Lens epithelial cell reaction after implantation of different intraocular lens materials

Relationship between anterior capsule opening and direction of intraocular lens decentration

PURPOSE

To compare intraocular lens (IOL) decentration between patients in whom the continuous curvilinear capsulorhexis (CCC) completely covers the IOL optic and those in whom it incompletely covers the IOL optic and determine how an incompletely covered CCC affects the IOL position.

SETTING

Tertiary hospital in Japan.

DESIGN

Single-center retrospective study.

METHODS

57 eyes of 57 patients (mean age 70.8 ± 6.2 years) that underwent phacoemulsification and IOL (SN60WF) implantation in the bag between April 2010 and April 2015 were included in this study. The patients were classified based on whether the CCC completely (CC group) or incompletely (NCC group) covered the IOL optic using an anterior eye segment analysis system (EAS-1000). The IOL decentration of the groups was analyzed using EAS-1000 at 1 week, 1 month, 3 months, and 6 months postoperatively and compared. The relationship between the NCC location and the IOL direction at 3 months postoperatively was analyzed.

RESULTS

The NCC group (25 eyes) had a significantly higher amount of IOL decentration than the CC group (32 eyes) at 1 week, 1 month, 3 months, and 6 months postoperatively ( P < .05). There was a correlation between the direction of IOL decentration and the NCC location, and IOL decentration in the NCC group occurred in the opposite direction to the NCC area.

CONCLUSIONS

An anterior capsule opening that completely covers the IOL optic is important to control IOL decentration.

Effects of intraocular lens anterior edge design on anterior capsule morphology changes following femtosecond laser-assisted capsulotomy

PURPOSE

To compare morphological changes in the anterior capsule of two intraocular lenses (IOLs) with different anterior edge designs 6 months after femtosecond laser-assisted capsulotomy surgery (FLACs).

METHODS

This study included 168 eyes from168 patients undergoing FLACs. Group A included 74 eyes from 74 patients who had an Acrysof IQ Restor SN6AD3 IOL implantation with a flat anterior edge and Group B included 94 eyes of 94 patients with a TECNIS Multifocal ZMB00 IOL implantation and a "peak-like" anterior edge. All patients were followed up for 6 months. We assessed anterior capsule morphological changes including variation of anterior opening diameters and lens epithelial cell (LEC) proliferation in four directions, variation of anterior opening area, and the level of anterior capsule opacification (ACO).

RESULTS

Variation of anterior opening diameters in 4 directions were significantly lower in Group B (P < 0.05). Obvious shrinkage ratio of anterior opening diameters and contraction of anterior opening area (P < 0.05) appeared in Group A. LEC proliferation was along the "peak" in Group B, while it spread to the edge of anterior capsule in Group A. ACO grades 6 months after operation in Groups A and B were as follows: grade I in 28.38% and 82.98% of eyes, grade II in 51.35% and 17.02% of eyes, and grade III in 20.27% and 0% of eyes, respectively.

CONCLUSIONS

These findings suggest that a "peak-like" IOL anterior edge design played an important role in maintaining the morphology of anterior capsule in the early postoperative stage.

Comparison of decentration, tilt and lenticular astigmatism of ıntraocular lens between sutured and sutureless scleral fixation techniques

PURPOSE

To evaluate at six months the intraocular lens (IOL) decentration, tilt and lenticular astigmatism between foldable sutured and sutureless scleral fixation IOLs compared to conventional phacoemulsification surgery.

METHODS

We retrospectively reviewed records for 22 eyes with sutureless scleral fixation, 16 eyes with sutured scleral fixation and 23 eyes with conventional phacoemulsification. IOL decentration and angle of IOL tilt were compared on Scheimpflug images 6 months after surgery. Lenticular astigmatism is described as the difference between refractive and net corneal astigmatism.

RESULTS

The angle of tilt in both meridians was significantly lower in the sutureless group than in the sutured group (P=0.008 horizontally and P=0.002 vertically). IOL decentration did not show a significant difference between the three groups in either horizontal or vertical meridians (P˃0.05). Lenticular astigmatism was significantly lower in the sutureless and control groups than in the sutured group (P=0.003 and P<0.001).

CONCLUSION

In addition to being relatively quick and easy to perform, the sutureless scleral fixation technique showed superior results in terms of IOL tilt and lenticular astigmatism at the six-month follow-up compared to the sutured technique.

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.

