Adhesion of soluble fibronectin, laminin, and collagen type IV to intraocular lens materials

Evaluation of Nd:YAG laser capsulotomy results in patients who underwent cataract extraction and intraocular lens implantation with the endocapsular phacoemulsification method

Background/Aim: Posterior capsular opacification (PCO) is a common complication that develops after cataract surgery, and it can be treated neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy. In this study, we aimed to investigate the effects of different intraocular lenses (IOLs) on the development of posterior capsule opacification (PCO), to determine the time between surgery and Nd:YAG laser capsulotomy, and to evaluate the efficacy, effectiveness, and complications of capsulotomy in patients who underwent cataract surgery with the phacoemulsification method and subsequently developed PCO. Methods: The cohort study included one eye of each of 153 cases (63 males, 90 females) who underwent cataract surgery with the phacoemulsification method in our clinic from August 1, 2006, through August 1, 2008, and subsequently developed PCO. According to the type of IOL implanted, the cases were divided into three groups: polymethylmethacrylate IOL (Group 1), hydrophilic acrylic IOL (Group 2), and hydrophobic acrylic IOL (Group 3). The control examinations of the patients who underwent Nd:YAG laser capsulotomy were undertaken before capsulotomy and at the first week, first month, and third month after capsulotomy. Results: Visual acuity improvement was detected in 96.7% of the 153 cases. It was determined that 9.1% of the cases had an intraocular pressure (IOP) increase of more than 5 mmHg at the third hour after capsulotomy and approached baseline values at the end of 1 week. The mean   total energy used in all the cases was 37.20 (14.70) mjl. The mean total energy used in 14 patients with an IOP elevation of above 5 mmHg was 71.07 (10.59) mjl. Nd:YAG laser capsulotomy was performed at an average of 6.29 (4.91) months in Group 1, 7.81 (4.35) months in Group 2, and 17.7 (12.35) months in Group 3. After capsulotomy, clinically significant cystoid macular edema was observed in 1.9% of the cases, IOL damage in 3.9%, and vitreous hemorrhage in 0.6%. Conclusion: In this study, the incidence of PCO development was found to be lower in the patients who underwent hydrophobic acrylic IOL implantation; therefore, this type of lens should be preferred for implantation. Although Nd:YAG laser capsulotomy is an outpatient treatment method that can be applied quickly and can increase visual acuity, it can also lead to complications. To eliminate most of these complications, it would be beneficial to minimize the energy used during the laser procedure.

Nd:YAG capsulotomy incidence associated with five different single-piece monofocal intraocular lenses: a 3-year Spanish real-world evidence study of 8293 eyes

OBJECTIVES

To investigate the associations between different single-piece monofocal intraocular lenses (IOLs) and neodymium-doped yttrium aluminum garnet laser (Nd:YAG) capsulotomy incidence 3 years after cataract surgery in a Spanish cohort.

METHODS

This is a longitudinal retrospective cohort study. Data were extracted from the electronic medical records of two large regional hospitals in Spain. Patients aged ≥65 years receiving cataract surgery with placement of five different IOLs and with ≥6 months of baseline data were included. We report the Nd:YAG capsulotomy incidence 3 years post cataract surgery, and the survival plot over the 3 years of follow-up time. The associated adjusted (age, gender, and diabetic retinopathy) multivariate analysis with odds ratios (ORs) and 95% CIs is also presented.

RESULTS

The cohort (53% female, mean age 75 ± 5.9 years) included 14,519 eyes (Alcon AcrySof = 2968, AJL LLASY60 = 1776, Medicontur Bi-flex = 5176, Zeiss Asphina = 4478, and IOL Tech Stabibag = 121). Of these, 8293 were retained until 3-year follow-up. At 3 years after cataract surgery, the Nd:YAG capsulotomy incidence was 5% for Alcon AcrySof, while it ranged from 21.2% to 31.1% for the other IOLs (p < 0.0001 for each comparison). The odds for Nd:YAG capsulotomy were significantly higher (p < 0.0001) for other IOLs compared with those of Alcon AcrySof (ORs = 8.85, 5.86, 5.74, 5.21 for AJL LLASY60, Medicontur Bi-flex, IOL Tech Stabibag, and Zeiss Asphina, respectively).

CONCLUSIONS

The lower Nd:YAG capsulotomy rates for Alcon AcrySof IOLs compared to the other IOLs support the importance of lens choice in reducing patient burden and treatment costs.

Long-term incidence of posterior capsular opacification in patients with non-infectious uveitis

Little is known about the long-term incidence of posterior capsule opacification (PCO) after cataract surgery in patients with uveitis. This retrospective study included 211 eyes of 146 patients with non-infectious uveitis who underwent cataract surgery and implantation of an Acrysof SN60WF (Surface: plasma-treated, Optic and Haptic: hydrophobic acrylic), iSert XY-1 (Surface: UV-ozone-treated, Optic and Haptic: hydrophobic acrylic), or iSert 251/255 (Surface: UV-ozone-treated, Optics: hydrophobic acrylic, Haptic: polymethyl methacrylate). The cumulative incidences of PCO and subsequent yttrium–aluminum-garnet (Nd:YAG) capsulotomy over the 5-year follow-up were analyzed, and patients who were implanted with different intraocular lenses (IOLs) were compared. Mixed-effects Cox proportional hazard models showed that, compared with the Acrysof group, the iSert XY-1 group had higher risks of PCO (adjusted HR, 7.26; 95% CI, 1.82–28.8) and Nd:YAG capsulotomy (adjusted HR, 6.50; 95% CI, 1.55–27.2). Similar results were obtained when the Acrysof group was compared with the iSert 251/255 group for PCO (adjusted HR, 8.22; 95% CI, 2.35–28.7) and Nd:YAG capsulotomy (adjusted HR, 8.26; 1.90–36.0). These data suggest that a plasma-treated surface, hydrophobic acrylic optic and hydrophobic acrylic haptic, of the IOL could enhance biocompatibility even under inflammatory conditions, thus suppressing PCO development.

Rotational stability of Toric intraocular lenses

BACKGROUND

A prospective study to evaluate the rotational stability of toric intraocular lenses (IOLs).

METHODS

A prospective study of 30 eyes in 29 patients. All patients with regular astigmatism of range 0.75-4 D were included in the study. Exclusion criteria included irregular corneal astigmatism, post-refractive surgery and corneal dystrophies. All patients underwent uncomplicated phacoemulsification cataract surgery by the same surgeon. Three eyes with corneal astigmatism of 0.75-1.5 D were implanted with the AcrySof SA60T3 IOL, eight eyes with astigmatism between 1.5 and 2.0 D received the SA60T4 IOL and eight eyes with astigmatism between 2.0 and 2.50 D received the SA60T5 and rest with astigmatism of 2.5 D and higher received SA60T6 and above models. Main outcome measure was the post-operative position of the lens, assessed at day 1, 1 week, 1 month and 6 months, using toric marker and the slit lamp.

RESULTS

There was no significant rotation of IOL observed during a follow-up period of 6 months. Overall, the post-operative rotation was within 5° in 95% of cases. There was no trend for either clockwise or anti-clockwise rotation. However, IOL rotation happens mostly within the first month of surgery, and if it is significant, it requires early repositioning.

CONCLUSION

Toric IOLs are very effective and consistent in correcting astigmatism during the cataract surgery. Once placed to its position, toric IOLs demonstrate rotational stability in the capsular bag.

