Effect of optic material on posterior capsule opacification in intraocular lenses with sharp-edge optics: Randomized clinical trial

doi:10.1016/j.ophtha.2004.07.032

Ophthalmology

Volume 112, Issue 1, January 2005, Pages 67-72

Presented in part at: German-Speaking Society for IOL Implantation and Refractive Surgery 18th Annual Meeting, February, 2004; Heidelberg, Germany.

https://doi.org/10.1016/j.ophtha.2004.07.032 Get rights and content

Purpose

Comparison of the intensity of posterior capsule opacification (PCO) between a silicone intraocular lens (IOL) and a hydrophobic acrylic IOL, both of them 3-piece and open-loop and having truncated optics with sharp edges.

Design

Randomized, controlled, patient- and examiner-masked trial with intrapatient comparison.

Participants and controls

One hundred six eyes of 53 patients with age-related bilateral cataract.

Methods

Each patient had cataract surgery in both eyes and received a silicone IOL in one eye and a hydrophobic acrylic IOL in the fellow eye. Follow-up examinations were at 1 and 3 years after surgery. The patients were examined at the slit lamp, visual acuity (VA) was assessed, and standardized high-resolution digital retroillumination images of the posterior capsule were taken. The amount of PCO was assessed subjectively at the slit lamp and objectively using automated image analysis software. Data of 56 eyes of 28 patients, who were examined at each follow-up, were analyzed.

Main outcome measure

Posterior capsule opacification intensity at 3 years as measured with automated image analysis.

Results

At 1 and 3 years after surgery, PCO did not differ between the silicone (1.6 and 1.9 [image analysis scores, 0–10 scale], respectively) and acrylic IOLs (1.7 and 2.2) (P > 0.24). Furthermore, there was no significant difference in best-corrected VA, rhexis/IOL overlap, capsular folds, and amount of anterior capsule opacification during the follow-up period. In each group, one neodymium:yttrium–aluminum–garnet (YAG) laser capsulotomy was performed during the entire study duration.

Conclusion

Silicone and hydrophobic acrylic are similarly effective in inducing the PCO-inhibiting effect of a rectangular, sharp optic edge. Three years after surgery, the PCO intensity and the YAG rate were low with both IOL models.

Section snippets

Patients and methods

A single-center, prospective, randomized, patient- and examiner-masked, controlled trial was performed at Vienna General Hospital. All the research and measurements followed the tenets of the Declaration of Helsinki, and informed consent was provided by the patients.

Participant flow

The age of the study patients was 78±4 years (mean ± SD). Of the 53 patients (106 eyes) included in the study, 28 (56 eyes) were available for all follow-up examinations. The chart in Figure 2 shows the participant flow.

Primary outcome

The amount of PCO was analyzed from the digital retroillumination images of the 1- and 3-year follow-ups by means of the AQUA software.¹² At 1 year, a mean objective PCO score of 1.6 was found for the silicone group, and a score of 1.7 for the acrylic group (scale: 0–10, P =

Discussion

The optic material, silicone and hydrophobic acrylic, had no significant impact on the main outcome variable of this study—namely, intensity of regeneratory PCO as assessed from retroillumination photographs. The long-term intensity of PCO 3 years after surgery was low for both IOL types. Only one case in each group needed Nd:YAG capsulotomy.

In the past, several authors have ascribed the low PCO rates of the Acrysof IOL to the sharp optic edge design, as seen in the animal model.15, 16 The

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Cited by (86)

