Outcomes and possible risk factors associated with axis alignment and rotational stability after implantation of the Toric implantable collamer lens for high myopic astigmatism

Rotational Stability After Implantation of Two Different Phakic Toric Intraocular Lenses

PURPOSE

To compare clinical outcomes and rotational stability of the toric implantable Collamer lens (TICL) and toric implantable phakic contact lens (TIPCL).

METHODS

Charts were reviewed from January 2011 to January 2023 to identify all TICLs and TIPCLs implanted by a single surgeon. Implant size was generally chosen according to the manufacturer's recommendation, but 15 TIPCLs 0.25 mm larger than recommended to increase vaulting were included.

RESULTS

Eighty-four TICLs and 98 TIPCLs were identified and yielded excellent refractive and visual results in eyes with high myopic astigmatism at the last follow-up visit. No case of acute glaucoma or cataract induction was observed. In total, 15 (8.2%) rotated lenses were recorded; 2 (2.4%) TICLs and 13 (13.3%) TIPCLs (P = .013). Eyes in both groups were similar in preoperative spherical equivalent, cylinder, white-to-white distance, anterior chamber depth (ACD), anterior chamber angle, and mean follow-up times (P = .925, .673, .822, .794, .358, and .873, respectively). Average TICL size was larger than TIPCL size (P < .001). Rotation of the lenses was positively correlated with cylinder and negatively correlated with ACD but not with vaulting (P = .001, r = 0.253; P = .011, r = -0.193; P = .488, r = -0.057; respectively). Vaulting was positively correlated with preoperative ACD (P ≤ .001, r = .329). In eyes with a rotated TIPCL, preoperative cylinder was higher and ACD was shallower than in eyes with a stable TIPCL (P = .001 and .007, respectively). Increasing the implant size had no significant effect on rotation rate (P = .685).

CONCLUSIONS

Although both implants were safe and effective in highly myopic eyes, TICL rotated less frequently than TIPCL and required fewer secondary interventions. Rotation was correlated with preoperative cylinder and ACD but not lens vaulting. [J Refract Surg. 2023;39(7):463-472.].

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of accommodation and accommodative micro-fluctuation after implantable collamer lens and LASIK surgery for myopia

BACKGROUND

To longitudinally analyze and compare the accommodative micro-fluctuation (MFs) and accommodative function between myopic patients after implantable collamer lens (ICL) implantation and laser in situ keratomileusis (LASIK).

METHODS

Patients with good corrected visual acuity (20/20 or better) and underwent ICL (V4c) and LASIK for myopic-correction (ranging from - 3.50 to - 8.50 D) were recruited. Refraction, amplitude of accommodation (AMP), accommodative lag, higher-order aberration (HOA), and MFs were recorded before surgery and 1 and 3 months after surgery. The ACOMEREF automatic refractor was used to measure the high-frequency component (HFC) of the MFs, which suggested tension of the ciliary muscle.

RESULTS

The study comprised 120 eyes. At 3 months after surgery, the manifest refractive spherical equivalent of the ICL and LASIK groups were - 0.11 and - 0.09 D, respectively (p = 0.46). HFC values were significantly higher at 1 month (p = 0.03) and 3 months postoperatively (p = 0.03) in the ICL group compared to that in the LASIK group. The ocular HOA of the ICL group was 1.08 ± 0.43 μm, which was lower than the LASIK group 1.45 ± 0.54 μm (p = 0.01). No significant differences in AMP and accommodative lag between groups were noted at 3 months postoperatively. There was a positive correlation between HFC and vault of the ICL lens (r² = 0.14, p = 0.005). There were no correlations between HFC and ocular HOA and postoperative MRSE in the two groups (all p>0.05).

CONCLUSIONS

The HFC increased significantly after an early period of ICL implantation compared to laser in situ keratomileusis for myopic correction, which indicated increased tension of the ciliary muscle, and had a positive correlation on the vault of the ICL lens; However, studies with longer follow-up time and more structural evaluation are needed.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Toric Implantable Collamer Lens for the Treatment of Myopic Astigmatism

Purpose

To report visual outcomes following surgical correction of myopic astigmatism with Visian Toric implantable collamer lens (ICL) (STAAR Surgical, Monrovia, CA, USA) at a single tertiary refractive center in the United States.

Patients and Methods

Toric ICL was implanted in 96 eyes (55 patients) with mean preoperative sphere of −8.98 ± 3.04 diopters (D) and cylinder of −2.67 ± 1.02 D from December 2018 to February 2021. Primary visual outcomes of efficacy, safety, stability, predictability of refractive correction, and astigmatic analysis were reported at three and twelve months postoperatively. Secondary subjective outcomes included patient-reported dry eye symptoms and glare/halos at postoperative visits. Other secondary outcomes were biometric data and postoperative vault over time.

