Anterior capsule opacification: a histopathological study comparing different IOL styles

Rotational stability of a new hydrophobic acrylic intraocular lens platform

PURPOSE

To evaluate rotational stability for ease of rotation of a new intraocular lens (IOL) platform with 4 haptics in an ex vivo model and compare it with a control single-piece lens with 2 open loops.

SETTING

Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.

DESIGN

Experimental study.

METHODS

10 human cadaver eyes were prepared as per the Miyake-Apple technique. After injection of the test or control lens, clockwise and counterclockwise rotations were attempted with a hook, with and without an ophthalmic viscosurgical device in place. Ease of rotation was scored as (1) very easy, (2) easy, (3) difficult, and (4) very difficult. Rotation of the entire eye containing test or control IOL was also performed with a multipurpose rotator (2 minutes; 220 revolutions per minute) to evaluate its effect on IOL alignment.

RESULTS

There were statistically significant differences regarding ease of rotation between test and control lenses in all 4 scenarios, with rotation being more difficult with the test lens ( P < .05, Wilcoxon signed-rank test). No change in the alignment of test or control lenses was observed after eye rotation with the multipurpose rotator.

CONCLUSIONS

The new IOL platform showed greater rotational stability than the control lens in this model, owing to design features such as 4 small arcs of contact between the haptics and the bag equator, a bulge at the distal end of each haptic, and arcuate haptics with curvatures oriented toward each other.

Surgical approach for management of complete anterior capsular contraction syndrome

Anterior capsular contraction syndrome is an uncommon but well-known complication associated with continuous curvilinear capsulorhexis performed during cataract surgery. It remains asymptomatic unless the constriction progresses to involve the visual axis or causes late intraocular lens-related complications. A male patient in his 50s presented with severely decreased vision in his right eye 2 years after uneventful cataract surgery. Slit-lamp biomicroscopy revealed capsular phimosis and a dense, central, fibrous plaque with total occlusion of the anterior capsulorhexis opening. Neodymium-doped yttrium aluminium garnet laser anterior capsulotomy and vitrectorhexis were attempted, but proved ineffective. Surgical excision with manual cutting of the fibrotic membrane was performed, successfully clearing the visual axis and restoring vision.

Cataract surgery in patients with retinitis pigmentosa: systematic review

Retinitis pigmentosa (RP) is an inherited bilateral retinal degenerative disease with an incidence of 1 in 4000 people. RP affects more than 1 million individuals worldwide. Although night blindness and restricted visual field are the most typical symptoms of these individuals, generalized vision loss due to cataracts can be expected in the latter stages of the disease. It has been demonstrated that posterior subcapsular cataract is the most prevalent cataract in younger individuals with RP, as opposed to age-related cataracts. Although most ophthalmologists may have a negative view of cataract surgery in patients with RP, it appears that it can play an important role in the visual restoration of patients with RP. However, there are concerns about performing cataract surgery for patients with RP. Herein, a systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses on databases of MEDLINE and Scopus.

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.

Posterior Capsule Opacification after Cataract Surgery via Implantation with Hydrophobic Acrylic Lens Compared with Silicone Intraocular Lens: A Systematic Review and Meta-Analysis

Hydrophobic acrylic intraocular lens (IOL) is the most popular material in cataract surgery. Posterior capsule opacification (PCO) is a long-term complication of cataract surgery. It can impair vision and adversely affect the prognosis of IOL delamination. The objective of this study was to perform a systematic review and meta-analysis to provide an updated evaluation of long-term complications and visual function after implantation with hydrophobic acrylic and silicone intraocular lenses. PubMed, Embase, and Cochrane Library were searched from January 2000 until March 2021. Randomized controlled trials (RCTs) and retrospective studies were finally included. The main outcomes were PCO value and neodymium-doped yttrium aluminum garnet (Nd : YAG) capsulotomy rate. Subgroup analysis was performed to compare hydrophobic acrylic and silicone IOLs during the follow-up period. Sensitivity analysis was also performed. The meta-analysis included a total of 17 studies. When the follow-up period was considered, the results of the analysis revealed higher PCO value (Group 3: standardized mean difference (SMD), −0.59; 95% confidence interval (CI), −0.90 to −0.28) and Nd : YAG capsulotomy rate (Group 3: risk ratio (RR), 0.60; 95% CI, 0.40–0.89) for hydrophobic acrylic IOLs than silicone IOLs during a long-term (≥6 years) follow-up. In conclusion, both the PCO value and the Nd : YAG capsulotomy rates were higher in hydrophobic acrylic IOLs group than the silicone IOLs group at long-term use (more than 6 years) after implantation.

Repositioning surgery of different intraocular lens designs in eyes with late in-the-bag intraocular lens dislocation

PURPOSE

To evaluate the long-term efficacy and safety after intraocular lens (IOL) repositioning by scleral suturing of 1-piece IOL compared with other IOL designs in the treatment of late in-the-bag IOL dislocation.

SETTING

Patients referred to Oslo University Hospital Oslo, Norway.

DESIGN

Prospective cohort study.