Application of Collagen I and IV in Bioengineering Transparent Ocular Tissues

Collagens represent a major group of structural proteins expressed in different tissues and display distinct and variable properties. Whilst collagens are non-transparent in the skin, they confer transparency in the cornea and crystalline lens of the eye. There are 28 types of collagen that all share a common triple helix structure yet differ in the composition of their α-chains leading to their different properties. The different organization of collagen fibers also contributes to the variable tissue morphology. The important ability of collagen to form different tissues has led to the exploration and application of collagen as a biomaterial. Collagen type I (Col-I) and collagen type IV (Col-IV) are the two primary collagens found in corneal and lens tissues. Both collagens provide structure and transparency, essential for a clear vision. This review explores the application of these two collagen types as novel biomaterials in bioengineering unique tissue that could be used to treat a variety of ocular diseases leading to blindness.

Foldable Glistening-Free Acrylic Intraocular Lens Biomaterials with Dual-Side Heterogeneous Surface Modification for Postoperative Endophthalmitis and Posterior Capsule Opacification Prophylaxis

Hydrophobic acrylic intraocular lenses (IOLs) are widely used in cataract treatment for posterior capsule opacification (PCO) prophylaxis. However, undesired glistening and postoperative endophthalmitis are two major potential risks. Hence, a series of poly(2-phenoxyethyl methacrylate-co-2-phenoxyethyl acrylate-co-2-ethylhexyl methacrylate) (PPPE) acrylic IOL materials were synthesized for "glistening-free" optimization. The selected PPPE with 2% 2-ethylhexyl methacrylate showed excellent optical, foldable, and thermomechanical properties. The anterior surface of PPPE was coated with polydopamine followed by gentamycin conjugation (PDA/GS). It inhibited bacterial adhesion by 74% and decreased the biofilm thickness by 87%. In inflammatory mimicking conditions, bacterial proliferation was restrained, with acidic-dependent GS release behavior. The surface of PPPE toward the posterior capsule remained hydrophobic. It was conducive to human lens epithelial cell adhesion, collagen IV and fibronectin adsorption, and the following "sealed sandwich structure" formation. In summary, the PPPE with a dual-side heterogeneous surface displayed good application prospects in postoperative endophthalmitis and PCO prevention.

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.

Long-term In Vivo Stability of Posterior Chamber Phakic Intraocular Lens: Properties and Light Transmission Characteristics of Explants

PURPOSE

To evaluate the in vivo durability of the surface and optical properties of the implantable Collamer lens (ICL).

DESIGN

Retrospective case series.

METHODS

We included patients who developed cataracts after having undergone ICL implantation from March 2003 to May 2014 and underwent ICL explantation followed by cataract surgery from March 2017 to December 2019 at the Nagoya Eye Clinic. ICL explants were submitted to Chukyo Medical Co, Ltd (Nagoya City, Japan) for laboratory analysis using ultraviolet-visible light spectroscopy, light microscopy (LM), and scanning electron microscopy. Patients' demographic and clinical data were collected and reviewed.

RESULTS

Thirteen eyes from 10 patients were studied. The average age at ICL explantation was 50.5 ± 8.5 years (range, 34.5-66.3 years). The average length of ICL stay in the eye (from implantation to explantation) was 10.5 ± 2.7 years (range, 4.4-13.7 years). No opacification or coloring of the ICL explants was observed by LM. The ICL explants showed almost the same light transmittance as that of unused ICLs. Scanning electron microscopy revealed no irregularities at the surface of the center and periphery of the optic and haptic footplate. The positioning holes did not show any deposition.

CONCLUSION

The ICLs remained in-eye for >10 years without any deterioration in the surface and optical properties of the ICL, despite their contact with the ciliary body and iris tissues and the continuous interaction with the aqueous humor components. The present study shows long-term in vivo stability of the ICL.

Systematic Study on the Biomechanical Stability of C-Loop Intraocular Lenses: Approach to an Optimal Design of the Haptics

To study the main design parameters that affect the mechanical stability of C-loop intraocular lenses, leading to an optimal design that minimizes the axial displacement, tilt and rotation. A total of 144 geometrical variations were studied on a 1-piece, non-angulated, C-loop hydrophobic acrylate intraocular lens. The study was performed in a finite element modeling simulation. The suitable set of variations was determined using a mixed-factorial analysis, allowing to analyse the impact of the different designs on the mechanical stability of the lens (compression force, axial displacement, tilt and rotation). The design parameters under study were: the length, width, thickness and opening angle of the haptic, the haptic-optic junction and the start of the haptic curvature. The compression (or reaction) force is affected by the haptic width, the haptic-optic junction, and the interaction between both. The axial displacement is mainly affected by the width and thickness of the haptic, and the size of the haptic-optic junction as well. The tilt is affected by the haptic thickness and the interaction between the haptic curvature and the haptic-optic junction. The rotation is affected by the start of the haptic curvature, the haptic-optic junction and the haptic width. The haptic-optic juntion is one of the most influential parameters affecting the four responses studied of the C-Loop IOL. The smaller the haptic-optic juntion, the better biomechanical stability.

Effect of AcrySof versus other intraocular lens properties on the risk of Nd:YAG capsulotomy after cataract surgery: A systematic literature review and network meta-analysis

OBJECTIVE

The purpose of this study was to evaluate the impact of different intraocular lens materials (IOL) and optic edge designs on the incidence of Nd:YAG laser capsulotomy.

METHODS

Randomized controlled trials (RCTs) reporting incidence of Nd:YAG capsulotomy in patients with monofocal IOLs were identified for systematic literature review (SLR) using Cochrane methodology. A network meta-analysis was conducted under a Bayesian framework. Mean hazard ratios (HRs), 95% credible intervals, and one-sided p-values were estimated for Nd:YAG capsulotomy incidence by comparing AcrySof IOLs with a group of non-AcrySof hydrophobic acrylic, hydrophilic acrylic, silicone, and PMMA IOLs. Sensitivity analysis was conducted comparing the risk of Nd:YAG capsulotomy between sharp- and round-edged designs of the above IOLs.

RESULTS

AcrySof IOLs had a lower risk of Nd:YAG capsulotomy compared to hydrophobic acrylic (HR: 2.68; 95% CrI: 1.41, 4.77; p < 0.01), hydrophilic acrylic (HR: 7.54; 95% CrI: 4.24, 14.06; p < 0.001), PMMA (HR: 3.64, 95% CrI: 1.87, 6.33; p < 0.001), and silicone (HR: 1.13; 95% CrI: 0.59, 1.91; p <0.1) IOLs. The risk for Nd:YAG was highest among sharp-edged IOLs for hydrophilic acrylic IOLs (HR: 9.32; 95% CrI: 4.32, 19.29; p < 0.01), followed by other hydrophobic acrylic (HR: 2.91; 95% CrI: 1.27, 5.88; p < 0.01), silicone (HR: 0.838; 95% CrI: 0.328, 1.74; p = 0.69), and PMMA (HR: 0.39; 95% CrI: 0.042, 1.49; p = 0.93) IOLs, compared to AcrySof. Acrysof IOLs had a lower risk of Nd:YAG compared to PMMA (HR: 3.25; 95% CrI: 1.21, 7.37; p < 0.01) and silicone, round edge IOLs (HR: 3.84; 95% CrI: 1.08, 10.64; p = 0.015).

CONCLUSION

The risk of Nd:YAG capsulotomy is lower in eyes implanted with AcrySof IOLs compared to non-AcrySof hydrophobic or hydrophilic acrylic IOLs. Sharp-edged AcrySof, PMMA, and silicone IOLs are comparable in terms of reducing the risk of Nd:YAG laser capsulotomy.

