Intraocular Pressure After Implantation of a Phakic Collamer Intraocular Lens With a Central Hole

Effect of phakic collamer intraocular lens with a central hole on structural tests measurements of retinal nerve fiber layer and macula

AIM

To evaluate whether the Visian Implantable Collamer Lens with a central port (V4c ICL®; STAAR Surgical, Switzerland) affects the retinal nerve fibre layer (RNFL), macula and optic nerve head (ONH) measurements obtained by optical coherence tomography (OCT), and Heidelberg Retina Tomography (HRT).

METHODS

This prospective study included myopic patients undergoing V4c ICL® implantation. RNFL thickness, macular thickness, ganglion cell analysis (GCA) and ONH main parameters were evaluated with RTVue OCT (Optovue Inc., USA) and Cirrus-HD OCT (Carl Zeiss Meditec, USA). ONH variables were also analysed with HRT-3 (Heidelberg Engineering, Germany). All measurements were performed before and 1 week and 12 months after the surgery.

RESULTS

31 eyes of 31 patients (mean age 30.1 ± 5.5 years) were included. Comparing with preoperative values, no significant differences in average RNFL thickness were found with RTVue, while a slight increase (4.3 µm) was detected with Cirrus-HD (85.2 ± 10.3 µm, preoperatively) at 1-week postoperatively (89.5 ± 8.3 µm; p < 0.05). Those changes were not observed at the last follow-up visit (86.6 ± 8.6 µm; p = 0.41). Cirrus-HD detected that macular thickness was slightly higher 1 week after surgery, compared with the preoperative examination (3.4% increase; p = 0.04). That difference remained stable at the 12-month postoperative visit (p = 0.01). GCA showed no changes. The ONH analysis with Cirrus-HD determined that rim area (p = 0.03) as well as disc area (p = 0.04) significantly increased. HRT-3 found no significant changes affecting those variables.

CONCLUSIONS

The implantation of V4c ICL® did not induce a clinically significant impact on the results of the RNFL/ONH analysis with OCT and HRT.

Primary observations of EVO ICL implantation for high myopia with concave iris

PURPOSE

To investigate the morphological changes of concave iris in myopic patients after EVO implantable collamer lens (ICL) implantation.

METHODS

EVO ICL candidates with posterior bowing iris were observed using ultrasound biometric microscopy (UBM) in this prospective nonrandomized observational study. Forty patients were enrolled, with 20 patients in the concave iris group and the other 20 patients in the control group. None of the patients underwent laser peripheral iridotomy. All patients received preoperative and postoperative examinations, which included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), subjective manifest refraction and intraocular pressure. UBM was used to observe iris curvature (IC), irido-corneal angle (ICA), posterior chamber angle (PCA), iris-lens contact distance (ILCD), iris-zonule distance (IZD) and ciliary process length (CPL). Anterior chamber angle pigment was observed by gonioscopy. The preoperative and postoperative data were analyzed using SPSS.

RESULTS

The average follow-up period was 13.3 ± 5.3 months. The mean efficacy indices were 1.10 ± 0.13 and 1.07 ± 0.11 (P = 0.58), and the safety indices were 1.19 ± 0.09 and 1.18 ± 0.17 in the control group and the concave iris group (P = 0.93), respectively. The IOP postoperatively were 14.13 ± 2.02 mmHg and 14.69 ± 1.59 mmHg in control and concave iris groups (P = 0.37). Preoperatively, the concave iris group was presented with greater IC (P < 0.0001), longer ILCD (P < 0.0001), wider ICA (P = 0.004), narrower PCA (P = 0.01), and shorter IZD (P = 0.03) than the control group. In the concave iris group, IC, ILCD and ICA were significantly decreased after ICL implantation (P < 0.0001), while PCA and IZD were significantly increased (P = 0.03 and P = 0.04, respectively). Postoperative IC, ILCD, ICA, PCA and IZD were not statistically different between groups (P > 0.05). There was no significant difference in pigment deposition grades between the two groups (P = 0.37).