METHODS

The study comprised 54 patients (54 eyes) with late in-the-bag IOL dislocation treated with IOL repositioning by scleral sutures (10-0 polypropylene). All operations were performed with an anterior approach and by 1 surgeon. The following IOL designs were repositioned: 1-piece foldable (n = 17), 3-piece foldable (n = 28), plate-haptic (n = 8), and 1-piece rigid (n = 1) IOLs. Patients were evaluated comprehensively preoperatively and at 6 months (80%), 1 year (67%), and 2 years (61%) postoperatively. The main outcome measures were efficacy regarding corrected distance visual acuity (CDVA) and spherical equivalent (SE) and safety regarding complications.

RESULTS

Postoperative visual acuity was similar for different IOL designs. The mean SE change to final observation was -0.08 (95% CI, -0.93 to 0.77) in the 1-piece IOL group (n = 11) and -0.98 (-1.73 to -0.23) in the 3-piece IOL group (n = 18) (P = .11). Regarding safety, no patients had uveitis-glaucoma-hyphema syndrome, retinal detachment, or endophthalmitis. The 3-piece IOL group had 1 case of redislocation and 1 case of iritis. No patients had symptoms related to clinical IOL decentration. Long-term intraocular pressure remained within normal limits with overlapping 95% CIs for different IOLs.

CONCLUSIONS

Repositioning surgery of 1-piece IOLs seems as efficient and safe as that for other IOL designs in the treatment of late in-the-bag IOL dislocation.

Long-term uveal and capsular biocompatibility of a new fluid-filled, modular accommodating intraocular lens

PURPOSE

To evaluate long-term uveal and capsular biocompatibility of a new fluid-filled modular accommodating intraocular lens (IOL) consisting of base and fluid lenses.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.

DESIGN

Experimental study.

METHODS

Bilateral phacoemulsification was performed on 8 rabbits; 1 eye received the test IOL (Juvene) and the other a hydrophobic acrylic control IOL (SA60AT). Slitlamp examinations were performed at postoperative weeks 1 and 4, and at months 2, 3, and 6. The rabbits were killed humanely at 6 months. After gross examination from the Miyake-Apple view, IOLs were removed for implant cytology. All globes were then processed for histopathologic examination.

RESULTS

Uveal biocompatibility was similar between test and control IOLs up to 6 months postoperatively. Anterior capsule opacification appeared absent in the test group, and posterior capsule opacification (PCO) was significantly less in comparison with the control group throughout the study. At 6 months, central PCO was scored as 0.12 ± 0.23 with test IOLs and as 4.0 ± 0 with control IOLs (P < .0001, 2-tailed t test: paired 2-sample for means). Histopathologic examination confirmed the relative lack of capsular opacification in test eyes in comparison to controls and the absence of toxicity in any eye.

CONCLUSIONS

Six weeks in the rabbit model corresponds to approximately 2 years in the human eye for PCO. In this model, the Juvene IOL maintained an open and expanded capsular bag, preventing overall capsular bag opacification while retaining excellent uveal and capsular biocompatibility.

Explantation/exchange of the components of a new fluid-filled, modular, accommodating IOL

PURPOSE

To evaluate the ease of replacement and capsular stability of a new fluid-filled, modular, accommodating intraocular lens (IOL) system composed of a monofocal base lens with a fluid lens clipped inside of it.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Experimental study.

METHODS

Five New Zealand rabbits underwent bilateral phacoemulsification with implantation of the test lens (Juvene, LensGen, Inc.) in both eyes (4 rabbits), or a control IOL in 1 eye (AcrySof, Alcon Laboratories, Inc.) and the test IOL in the other (1 rabbit). At 2 weeks, the 4 rabbits with bilateral Juvene IOLs had the clipped-in fluid lens exchanged for a new fluid lens in 1 eye, and the base and fluid lenses exchanged for a control lens in the contralateral eye. Slitlamp examinations were performed weekly for 4 weeks. The globes were enucleated and evaluated with ultrasound biomicroscopy, grossly from the posterior Miyake-Apple view, and histopathologically.

RESULTS

Explantation/exchange of the fluid lens was considered straightforward by the surgeon. Explantation of the base lens (4) was also safely performed, albeit more demanding, without any signs of damage to the capsular bag under clinical, ultrasound biomicroscopy, and pathological examination in the exchanged eyes. Less capsular bag opacification was observed with the Juvene lens system.

CONCLUSIONS

Explantation/exchange of the fluid lens component, or both fluid and base lenses, of this new lens system can be safely accomplished if necessary, because of its modular design and the relative lack of postoperative capsular bag opacification associated with it.

