Clinical outcomes of implantation of posterior chamber phakic intraocular lens for pathologic and non-pathologic myopia.

BACKGROUND: To compare the clinical outcomes of posterior chamber phakic intraocular lens (pIOL) implantation for non-pathological myopia and pathological myopia. METHODS: This retrospective case series study which were conducted in Beijing Tongren Eye Center between July 2017 and Oct 2021 comprised 192 eyes of 100 consecutive patients undergoing pIOL implantation. Eyes were divided into two groups based on having pathological myopia or not. Predictability, efficacy, safety, and adverse events were compared at 6 months after pIOL implantation. RESULTS: Our study included 86 non-pathological myopes (171 eyes, group1) and 14 pathological myopes (21eyes, group2) to analysis. The average ages were 25.5 and 33.0, respectively, and the spherical equivalent (SE) were -9.31D and -17.50D pre-operation. Six months after pIOL implantation, the SE were 0.00 and -0.50, respectively, and the refraction changes were statistically significant (P ≤ 0.05). Six months after surgery, 76.92% and 80.41% were within ± 0.50 D of the target and 92.31% and 95.88% were within ± 1.00 D. All eyes had unchanged BCVA or gained 1 or more lines in both groups and mean BCVA both improved a line 6m after operation. The efficacy index in the two groups were 0.95 and 0.88 and the safety index were 1.20, 1.33, respectively which was significantly different (P ≤ 0.05). Over the 6-month follow-up, no cataract, pigment dispersion glaucoma, pupillary block, or other vision-threatening complications happened, either. CONCLUSIONS: The pIOL performed well for the correction of both non-pathological and pathological myopia throughout the 6-month observation period. The clinical outcomes of pIOL implantation for non-pathological myopia are essentially equivalent to those for pathological myopia.

Comparison of peripheral iridectomy methods for posterior chamber phakic intraocular lens implantation in patients with brown irides.

BACKGROUND: We explore and compare the advantages and disadvantages of different operating methods for a peripheral iridectomy (PI) for phakic posterior chamber implantable contact lens (ICL) implantation in patients with dark-brown irides. METHODS: Forty-six patients completed this prospective comparative study. Neodymium: yttrium-aluminum-garnet (Nd:YAG) PI was performed in 15 patients (30 eyes) 2 weeks prior to surgery (YAG PI group). Surgical PI was performed in 17 patients (34 eyes) 2 weeks prior to the ICL implantation (preoperative PI group), and intraoperative PI was performed during ICL implantation in 14 patients (28 eyes) (intraoperative PI group). The postoperative recovery of visual acuity, intraoperative complications, operation duration, and patients' visual disturbances were compared. RESULTS: Compared with the preoperative BCVA, the uncorrected visual acuity (UCVA) at 1 week was markedly restored in the preoperative PI group (P = 0.004). UCVA in the three groups of patients had all recovered well at 1 and 3 months after ICL implantation and were significantly better than the preoperative BCVA (all P < 0.01). In the YAG PI group, iris bleeding occurred in nine eyes (30.0 %) and 14 eyes (46.7 %) had pigment dispersion; these values were significantly higher than those in the preoperative PI group (5.9 and 14.7 %, respectively, both P = 0.01). In the intraoperative PI group, elevated high intraocular pressure occurred in four eyes (14.3 %), and eight eyes (28.6 %) had varying degrees of pigment dispersion after ICL implantation. CONCLUSIONS: For patients with dark-brown irides, surgical PI performed 2 weeks prior to the implantation facilitated better postoperative recovery of visual acuity. TRIAL REGISTRATION: Current Controlled Trials ISRCTN35178162 . Retrospectively registered March 4th, 2013.

Bibliometric and visualized analysis of posterior chamber phakic intraocular lens research between 2003 and 2023.