Comparing the long-term impact on health care resources utilization and costs due to various single-piece acrylic monofocal intraocular lens implantation during cataract surgery: a cost-consequence analysis for the United Kingdom, Italy, and Denmark

PURPOSE

The objective of this study was to estimate the cost impact of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy and its complications due to single-piece acrylic monofocal intraocular lenses (IOLs) in the healthcare setting of United Kingdom, Italy, and Denmark.

MATERIALS AND METHODS

A hypothetical cost-consequence model was developed to estimate economic burden of Nd:YAG laser capsulotomy due to different single-piece acrylic monofocal IOLs. Cumulative incidence of Nd:YAG laser capsulotomy at 3 years after cataract surgery with five single-piece monofocal acrylic IOLs was sourced from retrospective data analysis of electronic medical records of cataract patients in the United Kingdom. Risk probability of post-Nd:YAG laser complications, ie, retinal detachment, glaucoma, and cystoid macular edema at 3 years was derived using published literature. Unit costs were taken from publicly available sources with all costs converted to euro (€). Number of cataract procedures per year for each country was sourced from Eurostat statistics.

RESULTS

For the estimated cataract procedures carried out nationally every year, single-piece monofocal hydrophobic AcrySof IOL was associated with substantially lower cases of Nd:YAG laser capsulotomy procedures and subsequent complications in 3 years after cataract surgery when compared to other single-piece monofocal acrylic IOLs. The total cost savings with the use of AcrySof over other IOLs in countries assessed ranged from €0.5 to €4.7 million (vs AMO Tecnis) and €2.1 to €17.9 million (vs Rayner C-/Super-flex).

CONCLUSION

Incidence of Nd:YAG capsulotomy due to the choice of IOL could significantly affect healthcare budgets in the post-cataract surgery period. Our analysis indicates that single-piece monofocal AcrySof IOLs is the most cost-saving treatment option for health care systems when compared to other acrylic single-piece IOLs.

Designing a bioactive scaffold from coassembled collagen–laminin short peptide hydrogels for controlling cell behaviour

Exploring the potential of bifunctional collagen–laminin mimetic peptide based co-assembling gels for cell culture applications.

Long-term effectiveness and safety of a three-piece acrylic hydrophobic intraocular lens modified with hydroxyethyl-methacrylate: an open-label, 3-year follow-up study

Background

Clareon^® is a new hydrophobic acrylic optic biomaterial designed for enhanced clarity and greater resistance to glistening. The present study evaluated the effectiveness and safety of a three-piece hydrophobic, monofocal intraocular lens (IOL) Model MA60NM, made of this new optic material.

Methods

In this prospective, multicenter, open-label study, eligible patients aged ≥60 years, underwent a unilateral implantation with IOL Model MA60NM following phacoemulsification. Patients were followed-up for up to 3 years after implantation. Visual outcome and serious adverse events (SAEs, cumulative and persistent) were compared to ISO grid rates (BS EN ISO 11979-7:2006). The primary effectiveness variable was Best Spectacle-Corrected Visual Acuity (BSCVA) at 1-year postoperative follow-up. In addition, posterior capsular opacification (PCO) was assessed qualitatively and graded by slit lamp exam on a 5-point scale at all visits.

Results

Overall, 179 and 138 patients completed the 1-year and 3-year postoperative follow-up, respectively. The BSCVA outcomes were better with IOL Model MA60NM than the ISO grid rates with 95.5% of patients at 1 year and 94.2% of patients at 3 years having achieved a BSCVA of 20/40 or better vs 92.5% in ISO grid. The incidence of cumulative or persistent SAEs was lower after Model MA60NM implantation than the ISO grid reference. The incidence of clinically significant PCO was 1.1% at the 1-year and 2.2% at the 3-year visit. Posterior capsulotomy rate was 1.1% at 1 year and 1.4% at 3 years.

Conclusion

The three-piece hydrophobic, monofocal IOL Model MA60NM was effective for the visual correction of aphakia and successfully met all the safety parameters as defined by the ISO criteria. PCO and posterior capsulotomy rates were low over the 3-year follow-up period. This study provides evidence and supports the long-term safety and effectiveness of the new optic biomaterial Clareon^®.

Comparative evaluation of rotational stability and visual outcome of toric intraocular lenses with and without a capsular tension ring

Purpose:

To evaluate the rotational stability of toric intraocular lens (IOL) when co-implanted with a capsular tension ring (CTR) as compared to that of a toric IOL without a CTR.

Methods:

This was a prospective randomized clinical trial performed in a tertiary care centre in India. Fifty adult human eyes with visually significant cataract and regular corneal astigmatism ≥1.5D divided into two groups of 25 eyes each, A and B by simple randomization. Eyes with corneal pathology, lens subluxation, and a specular endothelial cell count <2000/mm² were excluded from the study. The eyes in both the groups underwent standard phacoemulsification and were implanted with a toric IOL. In Group A, a CTR was put in the bag before IOL implantation. The groups were called for follow-up on day 1, 1 week, 1 month, and 3 months, postoperatively. The axis of the toric IOL on each visit was measured by slit lamp imaging in retroillumination and analyzed digitally.

Results:

Mean rotation of toric IOL at 3 months postoperatively was 1.85 ± 1.72° in Group A and 4.02 ± 2.04° in Group B. The difference was statistically significant (P = 0.003).

Conclusion:

Coimplantation of a CTR is a safe and effective technique for ensuring better rotational stability of toric IOLs.

Biomaterial Influence on Intraocular Lens Performance: An Overview

There is strong evidence that the IOL material is the factor having the greatest impact on posterior capsule opacification (PCO), anterior capsule opacification (ACO) development, and glistening formation after cataract surgery, even though there are other IOL features—such as haptic material and design and edge and optic design—that also have some influence. We reviewed the published literature describing the adverse events that are mainly related to the intraocular lens (IOL) material, such as PCO, ACO, and the subsequent capsule contraction, as well as glistening formation. The adverse events presented in this overview are the most common ones in clinical practice, and therefore, they are generally included in the clinical protocols for IOL evaluation.

ThinOptX vs AcrySof: Comparison of visual and Refractive Results, Contrast Sensitivity, and the Incidence of Posterior Capsule Opacification

PURPOSE

To evaluate the visual and refractive results, the changes in contrast sensitivity, and the incidence of posterior capsule opacification (PCO) after the implantation of UltraChoice 1.0 ThinOp-tX (ThinOptX Inc.) intraocular lens (IOL) and conventional acrylic foldable IOL (AcrySof MA30AC).

METHODS

Twenty-five patients were randomized into two groups prospectively. In Group 1, microincisional phacoemulsification and the ThinOptX IOL implantation were applied in one eye, and in Group 2, conventional phacoemulsification and the AcrySof IOL implantation were applied in the fellow eye. Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), surgically induced astigmatism (SIA), contrast sensitivity, and the incidence of PCO were observed in the two groups and comparisons were made.

RESULTS

Mean follow-up period was 12.8+/-1.5 months (range 11 to 14 months). In the last follow-up examination, UCVA and BCVA were significantly lower and the PCO scores were significantly higher in Group 1 (p<0.05). Although SIA was lower in Group 1, the difference was not statistically significant. Contrast sensitivity in higher spatial frequencies was significantly lower in Group 1 in the 6th month and 12th month visits. Capsular contraction was seen in 3 eyes (12%) in Group 1 whereas there was no capsular contraction or phimosis in Group 2.

CONCLUSIONS

Long-term evaluation of the ThinOptX IOL concludes with an increased rate of PCO, a diminished resistance to the capsular contraction vs the AcrySof IOL, and a decrease in visual performance. The poor after cataract performance of this rollable lens shows that microphacoemulsification and ThinOptX IOL implantation is not as effective as conventional hacoemulsification and AcrySof IOL implantation in the long term.