Late in-the-bag intraocular lens dislocation

This review aimed to evaluate the cumulative incidence, patient characteristics, predisposing conditions, and treatment outcomes for late in-the-bag intraocular lens (IOL) dislocation. Literature searches in PubMed (MEDLINE), Embase, and Cochrane Library Central database identified 1 randomized clinical trial, 1 prospective case series, 2 prospective cohort studies, and 36 retrospective studies of this condition, which showed that the cumulative incidence was 0.5% to 3%, it occurred on average 6 to 12 years after cataract surgery, and mean patient age was 65 to 85 years. Pseudoexfoliation syndrome, myopia, and previous vitreoretinal surgery were the most common predisposing conditions. Studies indicated that IOL repositioning and IOL exchange provided similar visual outcomes and were equally safe. The long-term visual outcome seemed satisfactory. However, the quality of evidence regarding treatment was in general quite low. More studies of late in-the-bag IOL dislocation are needed, and in particular, different surgical techniques should be included in high-quality clinical trials.

Weight of Different Intraocular Lenses: Evaluation of Toricity, Focality, Design, and Material

Purpose

To evaluate the weight of intraocular lenses (IOLs) depending on their material, dioptric power, toricity, focality, and haptic design.

Methods

Twenty-eight different IOL models from nine different medical companies (a total of 38 IOLs) and 1 capsular tension ring (CTR) were evaluated. IOLs were weighed using a precision scale, in hydrated conditions, as an approximation to their intraocular status.

Results

Hydrophilic IOLs were heavier than hydrophobic lenses (p < 0.001). Regarding toricity, no statistical differences were found comparing toric to non-toric models (p=0.1). Likewise, no differences were found between multifocal IOLs and monofocal IOLs (p=0.19). Dioptric power did not affect IOL weight: IOLs of <15DP had similar weights to those of ≥15D and IOLs of ≥24D had similar weights to those of <24 D (p=0.86 and p=0.59, respectively). Plate-design IOLs were significantly heavier than 1-piece C-loop (p < 0.001), 3-piece C-loop (p < 0.001), and 4-haptic lenses (p=0.001).

Conclusions

Of the characteristics analyzed that might influence IOL weight, lenses with hydrophilic material and plate-haptic design were found to be heavier. Toricity, focality, and dioptric power had no influence on IOL weight.

Time Course of Lens Epithelial Cell Behavior in Rabbit Eyes following Lens Extraction and Implantation of Intraocular Lens

Background

After cataract surgery, some lens epithelial cells (LECs) transdifferentiate into myofibroblast-like cells, which causes fibric posterior capsule opacification (PCO). Residual LECs differentiate into lens fiber cells, forming Elschnig pearls with PCO. This study was carried out to identify the time course of both types of LEC behavior in rabbit eyes following lens extraction and implantation of an intraocular lens (IOL).

Methods

Phacoemulsification and implantation of posterior chamber IOLs were performed in rabbit eyes. Following enucleation, immunohistochemical methods were used to detect α-smooth muscle actin (α-SMA), a marker for myofibroblast-like cells, in the pseudophakic rabbit eyes. A mouse monoclonal antibody against α-SMA was used.

Results

Soon after the operation, the LECs migrated and covered the lens capsule. Thereafter, the LECs around the anterior capsular margin were always positive for α-SMA. However, the distributions of these cells were not consistent. In some specimens, α-SMA-positive LECs were present around the IOL optic early after surgery, but most of them had disappeared several weeks after the surgery. The residual cells induced fibrotic PCO. In the other specimens, most LECs around the IOL optic except the anterior capsular margin were negative for α-SMA. In the peripheral region covered by the peripheral anterior and posterior capsules, LECs on the posterior capsule always differentiated into lens fiber cells and formed a Soemmering ring. Thereafter, migration of lens fiber cells from the Soemmering ring and differentiation of LECs in situ on the central posterior capsule consisted of Elschnig pearls type of PCO.

Conclusions

Although postoperative LEC behavior is not consistent, residual α-SMA-positive LECs induced fibrotic PCO. The lens fiber cells that migrated from the peripheral capsular bag or that were differentiated in situ covered the central posterior capsule, forming Elschnig pearls with PCO.

Cortical aspiration - The "POPS" technique

In the present study, we describe a step-by-step technique for cortex aspiration during cataract surgery- POPS (positioning, occlusion, posterior displacement, and swiping). Firstly, the aspiration probe is positioned under the bulk of cortical fibers beyond the capsulorhexis margin. Subsequently, the aspiration port is occluded with minimal vacuum, and the occluded port is displaced posteriorly to detach the cortical fibers off the anterior capsule. Now, tangential, arc-like swiping movements are performed while gradually increasing vacuum at the same time. The fibers are brought to the center and finally aspirated. This allows complete removal of the equatorial fibers and lens epithelial cells (LEC) with the least stress to the capsulozonular complex. Unlike the conventional technique, which involves the radial pull of cortical fibers, in this technique, there is swiping and posterior displacement of the cortical fibers before pulling towards the center and aspirating. We believe this technique will ensure safer, more effective cortical and LEC removal, reducing zonular stress.