An in vitro system to investigate IOL: Lens capsule interaction
2021, Experimental Eye Research
Posterior capsule opacification (PCO) is the most common complication associated with intraocular lens (IOL) implantation. Unfortunately, current in vitro models cannot be used to assess the potential of PCO due to their failure to simulate the posterior curvature of the lens capsule (LC) and IOL, a factor known to affect PCO pathogenesis in clinic. To overcome such a challenge, a new system to study IOL: LC interaction and potentially predict PCO was developed in this effort. It is believed that the interactions between an IOL and the lens capsule may influence the extent of PCO formation. Specifically, strong adhesion force between an IOL and the LC may impede lens epithelial cell migration and proliferation and thus reduce PCO formation. To assess the adhesion force between an IOL and LC, a new in vitro model was established with simulated LC and a custom-designed micro-force tester. A method to fabricate simulated LCs was developed by imprinting IOLs onto molten gelatin to create simulated three dimensional (3D) LCs with curvature resembling the bag-like structure that collapses on the IOL post implantation. By pushing the LC mold vertically downward, while measuring the change in position of the bending bar with respect to its start position, the adhesion force between the IOLs and LCs was measured.
An in vitro system that can measure the adhesion force reproducibly between an IOL and LC with a resolution of ~1 μN was established in this study. During system optimization, the 10% high molecular weight gelatin produced the best LC with the highest IOL: LC adhesion force with all test lenses that were fabricated from acrylic foldable, polymethylmethacrylate (PMMA) and silicone materials. Test IOLs exerted different adhesion force with the 3D simulated LCs in the following sequence: acrylic foldable IOL > silicone IOL > PMMA IOL. These results are in good agreement with the clinical observations associated with PCO performance of IOLs made of the same materials. This novel in vitro system can provide valuable insight on the IOL: LC interplay and its relationship to clinical PCO outcomes.
Edge profile of commercially available square-edged intraocular lenses: Part 2
2019, Journal of Cataract and Refractive Surgery
To analyze the sharpness of the posterior optic edge and edge thickness of intraocular lenses (IOLs) marketed with a square-edged profile.
University of Brighton and Brighton and Sussex University Hospitals NHS Trust, Brighton, England.
Laboratory study.
Fourteen square-edged 20.0 diopter IOLs were analyzed, including 9 hydrophobic IOLs (AF-1, AF-1 iSert, Clareon, EyeCee One Crystal, CT Lucia, Envista, EyeCee One, Vivinex iSert, and RayOne Hydrophobic) and 5 hydrophilic IOLs (Asphira, CT Asphina, Incise, Synthesis, and RayOne Hydrophilic). All the IOLs were scanned following a previously published standardized technique using environmental scanning electron microscopy. The posterior optic edges were scanned at a magnification of ×500 and ×200 to measure the radius of curvature of the posterior optic edges and the optic edge thickness.
The radius of curvature of the posterior optic edges ranged from 4.6 to 20.6 μm. Except for the Incise IOL (7.7 μm), all hydrophilic IOLs (Synthesis [10.6 μm], Asphira [13.7 μm], RayOne Hydrophilic [14.0 μm], CT Asphina [13.7 μm]) had a radius of curvature greater than 10.0 μm. For the hydrophobic IOLs, the radius of curvature was less than 10.0 μm for the Clareon (7.9 μm), EyeCee One Crystal (4.7 μm), Vivinex iSert (7.6 μm), and CT Lucia (4.6 μm), and greater than 10.0 μm for the Envista (19.7 μm), EyeCee One (13.7 μm), AF-1 iSert (19.7 μm), AF-1 (19.7 μm) and the RayOne Hydrophobic (20.6 μm). The Vivinex iSert (150.5 μm) and the Incise (218.2 μm) were the thinnest IOLs, and the RayOne Hydrophobic (375.8 μm) and RayOne Hydrophilic IOLs (477.1 μm) were the thickest of the hydrophobic and hydrophilic IOLs, respectively.