Comparative study of visual function and ocular aberrations of two different one-piece designed hydrophilic acrylic intraocular lens

PURPOSE

To determine whether the aspherical IOL, Tecnis ZCB00, can improve the visual quality by measuring visual acuity, wavefront aberrations, and contrast sensitivity.

METHODS

It was a retrospective case series. Patients who underwent phacoemulsification cataract surgery were divided into two groups. One group (Group TC) was implanted with one-piece aspherical acrylic IOL (Tecnis ZCB00, AMO); the other (Group SA) was implanted with one-piece spherical acrylic IOL (Sensar AAB00, AMO). Eighty-eight eyes were selected into this study, among them 43 eyes in 26 male cases and 45 eyes in 29 female cases. Thirty-six eyes in 23 cases were in Group TC, and 52 eyes in 32 cases were in Group SA. Three months postoperatively, aberrations were analyzed with i-Trace visual function analyzer (Tracy Technologies, USA). Contrast sensitivities were measured with Takaci-CGT-1000 contrast glare tester (Seiko, Japan).

RESULTS

All the 88 eyes underwent phacoemulsification with intraocular lens implantation, without complications during or after surgery. Three months postoperatively, the uncorrected vision acuity in Group TC was significantly better than in Group SA (P = 0.007). At the pupil size of 5.0 mm, higher-order aberrations in Group TC were significantly higher than in Group SA (P = 0.02), especially the spherical aberration (Z ₄⁰ ) (P < 0.001); at the pupil size of 4.0 mm, Z ₄⁰ in Group SA was statistically higher than in Group TC (P < 0.001); at the pupil size of 3.0 mm, higher-order aberrations such as coma (Z ₃^-1,1 ) and trefoil aberration (Z ₃^-3,3 ) in Group SA were obviously higher than in Group TC (P = 0.01). In the low spatial frequency, the contrast sensitivity and the glare sensitivity in Group TC were significantly higher than in Group SA (P < 0.05).

CONCLUSIONS

By the short-term follow-up (3 months), the aspherical acrylic IOL can reduce the higher-order aberrations (especially the spherical aberration) and increase the contrast sensitivity to improve the visual performance.

Incidence and associated factors of posterior capsule opacification in pseudophakic patients at Cipto Mangunkusumo Hospital

Background: Posterior capsule opacification (PCO) is the most common postoperative consequence of cataract surgery which may cause visual acuity reduction, yet the incidence in Indonesia has not been reported. The objectives of this study were to evaluate three years cumulative incidence of PCO and factors associated with PCO formation at Cipto Mangunkusumo Hospital, Jakarta.Methods: This was a retrospective descriptive study on patients with uneventful senile cataract surgery during year 2010. All related data were retrieved from medical records in year 2013, which included patient demographics, type of surgery, intraocular lens (IOL) characteristics (material, optic edge design and diameter). Moreover, time to first PCO diagnosis (month), and best corrected visual acuity (BCVA) pre-operatively, at time PCO was diagnosed and two weeks after Neodymium-doped yttrium aluminum garnet (Nd:YAG) laser were noted (decimal).Results: A total of 578 eyes (485 patients) were involved in this study. Three years cumulative incidence of the PCO was 8.82% (51 eyes). Phacoemulsification surgery was performed in 496 (85.8%) eyes. The median time to PCO diagnosis was 21 months (range 1 to 34 months), mean of BCVA was 0.50 ± 0.26. Age (<65 and >65 years old) was not associated to PCO. Higher incidence of PCO was found in patients using hydrophilic acrylic IOL (10.7%) than in hydrophobic acrylic (6.2%). After Nd:YAG laser was performed, BCVA was improved to 1.00.Conclusion: Three years cumulative incidence of PCO was 8.82% and there was no defined factor related to PCO formation, but higher percentage of PCO occured in patients using hydrophilic acrylic IOL than in hydrophobic acrylic. 

The effect of single-piece hydrophobic acrylic intraocular lenses on the development of posterior capsule opacification

PURPOSE

To evaluate the long-term effect of a single-piece hydrophobic acrylic intraocular lens (IOL), AcrySof SN60AT (Alcon Laboratories, Fort Worth, Texas, USA), on the development of posterior capsule opacification (PCO) 5 years postoperatively.

DESIGN

Prospective, observational, consecutive, case series.

METHODS

setting: Iladevi Cataract and IOL Research Center, Ahmedabad, India.

STUDY POPULATION

Three hundred and ninety eyes with uncomplicated age-related cataract were included. Patients with diabetes mellitus, glaucoma, high myopia, pseudoexfoliation, traumatic cataract, subluxated cataract, previous ocular surgeries, and allergy to dilating drops were excluded. intervention procedures: Digital retroillumination photographic documentation was performed and analyzed for PCO using Evaluation of Posterior Capsule Opacification software. The scores and areas were calculated.

MAIN OUTCOME MEASURES

PCO development and the influence of the anterior capsule cover (total on and part on) on the IOL optic was studied within the capsulorrhexis margin and the central 3.0 mm optic area.

RESULTS

There was a significant increase in PCO up to 3 years. No significant change in PCO was observed between 3 and 5 years within the capsulorrhexis margin and central 3.0 mm optic area. In the total on group, within the capsulorrhexis margin, significantly lower scores and areas were observed when compared with part-on scores and areas.

CONCLUSION

The increase in PCO up to 3 years was significant. Stabilization in PCO was observed between 3 and 5 years with no difference at 5 years. There was a low incidence of PCO in eyes with total anterior capsule cover over the IOL optic.

Cataract Surgery in Eyes with Low Corneal Astigmatism: Implantation of the Acrysof IQ Toric SN6AT2 Intraocular Lens

PURPOSE

To assess the refractive and visual outcomes following cataract surgery and implantation of the AcrySof IQ Toric SN6AT2 intraolcular lens (IOL) (Alcon Laboratories, Inc., Fort Worth, TX, USA) in patients with low corneal astigmatism.

METHODS

This study is a retrospective, consecutive, single surgeon series of 98 eyes of 88 patients (with low preoperative corneal astigmatism) undergoing cataract surgery and implantation of the AcrySof IQ Toric SN6AT2 IOL. Postoperative measurements were obtained 1-month postsurgery. Main outcome measures were monocular distance visual acuity and residual refractive astigmatism.

RESULTS

Mean preoperative corneal astigmatic power vector (APV) was 0.38±0.09 D. Following surgery and implantation of the toric IOL, mean postoperative refractive APV was 0.13±0.10 D. Mean postoperative distance uncorrected visual acuity was 0.08±0.09 logMAR. Postoperative spherical equivalent refraction (SER) resulted in a mean of -0.23±0.22 D, with 96% of eyes falling within 0.50 D of the target SER.

CONCLUSION

The AcrySof IQ Toric SN6AT2 IOL is a safe and effective option for eyes undergoing cataract surgery with low levels of preoperative corneal astigmatism.