Application of capsular bag relaxation for capsular contraction syndrome

The present study analyzed the surgical method and clinical effects of capsular bag relaxation surgery (CBRS) for the treatment of capsular contraction syndrome (CCS), which usually occurs post-phacoemulsification. The retrospective case study comprised of a total of 25 patients (25 eyes) who developed CCS after phacoemulsification and subsequently underwent CBRS. Among these patients, 15 patients (15 eyes) received actinoid relaxing incisions and 10 patients (10 eyes) underwent a second continuous curvilinear capsulorhexis. Postoperative naked-eye visual acuity was determined and compared with preoperative naked-eye visual acuity. Size changes of the transparent zone of the anterior capsule opening were observed under a slit lamp, as well as the anterior and posterior capsular membrane conditions and position of the intraocular lens (IOL). In addition, the presence of any subjective symptom, including glare or monocular diplopia, was investigated. A final 6-month postoperative follow-up was conducted for each patient. Visual acuity of all operated eyes improved to various extents. Notably, glare and monocular diplopia were no longer evident and patients could observe things clearly. Visual differences pre- and post-surgery were statistically significant (u=5.143, P<0.01). In addition, capsular bag shrinkage and relaxation were revealed under a slit lamp, the area of the transparent zone of the anterior capsule opening was expanded and the IOL remained centered. To conclude, CBRS is an effective treatment method for patients with CCS who are not suitable to receive laser treatment.

Intraocular Lenses: Overview of Designs, Materials, and Pathophysiologic Features

This article provides an overview of intraocular lenses (IOLs) currently used in cataract surgery. Aspects presented include design features related to IOL construction and sites of fixation; optic, filter, and haptic materials; as well as pathophysiologic features of uveal biocompatibility, capsular biocompatibility, and postoperative IOL opacification. This overview also includes supplementary (add-on; piggyback) lenses implanted in eyes that are already pseudophakic and considerations on IOLs used in the pediatric population. Different IOLs are made available to surgeons each year, including lenses with increasingly complex design characteristics owing to advancements in manufacturing and surgical techniques.

Impact of anterior capsular polishing on capsule opacification rate in eyes undergoing femtosecond laser-assisted cataract surgery

Purpose:

To evaluate the impact of anterior capsular polishing on capsule opacification and contraction in eyes undergoing femtosecond laser-assisted cataract surgery (FLACS).

Methods:

This prospective interventional comparative analysis included patients undergoing FLACS between August 2016 and May 2017. The eyes were subdivided into three groups based on the extent of intraoperative anterior capsular polishing performed: complete 360-degree polishing; inferior 180-degree polishing; and no polishing. Visual acuity, posterior capsular opacification (PCO) score, anterior capsular opacification (ACO) grade, and capsulorhexis diameter were evaluated at 1-week, 6-months, and 1-year postoperative visits.

Results:

The study included 99 eyes of 90 patients. No significant differences were observed between the three groups in ACO grade and capsulorhexis contraction at all follow-up visits. There was a statistically significant difference in PCO grade among the groups at 6-month and 1-year follow-up but it was found to be clinically insignificant. One eye in the no polishing group underwent neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy at the 1-year follow-up visit.

Conclusion:

A lower incidence of PCO was demonstrated in the 360-degree polishing group, although it was visually insignificant. No significant difference in postoperative capsular contraction was demonstrated between the cohorts up to one-year follow-up.

Late intraocular Lens dislocation following scleral depression: a case report

Background

The case describes a rare entity. Most cases of IOL dislocation are associated with surgical trauma or preexisting zonulopathy. This patient presents IOL dislocation following routine exam, suggesting the need of careful evaluation of zonular integrity on pseudopahkic patients.

Methods

Patient is a 65 year old who presented with sudden loss of vision and pain following retinal examination using scleral depression. Patient was diagnosed with late intraocular lens dislocation, which was subsequently for proper repositioning of IOL.

Conclusion

Pseduophakic eyes should be approached with caution when scleral indentation is attempted due to the possibility of zonular dehiscence and subsequent intraocular lens dislocation.

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.

Hyperopic shift caused by capsule contraction syndrome after microincision foldable intraocular Lens implantation: case series

Background

Increasing interest in microincision cataract surgery has led to the use of more flexible intraocular lens (IOL). Flexible IOL may cause more IOL deformation and refractive error when capsule contraction syndrome (CCS) occurred. In this retrospective observational case series study, the aim was to report four cases of hyperopic shift caused by CCS after phacoemulsification with microincision foldable intraocular lens implantation.

Case presentation

All of four patients underwent phacoemulsification and in-the-bag implantation of an Akreos MI60 (Bausch and Lomb) IOL from 2010 to 2016 in our clinic. These patients had been diagnosed with CCS and had undergone Nd:YAG laser anterior capsulotomy. The mean age of the patients with CCS was 66.8 ± 6.7 years and the mean time for development of CCS after the cataract surgery was 9.3 ± 6.9 months. The mean spherical equivalent (SE) value at the time of the CCS diagnosis was 0.88 ± 0.91 D, which had shown a hyperopic shift compared to the SE value of − 0.91 ± 1.29 D after cataract surgery. The mean SE decreased by − 0.47 ± 1.14 D after Nd:YAG laser anterior capsulotomy. The mean age, axial length, anterior chamber depth, and preoperative SE were not significantly different between the patient with CCS and the patients without CCS.