CONCLUSION

After EVO ICL implantation, the morphology of concave iris was significantly improved, which may reduce the risk of intraocular pigment dissemination caused by iris concavity. The concave iris has no impact on the safety of EVO ICL surgery during the follow-up.

EVO/EVO+ Visian Implantable Collamer Lenses for the correction of myopia and myopia with astigmatism

INTRODUCTION

Intraocular lens implantation in phakic eyes for the correction of refractive error is currently a widespread procedure. The EVO and EVO+ Visian Implantable Collamer Lenses (ICL) are two of the most prevalent lenses implanted. They incorporate a central orifice to avoid the need for iridotomy. The main difference between both ICL is the higher optical diameter zone provided by the EVO+, allowing a better quality of vision at night. This review aims to provide an overview of the current ICL models available for correcting myopia and myopic astigmatism.

AREAS COVERED

During the last decade, more than 100 scientific papers analyzing the performance of EVO and EVO+ lenses have been published. This review describes the objective visual performance achieved with the implantation of central hole ICL lenses and the subjective perception of the patients implanted with these lenses. In addition, the safety and the potential complications associated with undergoing an EVO and EVO+ ICL implantation have been addressed.

EXPERT OPINION

Refractive surgeons and candidates to undergo ICL implantation should be aware of the excellent safety and visual outcomes provided by the implantation of central hole ICL lenses. However, future research could address minor issues currently not resolved.

Analysis of perioperative problems related to intraocular Implantable Collamer Lens (ICL) implantation

PURPOSE

To introduce a modified procedure of ICL implantation, to summarize the perioperative problems and their corresponding treatment after myopia correction with Implantable Collamer Lens (ICL), and to compare the difference of complications between the no-hole ICL and hole ICL.

METHODS

We searched all articles on ICL-related perioperative problems and their corresponding treatment in Scopus, Embase, PubMed and Web of Science databases for the last 22 years.

RESULTS

ICL implantation is safe, effective, stable and predictable in the correction of myopia, hyperopia and astigmatism, but can also cause a series of perioperative problems, including intraoperative and postoperative complications.

CONCLUSION

There are many kinds of complications related to ICL, but the common intraoperative and postoperative complications mainly include abnormality of arch height, abnormal position of ICL, loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma, cataract and night vision symptoms. Compared with ICL without central pore, the incidence of complications such as loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma and cataract was relatively lower in central hole ICL, while postoperative complications such as night vision symptoms were obvious.

Three-year follow-up of posterior chamber phakic intraocular lens with a central port design after deep anterior lamellar keratoplasty

Background

To evaluate clinical outcomes of the Visian implantable collamer lens (ICL) with a central port to correct myopia and astigmatism after deep anterior lamellar keratoplasty (DALK) for keratoconus throughout 3 years of follow-up.

Methods

This study included 20 eyes of 20 patients that underwent V4c ICL (13 eyes with a spherical ICL and 7 eyes with a toric ICL) implantation after DALK. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure (IOP), endothelial cell density (ECD), and vault were analyzed.

Results

The mean UDVA improved from the preoperative 1.18 ± 0.33 logMAR to 0.25 ± 0.14 logMAR at 6 months after surgery (P < 0.0001) and remained unchanged throughout the whole follow-up (P = 0.4). All eyes gained lines of CDVA compared to preoperative values. At the last follow-up visit, all eyes achieved CDVA of 0.2 logMAR or better and 13 eyes (65%) 0.1 logMAR or better. At 6 months post-surgery, all eyes (100%) had a spherical equivalent within ± 1.50 D, and 19 (95%) within ± 1.00 D. The mean manifest spherical equivalent was stable over the postoperative follow-up (P = 0.25). No significant increase in IOP occurred in any case throughout the 3 years of follow-up. The loss in ECD from the preoperative baseline at the last follow-up visit was 2.27%.

Conclusions

The clinical outcomes suggest that the V4c ICL implantation for correction of myopia and regular astigmatism in post-DALK eyes was satisfactory in terms of effectiveness, safety, and stability during 3 years of follow-up.