Introduction: Myopia is causing a major public health concern, with its prevalence increasing globally. This study aimed to discuss posterior chamber phakic intraocular lens (pIOL) research publication trends and hotspots over the past 20 years. Methods: Bibliometric analysis was performed using the Web Science Core Collection to investigate posterior-chamber pIOL research publication trends. The extracted records were analyzed, and a knowledge map was built using VOSviewer v.1.6.20. The analysis included visualizing the annual publication count, countries/regions distribution, international and institutional collaborations, author productivity, and journal contribution, in addition to identifying knowledge bases and hotspots. Burst keywords were extracted using CiteSpace v.6.1.R. Results: In total, 791 articles on posterior chamber pIOLs published between 2003 and 2023 were retrieved. China had the highest number of publications, whereas Japanese papers received the most citations. Fudan University had the highest number of publications, with articles from Kitasato University having the highest number of citations. Regarding individual research, Xingtao Zhou has published the most significant number of articles, and Shimizu Kimiya had the highest number of citations. The top productive/influential journal was 'Journal of Cataract & Refractive Surgery'. The top cited references primarily focused on reporting the clinical outcomes of implantable collamer lens (ICL) for individuals with moderate to high myopia. The keywords primarily formed four clusters: posterior chamber pIOL clinical outcomes for myopic astigmatism correction, posterior chamber pIOL implantation complications, ICL size selection and postoperative vault predictions, and postoperative visual quality following posterior chamber pIOL implantation. Conclusion: This study presents the first bibliometric analysis of research trends in posterior chamber pIOL over the past two decades. We investigated the current state and emerging trends of global collaboration and research focal points in this field, offering fresh insights and guidance for researchers.

Long-term Comparison of Vault and Complications of Implantable Collamer Lens with and without a Central Hole for High Myopia Correction: 5 Years.

PURPOSE: To investigate the long-term safety, efficacy, stability, vault, and complications of implantable collamer lens with (ICL V4c) and without (ICL V4) a central hole for correcting high myopia. METHODS: 78 eyes (40 patients) underwent ICL V4c implantation and 78 eyes (48 patients) underwent ICL V4 implantation were enrolled. They were followed up for 5 years of the uncorrected and corrected distance visual acuity, spherical equivalent (SE), axial length, intraocular pressure, endothelial cell density and vault. RESUITS: The safety indices of the ICL V4c and V4 groups at 5 years were 1.25 ± 0.40 and 1.31 ± 0.40, respectively (P = .353). The efficacy indices were 0.90 ± 0.29 and 1.00 ± 0.44, respectively (P = .098). The preoperative, 1 month and 5 year postoperative logMAR UDVAs were respectively 1.54 ± 0.48, 0.11 ± 0.17, and 0.20 ± 0.26 in the V4c group and 1.56 ± 0.44, 0.14 ± 0.19, and 0.22 ± 0.26 in the V4 group (P = .703, 0.329, 0.585). The logMAR CDVAs were resepectively 0.13 ± 0.18, 0.02 ± 0.11, and 0.05 ± 0.16 in the V4c group and 0.18 ± 0.22, 0.05 ± 0.14, and 0.09 ± 0.21 in the V4 group (P = .128, 0.169, 0.229). The SE were resepectively -15.10 ± 4.32 D, -0.71 ± 1.31 D and -1.65 ± 1.30 D in the V4c group and -15.44 ± 3.51 D, -0.61 ± 1.12 D and -1.40 ± 1.30 D in the V4 group (P = .585, 0.637, 0.296). The mean vault reduced by 97.31 ± 136.61 µm in the V4c group and by 99.74 ± 245.83 µm in the V4 group. Three eyes (3.85%) with mid-periphery anterior subcapsular opacification in the V4c group and two (2.56%) with cataract, one (1.28%) with central anterior subcapsular opacification in the V4 group were observed. The CDVA of 20/40 was obtained in the two cataract eyes after phacoemulcification and intraocular lens implantation. CONCLUSION: Long-term ICL V4c and ICL V4 implantations are safe, effective, and stable for high myopia correction. ICL V4c can potentially reduce the risk of lens opacification and may be more tolerant to low vault than ICL V4.

Case Report: Dislocation Into Vitreous Cavity and Removal of a Posterior Chamber Phakic Intraocular Lens.