Conclusions

In the case of IOL implantation with flexible materials in microincision cataract surgery, CCS can cause a hyperopic shift. Refractive error caused by CCS can be effectively corrected by Nd:YAG laser anterior capsulotomy.

Open-capsule intraocular lens to prevent posterior capsule opacification

PURPOSE

To develop a single-piece open-capsule intraocular lens (IOL) that can be inserted through a small incision and that prevents posterior capsule opacification (PCO) by expanding the capsule and circulating aqueous humor into the capsular bag.

SETTING

Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan.

DESIGN

Experimental study.

METHOD

Using the same hydrophobic acrylic material as the NY-60 IOL, a prototype open-capsule IOL was constructed. The IOL has a single optic and 2 haptics, with a 2.8 mm high spacer and holes through which aqueous humor circulates into the capsular bag by separating the anterior capsule from the posterior capsule and expanding the capsule. The open-capsule IOL or NY-60 (as a control group) was inserted in rabbit eyes. Posterior capsule opacification development was evaluated by measuring the thickness of the cell layer at the center of the posterior capsule on histopathologic specimens and statistically comparing the thickness between the open-capsule IOL group and control group.

RESULTS

The open-capsule IOL could be inserted through a 3.2 mm corneal incision using a D cartridge. The mean thickness of the cell layer at the center of the posterior capsule was 4.78 μm ± 2.61 (SD) in the open-capsule IOL group and 101.14 ± 25.19 μm in the control group and was significantly smaller in the open-capsule IOL group.

CONCLUSION

The prototype single-piece IOL could be implanted through a small incision and prevented PCO by expanding the lens capsule and circulating aqueous humor into the capsular bag.

Anterior and posterior capsule densitometry levels after femtosecond laser-assisted cataract surgery

AIM

To analyze and compare five different variables over one year follow-up (1wk, 1, 3, 6 and 12mo): anterior capsule (AC), and posterior capsule (PC) area densitometry values, AC and PC linear densitometry values, and AC opening area reduction ratio after femtosecond laser-assisted cataract surgery.

METHODS

This was a prospective comparative study. Seventy-one patients underwent femtosecond laser-assisted cataract surgery on single eye between June 2014 and December 2015. A 5.0 mm diameter laser assisted anterior capsulotomy was performed on all eyes. In every post-surgery evaluation, AC opacificaction (ACO) and PC opacification (PCO) density levels were provided by Oculus Pentacam^®HR using area and linear densitometry methods. Digital images were captured with a slit-lamp Topcon photographic camera and IMAGEnet^® 5 software. The AC opening area on the digital images was measured using the Sketchandcalc area calculator and converted to reduction ratio levels.

RESULTS

Using Pearson correlation coefficient (PCC), we found no correlation (r=-0.091, P=0.46) in the twelfth month assessment between the evolution of ACO area densitometry values and PCO area densitometry values considered as independent variables. We found no correlation, using PCC (r=-0.096, P=0.43) between the evolution of ACO linear densitometry values and PCO linear densitometry values, in the twelfth month visit, working both as independent variables. AC linear densitometry levels and AC area densitometry levels continued to grow strongly from sixth to twelfth months. Analysis of the values of AC opening area reduction ratio (1wk, 1, 3, 6, 12mo) revealed statistically significant differences between the values of successive examinations but the magnitude of the change decreased. In the final period of monitoring between six and twelve months the magnitude of change was low.

CONCLUSION

Our results show strong increases of Scheimpflug ACO densitometry values from the sixth to the twelfth month while capsulorhexis area reduction ratio levels displayed a considerable decrease. We found no correlation between ACO area and linear densitometry values and PCO area and linear densitometry values, in the twelfth month examination, working as independent variables.

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.

Complete occlusion of anterior capsulorhexis after uneventful cataract surgery, treated with YAG laser capsulotomy

Background

Capsular contraction syndrome (CCS) has been reported as an uncommon complication after an cataract extraction surgery with intact anterior capsulorhexis. This report is written to present a case of complete occlusion of the anterior capsulorhexis opening after an uneventful cataract surgery, which was treated with non-invasive treatment.

Case presentation

A 69-year-old woman complained of decreased visual acuity in her right eye, which had started 2 months ago. She underwent phacoemulsification with an uneventful anterior capsulorhexis before 3 months. A total occlusion of the anterior capsulorhexis opening with capsular phimosis was identified on slit-lamp biomicroscopy, and a circular anterior capsulotomy using neodymium-doped yttrium aluminum garnet (Nd:YAG) laser was performed immediately. The capsulotomy site remained clear after a couple of years.

Conclusions

It is supposed that proliferation of fibrotic tissue was relatively prominent in this case, rather than the appearance of capsular phimosis. This case can be an uncommon showing a total occlusion of the anterior capsulorhexis opening with prominent fibrotic proliferation pattern after an uneventful cataract surgery. Additionally, the occlusion could be removed with a non-invasive procedure, and was maintained clearly for several years.

