Phakic Posterior Chamber Intraocular Lens with a Central Hole in Treating Patients with Moderate to High Myopia: A Meta-Analysis

Posterior-Chamber Phakic Implantable Collamer Lenses with and without a Central Hole: A Comparative Study

Purpose

 This study aimed to compare the short-term outcome of implanting the Visian implantable collamer lens V4 ICL versus the Visian V4c ICL in patients with moderate and high myopia.

Patients and Methods

 This is a retrospective that was conducted on patients with moderate or high myopia who were scheduled for ICL implantation at our institution, Patients who underwent V4 ICL implantation with peripheral iridectomy were assigned to group A, and those who underwent V4c ICL implantation without peripheral iridectomy were assigned to group B. In group A, a preoperative peripheral iridectomy was performed. In group B, the patients received cycloplegic and dilating agents. The patients underwent a complete ocular examination preoperatively and during the follow-up visits that were conducted at 3, 6, and 12 months postoperatively.

Results

This study included 214 eyes from 107 patients; group A included 110 eyes, and group B included 104 eyes. Postoperatively, the UCVA and BCVA showed statistically significant improvement across the follow-up time points (p<0.001), with no significant difference between the two groups. No statistically significant difference was found between the two groups in the mean achieved correction or the residual refraction. Both groups showed a strong correlation between the target and the achieved correction, with R2 = 0.99 in the two groups. No significant difference was found between the two groups in the IOP across all time measures. However, the intraocular pressure showed a statistically significant postoperative increase in group A (p=0.004), and no significant change in group B (p=0.817). There was a downward slope in the vaults of both groups across time, with significant variation in the last follow-up measure compared to the 3-month measure in the two groups (p<0.001). No significant difference was found between the two groups across all time measures.

Conclusion

The current study adds new evidence concerning the feasibility, safety, and efficacy of ICL V4c implantation for the treatment of moderate and high myopia, with safer postoperative IOP.

Refractive outcomes of implantable collamer lens implantation in 1212 eyes with suboptimal corrected distance vision acuity

Purpose: To analyze the factors related to corrected distance vision acuity (CDVA) after implantable collamer lens (ICL) implantation in patients with preoperative suboptimal CDVA.Methods: This retrospective study included patients with suboptimal preoperative CDVA (CDVA ≤20/25) who underwent ICL implantation (V4 or V4c). Preoperative and postoperative clinical evaluations included CDVA, uncorrected distance visual acuity (UDVA), and refraction.Results: A total of 1,212 eyes from 731 patients were identified. CDVA increased in 90.8% of the eyes after surgery. Among them, 57.5% of the eyes (697 eyes) gained more than one line. The preoperative LogMAR CDVA was 0.32 ± 0.23, which significantly improved to 0.13 ± 0.17 postoperatively (p < 0.001). There was no significant difference between ICL V4c and ICL V4 in the LogMAR UDVA, sphere, cylinder, SE, LogMAR CDVA, efficacy index, and safety index after surgery (p > 0.05). For eyes with full correction, the postoperative LogMAR CDVA =0.575 * preoperative LogMAR CDVA -0.061 (p < 0.001, R² = 0.53). For eyes with partial correction, the postoperative LogMAR CDVA =0.536 * preoperative LogMAR CDVA - 0.007 * SE - 0.196 (P < 0.001, R² = 0.55).Conclusion: ICL implantation can improve CDVA in eyes with suboptimal CDVA. This study provides the postoperative outcomes of eyes with different preoperative CDVA, which makes it convenient for surgeons to communicate with such patients before surgery.

[Correction of ametropia with posterior chamber phakic intraocular lens]

Posterior chamber phakic intraocular lens (PIOL) implantation is a widely accepted and performed refractive surgery for correction of moderate and high myopia used when corneal laser ablation procedures are not suitable. This paper analyzes literature data to reveal the advantages and limitations of the technology.