Misdiagnosed opacification of a hydrophobic acrylic intraocular lens

A 75-year-old woman was referred for decreased visual acuity resulting from "opacification of the IOL" in the immediate period after uneventful bilateral cataract surgery with single-piece AcrySof IQ intraocular lens (IOL) implantation. A neodymium:YAG laser capsulotomy had been performed in both eyes to treat the complication. Anterior segment optical coherence tomography performed at presentation showed an opaque membrane enveloping the IOL. The membrane was peeled from the anterior IOL surface, and all adherences between the IOL and capsular bag were freed. One year later, the eyes remained stable; the uncorrected distance visual acuity was 20/20, the IOL was clear, and there was no evidence of recurrence of the membrane. Appropriate imaging for the diagnosis and surgical peeling with freeing of the adhesions between the IOL and the capsular bag were essential to the success in this case.

Circular YAG laser anterior capsulotomy for anterior capsule contraction syndrome

PURPOSE

To evaluate circular neodymium: YAG laser incision in cases of anterior capsular contraction syndrome (ACCS) by comparing it to radial Neodymium: YAG laser incision as for efficacy and safety.

SETTINGS

Ophthalmology Department, Benha University Hospitals.

METHODS

The study was done on 74 eyes of 66 patients with symptomatic ACCS. Eyes were randomly allocated to one of the two groups. Group I were treated by circular YAG laser anterior capsulotomy. Group II were treated by radial YAG laser anterior capsulotomy. All cases passed a full ophthalmic examination before laser capsulotomy, 1 week, 1 month, 6 months and 12 months after laser.

RESULTS

BCVA at the 1st week and the 1st month after the capsulotomy did not show any significant difference between the two groups; however at the 3rd and 6th months, the circular group showed better visual acuity than the radial group (p 0.001 and < 0.001, respectively). All post-YAG UCVA and BCVA were significantly higher than pre-YAG UCVA and BCVA in both groups. IOL decentration occurred in two cases in radial group. Circular group had significantly higher percentage of contraction relief (94.4%) than the radial group (66.7%) with p value 0.003.

CONCLUSION

Circular Nd:YAG anterior capsulotomy is more effective and safe than radial capsulotomy in 1-year follow-up.

Blue-light filtering intraocular lenses (IOLs) for protecting macular health

BACKGROUND

An intraocular lens (IOL) is a synthetic lens that is surgically implanted within the eye following removal of the crystalline lens, during cataract surgery. While all modern IOLs attenuate the transmission of ultra-violet (UV) light, some IOLs, called blue-blocking or blue-light filtering IOLs, also reduce short-wavelength visible light transmission. The rationale for blue-light filtering IOLs derives primarily from cell culture and animal studies, which suggest that short-wavelength visible light can induce retinal photoxicity. Blue-light filtering IOLs have been suggested to impart retinal protection and potentially prevent the development and progression of age-related macular degeneration (AMD). We sought to investigate the evidence relating to these suggested benefits of blue-light filtering IOLs, and to consider any potential adverse effects.

OBJECTIVES

To assess the effects of blue-light filtering IOLs compared with non-blue-light filtering IOLs, with respect to providing protection to macular health and function.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 9); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 25 October 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), involving adult participants undergoing cataract extraction, where a blue-light filtering IOL was compared with an equivalent non-blue-light filtering IOL.

DATA COLLECTION AND ANALYSIS

The prespecified primary outcome was the change in distance best-corrected visual acuity (BCVA), as a continuous outcome, between baseline and 12 months of follow-up. Prespecified secondary outcomes included postoperative contrast sensitivity, colour discrimination, macular pigment optical density (MPOD), proportion of eyes with a pathological finding at the macula (including, but not limited to the development or progression of AMD, or both), daytime alertness, reaction time and patient satisfaction. We evaluated findings related to ocular and systemic adverse effects.Two review authors independently screened abstracts and full-text articles, extracted data from eligible RCTs and judged the risk of bias using the Cochrane tool. We reached a consensus on any disagreements by discussion. Where appropriate, we pooled data relating to outcomes and used random-effects or fixed-effect models for the meta-analyses. We summarised the overall certainty of the evidence using GRADE.