Assessment of the Vault After Implantable Collamer Lens Implantation Using the KS Formula

PURPOSE

To examine the vault size after Implantable Collamer Lens (ICL) (KS-AquaPORT; STAAR Surgical) surgery using the KS formula.

METHODS

In this prospective study, the postoperative vault was examined using the KS formula in 121 eyes of 65 patients (28 men and 37 women) who underwent ICL implantation for myopia and myopic astigmatism. The mean horizontal angle-to-angle (ATA), anterior chamber depth, and axial length before surgery were 11.83 ± 0.40, 3.25 ± 0.34, and 26.52 ± 1.17, respectively. Anterior segment optical coherence tomography (CASIA2; Tomey Corporation) was used for ATA measurement.

RESULTS

Multiple regression analysis of the potential factors influencing the predicted vault error (postoperative vault - predicted vault by KS formula) showed that only ICL size was a significant factor (P < .001, r = 0.36). At an ICL size of 12.1 mm, the postoperative vault was smaller than the predicted vault, and the postoperative vault tended to be larger than the predicted vault at ICL sizes of 13.2 and 13.7 mm.

CONCLUSIONS

Vault prediction by the KS formula was generally good, but the ICL size influenced the vault prediction error; therefore, a modified KS formula was created to reduce the error in measurements of the postoperative vault. [J Refract Surg. 2021;37(9):636-641.].

Long-term Clinical Outcomes of Implantable Collamer Lens

Purpose: To evaluate the long-term clinical outcomes of implantable collamer lens (ICL) implantation in myopic patients.Methods: This retrospective study included 129 eyes of 68 patients who underwent ICL implantation for correction of myopia with a 10-year follow-up.Results: Ten years after ICL implantation, the mean uncorrected and corrected distance visual acuities (LogMAR) were 0.03 ± 0.13 and -0.07 ± 0.06, respectively. Ten years postoperatively, 52.7% and 84.5% of the eyes were within ± 0.5 and ± 1.0 diopters, respectively. The mean efficacy and safety indices were 0.91 ± 0.22 and 1.07 ± 0.19, respectively. There was no significant difference between mean preoperative (13.52 ± 2.88 mmHg) and postoperative (13.59 ± 3.55 mmHg) intraocular pressures. The endothelial cell density decreased from before surgery to 10 years after surgery (3,074 ± 365 cells/mm2, 2,812 ± 406 cells/mm2, respectively; mean decrease: 8.5 ± 10.8%; p = 0.011). Eight eyes (6.2%) developed cataract during follow-up, which was symptomatic in three eyes (2.3%) and treated with ICL explantation and phacoemulsification. Rhegmatogenous retinal detachment occurred in one eye (0.8%) and was treated with vitrectomy.Conclusions: ICL implantation for the correction of myopia had good efficacy and safety outcomes during long-term follow-up of 10 years. However, patients should be closely monitored for complications such as cataract formation, endothelial cell loss, and retinal detachment.

Posterior-chamber phakic implantable collamer lenses with a central port: a review

We aimed to summarize the outcomes reported following the implantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc) for myopia correction. A literature search in PubMed, Web of Science and Scopus was carried out to identify publications reporting clinical outcomes of patients who were implanted with the V4c ICL model and had a follow‐up period of at least 6 months. A total of 35 clinical studies published between 2012 and 2020 were included in the present review. A comprehensive analysis of the available data was performed, focusing on visual and refractive outcomes at different time‐points post‐surgery. In addition, adverse events and other parameters such as endothelial cell density, intraocular pressure and vault measurements—which were evaluated in some of the studies—were also compared. This review encompassed a total of 2904 eyes. The outcomes reported in this review lead us to conclude that ICL V4c implantation for myopia correction is a safe and efficient procedure, with stable visual and refractive outcomes and low adverse event rates. The patient’s anterior segment should be thoroughly characterized, and the ICL parameters should be carefully selected so as to achieve good outcomes and avoid complications.

