Sealed-capsule irrigation with distilled deionized water to prevent posterior capsule opacification--prospective, randomized clinical trial

Comparison of the Incidence of Nd:YAG Laser Capsulotomy Based on the Type of Intraocular Lens

Background and Objectives: Posterior capsular opacification (PCO) is the most common long-term complication of successful cataract surgery and can cause visual impairment. We aimed to investigate the effects of intraocular lens (IOL) characteristics on PCO by comparing the incidence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy for different types of intraocular lenses. Materials and Methods: A retrospective analysis was performed on 2866 eyes that underwent cataract surgery between January 2010 and December 2017, with at least 5 years of follow-up. The IOLs used for surgery were the hydrophobic lenses SN60WF (Alcon, Fort Worth, TX, USA), ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA), and MX60 (Bausch & Lomb, Rochester, NY, USA), and the hydrophilic lens MI60 (Bausch & Lomb, Rochester, NY, USA). We analyzed the incidence of Nd:YAG laser capsulotomy according to the type of IOL used. Results: The incidence of Nd:YAG laser capsulotomy was significantly higher with MI60 lenses (31.70%, 175/552 eyes) compared to SN60WF (7.90%, 113/1431 eyes), ZCB00 (10.06%, 64/636 eyes), and MX60 (10.57%, 13/123 eyes; p < 0.001) lenses. The incidence of Nd:YAG laser capsulotomy was significantly lower with the hydrophobic IOLs (8.68%, 190/2190 eyes) than with the hydrophilic IOL (31.70%, 175/552 eyes; p < 0.001). Over time, the rate of increase in the cumulative number of Nd:YAG laser capsulotomy cases was the highest with MI60. The cumulative rate of Nd:YAG laser capsulotomy during the first 3 years was 4.90% with SN60WF (70/1431 eyes), 6.76% with ZCB00 (43/636 eyes), 8.94% with MX60 (11/123 eyes), and 26.10% with MI60 (144/552 eyes) lenses. Conclusions: The incidence of PCO is influenced by the material of the IOLs. The hydrophilic IOL was associated with a higher rate of Nd:YAG laser capsulotomy than the hydrophobic IOLs, with a shorter time to Nd:YAG laser capsulotomy.

Posterior capsular opacification and Nd:YAG capsulotomy rates in patients implanted with square-edged and non-square-edged intraocular lenses in manual small-incision cataract surgery: A randomized controlled study

Purpose

To study posterior capsular opacification (PCO) and neodymium-doped yttrium aluminum garnet (Nd:YAG) capsulotomy rates in patients implanted with square-edged and non-square-edged intraocular lenses (IOLs) in manual small-incision cataract surgery (MSICS).

Setting

Tertiary eye care center.

Design

Prospective, comparative, and randomized controlled study.

Methods

This study included patients with senile cataracts scheduled for MSICS and IOL implantation. One eye of each patient was randomized to the implantation of square-edged (S group) or non-square-edged IOL (NSQ group). An independent observer analyzed PCO at 6, 12, 18, and 24 months under slit-lamp illumination.

Results

A total of 104 eyes were included in this study. The mean age of the participants in the two groups was 63.2 (±8.2) years, and there were 65 (62.5%) men and 39 women (37.5%). The mean best-corrected visual acuity (BCVA) values at 6, 12, and 18 months were 0.157 (±0.10), 0.11 (±0.12), and 0.12 (±0.11), respectively, in the S group and 0.17 (±0.10), 0.17 (±0.12), and 0.20 (±0.17), respectively, in the NSQ group. At 12 (P = 0.03) and 18 months (P = 0.01) follow-up, the BCVA of the S group was significantly better than that of the NSQ group. Four eyes in the NSQ group and one eye in the S group required Nd:YAG.

Conclusion

Evaluation of PCO and Nd:YAG capsulotomy rates showed that the 360° square of the posterior IOL edge plays a role in the prevention of PCO. Owing to the low cost of the material and the easy availability of IOLs manufactured from it, square-edged IOL has a definite role in the prevention of PCO in MSICS.

Evaluation of posterior capsular opacification and neodymium-doped yttrium aluminum garnet capsulotomy rates in patients with hydrophilic intraocular lens implantation with and without ocular viscoelastic device

Purpose

To study the effect of intraocular lens (IOL) implantation with and without ocular viscoelastic device (OVD) on posterior capsular opacification (PCO) in eyes with phacoemulsification.

