Evaluation of posterior capsule opacification of the Alcon Clareon IOL vs the Alcon Acrysof IOL using a human capsular bag model

Posterior Capsular Opacification and Glistening in Hydrophobic Monofocal Biaspheric Intraocular Lens Two Years After Implantation: A Case Control Study

Background: This study aims to analyze the prevalence and severity of posterior capsule opacification (PCO) and glistening in a new hydrophobic biaspheric monofocal intraocular lens (IOLs) 24 months after implantation. Methods: By means of a ambispective, observational, case-control design, a total of 297 eyes from 200 cataract surgery patients were included in the study (118 females and 82 males; mean age: 72.31 ± 9.87 years, ranging from 35 to 92) and examined at the Hospital Universitario y Politécnico la Fe, Valencia (Spain). Data corresponding to patients implanted with either Asqelio (Study IOL) or Clareon (Control IOL) monofocal IOLs at least 24 months prior to study visit were analyzed. Prevalence and intensity of PCO and IOL glistening were determined and graded for both groups by a single masked observer. Refractive outcomes by autorefractometry, visual acuity, and wavefront aberrations determined by ray tracing were also measured and compared. Results: Prevalence of PCO in patients implanted with the Study IOL 24 months after implantation was 4.0%, lower than that for the Control IOL. Intensity of PCO in both groups was low. One lens in each group presented a Grade 1 glistening after 24 months from implantation. Differences in visual acuity between Study and Control Groups were not significant (p=0.260 and 0.115 for UDVA and CVA, respectively). Residual spherical aberration was significantly lower in the Study Group than that in the Control Group (p=0.007). Conclusion: Prevalence of PCO was considerably lower for Asqelio IOL than for the Control IOL and reports available in the literature for other hydrophobic IOLs. Prevalence of glistening was minimal in both study and control IOLs. Trial Registration: ClinicalTrials.gov identifier: NCT04971863.

Long-term real-life outcomes of the Clareon® hydrophobic intraocular lens: the Clarte study in 191 eyes : 3-years real-life outcomes of the Clareon® intraocular lens

BACKGROUND

To describe and analyze the real-life refractive, functional and safety outcomes of the Clareon® intraocular lens (IOL) after 3 years.

METHODS

Data was collected retrospectively for observational purposes between July 2017 and December 2019 in the ophthalmology department of Desgenettes military hospital in Lyon, France. Eyes that underwent cataract surgery with Claeron® implantation were consecutively included. Patients with a systemic or ocular condition that could affect the visual outcome were excluded. Postoperative corrected (CDVA) and uncorrected (UDVA) distance visual acuities as well as capsule and IOL transparency were assessed at 1 month and 3 years.

RESULTS

A total of 326 eyes were analyzed at one month and 191 eyes were reassessed at the 3-year follow-up visit. At 3 years, the mean CDVA was 0.003 LogMAR (95% confidence interval [CI]: -0.003 to -0.01) and the mean UDVA was 0.075 (95% CI: 0.054 to 0.095). Three quarters of the patients had an UDVA ≥ 0.097 logMAR (20/25 Snellen equivalent) and 50% had an UDVA ≥ 0 (20/20). The absence of glistening was reported in 95.3% of cases and 4.7% [9] of patients experienced a clinically significant posterior capsular opacification (PCO) for which Nd:YAG treatment was required.

CONCLUSIONS

This real-life study reports high-performance and stable long-term refractive outcomes of the Clareon® IOL with good safety in terms of PCO and glistening.

Clinical performance and shape analysis of trifocal intraocular lenses via scanning electron microscopy

BACKGROUND

To evaluate visual performance after implantation of the TFNT (Acrysof Panoptix, Alcon, Fort Worth, Texas, USA) and CNWT (Clareon Panoptix, Alcon, Fort Worth, Texas, USA) intraocular lens (IOL), and compare the lens shape observed by scanning electron microscope (SEM).

METHODS

Eighteen patients (18 eyes) received implantation of the CNWT and Twenty patients (20 eyes) received implantation of the TFNT. Exclusion criteria were previous ocular surgeries, ocular pathologies, or corneal abnormalities. Intervention or Observational Procedure(s): Postoperative examination at 1 months including manifest refraction; evaluation of refractive error, distance-corrected visual acuity (DCVA) at 5 m, 1 m, 70 cm, 50 cm, 40 cm, and 30 cm, slit-lamp examination; defocus curve testing; contrast sensitivity (CS) was performed. The lens shape of the TFNT and the CNWT was examined under SEM.