Commercially marketed square-edged IOLs still differed in the sharpness of the posterior optic edge. More hydrophobic IOLs have rounder edges than those studied 10 years ago. Variations in the edge profile of hydrophobic IOLs were greater compared with the hydrophilic IOLs.
Incidence of posterior capsular opacification requiring Nd:YAG capsulotomy after cataract surgery and implantation of enVista <sup>®</sup> MX60 IOL
2018, Journal Francais d'Ophtalmologie
To evaluate incidence of posterior capsule opacification requiring Nd:YAG capsulotomy over 3 years in a large series of eyes implanted with the enVista^® MX60 Intraocular Lens (IOL).
A university-based, single-center, observational study of patients’ medical records was conducted. Uneventful cataract surgery patients with in-the-bag implantations of the enVista^® MX60 IOL with a minimum of 24 months follow-up were included in the study. Exclusion criteria were insufficient follow-up (< 24 months), intraoperative complications and combined surgery. The primary outcome measure was rate of YAG laser capsulotomy, while secondary outcome measures were time to YAG laser capsulotomy and rate of glistenings.
A total of 245 eyes of 143 patients received the MX60 IOL and were followed in the same center. Of these, 226 eyes were included in the study. Mean age was 80.7 ± 8.3 years and M/F ratio was 42/101 (29.4/70.6%). The mean preoperative distance (logMAR) visual acuity was 0.67 ± 0.5, while postoperatively it was 0.31 ± 0.5 and 0.32 ± 0.5 at the last visit. The Mean ± SD follow-up time (min-max) was 35.2 ± 7.2, (24–48.4) months. The incidence of Nd:YAG capsulotomy over 3 years was 5/226 (2.2%). Average time between surgery and Nd:YAG capsulotomy was 32.17 months. Univariate analysis of age, gender, presence of comorbidity and baseline visual acuity found no predictive factors for capsulotomy. No glistenings were reported at any postoperative visit.
The three-year cumulative incidence of PCO requiring Nd:YAG laser capsulotomy was 2.2% for the enVista^® MX-60 IOL, with no glistenings observed during follow-up. This low rate confirms the excellent safety profile of this IOL.
Évaluer l’incidence d’opacification de la capsule postérieure nécessitant une capsulotomie Nd:YAG sur 3 ans dans une série de yeux implantés avec une lentille intraoculaire (LIO) enVista MX60.
Il s’agit d’une étude observationnelle monocentrique analysée rétrospectivement à partir des dossiers médicaux des patients. Les patients opérés de la cataracte ayant reçu un implant enVista^® MX60 dans le sac avec un minimum de 24 mois de suivi ont été inclus dans l’étude. Les critères d’exclusion étaient un suivi insuffisant (< 24 mois), des complications périopératoires et une chirurgie combinée. Le critère de mesure principal était le taux de capsulotomie au laser YAG, tandis que les mesures secondaires étaient le délai de capsulotomie au laser YAG après l’implantation de la LIO et le taux de microvacuoles.
Un total de 245 yeux de 143 patients ont reçu les implants MX60 IOL et suivis dans le même centre. Parmi ceux-ci, 226 yeux ont été inclus dans l’étude. L’âge moyen était de 80,7 ± 8,3 ans et le rapport H/F de 42/101 (29,4/70,6 %). L’acuité visuelle préopératoire moyenne (logMAR) était de 0,67 ± 0,5, alors qu’en postopératoire elle était de 0,31 ± 0,5 et de 0,32 ± 0,5 lors de la dernière visite. Le temps de suivi moyen ± écart-type (min-max) était de 35,2 ± 7,2 (24–48,4) mois. L’incidence de la capsulotomie Nd:YAG sur 3 ans était de 5/226 (2,2 %). La durée moyenne entre la chirurgie et la capsulotomie Nd:YAG était de 32,17 mois. L’analyse univariée de l’âge, du sexe, de la présence d’une comorbidité et de l’acuité visuelle de référence n’a révélé aucun facteur prédictif de la capsulotomie. Aucun cas de microvacuole n’a été signalé lors d’une visite postopératoire pendant la période de suivi.