MAIN RESULTS

We included 51 RCTs from 17 different countries, although most studies either did not report relevant outcomes, or provided data in a format that could not be extracted. Together, the included studies considered the outcomes of IOL implantation in over 5000 eyes. The number of participants ranged from 13 to 300, and the follow-up period ranged from one month to five years. Only two of the studies had a trial registry record and no studies referred to a published protocol. We did not judge any of the studies to have a low risk of bias in all seven domains. We judged approximately two-thirds of the studies to have a high risk of bias in domains relating to 'blinding of participants and personnel' (performance bias) and 'blinding of outcome assessment' (detection bias).We found with moderate certainty, that distance BCVA with a blue-light filtering IOL, at six to 18 months postoperatively, and measured in logMAR, was not clearly different to distance BCVA with a non-blue-light filtering IOL (mean difference (MD) -0.01 logMAR, 95% confidence interval (CI) -0.03 to 0.02, P = 0.48; 2 studies, 131 eyes).There was very low-certainty evidence relating to any potential inter-intervention difference for the proportion of eyes that developed late-stage AMD at three years of follow-up, or any stage of AMD at one year of follow-up, as data derived from one trial and two trials respectively, and there were no events in either IOL intervention group, for either outcome. There was very low-certainty evidence for the outcome for the proportion of participants who lost 15 or more letters of distance BCVA at six months of follow-up; two trials that considered a total of 63 eyes reported no events, in either IOL intervention group.There were no relevant, combinable data available for outcomes relating to the effect on contrast sensitivity at six months, the proportion of eyes with a measurable loss of colour discrimination from baseline at six months, or the proportion of participants with adverse events with a probable causal link with the study interventions after six months.We were unable to draw reliable conclusions on the relative equivalence or superiority of blue-light filtering IOLs versus non-blue-light filtering IOLs in relation to longer-term effects on macular health. We were also not able to determine with any certainty whether blue-light filtering IOLs have any significant effects on MPOD, contrast sensitivity, colour discrimination, daytime alertness, reaction time or patient satisfaction, relative to non-blue-light filtering IOLs.

AUTHORS' CONCLUSIONS

This systematic review shows with moderate certainty that there is no clinically meaningful difference in short-term BCVA with the two types of IOLs. Further, based upon available data, these findings suggest that there is no clinically meaningful difference in short-term contrast sensitivity with the two interventions, although there was a low level of certainty for this outcome due to a small number of included studies and their inherent risk of bias. Based upon current, best-available research evidence, it is unclear whether blue-light filtering IOLs preserve macular health or alter risks associated with the development and progression of AMD, or both. Further research is required to fully understand the effects of blue-light filtering IOLs for providing protection to macular health and function.

Effect of number and position of intraocular lens haptics on anterior capsule contraction: a randomized, prospective trial

BACKGROUND

The present study aimed to evaluate the degree of anterior capsule contraction (capsulorhexis contraction) with three different single-piece, hydrophilic acrylic intraocular lenses (IOLs).

METHODS

Patients were prospectively randomized to be implanted with one of three types of IOLs during cataract surgery: the Ophtec Precizon (IOL A), the Lucid Korea Microflex (IOL B), and the Carl Zeiss Asphina (IOL C). One week, 2 weeks, and 6 months after surgery, the area of the anterior capsule opening was measured using digital retro-illumination images after dilation of the pupil. The data were then evaluated using POCOman software.

RESULTS

The study included 236 eyes of 202 patients. The area of the anterior capsule opening reduced by 3.53 ± 3.31 mm (17.06% ± 15.99%) between 1 week and 2 months post-operatively in the IOL A group, by 0.62 ± 1.32 mm (2.87% ± 6.03%) in the IOL B group, and by 1.09 ± 1.53 mm (4.72% ± 6.10%) in the IOL C group. The IOL B group showed minimal anterior capsule contraction 2 months after surgery (p < 0.001).

CONCLUSIONS

IOLs with a four-plate haptic design (IOL B) showed more anterior capsular stability than those with a two-loop plate haptic (IOL A) or two-plate haptic (IOL C) design. The number and position of haptics in a capsular bag may affect anterior capsule contraction. We assume that supporting the zonules evenly may play a role in anterior capsular stability.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN76566080 , Retrospectively registered (Date of registration: 14 Feb 2018).

Clinical efficacy of implantation of toric intraocular lenses with different incision positions: a comparative study of steep-axis incision and non-steep-axis incision

Background

To compare the clinical outcomes after implantation of AcrySof Toric IOLs with different clear corneal incisions.

Methods

Sixty cataract patients with regular corneal astigmatism who underwent phacoemulsification combined with implantation of an AcrySof Toric IOL were enrolled. They were divided into two groups according to the position of the clear corneal incision: steep-axis and non-steep-axis. Main outcome measurements included visual acuity, residual astigmatism and changes of corneal astigmatism 3 months postoperatively. Deviation of IOL axis according to the re-calculation using the actual surgically induced astigmatism (SIA) and visual function 3 months after surgery were also evaluated.