Results

At three and twelve months, 75 and 46 eyes were evaluated, respectively. At twelve months, the mean manifest refraction spherical equivalent (MRSE) was −0.23 ± 0.47 D with 93% achieving within ±1.00 D of target refraction. The manifest refractive cylinder (MRC) at twelve months was −0.73 ± 0.51 D, with 86% within ±1.00 D of target. Uncorrected distance visual acuity (UDVA) was 20/20 or better in 74% of eyes at twelve months. No patients lost ≥2 lines of corrected distance visual acuity (CDVA) at twelve months. The mean angle of error was −0.9 ± 10.2° at three months and −1.6 ± 12.8° at twelve months. One patient required bilateral lens rotation, four patients underwent secondary enhancement with LASIK/PRK, and seven patients underwent postoperative limbal relaxing incisions.

Conclusion

This initial single-site experience finds Toric ICL implantation for myopic astigmatism to be safe and effective. Patients can achieve markedly improved UDVA in a single surgery with stable vision over time and minimal adverse subjective symptoms.

Outcomes and complications of implantable collamer lens for mild to advance keratoconus

PURPOSE

To evaluate the outcome and safety of implantable collamer lens (ICL; (Visian, STAAR Surgical, Monrovia, CA, USA) in mild to advance keratoconus patients with myopia and myopic astigmatism.

METHODS

This retrospective study evaluated all patients who underwent ICL implantation for the management of keratoconus at a tertiary care eye hospital from January 2012 to January 2018. The mean duration of follow-up was 15.3 months (range, 3.13 to 38.97 months). Data were collected on preoperative and postoperative uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), refraction was compared, and adverse effects were evaluated.

RESULTS

Thirty-two eyes (32 patients) were evaluated. The median CDVA was 20/30 preoperatively and 20/20 at last follow-up. The median UDVA was 20/25 at last follow-up. Thirteen patients (40.6%) had 20/20 UDVA in comparison to none at baseline. The median spherical equivalent in diopters (D) was -7.875 D (-4.125 to -10.0 D) preoperatively and decreased to -0.3125 D at last follow-up. The median manifest refractive cylinder was 3.00 D (2.25 to 5.25 D) preoperatively and decreased to 1.125 D postoperatively. Cylinder axis rotation of 10° or greater occurred in 3 eyes (9.375%) and required repositioning of the ICL. One patient (3%) developed nonvisually significant anterior subcapsular cataract. One ICL (3.125%) had to be explanted due to residual refractive error and unsatisfactory vision.

CONCLUSION

ICLs are a suitable refractive option for the correction of refractive error associated with stable, nonprogressive keratoconus even in advance cases. However, the risk of ICL rotation and subsequent repositioning remain. Careful patient selection is necessary for achieving good outcomes and mitigating intraoperative and postoperative complications.

Clinical Effect and Rotational Stability of TICL in the Treatment of Myopic Astigmatism

Purpose

To investigate the clinical outcomes and possible risk factors associated with rotational stability after the implantation of a V4c toric implantable Collamer lens (TICL) for the correction of moderate to high myopic astigmatism.

Methods

A total of 112 eyes of 66 patients with moderate to high myopic astigmatism underwent TICL implantation. All patients were followed up for more than 1 year. The uncorrected and best-corrected visual acuity (UCVA and BCVA), astigmatism and spherical equivalent, intraocular pressure, vault, endothelial cell morphometry, and rotation of the TICL axis were assessed at l day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively. Postoperative rotation was defined as the angle between the intended axis and the achieved axis. Regression analysis was used to investigate the possible risk factors for TICL rotation postoperatively.

Results

The mean efficacy index and safety index 12 months postoperatively were 1.03 ± 0.09 and 1.05 ± 0.10, respectively. All patients had the same or better visual acuity than preoperatively. The mean astigmatism value decreased from -1.86 ± 0.79 D preoperatively to -0.37 ± 0.35 D. The mean absolute axis deviation of the TICL at the last follow-up was 2.75 ± 2.04° (range, 0°∼11°). The mean manifest refraction spherical equivalent (MRSE) changed from -9.04 ± 2.67 D preoperatively to -0.67 ± 0.51 D postoperatively. The logistic regression demonstrated that the absolute degree of TICL rotation had a significant association with the fixation angle of the TICL and the size of the lens (P=0.003, P=0.026, resp.).

Conclusion

The results of our study support that TICL implantation is safe, effective, and predictable in the treatment of moderate to high myopic astigmatism, with relatively good postoperative rotational stability.