Inflammatory response in the anterior chamber after implantation of an angle-supported lens in phakic myopic eyes

Purpose. To evaluate the inflammatory reaction after implantation of an angle-supported foldable acrylic anterior chamber IOL for myopia correction over time. Methods. Adult individuals seeking vision correction with stable myopia >7.0 D were included. Exclusion criteria are anterior chamber depth <2.8 mm, insufficient endothelial cell density, other preexisting ocular conditions, and prior eye surgery. Laser flare photometry and slitlamp examination were performed before and up to 1 year after implantation of an AcrySof Cachet IOL (Alcon Laboratories, Forth Worth, TX, USA). Postoperative treatment comprised antibiotic eye-drops for 5 days and nonsteroidal anti-inflammatory eye-drops (NSAIDs) for 4 weeks. Results. Average laser flare values of 15 consecutive eyes of 15 patients were 8.3 ± 9.7 preoperatively and 19.0 ± 24.2 (1 day), 24.0 ± 27.5 (1 week), 17.6 ± 13.4 (1 month), 14.9 ± 15.4 (3 months), and 10.0 ± 7.0 (1 year) photon counts/ms after implantation, respectively. Slitlamp examination yielded 0 or 1+ cells (SUN classification) in every one eye throughout the follow-up period. Conclusion. Results indicate a low maximum inflammatory response and a quick recovery to a long-term safe level. The use of NSAIDs seems sufficient in routine cases, thus avoiding potential drawbacks of using corticoids.

Intraocular lens-edge design and material factors contributing to posterior-capsulotomy rates: comparing Hoya FY60aD, PY60aD, and AcrySof SN60WF

PURPOSE

To compare neodymium-doped yttrium aluminum garnet laser posterior capsulotomy (LPC) rates between the Hoya FY60AD, Hoya PY60AD, and Alcon AcrySof SN60WF intraocular lenses (IOLs) after routine cataract surgery.

METHODS

In this retrospective comparative study, patients undergoing uncomplicated cataract surgery over a 3-year period were included, and those subsequently undergoing LPC were identified from laser clinic records. LPC rates at 2 years postoperatively were compared between the round-edged Hoya FY60AD, the newer sharp-edged Hoya PY60AD three-piece IOLs, and the one-piece AcrySof SN60WF IOL.

RESULTS

A total of 1,265 cataract operations were included, and 49 eyes (3.9%) underwent LPC within 2 years of surgery. Twenty-eight of 315 eyes (8.9%) implanted with the FY60AD underwent LPC by 2 years, compared to eleven of 254 (4.3%) with the newer sharp square-edged PY60AD and ten of 696 (1.4%) with the one-piece SN60WF (P < 0.05, Chi-squared analyses).

CONCLUSIONS

The newer, sharper-edged Hoya PY60AD IOL has a lower LPC rate than the Hoya FY60AD IOL at 2 years post-cataract surgery. The one-piece AcrySof SN60WF has a lower LPC rate than both the three-piece Hoya IOLs in the same time period postoperatively. Variations in IOL-edge design and material effect may have contributed to the different rates observed.

Etiology of surface light scattering on hydrophobic acrylic intraocular lenses

PURPOSE

To study the etiology of surface light scattering on hydrophobic acrylic intraocular lenses (IOLs).

SETTING

Alcon Research Laboratories, Fort Worth, Texas, USA.

DESIGN

Experimental study.

METHODS

Intraocular lenses were obtained from clinical explantations (n = 5), from human cadavers (n = 8), and from finished-goods inventory (controls). Surface light scattering was measured and imaged with the IOLs in various hydration states (dry, short-term wetted, and long-term hydrated) before and after proteins were quantified and removed. Selected IOL samples were analyzed with x-ray photoelectron spectroscopy, scanning electron microscopy (SEM) with energy-dispersion x-ray analysis, Fourier-transform infrared spectroscopy with attenuated total reflectance, and cryogenic SEM with a focused ion beam.

RESULTS

No inorganic deposits or organic changes were observed on any IOL surface. Under clinically relevant hydrated conditions, surface light-scattering intensity was independent of proteinaceous biofilm state (P≥.11). Instead, the hydration state of the IOLs significantly contributed to the intensity of surface light scattering (P<.001); clinically explanted and cadaver-eye IOLs (but not control IOLs) exhibited minimal scatter when dry, intermediate scatter when wetted, and maximum scatter when hydrated. Subsurface nanoglistenings with diameters less than a micron and with locations up to 120 μm from the surface of the IOLs were characterized by SEM with a focused ion beam and were identified as the source of the hydration-related surface light scattering.

CONCLUSION

Surface light scattering on hydrophobic IOLs was predominantly caused by hydration-related subsurface nanoglistenings within the acrylic IOL material.

Photoreactive elastin-like proteins for use as versatile bioactive materials and surface coatings

Photocrosslinkable, protein-engineered biomaterials combine a rapid, controllable, cytocompatible crosslinking method with a modular design strategy to create a new family of bioactive materials. These materials have a wide range of biomedical applications, including the development of bioactive implant coatings, drug delivery vehicles, and tissue engineering scaffolds. We present the successful functionalization of a bioactive elastin-like protein with photoreactive diazirine moieties. Scalable synthesis is achieved using a standard recombinant protein expression host followed by site-specific modification of lysine residues with a heterobifunctional N-hydroxysuccinimide ester-diazirine crosslinker. The resulting biomaterial is demonstrated to be processable by spin coating, drop casting, soft lithographic patterning, and mold casting to fabricate a variety of two- and three-dimensional photocrosslinked biomaterials with length scales spanning the nanometer to millimeter range. Protein thin films proved to be highly stable over a three-week period. Cell-adhesive functional domains incorporated into the engineered protein materials were shown to remain active post-photo-processing. Human adipose-derived stem cells achieved faster rates of cell adhesion and larger spread areas on thin films of the engineered protein compared to control substrates. The ease and scalability of material production, processing versatility, and modular bioactive functionality make this recombinantly engineered protein an ideal candidate for the development of novel biomaterial coatings, films, and scaffolds.

Reduction of Nd:YAG capsulotomy rates after implantation of a single-piece acrylic hydrophilic intraocular lens with 360° squared optic edge: 24-month results

BACKGROUND AND OBJECTIVE

Posterior capsule opacification remains a significant problem following cataract surgery. The aim of the study was to evaluate the incidence of symptomatic posterior capsule opacification requiring Nd:YAG capsulotomy in patients who underwent cataract extraction and implantation of the Rayner C-flex 570C intraocular lens (IOL) (Rayner Intraocular Lens, Ltd., Sussex, UK).

PATIENTS AND METHODS

A retrospective study of 3,461 eyes that underwent cataract extraction and insertion of the Rayner C-flex IOL from January 2004 to December 2005. The cases that received Nd: YAG capsulotomies were evaluated.

RESULTS

Over a 24-month period, 3,461 Rayner C-flex IOLs were implanted. Nd:YAG capsulotomy was performed in 58 of these cases. The rate of Nd:YAG capsulotomy was 0.6% at 12 months and 1.7% at 24 months. The mean time to Nd:YAG capsulotomy was 9.3 months (range: 1.3 to 22.7 months). The follow-up period was 5.3 to 29.0 months.

CONCLUSION

The incidence of symptomatic posterior capsule opacification with the Rayner C-flex IOL is low.

Ablation of lens epithelial cells with a laser photolysis system: histopathology, ultrastructure, and immunochemistry

PURPOSE

To evaluate efficacy of a neodymium:YAG (Nd:YAG) laser photolysis system in removing lens epithelial cells (LECs) and characterize the effect of the laser on laminin and fibronectin involved in LEC adhesion and migration.

METHODS

Cadaver eyes were evaluated using the Miyake technique. The lenses were removed with phacoemulsification. The modified Nd:YAG laser was used to clean the LECs from the capsule. Only the fornix was cleaned in some eyes and the anterior subcapsular area in other eyes. Some areas were not treated and acted as controls. Standard irrigation/aspiration (I/A) removal of LECs was performed in additional eyes. The eyes were analyzed using light microscopy and immunohistochemical staining.