RESULTS

Mean spherical equivalent was 0.11 ± 0.41 D (CNWT group) and 0.12 ± 0.34 D (TFNT group) 1 month postoperation. DCVA and defocus curve showed no significant difference between the two groups. CS was significantly higher in CNWT group than TFNT group at spatial frequencies of 6 cycles per degree (cpd). Observation of the IOL with a scanning electron microscope (SEM) revealed that CNWT group had improved diffraction structure and edge processing accuracy compared to TFNT group.

CONCLUSION

There was no significant difference between the two groups in the defocus curve and visual acuity at all distances. CS was better in the CNWT group than in the TFNT group. IOL surface features may affect CS.

The lens epithelium as a major determinant in the development, maintenance, and regeneration of the crystalline lens

The crystalline lens is a transparent and refractive biconvex structure formed by lens epithelial cells (LECs) and lens fibers. Lens opacity, also known as cataracts, is the leading cause of blindness in the world. LECs are the principal cells of lens throughout human life, exhibiting different physiological properties and functions. During the embryonic stage, LECs proliferate and differentiate into lens fibers, which form the crystalline lens. Genetics and environment are vital factors that influence normal lens development. During maturation, LECs help maintain lens homeostasis through material transport, synthesis and metabolism as well as mitosis and proliferation. If disturbed, this will result in loss of lens transparency. After cataract surgery, the repair potential of LECs is activated and the structure and transparency of the regenerative tissue depends on postoperative microenvironment. This review summarizes recent research advances on the role of LECs in lens development, homeostasis, and regeneration, with a particular focus on the role of cholesterol synthesis (eg., lanosterol synthase) in lens development and homeostasis maintenance, and how the regenerative potential of LECs can be harnessed to develop surgical strategies and improve the outcomes of cataract surgery (Fig. 1). These new insights suggest that LECs are a major determinant of the physiological and pathological state of the lens. Further studies on their molecular biology will offer possibility to explore new approaches for cataract prevention and treatment.

Comparative evaluation of an automated preloaded delivery system with a non-preloaded system

Purpose

To evaluate a single surgeon's experience with an automated preloaded intraocular lens (IOL) delivery system and a nonpreloaded system.

Methods

This was a prospective, observational case series. Phacoemulsification was performed under topical anesthesia by creating a temporal clear corneal incision. Patients were consecutively assigned to either the Clareon group (n = 50; the IOL was injected into the capsular bag by using an automated injector system) or the AcrySof group (n = 50; the IOL was injected into the capsular bag by using a conventional injector system). The main outcome measures were ease of implantation, intraoperative complications, postoperative centration, and visual acuity.

Results

Additional manipulation in the anterior chamber was not required in 38 (74%) eyes in the Clareon group and 41 (82%) eyes in the AcrySof group. However, seven eyes in the Clareon group and one eye in the AcrySof group required trailing haptic dislodgement from the optic. Furthermore, two eyes in the Clareon group and five eyes in the AcrySof group required injector rotation (varying from 10° to 90°) in the wound. Moreover, in two eyes of the Clareon group, the silicon plunger of the injector system crossed over the optic. None of the patients developed iris trauma and PCR during IOL manipulation. All the IOLs were centered in the capsular bag.

Conclusion

The automated IOL delivery system enables the controlled delivery of an IOL in the capsular bag. The effect of carbon footprints created by plastic generated from the delivery system and the implications of the CO₂ cylinder on the environment should be addressed.

Predicting the biomechanical stability of IOLs inside the postcataract capsular bag with a finite element model

BACKGROUND AND OBJECTIVES

Although cataract surgery is a safe operation in developed countries, there is still room for improvement in terms of patient satisfaction. One of the key issues is assessing the biomechanical stability of the IOL within the capsular bag to avoid refractive errors that lead to a second surgery. For that purpose, a numerical model was developed to predict IOL position inside the capsular bag in the short- and long-term.

METHODS

A finite element model containing the implanted IOL, the postcataract capsular bag, the zonules, and a portion of the ciliary body was designed. The C-loop hydrophobic LUCIA IOL was used to validate the numerical model and two more worldwide IOL designs were tested: the double C-loop hydrophobic POD FT IOL and the plate hydrophilic AT LISA IOL. To analyze the biomechanical stability in the long-term, the effect of the fusion footprint, which occurs days following cataract surgery, was simulated. Moreover, several scenarios were analyzed: the size and location of the capsulorexhis, the capsular bag diameter, the initial geometry of the capsular bag, and the material properties of the bag.

RESULTS

The biomechanical stability of the LUCIA IOL was simulated and successfully compared with the in vitro results. The plate AT LISA design deformed the capsular bag diameter up to 11.0 mm against 10.5 mm for the other designs. This design presented higher axial displacement and lower rotation, 0.19 mm and 0.2^∘, than the C-loop design, 0.09 mm and 0.9^∘.