Safety and efficacy of toric implantable collamer lens V4c model - A retrospective South Indian study

Purpose:

The aim of this study was to evaluate the safety, efficacy, and complications of V4c Toric implantable collamer Lens (TICL) implantation for myopic astigmatism in the south Indian population.

Methods:

In this retrospective observational case series, a total of 109 eyes of 67 patients who underwent V4c TICL implantation (ICL, V4C Staar Surgical, Nidau, Switzerland) between January 2012 and August 2019 were studied with a minimum follow-up period of 6 months (mean 24 months). The main outcome measures were objective and subjective refraction, uncorrected distance visual acuity, corrected distance visual acuity (CDVA), safety, predictability, adverse events, and postoperative complications.

Results:

At 6 months, mean manifest refractive spherical equivalent (SE) decreased from - 10.90 ± 3.7D preoperatively to - 0.02 ± 0.13D postoperatively (P < 0.001) and mean cylinder decreased from - 2.3 ± 1.3 D preoperatively to - 0.04 ± 0.2 D postoperatively (P < 0.001). Postoperatively, SE within ± 0.5 D and ± 1.0 D of attempted correction were achieved in 96.3 (105 eyes) and 100% (109 eyes), respectively. Manifest refractive cylinder within ± 0.5 D and ± 1.0 D of attempted correction were achieved in 97.2 (106 eyes) and 100% (109 eyes), respectively. Sixty-two percent (68 eyes) showed no change in CDVA postoperatively, and no eye had lost lines of CDVA. The safety index was 1.12, and the efficacy index was 1.10. Complications were seen in two eyes (1.8%) due to high postoperative vault requiring secondary surgical interventions.

Conclusion:

V4c TICL is a highly effective, safe, and predictable option in treating myopic astigmatism with excellent improvement in vision and spectacle independence.

Assessment of low-vault cases with an implantable collamer lens

This study aimed to examine clinical results in low-vault eyes after implementation of a Hole implantable collamer lens (KS-AquaPORT™, STAAR Surgical Company) in terms of visual outcomes and complications over a one-year follow-up period. This was a retrospective cohort study of subjects who underwent Hole implantable collamer lens surgery at Sanno Hospital, exhibited low vault, and were followed up for 1 year. Patients were included if they met the following criteria: 20≤ age ≤55 years; stable refraction ≥6 months; -1.0 to -20.0 diopters of myopia; endothelial cell density ≥1800 cells/mm²; and no history of ocular surgery, progressive corneal degeneration, cataract, glaucoma, or uveitis. Main outcome measurements were the safety and efficacy indices, predictability, and vault. Values were indicated as the mean ± standard deviation. Subjects included 16 patients (age: 38 ± 8 years; 6 males; 25 eyes). Toric lenses were utilized for 10 eyes. Implantable collamer lens size was 12.1, 12.6, and 13.2 mm for 18, 6, and 1 eye(s), respectively. One year postoperatively, the safety index was 1.07; for 22 eyes with a target refraction of that of emmetropic eyes, the efficacy index was 0.90; and 96% of eyes were within ± 0.50 diopters of attempted versus achieved spherical equivalent correction. Postoperative vault was 142 ± 60 μm. One year postoperatively, no additional surgery was required for rotation of toric implantable collamer lens, and no advanced cataracts, increased intraocular pressure, or decreased endothelial cells were observed. In conclusion, Hole implantable collamer lens yielded satisfactory visual outcomes and no postoperative complications for low-vault eyes, suggesting its suitability for such cases.

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

BACKGROUND

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

CASE PRESENTATION

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

CONCLUSIONS

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

Comparison of angle-to-angle distance using three devices in normal eyes

PURPOSE

To compare the angle-to-angle (ATA) distance, and the repeatability and the reproducibility of these measurements among the three devices.

METHODS

We performed the ATA measurements in 26 healthy subjects using anterior segment optical coherence tomography (CASIA2, Tomey, Japan), the Scheimpflug camera (Pentacam HR, Oculus, Wetzlar, Germany), and the combined Placido-ring corneal topography and Scheimpflug camera (TMS-5, Tomey). We also compared the repeatability and the reproducibility of the ATA measurements among these three devices.

RESULTS

The ATA in the CASIA2 group was significantly larger than that in the Pentacam group (Bonferroni test, p = 0.002), or that in the TMS-5 group (p < 0.001). The coefficient variation of the first and second ATA measurements for a single examiner was 0.44% in the CASIA2 group, followed by 0.84% in the TMS-5 group, and 1.92% in the Pentacam group. The coefficient variation of the ATA measurements for two examiners was 0.61% in the CASIA2 group, followed by 0.97% in the TMS-5 group, and 1.84% in the Pentacam group.

