Effects of tilt and decentration of Visian Implantable Collamer Lens (ICL V4c) on visual quality: an observational study

Subjective and objective changes in visual quality after implantable collamer lens implantation for myopia

With the wide application of implantable collamer lens (ICL) surgery for myopia correction, the range of refractive correction has expanded (up to -18.00 D for myopia), and the safety, effectiveness, predictability and stability of ICLs have been well documented. However, achieving good visual quality after ICL implantation has also become very important. This article systematically reviews objective and subjective visual quality after ICL surgery. First, parameters used to assess objective visual quality after ICL surgery are introduced, including higher-order aberrations, the modulation transfer function (MTF) cutoff (cycles per degree [cpd]), the Strehl 2D ratio (SR), and the objective scatter index (OSI). Notably, various post-operative objective visual quality measurements have been improving over time. However, halos and glare caused by ICL implantation are notable postoperative complications. In further discussions, we also focus on factors that can affect visual quality, such as ICL position changes, pupil size, and the ICL optical zone. Furthermore, measures to improve postoperative visual quality, such as the selection of the surgical incision and mode, are provided. This review explores the potential mechanisms, emphasizes the importance of pre- and postoperative measures, and provides guidance for good postoperative visual quality. Additionally, this review aims to address the factors influencing visual quality and postoperative outcomes to optimize vision after ICL implantation.

Characterization of vault with two models of posterior chamber phakic intraocular lenses

PURPOSE

To evaluate and compare dynamic vault range (DVR) and asymmetry of the vault during a 3-month follow-up after the implantation of 2 posterior chamber phakic intraocular lenses (pIOLs).

SETTING

Aver Clinic, Madrid, Spain.

DESIGN

Prospective comparative study.

METHODS

119 eyes (65 patients) that underwent refractive surgical correction with implantation of 1 of 2 distinct pIOLs were enrolled: Eyecryl Phakic from Biotech Vision Care (Eyecryl group, 72 eyes) and Evo Visian Implantable Contact Lens from Staar Surgical (ICL group, 47 eyes). Besides evaluation of visual acuity, refraction, and ocular integrity, the pIOL vault centrally and at 2 mm nasally and temporally as well as the DVR from photopic (50 lux) to mesopic (10 lux) illumination conditions were measured.

RESULTS

No significant differences were found between the pIOL groups in visual and refractive outcomes ( P ≥ .454). No significant differences between the groups were found in central (523.72 ± 168.4 vs 494.16 ± 156.7 μm, P = .248) and temporal (499.43 ± 155.8 vs 431.28 ± 150.5 μm, P = .067) vaults. However, nasal vault was significantly lower in the ICL group (465.6 ± 149.1 vs 375.4 ± 144.0 μm, P = .045). A trend of a larger DVR was observed in the ICL group, although differences between groups did not reach statistical significance (54.00 ± 36.39 vs 86.5 ± 57.9 μm, P = .070). The pIOL diameter only correlated significantly with vault measurements in the ICL group ( r ≥ 0.650, P < .001).

CONCLUSIONS

The Eyecryl pIOL showed more symmetric vaults and a trend of fewer light-induced changes in the central vault compared with the ICL pIOL. The clinical relevance of this finding should be investigated further.

Effects of clear corneal incision location and morphology on corneal surgically induced astigmatism and higher-order aberrations after ICL V4c implantation

Purpose

To evaluate the effects of clear corneal incision (CCI) location and morphology on corneal surgically induced astigmatism (SIA) and higher-order aberrations (HOAs) in patients receiving implantable collamer lens (ICL V4c) implantation.

Methods

This retrospective study classified right eyes that underwent ICL implantation into two groups based on temporal or superior CCI. The Pentacam HR analyzer was used to measure the corneal astigmatism and HOAs. Analysis of the clear corneal incision (CCI) morphology, including incision width (Angle-W), incision length (IL), incision angles (Angle-En/Ex), and distance from the incision to corneal apex (Dis-En/Ex), was conducted using anterior segment optical coherence tomography (AS-OCT).

Results

There were 75 eyes in the temporal CCI group and 47 eyes in the superior CCI group. Both groups showed satisfactory safety and efficacy postoperatively. In the temporal CCI group, Dis-En and Dis-Ex were considerably longer, whereas the superior CCI group displayed a significantly wider Angle-W. The anterior and posterior corneal SIA were comparable in both groups. Anterior corneal SIA was significantly correlated to Dis-En and Dis-Ex in the superior CCI group. Superior CCI caused a notable rise in corneal Z (3, 3), while temporal CCI led to increased Z (3, 1). CCI morphology was correlated to corneal Z (4, -4) and Z (4, 4) in the superior CCI group.