RESULTS

Histopathologic evaluation showed that the laser removed the LECs from the anterior lens capsule and from the fornix. Immunohistochemical staining showed fibronectin and laminin staining in the untreated areas that was absent in the treated areas. Standard I/A removal of the LECs showed absence of cells but persistent laminin and fibronectin. Electron microscopy showed epithelial cells in untreated areas with an absence of the LECs and debris in treated areas.

CONCLUSIONS

The laser photolysis system removed LECs from the anterior lens capsule and capsule fornix. Along with the cells, laminin, fibronectin, and cell debris remained in the untreated areas but were removed by the treatment. This treatment may be useful in preventing posterior capsule opacification.

Acrylic toric intraocular lens implantation: a single center experience concerning clinical outcomes and postoperative rotation

Purpose:

To present clinical results of toric intraocular lens (IOL) implantation for preexisting astigmatism correction and determine the time of any postoperative rotation.

Patients and methods:

Twenty-nine eyes of 19 patients underwent uncomplicated phacoemulsification and were implanted with an Acrysof ^© toric IOL. Uncorrected visual acuity, residual astigmatism, and postoperative rotation of the IOL were estimated one and six months after the operation.

Results:

Uncorrected visual acuity was ≥0.5 in 26 of 29 eyes (89.7%) and ≥0.8 in 19 of 29 patients (65.5%). The mean toric IOL axis rotation was 2.2 ± 1.5° (range 0.6–7.8°) one month postoperation and 2.7 ± 1.5° (range 0.9–8.4°) six months postoperation.

Conclusion:

Implantation of one-piece hydrophobic acrylic toric IOLs appears to have acceptable stability, which encourages visual outcome and emerges as an attractive alternative for correction of refractive astigmatism.

Optical coherence tomography evaluation of posterior capsule opacification related to intraocular lens design

PURPOSE

To evaluate posterior capsule opacification (PCO) and the impact of different intraocular lens (IOL) models on PCO characteristics using optical coherence tomography (OCT).

METHODS

Eighty-three eyes with PCO (fibrosis or pearl type) and 32 pseudophakic eyes without PCO were included. Horizontal 3.0 mm long OCT scans of the posterior capsule were obtained. Measurements and means of the peak posterior capsule intensity (PCI) and posterior capsule thickness (PCT) (distance between 2 spikes at posterior capsule) at 3 scan points were recorded. The PCI and PCT were compared with best corrected visual acuity (BCVA) and IOL data.

RESULTS

The PCT was high for IOLs with a rounded edge (P = .001) and with poly(methyl methacrylate) (PMMA) IOLs (P<.001). If the IOL optic was concave-convex, the PCT was higher than if the optic was biconvex (P = .001). The PCT of hydrophilic acrylic IOLs was higher than of hydrophobic acrylic IOLs (P = .04). Multivariate analysis of PCT showed that PMMA was the only factor statistically associated with PCT (P = .02). The worse logMAR BCVA correlated significantly with a higher PCT value (P<.001) but not with PCI (P = .42). An IOL size of 12.5 mm was related to fibrosis-type PCO (odds ratio, 3.14; P = .04).

CONCLUSIONS

The PCT was most affected by IOL characteristics. Poly(methyl methacrylate) IOLs and IOLs with rounded edges were associated with higher PCT. Hydrophilic acrylic IOLs were associated with greater PCT than hydrophobic IOLs. Posterior capsule thickness was a factor in decreased BCVA.

Delayed accumulation of lens material behind the foldable intraocular lens

Foldable acrylic intraocular lenses (IOLs) are known to reduce posterior capsule opacification by preventing migration of lens epithelial cells with its square edge design and its property of tackiness. Studies have reported a mean adhesiveness to posterior capsule more than three times higher for certain acrylic foldable IOLs than polymethyl methacrylate IOLs. The authors would like to report two cases where the force of tackiness was compensated, thereby presenting with delayed accumulation of lens material in the capsular bags behind the IOL with temporary loss of vision.

The Relationship between the Adhesion Characteristics of Acrylic Intraocular Lens Materials and Posterior Capsule Opacification

PURPOSE

To investigate the relationship between the adhesion characteristics of similarly designed hydrophobic acrylic intraocular lenses (IOLs) and posterior capsule opacification (PCO).

METHODS

Three similarly shaped hydrophobic acrylic IOLs with a sharp-edged optic were used. Adhesive force of IOLs was measured with a tackiness tester. Human lens epithelial cells (LECs) were grown on each IOL for 48 h. LECs were then stained with crystal violet, which served as an index of the amount of cells attached to IOLs. Cellular migration and proliferation assays were performed using chamber inserts containing a collagen membrane. After 96 h of incubation, the collagen membranes were stained with hematoxylin and eosin for analysis. Three similarly shaped IOLs were implanted in rabbits. The eyes were enucleated 3 weeks later and analyzed for PCO area.

RESULTS

Hydrophobic acrylic IOLs were classified into three groups: A (less adhesive), B (moderately) and C (highly). The migration area of LECs on the collagen membrane was 5.65 +/- 4.5% in group A, 2.83 +/- 2.1% in group B, and 1.41 +/- 1.5% in group C, with a significant difference between groups A and C (p < 0.05). The mean percentage area of PCO in the rabbit eye was 19.4 +/- 16.7% in group A, 17.5 +/- 8.5% in group B, and 5.5 +/- 3.8% in group C, with a significant difference between groups A and C (p < 0.05).

CONCLUSION

Adhesive force of hydrophobic acrylic IOLs may play an important role in preventing PCO. Among the similarly shaped hydrophobic acrylic IOLs, IOLs of highly adhesive material inhibited LEC migration and PCO more than IOLs of less adhesive material.

Biomatériaux dans la chirurgie du cristallin

The first lens implantations were performed by Sir Harold Ridley in 1949 using rigid poly-methyl-methacrylate (PMMA) lenses. This biomaterial was used exclusively for more than 30 years. In the early 1970s, Charles Kelman introduced phacoemulsification, reducing the incision size and beginning biomaterial diversification, including foldable materials. More than 50 years after the introduction of PMMA, the range of biomaterials used for intraocular lenses remains extremely limited. Among the materials tested, acrylic polymers and silicon elastomeres are the only remaining materials used for optics. In vivo tolerance is no longer the sole criterion in choosing biomaterials: clinical performance now plays a major role, including injection abilities, optical qualities, and long-term postoperative intraocular behavior. Together with lens design, the analysis of the physical and chemical characteristics of biomaterials will contribute to the choice of the best intraocular lens.

Effect of intraocular lens edge profile on posterior capsule opacification after extracapsular cataract surgery in a developing country

PURPOSE

To determine whether square-edged polymethyl methacrylate (PMMA) intraocular lenses (IOLs) reduce posterior capsule opacification (PCO) in the context of extracapsular cataract surgery in a developing country.

SETTING

A rural hospital in India.

METHODS

This was a prospective randomized double-masked fellow-eye controlled study. Over a 4-month period, 118 patients with normal eyes apart from age-related cataract were randomized to receive a square-edged or round-edged PMMA IOL in the first eye. The IOLs were identical apart from the edge profile. The fellow-eye had implantation of the alternative IOL within 1 month. Retroillumination images of the posterior capsule were taken using a dedicated camera system and analyzed to quantify the PCO area using POCO software 1 and 2 years postoperatively and the PCO area and severity using POCOman semiqualitative software at 2 years. Visual acuity was measured using a Gujarati logMAR chart.