Results

The corneal astigmatism decreased significantly in steep-axis group 3 months postoperatively (P < 0.05). Besides, more patients in non-steep-axis group were with irregular corneal astigmatism after the surgery (43.33% vs 10%, P = 0.004). The deviation of IOL axis according to the re-calculation using the actual SIA was significantly larger in non-steep-axis group than that of steep-axis group (P < 0.001). Moreover, the postoperative visual function was better in eyes of steep-axis group in various measurements, including point spread function, modulation transfer function and high-order aberrations.

Conclusion

Steep-axis clear corneal incision could reduce the cylinder power of toric IOL and lower the chance of postoperative irregular astigmatism, which may consequently improve the postoperative visual quality.

Factors influencing 1-year rotational stability of AcrySof Toric intraocular lenses

PURPOSE

To investigate the 1-year rotational stability of AcrySof Toric intraocular lenses (IOLs) and factors influencing their stability.

METHODS

This retrospective study enrolled 75 patients who underwent phacoemulsification, and were implanted with an AcrySof Toric IOL for 1 year. Their preoperative clinical data were reviewed. The 1-year clinical outcomes included uncorrected visual acuity, best-corrected visual acuity and residual astigmatism. Rotation of the IOL and the grade of anterior capsular opacification (ACO; graded from 0=none to 3=severe) were evaluated after mydriasis.

RESULTS

Of the 75 eyes analysed, 29.33% had high myopia. Residual astigmatism at 1 year (-0.76±0.47 dioptre(D)) was significantly reduced compared with the preoperative corneal astigmatism (2.08±0.71 D). The mean absolute rotation of the IOL was 8.83±5.26°. Toric IOL rotation was significantly and positively correlated with the degree of residual astigmatism in the T3 (Pearson's r=0.552, p<0.001) and T4 groups (Pearson's r=0.622, p=0.003). Regarding factors associated with IOL rotation, toric IOL rotation was positively correlated with axial length (AXL; Pearson's r=0.335, p=0.003) and negatively correlated with ACO grade (Spearman's r=-0.541, p<0.001). On multiple linear regression analysis, only AXL (B=0.889, p=0.031) and ACO grade (B=-3.216, p<0.001) were predictors of toric IOL rotation (R(2)=0.397).

CONCLUSIONS

Long AXL is a risk factor for toric IOL rotation, while higher ACO grade may decrease toric IOL rotation, indicating that reducing the polishing of anterior capsule may improve the rotational stability of a toric IOL.

TRIAL REGISTRATION NUMBER

NCT02182921.

RGD surface functionalization of the hydrophilic acrylic intraocular lens material to control posterior capsular opacification

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient's age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO. On the other hand, we have previously demonstrated that the adhesion of LECs is favored on hydrophobic compared to hydrophilic materials. By combining these two facts and contemporary knowledge in PCO development via the EMT pathway, we propose a biomimetically inspired strategy to promote LEC adhesion without de-differentiation to reduce the risk of PCO development. By surface grafting of a cell adhesion molecule (RGD peptide) onto the conventional hydrophilic acrylic IOL material, the surface-functionalized IOL can be used to reconstitute a capsule-LEC-IOL sandwich structure, which has been considered to prevent PCO formation in literature. Our results show that the innovative biomaterial improves LEC adhesion, while also exhibiting similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties compared to the starting material. In addition, compared to the hydrophobic IOL material, our bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression, which is the crucial pathway to induce PCO. The in vitro assays suggest that this biomaterial has the potential to reduce the risk factor of PCO development.

Optical coherence tomography and 3-dimensional confocal structured imaging system-guided femtosecond laser capsulotomy versus manual continuous curvilinear capsulorhexis

PURPOSE

To compare the features of capsulotomy obtained during femtosecond laser-assisted cataract surgery with those of continuous curvilinear capsulorhexis (CCC) obtained using a standard manual technique.

SETTING

Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, Italy.

DESIGN

Prospective randomized clinical study.

METHODS

Candidates for cataract extraction were randomized into 1 of 3 groups as follows: Lensx femtosecond laser-assisted cataract surgery capsulotomy (laser group 1), Lensar femtosecond laser-assisted cataract surgery capsulotomy (laser group 2), and manual CCC (manual group).