CONCLUSIONS

All optomechanical biomarkers were optimal, assuring good optical performance of the three IOLs under investigation. Our findings showed that the capsulorexhis size influences the stiffness of the capsular bag; however, the shape in the anterior and posterior curvature surfaces of the bag barely affect. The results also suggested that the IOL is prone to mechanical perturbations with the fusion footprint, but they were not high enough to produce a significant refractive error. The proposed model could be a breakthrough in the selection of haptic design according to patient criteria.

Comparison of Visual Outcomes and Patient Satisfaction Following Cataract Surgery with Two Monofocal Intraocular Lenses: Clareon® vs AcrySof® IQ Monofocal

Aim:

This study aimed to compare the performance of two monofocal Intraocular Lenses (IOL) platforms.

Background:

The Clareon® Intraocular Lens (IOL) is a relatively new monofocal lens platform designed to improve postoperative results compared to other monofocal platforms.

Objective:

This study aimed to assess and compare the visual and refractive outcomes, and incidence of YAG capsulotomy of the Clareon® IOL and a standard non-preloaded AcrySof® monofocal IOL following contralateral implantation in patients undergoing cataract surgery.

Methods:

A total of 20 patients (40 eyes; 12 female, average age 72.8±6.4 years) who had undergone contralateral implantation of an AcrySof® IQ monofocal lens (SN60WF or SN6AT; Alcon; Texas, USA) and a Clareon®monofocal lens (CNAOT0; Alcon; Texas, USA) were selected. Uncorrected Distance Visual Acuity (UDVA), Contrast Sensitivity (CS), kinetic perimetry, and refraction were measured 1 month following the second surgery and subjective vision was measured 6 months following the second surgery using a quality-of-life questionnaire.

Results:

There was no difference in postoperative UDVA (P=0.94), CS (P>0.05), or refraction (P=0.64) between eyes that received the Clareon® and AcrySof® IQ lenses. Clareon® eyes had a higher incidence of glare/haloes and positive dysphotopsia while AcrySof® IQ eyes had a higher incidence of negative dysphotopsia. Patient satisfaction was similar between the groups (P=0.86), although 25% of patients reported more clarity in the eye that received the Clareon® lens. The incidence of posterior capsular opacification was low for both groups.

Conclusion:

Clareon® and AcrySof® IQ lenses perform similarly, providing good refractive, visual, and subjective outcomes. Clareon® is available as a preloaded lens option and may reduce PCO and the need for Nd: YAG capsulotomy.

Factors Affecting Posterior Capsule Opacification in the Development of Intraocular Lens Materials

Posterior capsule opacification (PCO) is the most common complication arising from the corrective surgery used to treat cataract patients. PCO arises when lens epithelial cells (LEC) residing in the capsular bag post-surgery undergo hyper-proliferation and transdifferentiation into myofibroblasts, migrating from the posterior capsule over the visual axis of the newly implanted intraocular lens (IOL). The developmental pathways underlying PCO are yet to be fully understood and the current literature is contradictory regarding the impact of the recognised risk factors of PCO. The aim of this review is firstly to collate the known biochemical pathways that lead to PCO development, providing an up-to-date chronological overview from surgery to established PCO formation. Secondly, the risk factors of PCO are evaluated, focussing on the impact of IOLs’ properties. Finally, the latest experimental model designs used in PCO research are discussed to demonstrate the ongoing development of clinical PCO models, the efficacy of newly developed IOL technology, and potential therapeutic interventions. This review will contribute to current PCO literature by presenting an updated overview of the known developmental pathways of PCO, an evaluation of the impact of the risk factors underlying its development, and the latest experimental models used to investigate PCO. Furthermore, the review should provide developmental routes for research into the investigation of potential therapeutic interventions and improvements in IOL design in the aid of preventing PCO for new and existing patients.

Effectiveness and Safety of the Clareon Monofocal Intraocular Lens: Outcomes from a 12-Month Single-Arm Clinical Study in a Large Sample

Purpose

This study assessed effectiveness and safety of the novel Clareon intraocular lens (IOL; model SY60CL; Alcon Vision LLC).

Patients and Methods

This was a prospective, single-arm, unmasked clinical trial at 16 investigative clinical sites in the United States. Included were adults ≥22 years who required cataract extraction by phacoemulsification. Following phacoemulsification, 350 subjects received SY60CL IOL unilaterally; 342 completed the study. Monocular best corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA) were evaluated. The primary effectiveness endpoint was the percentage of subjects with CDVA ≤0.3 logMAR at month 12. Safety was assessed by monitoring adverse events (AEs). Visual acuity and safety outcomes were compared with historical safety and performance endpoint (SPE) rates.

