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

PURPOSE: To explore the effectiveness and rotational stability of vertical implantation of the Implantable Collamer Lens (ICL) (STAAR Surgical) to treat myopia. METHODS: This was a prospective, randomized, controlled study, including 78 eyes from 46 patients with myopia who underwent ICL implantation. The patients were randomly divided into vertical and horizontal implantation groups. At 1 day, 1 week, 1 month, and 3 months after surgery, rotational stability was evaluated using the postoperative axis deviation from the intended axis by the digital anterior segment photograph. The vault, crystalline lens rise, anterior chamber depth, manifest refraction spherical equivalent, intraocular pressure, and visual acuity values were obtained before and after surgery. RESULTS: A 3-month follow-up period showed significant differences between the efficacy indexes in the horizontal (1.11 ± 0.02) and vertical (1.13 ± 0.02) groups ( P = .455). No significant difference was observed in the postoperative manifest refraction spherical equivalent between the horizontal (−0.27 ± 0.18 diopters) and vertical (0.01 ± 0.08 diopters) groups ( P = .151). Also, no statistically significant difference was observed in the corneal endothelial cells and intraocular pressure between groups ( P = .555, P = .464). The rotation angle of the horizontal group was greater at 1 week, 1 month, and 3 months (3.14° ± 2.13°, 2.97° ± 2.01°, 3.27° ± 2.12°, respectively) compared to that of the vertical group (1.30° ± 1.29°, 1.85° ± 1.60°, 1.74° ± 1.33°, respectively) ( P < .001 for all). From 1 week to 3 months, the changing angle of horizontal (0.31° ± 1.86°) and vertical (0.49° ± 1.33°) ICL rotation displayed a positive correlation with the changing vault of horizontal (48.41 ± 86.02 mm) and vertical (39.64 ± 78.43 mm) ICL rotation ( r = 0.242, 0.335, P = .033, .037). CONCLUSIONS: The study supports great efficacy and safety in both vertical and horizontal implantation, with the vertical implantation group displaying better stability. [ J Refract Surg. 2022;38(10):641–647.]

The Effectiveness and Rotational Stability of Vertical Implantation of the Implantable Collamer Lens for the Treatment of Myopia

Huang¹,

Ji²,

Zheng³

et al. 2022

Rotational Stability After Implantation of Two Different Phakic Toric Intraocular Lenses

Kılıç¹,

Forster²,

Mertens³

et al. 2023

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.]

Rotational Stability, Footplate Position, and Visual Outcomes of Toric Implantable Collamer Lenses in Eyes With Low Vault

Ye,

Wan,

Hou

et al. 2024

Purpose: To evaluate the clinical outcomes, rotational stability, and footplate position of the toric Implantable Collamer Lens (TICL) (STAAR Surgical) in eyes with low vault and analyze factors related to rotational stability. Methods: This prospective observational study included 59 eyes of 59 patients with insufficient vault (< 250 µm). Postoperative rotation was defined as the difference between the achieved angle and the intraoperative fixation angle, and assessed with a digital anterior segment photograph after full mydriasis at 1 week and 1, 3, and 6 months postoperatively. Ultrasound biomicroscopy was used to determine the ciliary body morphology and position of the footplate. Correlation analysis was employed to identify the risk factors associated with TICL rotation at 6 months postoperatively. Results: At 6 months postoperatively, the mean central vault was 137.4 ± 61.0 µm (range: 40 to 236 µm), and the mean efficacy and safety indices were 1.04 and 1.15, respectively. The mean manifest refractive astigmatism decreased from −1.67 ± 0.82 diopters (D) preoperatively to −0.43 ± 0.33 D postoperatively, and the mean absolute rotation was 4.50 ± 3.08 degrees (range: 0 to 12.50 degrees). The angle of rotation was correlated with the preoperative spherical power ( r = −0.318, P = .014), the average value of TICL footplates position ( r = 0.284, P = .029), and postoperative astigmatism ( r = −.469, P⩽ .001). Conclusions: TICL implantation is predictable, safe, and effective in correcting myopic astigmatism in eyes with low vault. The rotational stability was acceptable and related to the malposition of the footplate and preoperative spherical power. [ J Refract Surg . 2024;40(7):e460–e467.]