RESULTS

Each group comprised 30 eyes (30 patients). The capsulotomies in laser group 1 and laser group 2 showed significantly better circularity than the manual CCCs at 7 days (P<.001). There was a significant correlation between the intended versus achieved capsulotomy size in the 2 laser groups. Both laser groups had better intraocular lens (IOL) centration than the manual group at all timepoints (P<.001). Between-group differences in uncorrected and corrected distance visual acuities were not statistically significant. The residual spherical equivalent and mean absolute error were statistically significantly smaller in the 2 laser groups than in the manual group (P=.038) and increased significantly over time in all the groups (P<.001).

CONCLUSIONS

Femtosecond laser capsulotomies showed better circularity with more predictable size than manual CCCs. In addition, IOL centration was better immediately after surgery and over time with better refractive results in the 2 laser groups.

Scanning electron microscopy evaluation of capsulorhexis in femtosecond laser-assisted cataract surgery

PURPOSE

To use scanning electron microscopy (SEM) to evaluate capsulorhexis-cut quality obtained during femtosecond laser-assisted cataract surgery at different energy settings and evaluate whether there are differences between this technique and a standard manual technique.

SETTING

Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, Italy.

DESIGN

Prospective nonrandomized single blinded study.

METHODS

Sixty capsulorhexes obtained using the conventional manual technique and the femtosecond laser with different laser energy settings were divided into 5 groups as follows: Group 1 (12 capsulorhexes) obtained with the manual technique and Groups 2 to 5 (each with 12 capsulorhexes) obtained with the femtosecond laser at 7.0 μJ, 13.5 μJ, 14.0 μJ, and 15.0 μJ, respectively. All samples were evaluated using SEM to compare the thickness along the capsulorhexis edge and the overall irregularity of the cut surface.

RESULTS

Capsulorhexes obtained with the femtosecond laser at all energy settings were perfectly circular with negligible deformation. Group 1 and Group 2 had a significantly higher thickness and lower thickness, respectively, of the capsulorhexis edge than the other 3 groups (P<.001). There was also a statistically significant correlation between the degree of irregularity and increasing energy (P<.001).

CONCLUSIONS

The use of the femtosecond laser in cataract surgery resulted in better capsulorhexis geometry and circularity than the manual capsulorhexis. The cut surface was smoother in the manual group. In the femtosecond laser groups, the degree of irregularity was higher at increasing energy settings.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Astigmatism correction with toric IOL: analysis of visual performance, position, and wavefront error

PURPOSE

To evaluate astigmatism correction, visual performance, intraocular lens (IOL) position, and wavefront error after implantation of toric IOLs in patients with cataract.

METHODS

This prospective study comprised 30 eyes of 30 patients with cataract who were candidates for phacoemulsification and implantation of the AcrySof toric IOL (Alcon Laboratories, Inc., Fort Worth, TX). Mean preoperative corneal keratometric and subjective refractive cylinder were 2.10 ± 0.47 and 2.17 ± 0.41 diopters (D), respectively.

RESULTS

The refractive cylinder decreased significantly from 2.17 ± 0.41 to 0.73 ± 0.45 D (P = .001) at 180 days postoperatively. The difference between preoperative corneal astigmatism and postoperative refractive astigmatism was statistically significant (P < .05). At 180 days postoperatively, the uncorrected distance visual acuity was 0.20 logMAR (Snellen 20/32) in 100% of patients and 0.0 logMAR (Snellen 20/20) in 64% of patients. The root mean square of internal coma and trefoil aberrations showed a trend toward reduction; internal spherical aberration significantly decreased, whereas corneal trefoil aberration significantly increased (P < .05). A low amount of IOL decentration and tilt were detected at 30 and 180 days postoperatively, respectively.

CONCLUSIONS

Toric IOL implantation is an effective procedure for correction of preexisting corneal astigmatism, improving visual performance, and inducing a low amount of higher-order aberrations. Moreover, the toric IOLs is well positioned early after surgery and stable over time.

Anti-inflammatory effect of low-molecular-weight heparin in pediatric cataract surgery: a randomized clinical trial

PURPOSE

To determine if intraocular infusion of low-molecular-weight heparin (enoxaparin) reduces postoperative inflammation in pediatric eyes undergoing cataract surgery with IOL implantation.

DESIGN

Prospective masked randomized controlled trial.

METHODS

setting: Private, institutional practice. study population: Twenty children (40 eyes) undergoing bilateral cataract surgery with IOL implantation were randomized to receive enoxaparin in the intraocular infusion fluid (BSS) (Group I) or not to receive enoxaparin (Group II). The first eye was randomly assigned to 1 of the 2 groups and the second eye received alternate treatment. observation procedure: Patients were followed up in the first week and 1 and 3 months after surgery. main outcome measures: Anterior chamber flare and cells (Hogan's criteria), cell deposits on IOL, posterior synechiae.