Safety and Efficacy of a New Posterior Chamber Phakic Intraocular Lens in Cases of High Myopia: Early Results

Purpose

To demonstrate the visual outcomes of a foldable, hydroxy ethyl-methacrylate, single-piece, posterior chamber phakic intraocular lens (pIOL).

Study Type

Retrospective study.

Materials and Methods

Patients presenting with moderate to high myopia who underwent surgical correction with a posterior chamber phakic IOL (refractive intraocular lens, phakic intraocular lens, Appasamy Associates, Chennai, India) were retrospectively reviewed. Only patients with at least one-year follow-up were included. Manifest refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), endothelial cell density (ECD), and pIOL vault were analyzed 1, 3, 6, and 12 months after surgery. Intraoperative and postoperative events were recorded in all cases.

Results

The study included 30 eyes from 15 patients. The mean patient age was 25.8 ± 3 years. The spherical equivalent of manifest refraction was −11.47 ± 4.38 D preoperatively and −0.44 ± 0.55 D postoperatively. The preoperative CDVA was 0.17 ± 0.12 logMAR. The postoperative UDVA was 0.053 ± 0.11 logMAR (min: −0.17 and max: 0.2) and 0.019 ± 0.091 logMAR (min: −0.17 and max: 0.2) at the end of 1 month and 6 months, respectively. At the end of the 12-month visit, the postoperative UDVA was 0.032 ± 0.094, and the safety index was 2.42. The mean ECD was 2639 cells/mm² (min: 2389 and max: 2993 with SD: 139.53) at the preoperative visit and 2445 cells/mm² (min: 2050 and max: 2701) at the 12-month visit (5.8% loss, p less than 0.001). ECD loss from 6 months to 12 months was not statistically significant. No significant cataract formation, significant endothelial cell loss, glaucoma, uveitis, or any other vision-threatening complication were observed.

Conclusion

Based on postoperative experience, we found that RIL phakic IOLs are safe and effective for treating high myopia at short-term follow-up.

Posterior-Chamber Phakic Intraocular Lens Implantation in Patients over 40 Years of Age

Purpose

To assess the efficacy, safety, and predictability of the Visian Implantable Collamer Lens (ICL) model having a central port in patients over 40 years of age.

Methods

This study included 33 eyes from 21 patients who underwent V4c ICL implantation for the correction of myopia and myopic astigmatism. We assessed uncorrected (UDVA) and corrected (CDVA) distance visual acuity, refraction, intraocular pressure (IOP), endothelial cell density (ECD), vault, and adverse events occurring over a 1-year period.

Results

Mean age of the patients at the time of implantation was 43.52 ± 4.49 years (range: 40 to 56 years). Efficacy and safety indexes were 1 and 1.09, respectively. Surgical outcomes for CDVA were as follows: no eye lost any lines, 19 eyes (57.58%) showed no CDVA changes, 7 eyes (21.21%) gained 1 line, 4 eyes (12.12%) gained 2 lines, and 3 eyes (9.09%) gained ≥3 lines. Mean postoperative spherical equivalent (SE) was −0.09 ± 0.47 D. A total of 29 eyes (87.8%) were within ±0.50 D and 31 eyes (93.9%) were within ±1.00 D of the desired SE. At 1-year, mean IOP was 15.27 ± 3.03 mmHg (range: 9 to 20 mmHg, p=0.12 pre vs. post) and mean ECD was 2516 ± 234 cells/mm² (p=0.29 pre vs. post). Mean postoperative vault was 320 ± 136 μm, with 201–300 μm being the most prevalent vault range for 9 eyes (31.03%). None of the eyes showed a vault >701 μm. There were neither intraoperative nor postoperative complications; in fact, all ICL implantation procedures were uneventful.

Conclusions

Our study's findings support the use of this lens in patients over 40 years of age. A long follow-up period is advisable to monitor ICL position relative to the crystalline lens.