Effect of anterior capsule contraction on visual function after cataract surgery

Biomaterials in Relative Devices for Traumatic Cataract: Recent Advances and Future Perspectives

Ocular trauma deprives one of the vision for high-quality life. Management of a traumatic cataract requires extensive surgical experience with a range of biomaterials and biomedical devices including intraocular lenses (IOLs), capsular tension rings (CTRs), prosthetic iris (PSI) implants, bandage contact lenses (BCLs), artificial corneas (ACs), and surgical sutures. Numerous demands, involving biocompatibility, cell toxicity, processability, mechanical strength, toughness/flexibility, transparency/opacity, hydrophilicity/hydrophobicity, and stability/biodegradability, are widely considered for fabricating these biomaterials and devices. Furthermore, a multifunction including drug-release and photothermal therapy is also endearing to those biomaterials in IOLs, CTRs, BCLs, and surgical sutures for anti-inflammational and antibacterial characteristics during traumatic cataract treatments. More recently, 3D printing has been demonstrated to effectively fabricate PSI and ACs with complex shapes to meet the personal requirements of patients. We summarize the main principles and the recent achievements of these advances. We also suggest the potential directions for their future development and discuss the remaining challenges.

Exploring anterion capsular contraction syndrome in cataract surgery: insights into pathogenesis, clinical course, influencing factors, and intervention approaches

Anterior capsular contraction syndrome (ACCS) is a challenging complication that can occur following phacoemulsification cataract surgery. Characterized by capsular bag wrinkling, intraocular lens (IOL) decentration and tilt, ACCS can have negative effects on visual outcomes and patient satisfaction. This review aims to investigate the pathogenesis, clinical course, influencing factors, and intervention approaches for ACCS after cataract surgery. By understanding the underlying mechanisms and identifying factors that contribute to ACCS, surgeons can enhance their ability to predict and manage this complication. Various intervention strategies are discussed, highlighting their importance in reducing complications and improving surgical outcomes. However, further research is needed to determine optimal prevention and management strategies through long-term follow-up and comparative analyses. Advancements in this field will ultimately lead to improved visual outcomes and optimized cataract surgery for patients.

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.

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.

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.

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.

[Capsule contraction syndrome in pseudophakia]

This is a review of the literature on capsule contraction syndrome (CCS) in pseudophakic patients that involves severe fibrosis along the margin of the anterior capsule's opening and progressive contraction of the capsular bag. Possible causes of CCS and principles of its prevention and treatment have been analyzed.

Elevated TGF-β2 level in aqueous humor of cataract patients with high myopia: Potential risk factor for capsule contraction syndrome

PURPOSE

To evaluate the level of transforming growth factor-β2 (TGF-β2) in the aqueous humor of highly myopic cataract patients and its correlation with capsule contraction syndrome.

SETTING

Eye and ENT Hospital of Fudan University, Shanghai, China.

DESIGN

Prospective comparative case series.

METHODS

The highly myopic cataract patients were divided into the following 2 groups according to the Lens Opacity Classification System III: nuclear color (NC) 2 to 3 and NC 5 to 6. Aqueous humor TGF-β2 concentrations were assayed in the highly myopic cataract and age-related cataract groups. The TGF-β2, TGF-βRII (the type II receptor for TGF-β2), and α-smooth muscle actin (α-SMA) expressions in lens epithelial cells (LECs) were detected by real-time polymerase chain reaction and immunofluorescent staining.

RESULTS

The study comprised 40 highly myopic cataract patients (40 eyes) and 20 patients (20 eyes) with age-related cataract as the control group. Compared with the control group, the highly myopic cataract group had significantly higher TGF-β2 concentration in the aqueous humor and increased TGF-βRII expression in LECs, especially in NC 5 to 6 cases. Expression of α-SMA was barely detectable in both groups.

CONCLUSION

In highly myopic cataract patients, especially those with dark nuclei, elevated aqueous humor TGF-β2 levels and the upregulated TGF-βRII expression in LECs might contribute to the pathogenesis of capsule contraction syndrome through transdifferentiation of LECs into myofibroblasts.