RESULTS

One week postoperatively, no eyes had >grade 2 flare/cells. Proportion of eyes with grade 2 cells was higher in eyes that did not receive enoxaparin (Group II: 80% vs Group I: 40%, P = .009). In the first week >10 small cell deposits were noted in the eyes that received enoxaparin (Group I: 20%, Group II: none, P = .005). Large cell deposits first appeared at 1 month in 40% of eyes in Group I and 55% of eyes in Group II (P = .34) and increased at 3 months (60% in both groups, P > .999). Posterior synechiae were seen in 10% of eyes in Group I at 1 month, which persisted at 3 months; no eyes in Group II showed posterior synechiae (P = .14).

CONCLUSION

The results of our study suggest that there does not seem to be a benefit of using enoxaparin in the infusion fluid with respect to early postoperative inflammation.

AFM study for morphological characteristics and biomechanical properties of human cataract anterior lens capsules

The aim of this study was to quantitatively investigate the morphologies (surface roughness) and biomechanical properties (Young's modulus) of human anterior lens capsules (ALCs) for noncataract and cataract groups using atomic force microscopy. Eight human ALCs obtained during phacoemulsification from patients with senile cataracts (72 ± 13 years) were investigated in both the hydrated and dehydrated conditions. The cataract group showed clearly the proliferated lens epithelial cells (LECs) with a monomorphic cell structure, a diameter of 12.54 ± 4.31 μm, and a height of 0.23 ± 0.04 μm, whereas the control group showed no LECs. A substantial amount of false-positive calcification was observed caused by the deposition of remnants of dried salt solution. Cataract group showed significantly higher surface roughness (382.06 nm, p ≤ 0.001) than control group in the anterior side of ALCs, whereas cataract group showed significantly lower surface roughness (353.79 nm, p ≤ 0.001) than control group in their posterior side. Cataract group showed significantly higher Young's modulus (69.52 kPa, p ≤ 0.001) compared to the control group, regardless of the ALC side. Therefore, it is significant that this study provides a new method to examine the nanostructural characteristic and biomechanical property of human ALCs through a nanometer-scale resolution microscopy technique.

Lens epithelial cell response to atmospheric pressure plasma modified poly(methylmethacrylate) surfaces

Selective control of cellular response to polymeric biomaterials is an important consideration for many ocular implant applications. In particular, there is often a need to have one surface of an ophthalmic implant capable of promoting cell attachment while the other needs to be resistant to this effect. In this study, an atmospheric pressure dielectric barrier discharge (DBD) has been used to modify the surface region of poly(methyl methacrylate) (PMMA), a well established ocular biomaterial, with the aim of promoting a controlled response to human lens epithelial cells (LEC) cultured thereon. The DBD plasma discharge environment has also been employed to chemically graft a layer of poly(ethylene glycol) methyl ether methacrylate (PEGMA) onto the PMMA and the response to LEC likewise determined. Two different molecular weights of PEGMA, namely 1000 and 2000 MW were used in these experiments. The LEC response to DBD treated polystyrene (PS) samples has also been examined as a positive control and to help to further elucidate the nature of the modified surfaces. The LEC adhered and proliferated readily on the DBD treated PMMA and PS surfaces when compared to the pristine polymer samples which showed little or no cell response. The PMMA and PS surfaces that had been DBD grafted with the PEGMA(1000) layer were found to have some adhered cells. However, on closer inspection, these cells were clearly on the verge of detaching. In the case of the PEGMA(2000) grafted surfaces no cells were observed indicating that the higher molecular weight PEGMA has been able to attain a surface conformation that is capable of resisting cell attachment in vitro.

Determination of albumin sorption to intraocular lenses by radiolabeling and confocal laser scanning microscopy

PURPOSE

To determine albumin adsorption profiles and penetration depth of 3 intraocular lens (IOL) materials over time using confocal laser scanning microscopy (CLSM) and radiolabeling.

SETTING

Centre for Contact Lens Research, School of Optometry, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada.

METHODS

Poly(methyl methacrylate) (PMMA), silicone, and foldable hydrophilic acrylic IOLs were incubated in 0.5 mg/mL bovine serum albumin (BSA) for 1, 7, and 14 days. The BSA was conjugated with lucifer yellow VS to allow identification of the protein location by fluorescent imaging with CLSM. Next, the protein uptake was quantified using 2% (125)I-labeled BSA.

