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK). Visual acuity and refractive error were assessed pre and 3-months postoperatively and the efficacy and safety indices calculated accordingly.

Results

A total of 30 eyes of 17 patients were included in this study. At 3 months, the mean logMAR uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and spherical equivalent were − 0.03 ± 0.11 (include logMAR), − 0.04 ± 0.09 (include logMAR), and − 0.06 ± 0.33 diopters (D), respectively. The 3-month Snellen UDVA was better than 20/20 for 83% of eyes, and 97% of eyes showed an unchanged or improved CDVA after surgery. The mean efficacy and safety indices were 1.11 ± 0.22 and 1.13 ± 0.20, respectively. Further, 93 and 100% of eyes were within ±0.5 and ± 1.0 D of the attempted spherical equivalent refraction, respectively.

Conclusions

ICL implantation in eyes with myopic regression after previous LVC surgery showed safe, effective, and predictable outcomes.

Trial registration

retrospectively registered.

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.

Long term efficacy and safety profiles following posterior chamber phakic intraocular lens implantation in eyes with ≥ 10-year follow-up

PURPOSE

Evaluate long-term efficacy, safety, predictability and stability of a posterior chamber phakic intraocular lens (Visian ICL) in eyes with ≥10-year follow-up.

SETTING

Instituto de Microcirugía Ocular, Barcelona, Spain.

DESIGN

Retrospective study.

METHODS

Eyes undergoing ICL implantation from 2008-2011 with ≥10-year follow-up were included. Variables analyzed were: preoperative, 1-month, 1-year, 5-years and last follow-up uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, spherical equivalent (SE), endothelial cell count (ECC) and intraocular pressure (IOP). Descriptive statistics were performed and results reported following the Standard for Reporting Refractive Surgery Outcomes.

RESULTS

45 eyes (26 patients) were analyzed, mean follow-up 11.35 ± 1.30 years. Mean preoperative SE was -10.06 ± 3.40D and mean preoperative cylinder -1.55 ± 1.45D. At last follow-up, efficacy and safety indices were 0.79 and 1.12, respectively. In total, 32 (71%) eyes achieved an UDVA of ≥20/40. 22 (49%) eyes gained ≥1 line of CDVA, and 2 (4%) eyes lost ≥2 lines of CDVA. At final follow-up, 19 (42%) and 29 (64%) eyes were within ±0.50D and ±1.00D of attempted SE correction, respectively. 31 (69%) eyes had ≤1.00D of postoperative astigmatism and 29 (74%) eyes were within ±15° from the intended correction axis. At the last visit, a statistically significant myopic progression of -0.75 ± 1.20D was observed (p=0.01). ECC loss at last follow-up was 9.85 ± 11.35%. IOP remained stable. There were no intraoperative complications. 3 eyes (7%) developed cataract after 10 years.

CONCLUSIONS

Long-term results demonstrate that ICL is effective, predictable, stable and safe.

Prediction of the trabecular iris angle after posterior chamber phakic intraocular lens implantation

PURPOSE

To create an equation for predicting the trabecular iris angle (TIA) and to verify its accuracy after implantable collamer lens (ICL) implantation.

SETTING

Nagoya Eye Clinic, Nagoya, Japan.

DESIGN

Retrospective evaluation of a screening approach.

METHODS

The subjects included 174 eyes (174 patients) that underwent ICL implantation. Patients were randomly assigned to the prediction equation group (116 eyes) or verification group (58 eyes). Anterior segment optical coherence tomography (AS-OCT; CASIA2 TOMEY) was performed before and 3 months after ICL surgery. For the prediction group, a prediction equation was created with the preoperative AS-OCT parameters and ICL size as independent variables and the postoperative anterior chamber depth (ACD) as dependent variables. Then, by applying the predicted post-ACD and preoperative AS-OCT parameters as independent variables and TIA after ICL surgery as the dependent variable, a prediction equation was created to predict the postoperative TIA (post-TIA) after ICL surgery. Each prediction equation was created using stepwise multiple regression analysis, and its accuracy was verified by a Bland-Altman plot in the verification group.

RESULTS

The explanatory variables (standardized partial regression coefficient) selected in the post-TIA prediction equation were post-ACD (0.629), TIA750 (0.563), iris curvature (0.353), pupil diameter (-0.281), iris area (-0.249), and trabecular iris space area 250 (-0.171) (R2 = 0.646). There were no clinically significant systematic errors between measured and predictive post-TIA values in the verification group. The average absolute prediction error was 3.43° ± 2.22°.