RESULTS

One hundred fifteen patients were available for examination at 1 year and 107 at 2 years. With POCO software, the PCO area was reduced in the square-edged IOL group at 1 year (median 30% versus 20%, P=.001) and at 2 years (median 45% versus 35%, P=.006). With POCOman, the PCO area and severity were reduced in the square-edged group at 2 years (median 41.5% versus 33.2%, P=.019 and 0.59 versus 0.46, P=.037, respectively). There was no significant difference in visual acuity between the 2 groups at 1 or 2 years.

CONCLUSIONS

Sophisticated image analysis techniques can be used in developing countries to quantify PCO. Using extracapsular surgery, square-edged PMMA IOLs reduced the PCO area and severity compared with an identical round-edged IOL; however, the differences were not as marked as those reported with phacoemulsification. This may be due to the difficulty of performing a capsulorhexis that lies on the IOL surface in this situation. Nevertheless, square-edged IOLs offer a potential benefit for extracapsular surgery in the developing world.

Posterior capsule opacification after extra capsular cataract extraction in Indian rural population: foldable acrylic vs poly (methyl-methacrylate) intraocular lenses a randomized clinical trial

PURPOSE

To compare the performance of single-piece acrylic vspoly (methylmethacrylate) intraocular lenses (IOL) on the development of posterior capsule opacification (PCO) after conventional extra capsular cataract extraction (ECCE).

MATERIALS AND METHODS

One hundred and eighty-two eyes of 91 patients with bilateral senile cataract undergoing ECCE were prospectively randomized to receive a single-piece Alcon AcrySof SA60AT IOL or a single-piece EPOCH polymethylmethacrylate IOL in the first eye to have surgery. At 1, 6 and 12 months post-operative follow-up, digital retro illumination images of the posterior capsule were taken for PCO assessment semi-objectively using PCO (POCO automated analysis software) system. Relationship of anterior capsule contact (total off and partial cover) on optic for PCO was analyzed.

RESULTS

The AcrySof IOL was associated with less PCO than EPOCH lens at 6 months (10.01+/-8.75% vs 32.26+/-27.44%; P<0.001) and 1-year (11.65+/-10.55% vs 38.38+/-29.62%; P<0.001) follow-up. The EPOCH IOL showed a remarkably significant difference on development of PCO with anterior capsule overlap on IOL optic (total off and part on) 1 year (P<0.039), whereas no such difference was observed with the AcrySof IOL (P=0.197).

CONCLUSION

The AcrySof IOL led to significantly less PCO than the EPOCH IOL post-operatively after extracapsular cataract extraction.

Influence of three-piece and single-piece designs of two sharp-edge optic hydrophobic acrylic intraocular lenses on the prevention of posterior capsule opacification: a prospective, randomised, long-term clinical trial

BACKGROUND

Posterior capsule opacification (PCO) is still a major long-term complication of modern cataract surgery. We evaluated the impact of sharp-edged intraocular lenses (IOLs) with different haptic designs made from the same hydrophobic acrylic material on posterior and anterior lens capsule opacification.

SETTING

Eye clinic of Kaunas University of Medicine, Lithuania. Prospective randomised clinical study.

METHODS

Seventy-four eyes of 74 patients scheduled for cataract surgery were included in a prospective randomised clinical study. Thirty-seven eyes of 37 patients received a three-piece acrylic hydrophobic (AcrySof, MA3OBA, Alcon) IOL; and thirty-seven eyes of 37 patients received a one-piece acrylic hydrophobic (AcrySof, SA3OAL, Alcon) IOL. Visual acuity, anterior capsule opacification (ACO), capsular folds, capsulorrhexis/optic overlapping and posterior capsule opacification (PCO) were evaluated. ACO was assessed subjectively. PCO values in the entire IOL optic area and in the central 3 mm optic zone were assessed using a photographic image-analysis system (EPCO2000). Follow-ups were performed postoperatively at 1 day, 6 months, 1 year and 2 years.

RESULTS

There were no significant differences in best corrected visual acuity, grade of ACO and capsulorrhexis/optic overlapping between IOL types during the follow-up period. Patients in the one-piece acrylic hydrophobic IOL group more frequently presented with capsular folds behind the IOL optic area than those in the three-piece IOL group. In the three-piece acrylic hydrophobic IOL group, PCO values (mean (SD)) of the entire IOL optic area were significantly lower six months postoperative (three-piece: 0.002 (0.009); one-piece: 0.007 (0.017); p=0.04), one year postoperative (three-piece: 0.004 (0.016); one-piece: 0.026 (0.041); p=0.001) as well as one year postoperative in the central 3 mm optic zone (three-piece: 0.000 (0.0002); one-piece: 0.019 (0.049); p=0.001). However, two years postoperative, the PCO values of the groups did not show significant differences (entire IOL optic area: three-piece, 0.136 (0.223); one-piece, 0.154 (0.190); p=0.18; central zone: three-piece, 0.023 (0.065); one-piece: 0.020 (0.039); p=0.44).

CONCLUSION

The 2 year follow-up after cataract surgery showed no significant difference in ACO and PCO development between three-piece and one-piece acrylic hydrophobic intraocular lenses.

Removal of lens epithelial cells to delay anterior capsule–intraocular lens adherence

To test the theory that removing lens epithelial cells at the time of cataract extraction with intraocular lens (IOL) implantation or refractive lens exchange might decrease the rate at which the anterior capsule becomes adherent to the lens optic postoperatively, we performed the technique in approximately 200 eyes that were considered likely to require postoperative IOL exchange. In 4 eyes that had an IOL exchange procedure 6 to 12 weeks after the primary procedure, the anterior capsule was nonadherent or weakly adherent to the lens optic.

Effect of cortical cleaving hydrodissection on posterior capsule opacification in age-related nuclear cataract

PURPOSE

To evaluate the effect of multiquadrant cortical cleaving hydrodissection on the development of posterior capsule opacification (PCO) after phacoemulsification.

SETTING

Iladevi Cataract and IOL Research Center, Ahmedabad, India.

METHODS

A prospective randomized triple blind clinical trial was conducted in 86 eyes (86 patients) having phacoemulsification. Eyes were assigned randomly to Group 1, multiquadrant cortical cleaving hydrodissection and hydrodelineation (n = 48 eyes), or Group 2, no multiquadrant cortical cleaving hydrodissection, only hydrodelineation (n = 38 eyes). Age-related nuclear sclerosis (grading system of 1 to 5) and age greater than 50 years were included. Diabetes mellitus and associated eye diseases were excluded. Standard phacoemulsification with implantation of an AcrySof MA30BA intraocular lens (IOL) was done in both groups. High-resolution digital retroillumination images of the posterior capsule were analyzed at 4 years using POCOman software. Seven patients dropped out (8.1%). Outcome measures were incidence and percentage area of PCO. Test of proportions, independent sample t test, and 95% confidence intervals (CIs) were noted.

RESULTS

In Groups 1 and 2, the mean age was 58 years +/- 4 (SD) and 57 +/- 5 years, respectively (P = .702; 95% CI, 1.90-2.81); mean follow-up was 48.4 +/- 2.5 months and 49.3 +/- 1.9 months, respectively (P = .687; 95% CI, 1.186-0.7856); incidence of PCO was 11 of 44 (25%) and 12 of 35 (34.3%), respectively (P = .317; 95% CI, 0.359-0.0889); percentage area of PCO was 14.3% and 25.6%, respectively (P = .006; 95% CI, -19.19 to -3.44). One of 44 eyes (2.27%) and 2 of 35 eyes (5.7%) in the groups, respectively, had a neodymium:YAG capsulotomy.

CONCLUSION

Although no difference was noted in the incidence of PCO, in eyes that had PCO, the percentage of the area of the central posterior capsule involved by PCO was significantly lower in eyes that had multiquadrant cortical cleaving hydrodissection than in those that did not.