RESULTS

Confocal laser scanning microscopy showed increasing BSA uptake for silicone and PMMA IOLs after 14 days of incubation (P<.05), with an apparent penetration depth of 8.7 microm +/- 1.9 (SD) and 9.2 +/- 1.4 microm, respectively. For hydrophilic acrylic IOLs, BSA was detected at a depth of 38 +/- 7.4 microm after 1 day, followed by an increase to 192.7 +/- 16.2 microm after 14 days. Despite the penetration depth into the hydrophilic acrylic IOLs, quantitative results confirmed that PMMA and hydrophilic acrylic deposited significantly less BSA (mean 278.3 +/- 41.7 ng and 296.5 +/- 33.1 ng, respectively) than silicone IOLs (mean 392.6 +/- 37.6 ng) (P<.05).

CONCLUSIONS

Silicone and PMMA IOL materials showed BSA sorption near the lens surface only, while BSA penetrated deep into the hydrophilic acrylic IOL matrix. Combining the qualitative CLSM method and quantitative radiolabeling technique provided detailed information on protein interactions with implantable biomaterials.

Visual performance and biocompatibility of 2 multifocal diffractive IOLs

PURPOSE

To evaluate the distance and near functional capacity, wavefront error and biocompatibility in patients with 2 diffractive multifocal intraocular lenses (MIOLs).

SETTING

Ophthalmology Department of Chieti-Pescara University (Italy).

METHODS

This prospective study comprised 28 eyes of 28 senile cataract patients having phacoemulsification and implantation of the Tecnis ZM900 MIOL (Group 1) and the AcrySof ReSTOR MIOL (Group 2). The main outcome measures, over a 6-month follow-up period, were spherical equivalent, distance visual acuity at high and low contrast, near visual acuity, and defocus curve. Wavefront error was evaluated in both groups. Capsule opacification was also assessed.

RESULTS

The high and low contrast uncorrected and best corrected visual acuity for distance did not show statistically significant differences between the 2 groups. The distance corrected near visual acuity was 1.86 +/- 1.66 in Group 1 and 1.93 +/- 1.12 in Group 2. The depth of focus was 4.5 diopters in both groups. The root mean square of total aberration and of spherical and coma aberrations were significantly lower in Group 1 than in Group 2. A higher percentage of patients with Tecnis MIOLs showed a more severe grade of anterior fibrosis. Posterior opacification was minimal and not significantly different between the 2 groups.

CONCLUSION

Diffractive MIOLs were effective in improving functional capacity for distance and near and provided a good quality of vision due to a significant reduction in spherical aberration, particularly in the Tecnis MIOLs. The higher capsular biocompatibility of the ReSTOR MIOL compared with the Tecnis MIOL could ensure long-term stability.

Longterm results of 1 CU® accommodative intraocular lens implantation: 2-year follow-up study

PURPOSE

To evaluate the longterm efficacy of 1 CU accommodative intraocular lenses (IOLs) to restore near visual performance.

METHODS

This prospective study comprised 14 eyes previously included in a 6-month, case-control clinical trial, undergoing phacoemulsification and implantation of a 1 CU accommodative IOL. The main outcome measures were subjective refraction, uncorrected distance visual acuity (UCDVA), best corrected distance VA (BCDVA), distance-corrected near VA (DCNVA), best corrected near VA (BCNVA), and subjective amplitude of accommodation (AA). In addition, anterior and posterior capsule opacification were assessed. Patients were examined over a 2-year follow-up period.

RESULTS

Distance and near visual performance worsened after 6 months. Uncorrected DVA and BCDVA were 0.8 +/- 2.1 and 1.0 +/- 0.8 at 6 months and 0.4 +/- 0.1 and 0.6 +/- 0.1 at 1 year, respectively (p = 0.001). Distance-corrected NVA and BCNVA were 3.7 +/- 2.1 Jaeger (J) and 1.0 +/- 0.7 J at 6 months and 8.1 +/- 0.7 J and 1.5 +/- 0.5 J at 1 year, respectively (p = 0.001). Anterior and posterior capsule opacification were present, respectively, in 28% and 21% of patients at 6 months and in 100% of patients at 1 and 2 years (p < 0.001). After Nd:YAG laser capsulotomy (performed in 100% of patients), UCDVA and BCDVA increased to 0.7 +/- 0.2 (p = 0.007) and 1.0 +/- 0.1 (p = 0.001), respectively, at 2 years. Distance-corrected NVA improved to 7.3 +/- 0.5 J (p = 0.006). Mean AA was 1.9 +/- 0.8 D at 6 months, 0.3 +/- 0.2 D (p = 0.004) at 1 year and 0.3 +/- 0.2 D at 2 years.