L’incidence cumulée sur trois ans de la PCO nécessitant une capsulotomie au laser Nd:YAG de 2, 2 % pour la LIO enVista^® MX-60 sans microvacuole observé pendant le suivi suggère un bon profil de sécurité de ce type d’implant de chambre postérieure.
Intraindividual comparison of capsule behavior of 2 hydrophobic acrylic intraocular lenses during a 5-year follow-up
2017, Journal of Cataract and Refractive Surgery
To evaluate and compare the 5-year postoperative anterior (ACO) and posterior capsule opacification (PCO), the occurrence of glistenings, and the level of anterior capsule retraction after implantation of 2 designs of 1-piece hydrophobic acrylic IOLs.
Hospital St. John, Vienna, Austria.
Randomized controlled prospective case series.
Patients had an Acrysof SA60AT IOL (Group A) implanted in 1 eye and a Tecnis ZCB00 IOL (Group B) implanted in the fellow eye. At 1, 3, and 5 years, the PCO level was evaluated with the Evaluation of Posterior Capsule Opacification software. The level of ACO and capsule retraction was graded subjectively. Glistenings were scored as present or not present.
Fifty eyes of 25 patients were evaluated after 5 years. No significant differences in PCO scores were found between the 2 groups at all follow-up visits (1 year: 0.06 ± 0.12 [SD] versus 0.07 ± 0.13, P = .35; 3 years: 0.23 ± 0.36 versus 0.22 ± 0.32, P = .66; 5 years: 0.36 ± 0.41 versus 0.36 ± 0.54, P = .98). A significant increase in PCO score was found between 3 and 5 years (P < .01). Anterior capsule opacification was present in Group A and Group B in 18.0% and 2.7% of eyes (P = .03), in 92.0% and 24.0% of eyes, and in 100% and 52% of eyes (P < .01) at 1, 3, and 5 years, respectively. Glistenings (5 years 100%) were observed in Group A.
Both IOLs had a comparable PCO rate 5 years after surgery, although more ACO and retraction as well as glistenings were observed in Group A.
Intraindividual comparative analysis of capsule opacification after implantation of 2 single-piece hydrophobic acrylic intraocular lenses models: Three-year follow-up
2015, Journal of Cataract and Refractive Surgery
To compare the 3-year postoperative anterior (ACO) and posterior (PCO) capsule opacification and the level of anterior capsule retraction after implantation of 2 single-piece hydrophobic acrylic intraocular lens (IOL) models.
Hospital of St. John of God, Vienna, Austria.
Comparative randomized controlled double-blind clinical trial.
Eyes with bilateral cataract were evaluated. Each patient had an Acrysof SA60AT (interrupted optic edge) IOL implanted in 1 eye (Group A) and a Tecnis ZCB00 (continuous optic edge) IOL implanted in the fellow eye (Group B). One and 3 years postoperatively, PCO was evaluated using Evaluation of Posterior Capsule Opacification software and the ACO level and capsule-retraction level were evaluated and graded subjectively.
The study evaluated 100 eyes of 50 patients ranging from 61 to 80 years. Postoperatively, there were no statistically significant differences in PCO between Group A and Group B at 1 year (0.06 ± 0.12 [SD] and 0.07 ± 0.13, respectively; P = 4.35) or 3 years (0.23 ± 0.36 and 0.22 ± 0.32, respectively; P = .66). In Group A and Group B, ACO was present in 18.0% of eyes and 2.7% of eyes, respectively, at 1 year (P = .03) and in 92.0% and 24.0%, respectively, at 3 years (P < .01). Capsule phimosis (18.0% at 1 year; 30.0% at 3 years) and glistenings (66.0% at 1 year; 86.0% at 3 years) were observed in Group A only.
Both IOLs had similarly low PCO rates 3 years postoperatively, although more ACO and capsule retraction were observed in eyes with the interrupted optic edge IOL.
No author has a financial or proprietary interest in any material or method mentioned.
A simple method to shorten the unfolding time of prehydrated hydrophobic intraocular lens
2014, Canadian Journal of Ophthalmology
To evaluate the effect of warm ophthalmic viscosurgical devices (OVDs) on the unfolding time of prehydrated hydrophobic acrylic intraocular lenses (IOLs).
