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

A comparative study of two phakic posterior chamber implantable lenses

This study aimed to compare the postimplantation clinical outcomes of 2 types of posterior chamber phakic intraocular lenses (IOLs): Visian™ implantable collamer lenses (ICL; EVO+ V5; Staar Surgical, Monrovia, CA) and an implantable phakic contact lens (IPCL) (IPCL V2.0, Care Group Sight Solution, India) to correct high myopia and myopic astigmatism. This retrospective study included patients who had undergone phakic IOL implantation performed by a single surgeon between March 2021 and March 2022. Preoperative assessments included slit-lamp examination, fundus examination, spherical equivalent, uncorrected distant visual acuity (UDVA), corrected distant visual acuity (CDVA), specular microscope parameters, and optical quality analysis system parameters. Postoperative assessments after 1 year included slit-lamp examination to detect adverse effects and spherical equivalent, UDVA, CDVA, specular microscope, optical quality analysis system, and anterior-segment optical coherence tomography. Eighty eyes from 42 patients (47 eyes from 24 patients in the ICL group and 33 eyes from 18 patients in the IPCL group) were included. No statistically significant differences were observed between the 2 groups regarding preoperative parameters. At 1-year postoperatively, the mean UDVA in the ICL and IPCL groups was 0.019 ± 0.040 logMAR and 0.019 ± 0.041 logMAR, respectively. The mean CDVA was 0.001 ± 0.008 logMAR and 0.001 ± 0.007 logMAR in the ICL and IPCL groups, respectively, showing no statistically significant differences. The postoperative parameters did not differ significantly between the 2 groups. The visual acuity and refractive results of both groups were excellent, and both groups exhibited similar efficacy and safety profiles.

Meridional analysis for calculation of the toric power of phakic IOLs

PURPOSE

To present a reproducible method to calculate the toricity needed at the intraocular lens (IOL) plane with toric phakic IOLs (ICL, Staar Surgical) and compare its results with those obtained with the online calculator provided by the manufacturer.

DESIGN

Retrospective case series.

SETTING

Private practice, Buenos Aires, Argentina.

METHODS

The formula originally described by Holladay to calculate the IOL power in phakic eyes was used to calculate the required spherical power along the less refractive meridian and along the more refractive meridian. Meridional analysis was applied to calculate the required toricity at the IOL plane and the surgically induced corneal astigmatism was incorporated into the calculations. The refractive cylinder predicted by this method and by the online calculator of the manufacturer were compared to the postoperative refractive cylinder by means of vector analysis. The possible changes in the ratio of toricity in patients with different amounts of astigmatism and anterior chamber depth are assessed in a theoretical section.

RESULTS

In 35 eyes, the measured mean postoperative refractive cylinder was 0.09 D @ 99°, the mean predicted postoperative refractive astigmatism was 0.04 D @ 102° according to the manufacturer's online calculator and 0.09 D @100° according to our method. With both methods, 91.43% of eyes had an absolute cylinder prediction error within ±0.50 diopters.

CONCLUSIONS

The method described in this article to calculate the toricity of phakic IOLs has a refractive accuracy similar to that of the original calculator developed by the manufacturer.

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.].

Intraocular Implantable Collamer Lens with a Central Hole Implantation: Safety, Efficacy, and Patient Outcomes

This review summarizes the available literature and provides updates on the efficacy, safety, and patient outcomes of phakic intraocular lens implantation using implantable collamer lens (ICL), with a focus on newer models with a central port (EVO/EVO+ Visian Implantable Collamer Lens, STAAR Surgical Inc.). All studies included in this review were identified from the PubMed database and were reviewed for relevancy of their topic. Data on hole-ICL implantation performed between October 2018 and October 2022 in 3399 eyes showed a weighted average efficacy index of 1.03 and a weighted average safety index of 1.19 within an average follow-up of 24.7 months. The incidence of complications such as elevated intraocular pressure, cataract, and corneal endothelial cell loss was low. Moreover, both quality of vision and quality of life improved after ICL implantation, confirming the benefits of this procedure. In conclusion, ICL implantation is a promising refractive surgery alternative to laser vision correction with excellent efficacy, safety, and patient outcomes.

Implantable collamer lens versus small incision lenticule extraction for high myopia correction: A systematic review and meta-analysis

Purpose

To compare the efficacy, safety, predictability and visual quality between implantable collamer lens (ICL) implantation and small incision lenticule extraction (SMILE) for high myopia correction in adults.

Methods

A systematic review and meta-analysis was conducted. A comprehensive literature search was done based on databases including PubMed, Science Direct, Embase, and the Cochrane Central Register of Controlled Trials. The efficacy index, safety index, changes in Snellen lines of corrected distance visual acuity (CDVA), predictability (difference between post-operative and attempted spherical equivalent error, SER), incidence of halos, and change in higher-order aberrations (HOAs) were compared. Mean difference (MD) and 95% confidence interval (CI) was used to estimate continuous outcomes, risk ratio (RR) and 95%CI was used to estimate categorical outcomes.

Results

Five observational studies involving 555 eyes were included in this review. Studies’ sample sizes (eyes) ranged from 76 to 197. Subjects’ refraction ranged from -6 diopter (D) to -12D. Study duration of most researches were 6 months or 12 months. Compared to SMILE, ICL implantation showed better efficacy index (MD=0.09, 95%CI:0.01 to 0.16) and better safety index (MD=0.08, 95%CI: 0.00 to 0.16). Compared with SMILE, more ICL-treated eyes gained one or more Snellen lines of CDVA (RR=1.54, 95%CI:1.28 to 1.86), more gained two or more lines (RR=2.09, 95%CI:1.40 to 3.13), less lost one or more lines (RR=0.17, 95%CI:0.05 to 0.63). There was no difference in predictability between two treatments, RRs of predictability of within ±0.5D and ±1D were 1.13 (95%CI: 0.94 to 1.36) and 1.00 (95%CI: 0.98 to 1.02). Compared with SMILE, ICL implantation came with a higher risk of halos [RR=1.79, 95%CI: 1.48 to 2.16] and less increase in total HOAs (MD=-0.23, 95%CI: -0.42 to -0.03).

Conclusion

Compared with SMILE, ICL implantation showed a higher risk of halos, but equal performance on SER control, and better performance on efficacy index, safety index, CDVA improvement and HOAs control. Overall, ICL implantation might be a better choice for high myopia correction in adults.

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.