PURPOSE: To report a rare case of delayed dislocation of a novel posterior chamber phakic intraocular lens into the vitreous cavity, which was successfully treated by a reformed technique. CASE PRESENTATION: A 29-year-old female received Ejinn phakic refractory lens (EPRL) implantation to correct her high myopia. Spontaneous dislocation into the vitreous cavity occurred 26-months post-operatively without traumatic history. Pars plana vitrectomy combined with cutting the EPRL into two equal pieces was performed to remove the dislocated EPRL. CONCLUSION: Dislocation into the vitreous cavity of EPRL can be successfully and easily removed by our reformed technique. Concerns about zonules-related complications pre-operatively, intraoperatively, and post-operatively must be raised in the practice of EPRL implantation.

Five-year outcomes of EVO implantable collamer lens implantation for the correction of high myopia and super high myopia.

BACKGROUND: To evaluate the long-term safety, efficacy, predictability, and stability of implantable collamer lens with a central hole (EVO ICL) implantation for correcting high myopia (HM) and super high myopia (SHM). METHODS: This prospective study evaluated 83 eyes of 46 patients who were divided into groups based on their spherical equivalent refractive error (SE): HM group (- 12 D ≤ SE < - 6 D) and SHM group (SE < - 12 D). They were followed up for 5 years after ICL implantation; assessments of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive error, axial length, intraocular pressure, corneal endothelial cell density, and vault were conducted, and a questionnaire was administered. RESUITS: At 5 years postoperatively, the safety indices of the HM and SHM groups were 1.03 ± 0.10 and 1.32 ± 0.39, and the efficacy indices were 0.83 ± 0.25 and 0.86 ± 0.32, respectively. In the HM group, 60.47% and 79.07% of the eyes were within ± 0.50 D and ± 1.00 D of the attempted correction, while it was achieved for 22.50% and 47.50% of the eyes in the SHM group, respectively. The SE of the HM group decreased from - 9.72 ± 1.41 D preoperatively to 0.04 ± 0.39 D 1 month postoperatively and - 0.67 ± 0.57 D 5 years postoperatively, while in the SHM group, it decreased from - 15.78 ± 3.06 D preoperatively to - 0.69 ± 0.97 D 1 month postoperatively and - 1.74 ± 1.19 D 5 years postoperatively. CONCLUSION: EVO ICL implantation is safe, effective, and predictable for correcting HM and SHM. CDVA improved more after surgery for SHM, but the growth of axial length still needs attention.

Posterior chamber collamer phakic intraocular lens implantation: Comparison of efficacy and safety for low and moderate-to-high myopia.

PURPOSE: To compare visual, refractive and safety outcomes of central-hole posterior chamber collamer phakic intraocular lens implantation for low and moderate-to-high myopia. SUBJECTS/METHODS: This retrospective cohort study included 338 eyes submitted to posterior chamber collamer phakic intraocular lens implantation that completed a 12-month postoperative follow-up. Two groups were defined depending on preoperative spherical equivalent: group 1 comprised 106 eyes with manifest spherical equivalent of -6.00 D or less; group 2 comprised 232 eyes with manifest spherical equivalent higher than -6.00 D. Effectiveness, predictability, stability and safety outcomes were compared preoperatively and at 1, 6 and 12 months postoperatively. RESULTS: At 1-year postoperative, uncorrected and corrected visual acuities were 0.02 ± 0.17 and -0.01 ± 0.12 logMAR (group 1) and 0.04 ± 0.20 and 0.01 ± 0.16 logMAR (group 2), with an efficacy index of 1.05 ± 0.17 and 1.17 ± 0.28. Respectively, 92 (86.8%) and 199 (85.8%) eyes were within ±0.50 D of targeted refraction, and postoperative manifest refraction changes were -0.07 ± 0.25 D and -0.07 ± 0.35 D. Intraocular pressure did not change significantly. The mean rate of endothelial cell loss was 1.12% and 1.10%, respectively. One case of anterior subcapsular cataract (group 2) was observed. ICL exchange occurred in one case (group 1) and three cases (group 2). No vision-threatening complications were reported. CONCLUSION: The posterior chamber collamer phakic intraocular lens implantation demonstrated high visual and refractive efficacy with an excellent safety profile for the correction of both low and moderate-to-high myopia, revealing equivalent 1-year outcomes regardless of the degree of preoperative myopia.