Results

At 12 months post-implantation, 99.7% of subjects receiving the SY60CL IOL achieved monocular CDVA ≤0.3 logMAR (primary effectiveness endpoint; 1-sided 95% upper confidence limit >SPE rate); 99.7% and 86.8% of subjects achieved monocular CDVA of ≤0.34 (20/40 Snellen or better) and ≤0.04 logMAR (20/20 Snellen or better), respectively. At 12 months, >95% of subjects achieved mean monocular UDVA ≤0.3 logMAR; 97.1% and 57.6% of subjects achieved monocular CDVA of ≤0.34 and ≤0.04 logMAR, respectively. Mean monocular CDVA and UDVA were -0.05 and 0.04 logMAR, respectively. AEs were within SPE limits. The most common nonserious ocular AE was posterior capsule opacification (5.4%). Serious AEs were <1%, and no serious ocular AEs were assessed as related to the device. There were no observations for IOL glistenings at 12 months.

Conclusion

Results of this study supported effectiveness and safety of the SY60CL IOL. Visual acuity outcomes with the SY60CL IOL exceeded the SPE rates for monocular CDVA and AEs were within the limit of historic SPE rates. (Model number SY60WF is the Clareon lens approved by the FDA.).

Comparison of posterior capsule opacification between Clareon CNA0T0 and Tecnis ZCB00 intraocular lenses

INTRODUCTION

The purpose is to compare posterior capsule opacification (PCO) and its impact on vision between Clareon CNA0T0 (Alcon) and Tecnis ZCB00 intraocular lenses (IOLs) (Johnson&Johnson) 1, 6, and 12 months after implantation.

METHODS

A prospective observational study was performed at the Nuestra Señora de Gracia Hospital (Zaragoza, Spain). Fifty eyes (50 patients) with Tecnis IOL (group 1) and 60 eyes (60 patients) with Clareon IOL (group 2) were enrolled. One, 6, and 12 months after age-related cataract surgery by five different surgeons, the following tests were performed: mesopic corrected distance visual acuity (CDVA), CSV1000-E test, KR-1W wavefront analyzer, OQAS II, Catquest-9SF questionnaire and mydriatic slit-lamp pictures. PCO intensity was quantified and the area of opacification was measured using ImageJ (NIH).

RESULTS

Mean age was 71.20 ± 6.79 years in group 1, and 71.73 ± 8.17 years in group 2 (p = 0.72); mean axial length was 23.46 ± 1.14 and 23.53 ± 0.91 mm, respectively (p = 0.72); mean IOL power was 21.69 ± 2.26 D and 21.28 ± 2.44 D, respectively (p = 0.37). One month after surgery there were differences in intensity of PCO (0.73 ± 0.60 and 1.05 ± 0.71, respectively, p = 0.02). Six months after surgery statistical differences were found in VA with 20% CS in mydriatic conditions (0.26 ± 0.21 logMAR (20/36) and 0.18 ± 0.17 logMAR (20/30), respectively, p = 0.04). Twelve months after surgery, no differences were detected between groups. As for the evolution of PCO within the Clareon group, high order aberrations (p < 0.05) and the Strehl ratio (p = 0.02) decreased.

CONCLUSION

There are no differences in slit-lamp pictures or visual function between both IOLs during the first 12 months after implantation.

Posterior capsule opacification: What's in the bag?

Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions.

Refractive stability of a new single-piece hydrophobic acrylic intraocular lens and corneal wound repair after implantation using a new automated intraocular lens delivery system

PURPOSE

To investigate refractive stability and characterize corneal incision repair up to 3 months after implantation of a new hydrophobic acrylic intraocular lens (IOL) with hydroxyethylmethacrylate using a new automated IOL delivery system.

METHODS

This prospective case series included 50 eyes of 50 patients undergoing phacoemulsification and implantation of the Clareon® CNA0T0 IOL using the AutonoMe® automated delivery system in the Department of Ophthalmology, Keio University School of Medicine. The clinical data were collected from 46 eyes of 46 patients preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively. Endothelial-side incision gaping, posterior incision retraction, and Descemet's membrane detachment were recorded as present or absent using anterior-segment optical coherence tomography postoperatively.

RESULTS

The uncorrected distance and corrected distance visual acuities improved and stabilized 1 week postoperatively. The anterior chamber depth was stable from 1 week postoperatively. The subjective refraction was stable from 1 day postoperatively. Descemet's membrane detachments and endothelial-side wound gaping were seen in 19 (41.3%) eyes and 34 (73.9%) eyes 1 day postoperatively and decreased gradually. Posterior incision retraction was seen in eight eyes (17.4%) on day 1 and increased to 19 eyes (41.3%) 3 months postoperatively.

CONCLUSIONS

The Clareon IOL had excellent refractive stability from day 1 postoperatively. The AutonoMe automated delivery system enables safe IOL implantation through a 2.4-mm corneal incision, although the wound required longer than 1 month to heal postoperatively.