Toric Implantable Collamer Lens V4c Research Articles

Changes in ocular parameters the crystalline lens after implantation of a collamer lens

ABSTRACT Clinical relevance Understanding changes in ocular anatomical parameters after intraocular lens implantation will allow a more accurate determination of dioptric power prior to surgery. Background The crystalline lens position might change due to the implantation and removal of an implantable collamer lens (ICL) or toric implantable collamer lens (TICL). This study aimed to assess the effect of ICL implantation on position of the crystalline lens. Methods This retrospective study was conducted on patients who underwent V4c ICL or V4c TICL implantation between March and September, 2018. Preoperative and post-operative (2 weeks, 3 months and 6 months) axial length, central corneal thickness, crystalline lens position, crystalline lens thickness and vault height were analysed. Multivariable linear regression was used to determine the variables associated with 6-month changes in lens position. Results This study included 117 eyes of 117 patients. There were decreases in all vertical distance measures from the central corneal endothelium to the anterior and posterior crystalline lens capsule (all p > 0.05). The amount of reduction was related to the crystalline lens position before the operation and crystalline lens thickness after the operation (all p < 0.01). An error in anterior chamber depth and lens thickness may appear when the ICL/TICL is close to the crystalline lens. Conclusion Phakic intraocular lens implantation resulted in lens thickening and forward movement on day 1 post-operatively, which becomes stable within 6 months. Preoperative lens position and post-operative lens thickness were related to the amount of movement.

Polar value analysis of astigmatic change and rotational stability after implantation of V4c toric implantable collamer lens.

BackgroundTo evaluate the clinical results and rotational stability of V4c toric implantable collamer lens (TICL, STAAR Surgical Company, Monrovia, CA, USA) in patients with moderate to high myopic astigmatism. Retrospective, interventional case series was performed at Shenzhen Eye Hospital, Shenzhen, Guangdong, China.MethodsThis study enrolled 43 patients (72 eyes) who received TICL implantation to correct myopia and myopic astigmatism. The patients underwent visual and refractive examinations before and 1 month after surgery. Astigmatic changes were estimated using polar value analysis. The difference between the achieved axis and the intended axis at the last follow-up was taken as the rotation of the V4c TICL.ResultsAt 1 month postoperatively, the mean safety and efficacy indices were 1.17 and 1.13, respectively. A significant reduction of 8.92±2.58 D was observed in the spherical equivalent refraction (SER), which decreased from −9.29±2.41 D preoperatively to −0.37±0.55 D postoperatively. The astigmatic error of treatment in cylinder format was calculated to 0.50±0.41 @ 15.08° relative to the preoperative stronger meridian at 1 month, postoperatively. At 1 month postoperatively, the mean absolute rotation was 8.30±10.00 degrees (median =5.46 degrees; range, 0.00–58.88 degrees).ConclusionsTICL could achieve good astigmatic outcomes for correcting moderate to high myopic astigmatism. After TICL implantation, corneal astigmatism remained unchanged. To optimize postoperative astigmatic outcomes in TICL, polar value analysis can be used to build a nomogram.

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.