Conclusion

CCI locations caused slight variations in postoperative corneal SIA and HOAs following ICL implantation. Optimal postoperative visual outcomes may be better achieved with a CCI design featuring an increased distance from the corneal centroid and a decreased Angle-W.

Measurement of the distance between corneal apex and pupil center in patients following small-incision lenticule extraction or implantable collamer lens implantation and its correlation with the surgical-induced astigmatism

BACKGROUND

To investigate the change in the distance between corneal apex and pupil center after small-incision lenticule extraction (SMILE) or implantable collamer lens (ICL) implantation and its correlation with surgical-induced astigmatism (SIA).

METHODS

This study included patients who had undergone SMILE (n = 112) or ICL implantation (n = 110) to correct myopia and myopic astigmatism. The angle kappa was measured using a Scheimpflug imaging device (Pentacam) and represented as Cartesian values between the pupil center and the corneal vertex (X, Y) and chord u ([Formula: see text]orientation), and was compared pre- and post-operative.

RESULTS

Following SMILE, the magnitude of chord u[Formula: see text]) significantly increased in both eyes (Wilcoxon signed-rank test, OD: P<0.001; OS: P=0.007), while no significant change was observed in the orientation. A significant correlation was found between the J0 component of SIA and the change in the magnitude of chord u for both eyes (OD: R2=0.128, P<0.001; OS: R2=0.033, P=0.004). After ICL implantation, the orientation of the chord u was significantly different in the right eye (Wilcoxon signed-rank test, P = 0.008), and the Y-intercept significantly decreased in both eyes (Wilcoxon signed-rank test, P<0.001). A significant correlation was found between J0 of SIA and the change in the magnitude of chord u for the right eyes (R2=0.066, P=0.002). A significant correlation was found between J45 of SIA and the change in the magnitude of chord u for the left eyes (R2=0.037, P=0.044).

CONCLUSIONS

The magnitude of the chord u increased following the SMILE procedure, whereas the Y-intercept significantly decreased after ICL implantation. SIA was related to the change in the magnitude of chord u.

Effects of Decentration of Implantable Collamer Lens V4c on Visual Quality With the OPD-Scan III Aberrometer

PURPOSE

This study aimed to analyze the relationship between visual quality and implantable collamer lenses (ICL) decentration.

DESIGN

Prospective treatment evaluation clinical study METHODS: This prospective study included 119 eyes with ICL implantation. Refractive parameters and ocular aberrations were examined pre- and postoperatively. ICL decentration and higher-order aberrations (HOAs) were evaluated using the OPD-Scan III aberrometer.

RESULTS

At the 1-month follow-up, the mean values for decentration were 0.38 ± 0.19 mm (0.02-0.78). Regarding the position of decentration in right and left eyes, 22.8% and 17.7% were located in the superior nasal section, 0% and 6.5% in the inferior nasal section, 50.9% and 53.2% in the superior temporal section, and 26.3% and 22.6% in the inferior temporal section, respectively. The root mean square values of whole-eye total HOAs, coma, and trefoil had significantly increased. Decentration had a significant negative correlation with variation in the pre- and postoperative trefoils of the whole eye.

CONCLUSIONS

ICL decentration had a slightly negative correlation with trefoil and slightly affected visual quality.

Clinical and Aberrometric Outcomes of a New Implantable Collamer Lens for Myopia and Presbyopia Correction in Phakic Patients

PURPOSE

To assess the clinical and aberrometric outcomes of a new Implantable Collamer Lens (EVO Viva ICL; STAAR Surgical) to correct moderate to high myopia and presbyopia.

METHODS

The study included 80 eyes of 40 patients who had bilateral EVO Viva ICL implantation. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, presbyopic add power, binocular through-focus visual acuity, total ocular spherical aberration (SA), coma aberration, and root mean square of ocular higher order aberrations (RMS HOAs) (i-Trace Aberrometer; Tracey Technologies) for a 4.5-mm pupil size were evaluated.