CONCLUSIONS

Post-TIA can be accurately predicted from the predicted post-ACD and other preoperative AS-OCT parameters.

Short-Term Efficacy and Safety of Cataract Surgery Combined with Iris-Fixated Phakic Intraocular Lens Explantation: A Multicentre Study

The purpose of this study was to evaluate the short-term efficacy and safety of cataract surgery for patients with iris-fixated phakic intraocular lenses (pIOLs). This study included 96 eyes of 91 patients. The changes in the logMAR uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), subjective spherical equivalent (SE), astigmatism, and endothelial cell density (ECD) were collected retrospectively. The intraoperative and postoperative complications also were investigated to assess the surgical safety. The preoperative UCVA and BCVA improved significantly at month 1 postoperatively, respectively (p < 0.001 for both comparisons). The efficacy and safety index at month 1 postoperatively were 1.02 ± 0.56 and 1.31 ± 0.64, respectively. The SE at month 1 postoperatively was significantly (p < 0.001) higher compared to preoperatively, whereas the subjective astigmatism did not differ significantly (p = 0.078). The ECD significantly decreased at month 1 (p < 0.001). The most common postoperative complication was intraocular pressure elevation exceeding 25 mmHg in 10.4% of eyes, which was controlled with medications in all cases until month 1 postoperatively. No intraoperative complications developed. Cataract surgeries for patients with iris-fixated pIOLs were performed safely with good visual outcomes.

Long-term Clinical Outcomes of Implantable Collamer Lens

Purpose: To evaluate the long-term clinical outcomes of implantable collamer lens (ICL) implantation in myopic patients.Methods: This retrospective study included 129 eyes of 68 patients who underwent ICL implantation for correction of myopia with a 10-year follow-up.Results: Ten years after ICL implantation, the mean uncorrected and corrected distance visual acuities (LogMAR) were 0.03 ± 0.13 and -0.07 ± 0.06, respectively. Ten years postoperatively, 52.7% and 84.5% of the eyes were within ± 0.5 and ± 1.0 diopters, respectively. The mean efficacy and safety indices were 0.91 ± 0.22 and 1.07 ± 0.19, respectively. There was no significant difference between mean preoperative (13.52 ± 2.88 mmHg) and postoperative (13.59 ± 3.55 mmHg) intraocular pressures. The endothelial cell density decreased from before surgery to 10 years after surgery (3,074 ± 365 cells/mm2, 2,812 ± 406 cells/mm2, respectively; mean decrease: 8.5 ± 10.8%; p = 0.011). Eight eyes (6.2%) developed cataract during follow-up, which was symptomatic in three eyes (2.3%) and treated with ICL explantation and phacoemulsification. Rhegmatogenous retinal detachment occurred in one eye (0.8%) and was treated with vitrectomy.Conclusions: ICL implantation for the correction of myopia had good efficacy and safety outcomes during long-term follow-up of 10 years. However, patients should be closely monitored for complications such as cataract formation, endothelial cell loss, and retinal detachment.

Seven-year follow-up of posterior chamber phakic intraocular lens with central port design

BACKGROUND

To assess the clinical outcomes of the Visian Implantable Collamer Lens (ICL) with a central port throughout 7 years of follow-up.

METHODS

Eighty-four eyes of 52 patients were evaluated over a follow-up period of 7 years after V4c ICL implantation. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure (IOP), endothelial cell density (ECD) and vault were analysed.

RESULTS

The mean postoperative UDVA (logMAR) was 0.04 ± 0.11, 0.13 ± 0.19 and 0.17 ± 0.23 at 1-, 5- and 7-years, respectively (P < 0.0001). The mean CDVA (logMAR) remains unchanged throughout a 7-year follow-up period (0.02 ± 0.08 and 0.02 ± 0.08, at 5- and 7-years, respectively, P = 0.2). At all follow-up visits, more than 95% of the eyes achieved a CDVA of 20/25 or better and more than 85% a CDVA of 20/20. At the end of the follow-up (7 years), no eye lost more lines of CDVA, 56 eyes (66.7%) and 28 eyes (33.3%) gained lines of CDVA. At 7-years, the spherical equivalent was - 0.62 ± 0.62 D. No significant increase in IOP (> 20 mmHg or an increase higher than 5 mmHg) occurred in any case throughout the 7-year of follow-up. The loss in ECD from the preoperative baseline at the last follow-up visit was 2.6%. No intraoperative or postoperative complications or adverse events occurred during the follow-up period.

CONCLUSIONS

The outcomes of this study show the long-term viability of the V4c ICL implantation as a surgical option for the correction of myopia.

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.