Experimental study and human trial.
Three foldable hydrophobic acrylic IOLs (enVista MX60, AcrySof SN60AT, and Tecnis 1 ZCB00).
The unfolding times of 3 kinds of IOLs were measured according to temperature from 26°C to 32°C in a transparent container filled with a mixture of OVDs and balanced salt solution. The unfolding time of each IOL was measured 4 times for each temperature. Unfolding time was defined as the time required for the folded IOL to recover ≥90% of its overall optic diameter before folding. In human trials, the unfolding time of the MX60 in a capsular bag filled with 30°C OVDs was compared with that filled with room temperature OVDs for 4 cases in each group.
The unfolding time of the MX60 (215 ± 25 seconds) was significantly longer than that of the SN60AT (28 ± 7 seconds) and the ZCB00 (29 ± 7 seconds) at 26°C (p = 0.013). However, there were no differences in the unfolding time of 3 IOLs at 32°C. In human trials, the unfolding time of the MX60 was shorter in a capsular bag filled with 30°C OVDs (32 ± 13 seconds) than if filled with OVDs kept at room temperature (127 ± 27 seconds; p = 0.029).
When fast and complete unfolding characteristics are needed, filling the anterior chamber and capsular bag with OVDs warmed to 30°C before IOL implantation is recommended.
Évaluation de l’effet de dispositifs viscochirurgicaux ophtalmiques (DVO) chauds dans la durée de déploiement des lentilles intraoculaires (LIO) acryliques hydrophobiques préhydratées.
Étude expérimentale et essais humains.
Trois LIOs acryliques hydrophobiques pliables (enVista MX60, AcrySof SN60AT et Tecnis 1 ZCB00).
Les temps de déploiement des trois types de LIOs ont été mesurés selon la température de 26°C à 32°C dans un contenant transparent rempli d’un mélange de DVOs et de solution saline équilibrée. Le temps de déploiement de chaque LIO a été mesuré quatre fois pour chaque température. Le temps de déploiement a été défini comme étant le temps requis pour que la LIO recouvre 90% ou plus de son diamètre optique global avant le replis. Dans les essais humains, la durée du déploiement de MX60 dans un sac capsulaire rempli de DVO à 30°C a été comparée avec celle du sac capsulaire rempli avec le DVO à la température ambiante pour quatre cas de chaque groupe.
La durée de déploiement de MX60 (215±25 sec) a été significativement plus longue que celles de SN60AT (28±7 sec) et de ZCB00 (29±7 sec) à 26°C (P=0,013). Toutefois, il n’y avait pas de différence dans la durée du déploiement des trois LIOs à 32°C. Dans les essais humains, la durée de déploiement de MX60 a été plus courte dans un sac rempli de DVO à 30°C (32±13 sec) que celle avec le sac qui avait été rempli avec des DVOs à la température ambiante (127±27 sec) (P=0.029).
Lorsque les caractéristiques de déploiement complet et rapide sont nécessaires, le remplissage de la chambre antérieure et du sac capsulaire avec des DVOs à 30°C de chaleur avant l’implantation de la LIO est recommandé.

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: Manuscript no. 240337.

: The authors have no financial or proprietary interest in any of the materials or equipment mentioned in this study.

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Original articleEffect of optic material on posterior capsule opacification in intraocular lenses with sharp-edge optics: Randomized clinical trial

Purpose

Design

Participants and controls

Methods

Main outcome measure

Results

Conclusion

Section snippets

Patients and methods

Participant flow

Primary outcome

Discussion

J Cataract Refract Surg

J Cataract Refract Surg

J Cataract Refract Surg

J Cataract Refract Surg

Ophthalmology

J Cataract Refract Surg

J Cataract Refract Surg

J Cataract Refract Surg

J Cataract Refract Surg

J Cataract Refract Surg

J Cataract Refract Surg

Original article
Effect of optic material on posterior capsule opacification in intraocular lenses with sharp-edge optics: Randomized clinical trial