Comparison of posterior capsule opacification between fellow eyes with two types of acrylic intraocular lens

PURPOSE

To compare the degree of posterior capsule opacification (PCO) and visual function between fellow eyes that received two different types of hydrophobic acrylic intraocular lenses (IOLs).

METHODS

Forty-five patients underwent bilateral phacoemulsification and implantation of an Alcon AcrySof IOL (MA60AC) in one eye and an AMO Sensar IOL (AR40e) in the fellow eye. The PCO density value was measured using the Scheimpflug videophotography system at 1, 6, 12, and 24 months after surgery. The incidence of eyes that required a neodymium:YAG (Nd:YAG) laser capsulotomy, visual acuity, and contrast sensitivity with and without a glare source were also examined.

RESULTS

The mean PCO value did not show a significant increase in either the AcrySof MA60AC or Sensar AR40e IOL groups, and was similar between the two groups throughout the 24-month follow-up period. The incidence of Nd:YAG laser capsulotomy was also the same between the groups. No significant difference was found in mean visual acuity between the two IOL groups during the follow-up, and there was no significant difference in photopic or mesopic contrast visual acuity with and without a glare source at 1 and 24 months after surgery.

CONCLUSION

The degree of PCO in eyes with an AcrySof IOL are almost the same as that in eyes with a Sensar IOL, with the results that visual acuity and contrast sensitivity with and without glare are similar.

Suppression of fibroblast and bacterial adhesion by MPC coating on acrylic intraocular lenses

PURPOSE

To investigate cell adhesion to intraocular lens (IOL) surfaces having different properties using bacteria and fibroblasts.

SETTING

Department of Ophthalmology, Tokyo Medical University Hospital, Tokyo, Japan.

METHODS

The polished acrylic IOLs VA60-BB and VA-60-CB (Hoya) were used with no coating or after coating with poly(2-methacryloyloxyethyl phosphocholine-co-n-butyl-methacrylate) (MPC) or methane gas plasma. Each IOL was placed in a culture of Staphylococcus aureus (5 x 10(7) colony forming units [CFU]/mL) or fibroblasts (SUSM-1, 1 x 10(4) cells/mL), and the cells adhering to the IOL surface were counted after the culture. Fibroblast adhesiveness was evaluated by centrifuging post-culture IOLs in test tubes at up to 15,000 rpm and looking at the ICAM-1 mRNA expression in the adhering fibroblasts using real-time polymerase chain reaction.

RESULTS

After 1 minute in the bacterial culture, the mean adhering bacteria count was 0.7 x 10(6) CFU in the MPC-coated IOL group and about 2.0 x 106 CFU in the noncoated IOL group (P = 0.03) and the plasma-coated IOL group (P = 0.02). After 96 hours in the fibroblast culture, the adhering fibroblast count was 2.2/mm2 in the MPC-coated IOL group, significantly lower (P = 0.009) than 57.6/mm2 in the noncoated IOL group and 125.8/mm2 in the plasma-coated IOL group. Cell adhesion and ICAM-1 mRNA expression were weak on the MPC-coated IOL, intermediate on the noncoated IOL, and relatively strong on the plasma-coated IOL.

CONCLUSION

The MPC-coated IOL surface inhibited bacterial and fibroblast adhesion, which is an initial stage of cell proliferation and expression, suggesting that MPC coating may provide an effective means of reducing the risk for endophthalimitis in IOL implantation.

Tissue reaction to hydrophilic intraocular lenses

The implant of intraocular lenses (IOLs) following cataract surgery induces a foreign body reaction to the IOL and a lens epithelial cell reaction. The host response to the IOL is mainly influenced by biomaterial properties. With the increasing use of phacoemulsification and small incision cataract surgery, there is growing interest in the use of foldable IOLs made of different materials. Hydrophilic acrylic IOLs include a wide group of foldable biomaterials different in terms of water content. These lenses have been reported to show a good biocompatibility after implantation. Nevertheless, tissue reaction to the implant of hydrophilic lenses is variable and not directly related to the hydrophilicity of their surface. A different adsorption of proteins on the IOL optic surface might be responsible for the different cellular reaction and lens epithelial cell response. Other properties besides hydrophilicity should be taken into account to classify IOL biomaterials.

Effect of hydrodissection alone and hydrodissection combined with rotation on lens epithelial cells

PURPOSE

To evaluate the impact of corticocleaving hydrodissection alone and hydrodissection combined with rotation on lens epithelial cells (LECs) and residual cortical fibers (RCFs).

SETTING

Iladevi Cataract and IOL Research Center, Ahmedabad, India.

METHODS

An experimental laboratory study of 20 fresh human cadaver eyes (10 pairs) was conducted. A single eye from each pair was assigned to the control group, in which no hydrodissection and no rotation were performed (control). The other eye was randomized to corticocleaving hydrodissection alone (Group 1) or corticocleaving hydrodissection with rotation (Group 2). Cataract extraction was standardized. Capsule polishing was omitted. Area of LEC loss (%) in the preequatorial zone (PZ) and equatorial zone (EZ) was calculated as: [Area of capsule without cells/Total area of capsule] x 100. Area of presence of RCFs (%) was calculated as: [Circumference of EZ of capsule with RCF/Total circumference of EZ of the capsule] x 100. The Mann-Whitney U and the Wilcoxon signed rank tests were applied.

RESULTS

In the control group, area of cell loss (%) was 3.9 +/- 3.2 in the PZ and 2.7 +/- 0.8 in the EZ; presence of RCFs (%) was 83.8 +/- 1.7. Area of LEC loss (%) in Groups 1 and 2 was 24.8 +/- 4.5 and 42.6 +/- 5.4 (P = .008) in the PZ and 22.4 +/- 2.1 and 54 +/- 2.5 (P = .008) in the EZ, respectively. Area of presence of RCFs (%) in Groups 1 and 2 was 34.2 +/- 3.7 and 23.7 +/- 3.7 (P = .008), respectively.

CONCLUSION

Corticocleaving hydrodissection combined with rotation removed significant quantities of LECs and RCFs.

Lens epithelial cell ongrowth: Comparison of 6 types of hydrophilic intraocular lens models

PURPOSE

To compare the ongrowth of lens epithelial cells (LECs) on the anterior surface of 6 different hydrophilic intraocular lenses (IOLs).

SETTING

Medical University of Vienna, Department of Ophthalmology and Optometry, Vienna, Austria.

METHODS

Six models of hydrophilic IOLs were compared in this prospective study: Visionflex A-100 (Distra Softcryl), Rayner Centerflex 570H (Rayner), Collamer CC4204BF-IOL (Staar), Injectacryl F 3000 (Distra), Hydroview H60M (Bausch & Lomb), and MemoryLens (ORC). Postoperative biomicroscopic examinations were performed 1, 3, 7, 30, 90, 180, and 365 days after surgery. Lens epithelial cells in each quadrant of the anterior capsule-free lens surface were graded. The product with the highest density and the number of quadrants with this density were used to measure LEC ongrowth.

RESULTS

The Hydroview and Visionflex IOLs showed significantly more LECs than the other IOLs starting on day 7 after surgery (P < .028). There was a statistically significant difference in LEC ongrowth on the Memory IOL compared with all other IOLs from day 30 onward (P < .001). The Rayner, Collamer and Injectacryl IOLs had the fewest LECs on the anterior surface compared with all other IOLs from day 7 until the final examination.

CONCLUSIONS

The findings show that LEC ongrowth on the IOL surface is material dependent. The findings suggest that the material of the recently developed hydrophilic IOLs induces less LEC ongrowth than older models.