CONCLUSIONS

The ATA distance measured with the CASIA2 was ~0.40 and 0.56 mm larger than that with the Pentacam and the TMS-5, respectively. The CASIA2 provided the highest repeatability and reproducibility of the ATA measurements, followed by the TMS-5, and the Pentacam. These three instruments cannot be used interchangeably in terms of ATA measurements.

A comparison of visual outcome and rotational stability of two types of toric implantable collamer lenses (TICL) : V4 versus V4c

PURPOSE

To compare the efficacy and rotational stability after implantation of two types of toric implantable collamer lenses (Toric ICL™(TICL);V4 and V4c, STAAR Surgical Co.).

STUDY DESIGN

Retrospective case series.

METHODS

This retrospective study evaluated total 48 eyes of 48 patients who underwent the implantation with V4 and V4c TICL with a central hole; A twenty-four eyes of 24 patients with V4 TICL and 24 eyes of 24 patients with V4c TICL with a central hole. Visual acuity, manifest refraction, and intraocular pressure were evaluated before and after surgery. Rotational stability (disparity between the intended axis and achieved axis) was assessed in both groups using digital anterior segment photographs, and vector analysis was also performed.

RESULTS

Uncorrected visual acuity improved in both groups without significant difference (P = .111). There were no statistical differences between two groups in postoperative SE and cylindrical errors (P = .067 and .384, respectively). The mean value of rotation was 4.17±3.31° and 3.39±2.36° in the V4 and V4c TICL groups, respectively without significant difference (P = .364). Vector analysis of astigmatic correction showed no significant diffrence between two groups.

CONCLUSION

V4 and V4c TICL have similar efficacy with regard to visual acuity and refractive outcomes and rotational stability.

Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens

The purpose of this review is to summarize relevant data from publications appearing in the peer-reviewed scientific literature over the past decade since US Food and Drug Administration approval of the implantable collamer lens (ICL), and, in particular, to review studies relating to sizing methodology, safety, and effectiveness, as well as more recent studies reporting clinical outcomes of the V4c Visian ICL with KS Aquaport, VICMO. A literature search was conducted using two databases, PubMed.gov and Science.gov, to identify all articles published after 2005 related to the Visian ICL (STAAR Surgical, Inc.). Articles were examined for their relevance to sizing methodology, clinical safety, and effectiveness, and the references cited in each article were also searched for additional relevant publications. The literature review revealed that all currently reported methods of determining the best-fit size of the ICL achieve similarly satisfactory results in terms of vault, the safe distance between the crystalline lens and the ICL. Specifically, meta-analysis demonstrated that sulcus-to-sulcus and white-to-white measurement-based sizing methods do not result in clinically meaningful nor statistically significant differences in vault (two-sample two-sided t-test using pooled mean and standard deviations; t (2,594)=1.33; P=0.18). The reported rates of complications related to vault are very low, except in two case series where additional risk factors such as higher levels of myopia and older age impacted the incidence of cataract. On the basis of preclinical studies and initial clinical reports, with up to 5 years of follow-up, the new VICMO central port design holds promise for further reduction of complications. Given its safety record and the significant improvement in vision and quality of life that the ICL makes possible, the benefits of ICL implantation outweigh the risks.

Evaluation of early results of quick-chop phacoemulsification in the patients with high myopic cataract

AIM

To assess the early surgical outcomes of quick-chop phacoemulsification technique in patients with high myopia.

METHODS

The data of patients with high myopia who underwent quick-chop phacoemulsification were reviewed retrospectively. There were 42 eyes of 31 patients. The axial length was more than 26 mm in all eyes. All eyes underwent quick-chop phacoemulsification surgery with the placement of an intraocular lens (IOL) in the capsular bag. Postoperative visits were performed at 1, 3d; 2wk, 1mo. Early postoperative best corrected visual acuity (BCVA), preoperative and postoperative corneal endothelial cell density (ECD), central corneal thickness (CCT) and postoperative complications were assessed. Paired sample t-test or Wilcoxon tests were used to compare data between preoperative and postoperative data.

RESULTS

There was no statistically significant difference between preoperative and postoperative ECD and CCT. Retinal detachment was developed in one eye at postoperative first day. There was an iris prolapsus from side port insicion.

CONCLUSION

Quick-chop phacoemulsification technique is a safe surgical technique. However we can encounter some complications in high myopic eyes due to histopathological differences. Both side port and clear corneal tunnel insicion size is crucial for preventing postoperative complications. If any persistent leakage is noticed, suture should be placed.