CONCLUSIONS

Patients implanted with 1 CU IOLs lost their accommodation capacities with time because of the high incidence and degree of anterior and posterior capsule opacification. The accommodative lens material and design may have played a role in capsule fibrosis.

Effect of the hydrophilicity of acrylic intraocular lens material and haptic angulation on anterior capsule opacification

AIM

To evaluate the influence of hydrophilic and hydrophobic acrylic material and haptic angulation on anterior capsule opacification (ACO).

METHODS

Prospective study on 53 patients with bilateral age-related cataract. Patients underwent standard cataract surgery by the same surgeon and randomly received a hydrophilic acrylic intraocular lens (IOL) in one eye and a hydrophobic acrylic IOL in the other eye. Forty five of these patients completed the one-year follow-up. The following parameters were assessed: decentration, buttonholing, anterolenticular gap (ALG), ACO, outgrowth and refractive outcome.

RESULTS

At the one-year follow-up, ACO was seen in 80% of the hydrophilic and 100% of the hydrophobic IOLs. ACO was more intense in the hydrophobic IOLs (p<0.001). Outgrowth was seen in 42% of the hydrophilic and 2% of the hydrophobic IOLs (p = 0.0003). No case of persisting ALG was seen in the hydrophobic IOLs, but in 42% of the hydrophilic IOLs. The refractive outcome was -0.29 (SD 0.56) dioptres for the hydrophilic and 0.003 (SD 0.44) dioptres for the hydrophobic IOLs (p<0.001).

CONCLUSION

These results suggest that there is less ACO in hydrophilic acrylic than in hydrophobic acrylic IOLs. Although material properties might play a role, the angulated haptics of the hydrophilic IOLs exert an additional effect by the persisting ALG and a lack of contact between the IOL and the anterior capsule.

Improvement of the surface biocompatibility of silicone intraocular lens by the plasma‐induced tethering of phospholipid moieties

To improve the surface biocompatibility of the silicone intraocular lens (IOL), 2-methacryloyloxyethyl phosphorylcholine (MPC) was tethered onto the IOL through air plasma treatment. Chemical changes on the IOL surface were characterized by X-ray photoelectron spectroscopy (XPS) to confirm the covalent binding of MPC. Morphologies of the IOL surfaces were observed by scanning electron microscopy (SEM) to optimize the plasma treatment process. The hydrophilicity and biocompatibility of the control and modified IOLs were compared by the measurements of water contact angle, platelet adhesion, macrophage cell culture, and lens epithelial cell (LEC) attachment. It was found that, after the tethering of MPC, the hydrophilicity of the IOL can be improved significantly and permanently, and the platelet, macrophage, and LEC adhesion on the IOL surface are obviously suppressed, which indicated the enhancement of surface biocompatibility.

Phacoemulsification and Implantation of an Accommodating IOL After PRK

PURPOSE

To present a case of phacoemulsification and implantation of an accommodating intraocular lens (IOL) in a patient with cataract formation after previous refractive surgery.

METHODS

A 50-year-old man, who initially had photorefractive keratectomy to correct moderate myopia, developed a cataract in one eye. He subsequently underwent phacoemulsification and implantation of a 1CU accommodating IOL, as he wished to remain spectacle independent.

RESULTS

The patient's distance vision was fully restored. However, accommodative function, which was assessed using subjective and novice objective techniques, was only partially restored.

CONCLUSIONS

Although the accommodating IOL fully restored the patient's distance vision, accommodative function was only partially restored.

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.

Capsular bag distension syndrome after combined cataract and glaucoma surgery

PURPOSE

To report four cases of capsular bag distension syndrome (CBDS) after combined cataract and glaucoma surgery.

METHODS

We describe the clinical features and evolution of each case after individual treatment.

CASE REPORTS

We report four cases of CBDS after phacoemulsification, combined with trabeculectomy in two cases and with an Ahmed aqueous drainage device implantation in the other two cases. The space between the intraocular lens (IOL) and the posterior capsule was occupied by an optically clear liquid in two cases and by a turbid liquid in the other two cases, with posterior bowing of the capsule into the anterior vitreous. A myopic shift and anterior chamber shallowing occurred in three cases. After posterior Nd:YAG laser capsulotomy, the CBDS resolved in three cases. In case 1, a surgical posterior capsulotomy and anterior vitrectomy were necessary.

DISCUSSION

Capsular bag distension syndrome should be included in the differential diagnosis of a shallow anterior chamber after combined cataract and glaucoma surgery.