Prevention of postoperative capsular bag opacification using intraocular lenses and endocapsular devices maintaining an open or expanded capsular bag

Postoperative capsule opacification is a multifactorial physiological consequence of cataract surgery that remains the most common complication of this procedure. A literature review that included several intraocular lenses (IOLs) and endocapsular devices studied in our laboratory found that devices maintaining the capsular bag in an open or expanded state were associated with improved bag clarity. This observed effect likely occurs secondary to the complex interactions of myriad mechanisms, which include formation of a barrier to lens epithelial cell (LEC) migration, mechanical compression of residual LECs, mechanical stretch at the level of the capsule equator, maintenance of overall bag contour, and enhanced endocapsular circulation of aqueous humor. We review the designs of endocapsular devices and IOLs that minimize the degree of postoperative capsule opacification by preventing capsular bag collapse and discuss the underlying mechanisms that contribute to this phenomenon.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Anterior capsule opacification after femtosecond laser-assisted cataract surgery: Clinical classification versus Scheimpflug device densitometry values

PURPOSE

To compare the clinical classification of anterior capsule opacification (ACO) after femtosecond laser-assisted cataract surgery with the mean density values of ACO provided by rotating Scheimpflug device (Pentacam HR) densitometry software and to determine which densitometry method correlates best with the clinical classification.

SETTING

Ophthalmology Department, Donostia University Hospital, Donostia-San Sebastian, Spain.

DESIGN

Prospective comparative study.

METHODS

Femtosecond laser-assisted cataract surgery was performed using the Victus platform between June 2014 and March 2015. Inclusion criteria were age between 55 years and 85 years, a pupil diameter larger than 6.0 mm in full mydriasis, no intraoperative complications, a curvilinear anterior capsulotomy without tears, and an intraocular lens in the correct intracapsular position at the end surgery. The ACO was measured by a clinical classification ranging from 0 to 4. In addition, ACO density was measured with the Scheimpflug device using 3 densitometry methods (area, linear, and peak).

RESULTS

The study comprised 32 eyes of 32 patients. Area and linear densitometry values provided by the Scheimpflug device had a strong correlation with the values obtained by clinical classification, whereas peak densitometry values had a very weak correlation at 6 months (area densitometry: Spearman ρ = 0.78; P < .0005; linear densitometry: ρ = 0.73; P < .0005; peak densitometry ρ = 0.21; P = .2).

CONCLUSION

The Scheimpflug device provided an objective measurement of ACO after cataract surgery.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Sustained-release genistein from nanostructured lipid carrier suppresses human lens epithelial cell growth

AIM

To design and investigate the efficacy of a modified nanostructured lipid carrier loaded with genistein (Gen-NLC) to inhibit human lens epithelial cells (HLECs) proliferation.

METHODS

Gen-NLC was made by melt emulsification method. The morphology, particle size (PS), zeta potentials (ZP), encapsulation efficiency (EE) and in vitro release were characterized. The inhibition effect of nanostructured lipid carrier (NLC), genistein (Gen) and Gen-NLC on HLECs proliferation was evaluated by cell counting kit-8 (CCK-8) assay, gene and protein expression of the proliferation marker Ki67 were evaluated with real-time quantitative polymerase chain reaction (RT-qPCR) and immunofluorescence analyses.

RESULTS

The mean PS of Gen-NLC was 80.12±1.55 nm with a mean polydispersity index of 0.11±0.02. The mean ZP was -7.14±0.38 mV and the EE of Gen in the nanoparticles was 92.3%±0.73%. Transmission electron microscopy showed that Gen-NLC displayed spherical-shaped particles covered by an outer-layer structure. In vitro release experiments demonstrated a prolonged drug release for 72h. The CCK-8 assay results showed the NLC had no inhibitory effect on HLECs and Gen-NLC displayed a much more prominent inhibitory effect on cellular growth compared to Gen of the same concentration. The mRNA and protein expression of Ki67 in LECs decreased significantly in Gen-NLC group.

CONCLUSION

Sustained drug release by Gen-NLCs may impede HLEC growth.

Capsule contraction syndrome with a microincision foldable hydrophilic acrylic intraocular lens: two case reports and review of the literature

Here we present 2 cases of capsule contraction syndrome (CCS). In both cases, a hydrophilic acrylic Akreos MI60 (Bausch and Lomb) intraocular lens (IOL) was implanted in the capsular bag through microincision cataract surgery, and the literature on the subject is reviewed. Since CCS has been described after the implantation of every IOL type, it is unlikely that the Akreos MI60 chemical and physical properties may cause CCS. When CCS occurs with IOLs composed of increasingly flexible materials that are inserted through incisions of decreasing size, a severe dislocation and deformation of IOL optics and haptics may develop. In both cases illustrated here, Nd:YAG laser anterior capsulotomy was highly effective. Hence, also based on the literature, which reports severe complications as a result of surgical intervention, it is suggested that Nd:YAG laser anterior capsulotomy be the first line of CCS treatment when the luxation of an IOL capsular bag is absent.

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.

Anterior capsular phimosis occluding the capsulorhexis opening after cataract surgery in a diabetic patient with high hemoglobin A1C

PURPOSE

To report a case of complete occlusion of the capsulorhexis opening in a DM patient with high hemoglobin A1C level.