FINANCIAL DISCLOSURE

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

Elevated Transforming Growth Factor-β2 in the Aqueous Humor: A Possible Explanation for High Rate of Capsular Contraction Syndrome in High Myopia

Purpose. The purpose of the study was to elucidate the role of transforming growth factor-beta 2 (TGF-β2) in the development of high myopic capsular contraction syndrome. Methods. Nineteen cases of capsular contraction syndrome, including 14 with high myopia, were collected, and their clinical data were reviewed. Aqueous humor and anterior capsular membranes were obtained during capsulotomy. Hematoxylin-eosin and immunohistochemical staining with anti-TGF-β2 antibody were performed on capsular membranes. TGF-β2 levels in aqueous humor were assayed using ELISA and western blot. Results. High myopia was significantly associated with the incidence of capsular contraction syndrome (odds ratio: 14.74, P < 0.001, 95% CI: 5.29–41.05). Histopathological analysis revealed proliferation of fibroblast-like lens epithelial cells on the shrunken anterior capsule, labeled with TGF-β2 antibodies. ELISA and Western blot showed higher levels of TGF-β2 in aqueous humor of patients with capsular contraction syndrome and high myopia. Conclusions. High myopia is a risk factor for capsular contraction syndrome. Elevated TGF-β2 levels in high myopic cataract patients may play an important role in the pathogenesis of capsular contraction syndrome.

Anterior capsule contraction treated by femtosecond laser capsulotomy

PURPOSE

To describe a new method to treat severe anterior capsule contraction using a femtosecond laser anterior capsulotomy.

METHODS

Case report.

RESULTS

A 48-year-old woman with a history of myotonic dystrophy experienced a severe contraction of the anterior capsule following an uneventful phacoemulsification cataract surgery with a hydrophilic acrylic intraocular lens implanted in the capsular bag. A femtosecond laser anterior capsulotomy was performed using a non-applanating fluid-filled interface. The spectral-domain optical coherence tomography imaging system associated with the laser enabled precise centration and location of the capsulotomy with a posterior cut located between the anterior surface of the intraocular lens and the anterior capsule inner surface. The free-floating capsulotomy was easily removed after the laser procedure, and 8 days postoperatively visual acuity recovered and myopic shift regressed with an intraocular lens centered in the capsular bag.

CONCLUSIONS

Femtosecond laser assisted by a high-resolution imaging system appears to be a safe and efficient treatment for severe anterior capsule contraction.

Effect of haptic material and number of intraocular lens on anterior capsule contraction after cataract surgery

Purpose

To evaluate changes over time of the anterior capsule opening size after phacoemulsification, based on haptic number and composition of three acrylic intraocular lenses (IOLs).

Methods

Fifty-five patients (70 eyes) were included. All underwent phacoemulsification followed by implantation of either an acrylic IOL with two-haptic (one-piece, 26 eyes; three-piece, 22 eyes), or four-haptic (one-piece, 22 eyes). The area of the anterior capsule opening size was measured one week postoperatively (baseline) and at three months.

Results

There was a significant reduction in the area of the anterior capsule opening from one week as compared to three months postoperatively in all groups (p < 0.001). However, there was no significant difference in the reduction in the anterior capsule opening between the IOLs (p = 0.36).

Conclusions

The number and material of the haptic of the three acrylic IOLs did not influence the degree of anterior capsule opening shrinkage.

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.

Prevention of anterior capsule contraction by anterior capsule relaxing incisions with neodymium:yttrium-aluminum-garnet laser

PURPOSE

To examine the effect of two or three neodymium:yttrium-aluminum-garnet (Nd:YAG) laser relaxing incisions made in the anterior capsular rim on prevention of anterior capsule contraction after cataract surgery.

DESIGN

Randomized clinical trials.

METHODS

One hundred patients scheduled for bilateral cataract surgery were randomized to one of two groups: two or three relaxing incisions in the left eye and no incisions in the right eye, and relaxing incisions in the right eye and no incisions in the left eye. The anterior capsule opening area was measured using Scheimpflug photography immediately after capsulotomy and at one, three, and six months after capsulotomy, and the percentage reduction was calculated. The degree of intraocular lens (IOL) decentration and tilt and of posterior capsule opacification (PCO) also were examined.

RESULTS

There was no significant difference in the anterior capsule opening area between fellow eyes at baseline (P > or = .1770). In patients who underwent two incisions, no significant difference was found between fellow eyes in the opening area (P > or = .4098) or in the percentage of reduction (P > or = .8730) throughout follow-up. In patients who underwent three incisions, the opening area in eyes with capsulotomy was significantly greater than that in eyes without capsulotomy (P < or = .0154), and the percentage reduction was significantly smaller in eyes with capsulotomy than in eyes without capsulotomy (P < or = .0016). No significant differences were found in the IOL decentration and tilt, or in PCO.

CONCLUSIONS

Three relaxing incisions made in the anterior capsule decrease the anterior capsule contraction, whereas two incisions do not.