Short-term changes in and preoperative factors affecting vaulting after posterior chamber phakic Implantable Collamer Lens implantation

Background

To describe the very early vault changes in the first month after Implantable Collamer Lens (ICL) implantation and to evaluate the effect of preoperative biometric factors on vault.

Methods

Eighty-three eyes from eighty-three subjects with complete data who met follow-up requirements were recruited in this retrospective study between May 2019 and March 2020. We quantitatively assessed the postoperative vault at 2 h, 1 day, 1 week, and 1 month following implantation. Associations between the postoperative vault and age, ICL size, spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), flat keratometry (K), steep K, mean K, anterior chamber depth (ACD), crystalline lens thickness (LT), white-to-white (WTW) diameter obtained by three devices, horizontal and vertical sulcus-to-sulcus (STS) diameter, bright and dark pupil sizes (BPS and DPS) and DPS-BPS were investigated using Spearman’s correlation analysis and stepwise multiple regression analysis.

Results

The mean vault values at 2 h, 1 day, 1 week, and 1 month after ICL implantation were 672.05 ± 30.72, 389.15 ± 28.33, 517.23 ± 30.76 and 530.12 ± 30.22 μm, respectively. Significant differences were found in the vault values at 2 h, 1 day and 1 week after the operation. The ICL size (β = 0.942; p < 0.001), followed by horizontal STS (β = -0.517; p < 0.001), crystalline LT (β = -0.376; p < 0.001) and vertical STS (β = -0.257; p = 0.017), significantly influenced the vault at 1 month after the operation. The multiple regression equation was expressed as follows: central vault (µm) = -1369.05 + 657.121 × ICL size- 287.408 × horizontal STS − 432.497 × crystalline LT − 137.33 × vertical STS (adjusted R² = 0.643).

Conclusions

After ICL implantation, the vault decreased and then increased, but it did not return to the vault value 2 h after surgery. The ICL size, horizontal and vertical STS and crystalline LT are key factors for predicting postoperative vaulting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01963-x.

Posterior Chamber Phakic Intraocular Lens Implantation for Refractive Correction in Corneal Ectatic Disorders: A Review

PURPOSE

To summarize the indications and outcomes of posterior chamber phakic intraocular lens (PIOL) implantation in corneal ectasias including keratoconus, pellucid marginal degeneration (PMD), post-refractive surgery, and post-keratoplasty ectasias.

METHODS

A review of the literature was conducted using the relevant keywords from various databases up to August 15, 2020. All pertinent studies were reviewed, and the relevant articles were studied in detail for efficacy, stability, predictability, and safety outcomes. In addition, visual quality, corneal biomechanical outcomes, complications, the role of posterior chamber PIOL in combination treatment, and comparison of posterior chamber PIOL with other PIOLs for ectasias were also evaluated.

RESULTS

A total of 30 relevant studies (13 prospective, 13 retrospective, 4 case reports) on the subject were studied and summarized. All studies showed a favorable refractive outcome. Quality of vision remained unaffected and no significant complications were reported in any of the studies.

CONCLUSIONS

Posterior chamber PIOLs represent a viable option in the treatment of mild to moderate and stable corneal ectasia in patients with contact lens intolerance who have low irregular astigmatism, a clear central cornea, and good preoperative corrected distance visual acuity. [J Refract Surg. 2021;37(5):351-359.].

Astigmatism correction with toric implantable collamer lens in low and high astigmatism groups

PURPOSE

To analyze the target induced astigmatism (TIA), surgically induced astigmatism (SIA), difference vector (DV), and correction index (CI) in the correction of astigmatism with phakic lenses, and its influence on visual acuity, and to analyze the safety and efficacy indexes of the correction of high and low power astigmatism with toric phakic lenses.

DESIGN

Retrospective comparative study.

METHODS

The medical records of patients that were operated on at the research center during the period were analyzed. Results were divided into Low Astigmatism Group - LAG (33 eyes) and High Astigmatism Group - HAG (93 eyes) according to the implanted toric ICL lens power. Preoperative refraction and resultant postoperative refraction were analyzed by vector analysis. Visual acuity pre and postop, with and without optical correction, were compared.

RESULTS

A total of 126 eyes were studied. The average preop refraction was -5.02 D sphere with -2.61 D cylinder. The average ICL lens power implanted was -8.31 D sphere +2.77 D cylinder. Refractive remaining was -0.01 ± 0.11 D sphere -0.15 ± 0.28 D cylinder. The arithmetic average angle of error in the astigmatism correction was 1.08°. The resultant cylinder was -0.03 ± 0.12 D and -0.19 ± 0.30 D in the low and high astigmatism groups, respectively, with a mean UDVA -0.01 ± 0.10 and 0.01 ± 0.16 and CDVA -0.03 ± 0.08 and -0.01 ± 0.17 for each group. The safety and efficacy indexes for the low astigmatism group were 1.09 ± 0.16 and 1.05 ± 0.17, respectively, with 1.11 ± 0.17 and 1.06 ± 0.16 for the high astigmatism group.