METHODS

A 77-year-old woman with non-insulin-dependent diabetes underwent uncomplicated phacoemulsification in both eyes. One year later, she presented again because of reduced vision (best-corrected visual acuity of 16/20 in the right eye, 6/20 in the left eye). Dilated examination revealed marked anterior capsular contraction in the right eye and anterior capsular phimosis totally occluding the capsulorhexis opening in the left eye.

RESULTS

The severity of diabetic retinopathy and her fasting blood sugar (225 mg/dl) and hemoglobin A1C level (8.5%) increased during the previous year. Uncorrected visual acuity of 18/20 (OS) was achieved after a neodymium:YAG (Nd:YAG) radial anterior capsulotomy was performed.

CONCLUSION

Microvascular complications such as diabetic retinopathy or diabetic iritis can occur in patient with uncontrolled diabetes mellitus. The pathophysiology of anterior capsular phimosis in this patient is probably increased vascular permeability chronically associated with diabetes.

Multifocal IOL Implant with or without Capsular Tension Ring: Study of Wavefront Error and Visual Performance

Purpose

To evaluate visual performance and wavefront error after multifocal intraocular lens (MIOL) implant with or without capsular tension ring (CTR).

Methods

Sixty eyes of 60 candidates for phacoemulsification and MIOL implantation were included in the study and were randomly divided into 2 groups. Thirty eyes (group 1) were implanted with the AcrySof ReSTOR® SN60D3 MIOL and Corneal® ACPI 11 CTR and 30 eyes (group 2) received the same MIOL with no CTR.

Results

Twenty days and at 360 days after surgery, the uncorrected and corrected distance visual acuity at high and low contrast were not significantly different between the 2 groups. The root mean square (RMS) of ocular and internal wavefront error was significantly different in the 2 groups early after surgery and did not modify significantly over the 1-year follow-up period. The RMS of total and internal high-order aberrations and ocular and internal trefoil and coma aberrations were significantly lower in group 1 compared to group 2 (p<0.05). Ocular, corneal, internal modulation transfer function at high and low spatial frequencies and ocular, corneal, internal Strehl ratio were not significantly different between the groups. The IOL decentration and tilt were higher in group 1 compared to group 2.

Conclusions

ReSTOR MIOL was effective in improving visual performance and provided a good quality of vision due to a significant reduction of high-order spherical aberration. The implant of CTR additionally reduced the ocular wavefront error related to a reduction of third-order aberration related to better IOL position.

Sustained-release celecoxib from incubated acrylic intraocular lenses suppresses lens epithelial cell growth in an ex vivo model of posterior capsule opacity

PURPOSE

To determine whether celecoxib (CXB) can be released from incubated intraocular lenses (IOLs) sufficiently to inhibit lens epithelial cell (LEC) growth in an ex vivo model of posterior capsule opacification (PCO).

MATERIALS

LEC growth was evaluated for 14 days in canine lens capsules (LCs) that had been exposed to media containing 20 μM CXB for 1-5 days. After the incubation of hydrophilic and hydrophobic IOLs in CXB solution, the determination of the in vitro release of CXB from the IOLs was performed for up to 28 days. The incubated and nonincubated IOLs were evaluated in the ex vivo model of PCO, and the rate of LEC growth was evaluated over 28 days.

RESULTS

The treatment of LCs with 20 μM CXB for 4 and 5 days completely inhibited LEC growth. LEC repopulation did not occur after the removal of CXB. IOLs incubated in CXB for 24 h resulted in a sustained release of CXB in vitro at levels theoretically sufficient to inhibit PCO. LCs in the ex vivo model of PCO treated with acrylic IOLs incubated in CXB had significantly suppressed LEC ingrowth compared with untreated and IOL-only LCs.

CONCLUSIONS

A 4-day treatment of LCs with a concentration of 20 μM CXB may effectively prevent PCO. IOLs incubated in CXB for 24 h resulted in a sustained release of CXB in vitro at levels sufficient to inhibit LEC growth in the ex vivo model of PCO. Further studies are needed to determine whether CXB-incubated IOLs can effectively prevent the development of PCO in vivo.

Risk of late intraocular lens dislocation after cataract surgery, 1980-2009: a population-based study

PURPOSE

To estimate the long-term cumulative risk of late posterior chamber intraocular lens (IOL) dislocation after cataract extraction in a population-based cohort.

DESIGN

Retrospective cohort study and nested case-control study.

METHODS

The records of all residents of Olmsted County, Minnesota, who underwent cataract extraction from January 1, 1980, through May 31, 2009, (14 471 cases in 9577 residents) and who were diagnosed with late posterior chamber IOL dislocation in the same period were reviewed. Cases were identified through the Rochester Epidemiology Project. Three controls chosen from the cataract surgery cohort were matched to each IOL dislocation case by age, gender, and duration of follow-up. Records were reviewed to confirm case status and to ascertain risk factor information. The cumulative risk of IOL dislocation was estimated by using the Kaplan-Meier method. Logistic regression models assessed differences between cases and controls.