Assessment of low-vault cases with an implantable collamer lens

This study aimed to examine clinical results in low-vault eyes after implementation of a Hole implantable collamer lens (KS-AquaPORT™, STAAR Surgical Company) in terms of visual outcomes and complications over a one-year follow-up period. This was a retrospective cohort study of subjects who underwent Hole implantable collamer lens surgery at Sanno Hospital, exhibited low vault, and were followed up for 1 year. Patients were included if they met the following criteria: 20≤ age ≤55 years; stable refraction ≥6 months; -1.0 to -20.0 diopters of myopia; endothelial cell density ≥1800 cells/mm²; and no history of ocular surgery, progressive corneal degeneration, cataract, glaucoma, or uveitis. Main outcome measurements were the safety and efficacy indices, predictability, and vault. Values were indicated as the mean ± standard deviation. Subjects included 16 patients (age: 38 ± 8 years; 6 males; 25 eyes). Toric lenses were utilized for 10 eyes. Implantable collamer lens size was 12.1, 12.6, and 13.2 mm for 18, 6, and 1 eye(s), respectively. One year postoperatively, the safety index was 1.07; for 22 eyes with a target refraction of that of emmetropic eyes, the efficacy index was 0.90; and 96% of eyes were within ± 0.50 diopters of attempted versus achieved spherical equivalent correction. Postoperative vault was 142 ± 60 μm. One year postoperatively, no additional surgery was required for rotation of toric implantable collamer lens, and no advanced cataracts, increased intraocular pressure, or decreased endothelial cells were observed. In conclusion, Hole implantable collamer lens yielded satisfactory visual outcomes and no postoperative complications for low-vault eyes, suggesting its suitability for such cases.

The Relationship between Anterior Chamber Angle and Intraocular Pressure Early after V4c Implantable Collamer Lens Implantation

Purpose

To confirm the relationship between anterior chamber angle (ACA) and intraocular pressure (IOP) early after V4c implantable collamer lens (ICL) implantation.

Methods

Patients were assigned to two groups: (1) right eyes (control group) and (2) left eyes (experimental group), with miosis conducted immediately after ICL implantation in the left eyes. IOP, angle opening distance (AOD), trabecular-iris angle (TIA), and pupil diameter (PD) were compared between two groups at postoperative hours 1, 2, and 24. The relationship between ACA, PD, and IOP was analyzed by multiple linear regression.

Result

Thirty-six eyes of 18 patients were enrolled. The prevalence of ocular hypertension (OHT, defined as IOP ≥ 21 mmHg) was 61.11% and 16.67% in the right and left eyes, respectively, (χ² = 7.481, p=0.006). At postoperative hours 1 and 2, IOP and PD were significantly higher (p < 0.001) in the right eyes, and TIA and AOD were significantly lower (p < 0.05) in the right eyes than in the left eyes. There was no significant difference at 24 h postoperative in these parameters. After the right eye ICL implantation, the changes of AOD 500 and PD were both linearly correlated with postoperative IOP change (β = −23.707 and 1.731, respectively; p = 0.013 and 0.002, respectively).

Conclusion

The ACA was significantly narrowed immediately after V4c ICL implantation. There was a negative linear correlation between ACA and early IOP and a positive linear correlation between PD and early IOP. We recommend the use of intracameral miotics immediately after V4c ICL implantation to reduce the incidence of IOP spikes.

Comparison of angle-to-angle distance using three devices in normal eyes

PURPOSE

To compare the angle-to-angle (ATA) distance, and the repeatability and the reproducibility of these measurements among the three devices.

METHODS

We performed the ATA measurements in 26 healthy subjects using anterior segment optical coherence tomography (CASIA2, Tomey, Japan), the Scheimpflug camera (Pentacam HR, Oculus, Wetzlar, Germany), and the combined Placido-ring corneal topography and Scheimpflug camera (TMS-5, Tomey). We also compared the repeatability and the reproducibility of the ATA measurements among these three devices.