CONCLUSIONS

The correction of astigmatism by the implantation of toric phakic lenses of the posterior chamber is safe and effective, independently of the amount of cylinder corrected.

Three-Year Outcomes of Implantable Collamer Lens Followed by Excimer Laser Enhancement ("Bioptics") in the Treatment of High Myopic Astigmatism

Purpose

Describe three-year outcomes of spherical implantable Collamer lens (ICL) followed by excimer laser enhancement (bioptics) in eyes with high myopic astigmatism.

Patients and Methods

Retrospective case series of thirty-four cases that underwent bioptics enhancement at the Johns Hopkins Wilmer Eye Institute. All eyes had a preoperative sphere of −6.00 D or more with a cylinder of at least 2.00 D. Uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest spherical equivalent refraction (MSE), ICL vault measurements and central corneal thickness (CCT) were collected. Endothelial cell counts (ECC), root mean square (RMS) of higher order aberrations (HOAs), adverse events and subsequent surgeries were also assessed.

Results

All patients had a minimum follow-up of 3 years. Preoperative UDVA was 2.29 ± 0.46 logMAR and improved to 0.03 ± 0.23 logMAR at 3 years (p<0.05). MSE was −12.30 ± 4.05 preoperatively and changed to −0.21 ± 0.46 at 3 years (p<0.05). The efficacy and safety indices were 1.28 ± 0.32 and 1.47 ± 0.27 at 3 years post-enhancement. HOA did not significantly change throughout the follow-up (p<0.05). Endothelial cell loss at 12 months was calculated at 5.7%. Two eyes required ICL exchange due to vault-related issues.

Conclusion

Bioptics offered excellent long-term safe, predictable, and efficient outcomes for high myopic astigmatism and can be considered an option if toric ICL is not available. Results confirm that wavefront-guided photoablation remains an excellent option to manage residual refractive error after phakic IOL.

SMILE Versus Implantable Collamer Lens Implantation for High Myopia: A Matched Comparative Study

PURPOSE

To compare the safety, efficacy, and patient-reported quality of vision of small incision lenticule extraction (SMILE) and implantable Collamer lens (ICL) implantation for the treatment of high myopia.

METHODS

A database of 1,634 SMILE (Carl Zeiss Meditec AG, Jena, Germany) and 225 ICL implantation (STAAR Surgical, Monrovia, CA) procedures was screened for patients with a binocular preoperative manifest refraction spherical equivalent between -6.00 and -10.00 diopters (D) and plano target refraction. One-to-one matching was performed by preoperative manifest refraction spherical equivalent, age, and pupil size. All identified patients were then prospectively examined at their next regular postoperative follow-up visit and presented with the standardized and clinically validated Quality of Vision questionnaire to gauge patient-reported postoperative visual quality.

RESULTS

A total of 80 eyes (40 patients) were eligible for 1:1 matching. Mean postoperative follow-up was 27.8 ± 14.3 months in the SMILE group and 26.6 ± 17.7 months in the ICL group (P = .44). Regarding the percentage of eyes within ±0.50 D of plano target, refractive predictability was better in eyes treated with ICL implantation (90%) than SMILE (72.5%) (P = .045). Mean UDVA was comparable (ICL: -0.09 ± 0.10 logMAR; SMILE: -0.06 ± 0.09 logMAR; P < .09), but the efficacy (1.28 vs 1.05; P < .001) and safety (1.31 ± 0.22 vs 1.10 ± 0.25; P < .001) indices were higher after ICL implantation. ICL implantation induced significantly fewer higher order aberrations (total higher order aberrations: SMILE 0.724 ± 0.174 µm vs ICL 0.436 ± 0.114 µm; P < .01). Regarding subjective quality of vision, patients who had ICL implantation were significantly less bothered by visual disturbances, which were mainly halos after ICL and starbursts and fluctuations of vision after SMILE (P < .05).

CONCLUSIONS

In this refraction-matched comparative study, ICL implantation for high myopia yielded better refractive accuracy, better uncorrected distance visual acuity, fewer higher order aberrations, and better subjective quality of vision than SMILE. [J Refract Surg. 2020;36(3):150-159.].

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.