RESULTS

We identified 16 cases of late posterior chamber IOL dislocation, 9 with in-the-bag dislocations and 7 with out-of-the-bag dislocations. At 5, 10, 15, 20, and 25 years after cataract extraction, the cumulative risk of IOL dislocation was 0.1%, 0.1%, 0.2%, 0.7%, and 1.7%, respectively. There was no significant difference in the risk of late IOL dislocation after extracapsular cataract extraction when compared with phacoemulsification (P = .21) or between different decades of surgery (P = .92). Pseudoexfoliation and zonular laxity at surgery were associated significantly with late IOL dislocation (P = .01).

CONCLUSIONS

The long-term cumulative risk of late IOL dislocation after cataract extraction was low and did not significantly change over our nearly 30-year study period.

Pathology of 157 human cadaver eyes with round-edged or modern square-edged silicone intraocular lenses: analyses of capsule bag opacification

PURPOSE

To assess the degree of capsular bag opacification in human cadaver eyes with silicone intraocular lenses (IOLs), specifically comparing the differences between round-edged IOLs and modern square-edged IOLs.

SETTING

John A. Moran Eye Center, University of Utah, USA.

DESIGN

Experimental study.

METHODS

The eyes were immersed in 10% formalin on enucleation. They had anterior segment scanning with a very-high-frequency ultrasound (Artemis). After the eyes were sectioned at the equator, gross examination of the anterior segment was performed from the posterior aspect to assess the degree of capsular bag opacification, coverage of the IOL edge by the anterior capsule, and IOL fixation. Selected eyes also had histopathologic examination.

RESULTS

Eighty-seven eyes with a 3-piece round-edged IOL, 43 with a 3-piece square-edged IOL, 26 with a 1-piece plate IOL, and 1 with an accommodating IOL design were included in the analyses of capsular bag opacification. Comparison between 3-piece round-edged IOLs and square-edged IOLs showed statistically significant differences in central posterior capsule opacification (PCO) (P=.0001687) and peripheral PCO (P<.0001). In eyes with square-edged IOLs, PCO had a tendency to start in areas without capsulorhexis coverage of the optic. Twenty-one of 26 eyes with a silicone plate IOL had a neodymium:YAG posterior capsulotomy for dense PCO.

CONCLUSIONS

This first study using pseudophakic human cadaver eyes that includes a significant number of modern 3-piece silicone IOLs with square optic edges confirmed the role of this design in the prevention of PCO.

FINANCIAL DISCLOSURE

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

Anterior capsule relaxing incisions with neodymium:YAG laser for patients at high-risk for anterior capsule contraction

PURPOSE

To examine the effect of anterior capsule relaxing incisions created with a neodymium:YAG (Nd:YAG) laser on prevention of anterior capsule contraction after cataract surgery in high-risk patients.

SETTING

Hayashi Eye Hospital, Fukuoka, Japan.

DESIGN

Randomized masked clinical trials.

METHODS

Patients at high risk for anterior capsule contraction had anterior capsule relaxing incisions in either eye 3 days postoperatively. The anterior capsule opening was measured using a Scheimpflug videophotography system (EAS-1000) immediately and 1, 3, and 6 months after capsulotomy, and the percentage reduction in area was calculated. The degree of intraocular lens (IOL) decentration and tilt, posterior capsule opacification (PCO), and other complications were also assessed.

RESULTS

Of the 84 patients included, 30 had primary angle closure, 28 had pseudoexfoliation, and 26 had diabetic retinopathy. There was no significant difference in the mean opening area between fellow eyes at baseline. In patients with primary angle closure, the area was significantly greater and the percentage reduction in area was significantly less in the capsulotomy group than in the no-capsulotomy group (P≤.0428). In patients with pseudoexfoliation or diabetic retinopathy, the percentage reduction was significantly less in the capsulotomy group than in the no-capsulotomy group (P≤.0493), although there was no significant difference in area. No significant difference was found in IOL decentration or tilt, PCO, or incidence of other complications.

CONCLUSION

Neodymium:YAG laser anterior capsule relaxing incisions in the early period after cataract surgery were effective in preventing anterior capsule contraction in high-risk patients and had no adverse effects.

FINANCIAL DISCLOSURE

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

Computational model of evolving lens capsule biomechanics following cataract-like surgery

Cataract surgery is an invasive procedure whereby lens fibers are removed through a permanent central hole, or capsulorhexis, in the surrounding lens capsule and replaced with an artificial intraocular lens (IOL). Remnant lens epithelial cells subsequently transdifferentiate to a more contractile and synthetic wound-healing phenotype, which causes significant structural and mechanical adaptations of the residual lens capsule. The goal of this study is to present a computational model capable of capturing salient features of the biomechanical evolution of the lens capsule following cataract-like surgery. The model is shown to predict marked long-term increases in thickness and stiffness of the lens capsule nearest the edge of the capsulorhexis comparable to reported measurements. Such models represent a first step toward understanding better the long-term interactions between the residual lens capsule and implanted IOL, thus initiating a new paradigm for the design of improved IOLs, including those having an accommodative feature.