RESULTS

The ATA in the CASIA2 group was significantly larger than that in the Pentacam group (Bonferroni test, p = 0.002), or that in the TMS-5 group (p < 0.001). The coefficient variation of the first and second ATA measurements for a single examiner was 0.44% in the CASIA2 group, followed by 0.84% in the TMS-5 group, and 1.92% in the Pentacam group. The coefficient variation of the ATA measurements for two examiners was 0.61% in the CASIA2 group, followed by 0.97% in the TMS-5 group, and 1.84% in the Pentacam group.

CONCLUSIONS

The ATA distance measured with the CASIA2 was ~0.40 and 0.56 mm larger than that with the Pentacam and the TMS-5, respectively. The CASIA2 provided the highest repeatability and reproducibility of the ATA measurements, followed by the TMS-5, and the Pentacam. These three instruments cannot be used interchangeably in terms of ATA measurements.

Five-Year Follow-up of Correction of Myopia: Posterior Chamber Phakic Intraocular Lens With a Central Port Design

PURPOSE

To assess the long-term correction of moderate to high myopia using a posterior chamber phakic intraocular lens with a central port design.

METHODS

Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure (IOP), endothelial cell density (ECD), vault, and adverse events over a 5-year period were evaluated retrospectively.

RESULTS

A total of 147 eyes (83 patients) were evaluated. Mean postoperative UDVA and CDVA were 0.05 ± 0.11 and 0.02 ± 0.08 logMAR at 1 year and 0.13 ± 0.18 and 0.02 ± 0.09 logMAR at 5 years, respectively. More than 95% of eyes achieved CDVA of 20/25 or better at both follow-up periods. CDVA was unchanged or improved from one to three or more lines in all eyes. Preoperatively, mean spherical equivalent (SE) was -9.20 ± 3.02 diopters (D). At 1 year, the mean SE was -0.17 ± 0.26 D, with 91.53% of eyes within ±0.50 D and 100% of eyes within ±1.00 D of the target. At 5 years, the mean SE was -0.44 ± 0.47 D, with 67.4% of eyes within ±0.50 D and 90.1% of eyes within ±1.00 D of the target. Mean IOP was 12.74 ± 1.65 and 13.0 ± 2.03 mm Hg, at 1 and 5 years, respectively. No significant rise in IOP (> 20 mm Hg) occurred during the follow-up period. Mean ECD was 2,696 ± 358 and 2,645 ± 359 cells/mm² at 1 and 5 years, respectively, representing a non-significant loss of 0.43% from preoperative values (P = .304). Mean vault changed significantly from 398 ± 187 µm at 1 year to 340 ± 163 µm at 5 years (P < .001). No intraoperative or postoperative complications or adverse events occurred during the follow-up period.

CONCLUSIONS

The good long-term outcomes found in this study support the use of this lens with a central port design for the correction of moderate to high myopia. [J Refract Surg. 2019;35(3):169-176.].

The Implantable Collamer Lens with a central port: review of the literature

The purpose of this review is to summarize preclinical and clinical data from publications appearing in the peer-reviewed scientific literature relevant to the safety and effectiveness of the EVO Implantable Collamer Lens (ICL) posterior chamber phakic refractive lens with a central port (V4c Visian ICL with KS Aquaport, STAAR Surgical, Inc.). A literature search was conducted using PubMed.gov to identify all articles relating to the EVO ICL. Articles were examined for their relevance, and the references cited in each article were also searched for additional relevant publications. On the basis of a total of 67 preclinical studies and clinical reports, including effectiveness data on 1,905 eyes with average weighted follow-up of 12.5 months and safety data on 4,196 eyes with weighted average follow up of 14.0 months, the EVO ICL is safe and effective for the correction of a broad range of refractive errors. High levels of postoperative uncorrected visual acuity, refractive predictability, and stability demonstrate the effectiveness of the EVO ICL. Safety data suggest reduced rates of anterior subcapsular cataract and pupillary block compared with earlier models. Improved safety and proven effectiveness make EVO an attractive option for surgeons and patients.