Confounding sizing in posterior chamber phakic lens selection due to white-to-white measurement bias.

PURPOSE: To assess the agreement in the white-to-white (WTW) measurement with two different devices, the reproducibility and the probability of confusing sizing (PCS) in selecting a different implantable collamer lens (ICL). STUDY DESIGN: Retrospective observational case series. METHODS: Images of 192 eyes were captured with both devices. The WTW was measured automatically (OA) and manually (OM) with the Orbscan and Keratograph (KA and KM) by one examiner who repeated a total of four measures. A second examiner conducted a single manual measure for each device over the same image. The ICL sizing was computed for each measure of WTW and the PCS was calculated as the percentage of cases for which the confronted or repeated measure resulted in a different size of the ICL. The critical WTWs with highest PCS were identified. RESULTS: KM overestimated the WTW versus OM in 0.13 ± 0.18 mm (P < 0.001) but not in the automated method comparison, 0.01 ± 0.19 mm (P = 0.58). Inter-examiner reproducibility (R) was higher with OM than with KM, and the intra-examiner R decreased with the average of two measures in both cases. The PCS was higher with the increase of mean differences, the limits of agreement (LoAs), and R. WTWs from 11.1 to 11.2 mm, 11.6 to 11.7 mm, and 12.3 to 12.4 mm resulted in higher PCS. CONCLUSION: The mean difference is not enough to apply conversions between devices and the LoAs and R should be considered. Special attention should be taken for WTWs with higher PCS.

Implantation of posterior chamber phakic intraocular lens for myopia and hyperopia - long-term clinical outcomes.

PURPOSE: To evaluate long-term refractive outcomes of implantable collamer lens (ICL) implantation and late postoperative complications. METHODS: We assessed outcomes of patients who underwent ICL implantation (type ICM V4 for myopia, ICH V3 for hyperopia, TICM V4 for astigmatism) in our department between 1998 and 2013. It comprised 62 eyes (40 myopic and 22 hyperopic). The average follow-up period was 10.5 years. We evaluated: uncorrected and best-corrected visual acuity (UCVA and BCVA), spherical equivalent (SE), ICL vault, endothelial cell density and late postoperative complications. RESULTS: In myopes, the average UCVA was 1.0±0.37 and BCVA 1.18±0.38, in hyperopes 0.78±0.19 and 1.14±0.18, respectively. The average SE in myopes, whose target refraction was emmetropia, was -0.6±0.83 Dsf, in hyperopes +0.73±0.93. Central ICL vault was 206.16µm±105.94, (range 10-427) in myopes, 195.5µm±109.09, (range 20-404) in hyperopes. The most common late postoperative complication was cataract formation. Three myopic eyes (7.5%) developed symptomatic anterior subcapsular opacities with loss of at least two lines of BCVA. Cataract significantly affecting visual acuity occurred in 5 myopic eyes (12.5%) and 2 hyperopic eyes (9.09%). In these eyes, ICL removal and cataract surgery was performed. CONCLUSIONS: In our experience, ICL implantation in moderate and high ametropia was effective and relatively safe. The most common late complication was cataract formation. This complication can be managed effectively surgically with good refractive outcomes without loss of BCVA.

Femtosecond laser-assisted cataract surgery in a patient with posterior chamber phakic intraocular lens.

We describe a case of modified femtosecond laser settings for cataract extraction in a patient with a posterior chamber phakic intraocular lens (PIOL), to avoid incomplete treatment patterns and treatment displacement. Modification of laser settings (increased depth for the capsulotomy, increased vertical spot spacing for the capsulotomy and increased anterior and posterior capsule safety margins for lens fragmentation) seems to make femtosecond laser-assisted cataract surgery feasible in patients with posterior chamber PIOLs, as complete treatment patterns are achieved.