RESULTS

The mean binocular postoperative UDVA and CDVA were 0.09 ± 0.19 and 0.02 ± 0.03 logMAR, respectively. The postoperative spherical equivalent was -0.61 ± 0.54 diopters (D). The presbyopic add power reduced from +1.31 ± 0.74 D preoperatively to +0.44 ± 0.58 D after surgery (P < .0001). The mean visual acuity was 0.1 logMAR or better (20/25 or better) across the vergence range from +0.50 to -1.50 D, better than 0.2 logMAR (20/32 or better) up to the vergence of -2.00 D, and remained better than 0.3 logMAR (20/40 or better) up to the vergence of -2.50 D. The total ocular aberrations induced by EVO Viva ICL were -0.34 ± 0.09 µm of SA, 0.24 ± 0.18 µm of coma, and 0.26 ± 0.12 µm of RMS HOAs.

CONCLUSIONS

The outcomes support that the new ICL might be a good alternative for myopia and presbyopia correction in patients aged between 45 and 55 years. Further studies are needed to evaluate the threshold lens misalignment from which the patient´s visual quality would be affected. [J Refract Surg. 2023;39(9):589-596.].

Three-Dimensional Quantitative Description of the Implantable Collamer Lens in the Ocular Anterior Segment of Patients With Myopia

PURPOSE

To describe the 3-dimensional (3D) location of the implantable collamer lens (ICL) quantitatively in the posterior ocular chamber of patients with myopia.

DESIGN

Cross-sectional study.

METHODS

To obtain visualization models before and after mydriasis, an automatic 3D imaging method based on swept-source optical coherence tomography was created. Parameters like the ICL lens volume (ILV), the tilt of the ICL and crystalline lens, the vault distribution index, and topographic maps were evaluated to describe the ICL location. Using a paired sample t test and the Wilcoxon signed rank test, the difference between nonmydriasis and postmydriasis conditions was compared.

RESULTS

The study investigated 32 eyes from 20 patients. The 3D central vault did not differ significantly before (P = .994) or after mydriasis (P = .549) compared with the 2D central vault. After mydriasis, the 5-mm ILV decreased by 0.85 mm2 (P = .016), and the vault distribution index increased significantly (P = .001). The ICL and the crystalline lens exhibited tilt (nonmydriasis: ICL total tilt 3.78 ± 1.85 degrees, lens total tilt 4.03 ± 1.53 degrees; postmydriasis: ICL total tilt 3.84 ± 1.56 degrees, lens total tilt 4.09 ± 1.64 degrees). The phenomenon of asynchronous tilt of the ICL and lens was found in 5 eyes, leading to the spatially asymmetric distribution of the ICL-lens distance.

CONCLUSION

The 3D imaging technique provided exhaustive and reliable data for the anterior segment. The visualization models offered multiple perspectives on the ICL in the posterior chamber. Before and after mydriasis, the intraocular ICL position was described by the 3D parameters.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Effects of lighting conditions and accommodation on the three-dimensional position of Visian implantable collamer lens

Background

To investigate the effects of lighting conditions and accommodation on the three-dimensional position of Visian implantable collamer lens (ICL V4c).

Methods

This observational study recruited 62 eyes of 31 myopia patients underwent ICL V4c implantation. Anterior segment optical coherence tomography (AS-OCT) assessed the anterior chamber depth (ACD), ACD-ICL (distance from the corneal endothelium to anterior surface of the ICL V4c), vault (distance between the posterior ICL V4c surface and anterior crystalline lens surface), and crystalline lens tilt under various lighting conditions and accommodation relative to the corneal topographic axis at one year after ICL V4c implantation. Baseline was defined as the scotopic condition, which was also the non-accommodative stimulus condition. The ICL V4c tilt was analyzed using MATLAB. The significance level was set at P < 0.05.

Results

The ACD-ICL values were similar under various lighting conditions (P = 0.978) but decreased during accommodation (P < 0.001). The vault was significantly smaller under mesopic and photopic conditions than the baseline (P = 0.044 and P < 0.001, respectively) but remained unchanged during accommodation (P = 0.058). The inferotemporal proportion of ICL V4c (88.7%, 55 eyes) and crystalline lens (74.2%, 46 eyes) tilts were not significantly different (P = 0.063). Crystalline lens under various lighting conditions and accommodation exhibited similar tilts. The vertical tilt of ICL V4c was significantly larger under photopic conditions than the baseline (P = 0.038). The horizontal and total tilts were significantly decreased during accommodation (P = 0.043 and 0.013, respectively).

Conclusions

The axial position of ICL V4c in the anterior chamber was stable under various lighting conditions. Lighting conditions and accommodation may influence vertical, horizontal and total tilts of ICL V4c.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40662-022-00313-2.