Methods

This prospective, comparative, and randomized case series included 70 patients (140 eyes) with senile cataracts scheduled for phacoemulsification and IOL implantation in a tertiary eye c are center. One eye of each patient was randomized to one of the two groups, namely, control and OVD. After phacoemulsification, the IOL was placed in the capsular bag under balanced salt solution (BSS) in the control group, whereas the IOL was placed under OVD in the OVD group. PCO was analyzed by an independent observer at 6, 12, and 18 months under slit-lamp illumination.

Results

The mean age of the participants in the two groups was 61.2 (±9.9) years. Of the total participants, 68 (48.5%) were men and 72 (51.5%) were women. The mean keratometry (K1, K2) values of the OVD (44.26 ± 1.43, 44.93 ± 1.66) and control (44.51 ± 1.74, 44.69 ± 1.49) groups were similar. The mean IOL powers of the control and OVD groups were 21.25 (±1.94) and 21.53 (±1.86), respectively (P = 0.463). The mean best-corrected visual acuity (BCVA) of the control group at 6-, 12-, and 18-month follow-ups were 0.622 (±0.253), 0.315 (±0.203), and 0.063 (±0.163), respectively, whereas those of the OVD group were 0.592 (±0.253), 0.336 (±0.169), and 0.066 (±0.118), respectively (P = 0.922). None of the patients had postoperative raised intraocular pressure (IOP), uveitis, or endophthalmitis. Three and four eyes in the control and OVD groups, respectively, required neodymium-doped yttrium aluminum garnet (ND: YAG) capsulotomy at study termination (P = 0.999).

Conclusion

The hydroimplantation technique of the placement of hydrophilic IOL did not reduce the PCO rate in the 18-month follow-up period. The ND: YAG capsulotomy rate did not differ between the groups.

Lens Epithelial Cell Removal in Routine Phacoemulsification: Is It Worth the Bother?

PURPOSE

To review the literature on crystalline lens epithelial cell (LEC) removal in routine phacoemulsification and determine whether it should be incorporated as part of a surgeon's standard technique.

DESIGN

Perspective.

METHODS

Expert commentary with video demonstrations on techniques of removal of LECs and associated potential complications. Discussion incorporates the importance of LEC removal, a review of techniques to prevent posterior capsular opacification (PCO), and the effects of intraocular lens design on LEC proliferation and PCO.

RESULTS

The evidence suggests that LEC removal should be routinely performed as it can be carried out safely and with considerable short- and long-term benefits for patients. With effective cleanup, there is reduced anterior capsule opacification, fibrosis, and decentration of the capsular bag as well as reduced rates of posterior capsular opacification. Techniques for removal are easy to learn, with very low complication rates, and can reduce the risk of the long-term need for technically complex procedures such as intraocular lens explantation.

CONCLUSIONS

LEC removal from both the anterior and posterior capsule is part of a continuous, incremental improvement of cataract surgery and should be introduced to ophthalmology trainees during their formative years as part of their regular cataract surgery armamentarium.

Posterior Capsule Opacification: A Review of Experimental Studies

Posterior capsule opacification (PCO) is the most common complication of cataract surgery. It causes a gradual deterioration of visual acuity, which would otherwise improve after a successful procedure. Despite recent advances in ophthalmology, this complication has not been eradicated, and the incidence of PCO can be as high as 10%. This article reviews the literature concerning the pathomechanism of PCO and examines the biochemical pathways involved in its formation and methods to prevent this complication. We also review the reported tests performed in cell cultures under laboratory conditions and in experimental animal models and in ex vivo human lens capsules. Finally, we describe research involving human eyes in the clinical setting and pharmacological methods that may reduce the frequency of PCO. Due to the multifactorial etiology of PCO, in vitro studies make it possible to assess the factors contributing to its complications and search for new therapeutic targets. Not all pathways involved in cell proliferation, migration, and contraction of the lens capsule are reproducible in laboratory conditions; moreover, PCO in humans and laboratory animals may be additionally stimulated by various degrees of postoperative reactions depending on the course of surgery. Therefore, further studies are necessary.

Fluid-jet technique to polish the posterior capsule for phacoemulsification surgeries: efficacy and safety evaluation

PURPOSE

To compare the efficacy and safety of a fluid-jet technique with capsular polish in reducing residual lens fibers (RLFs) in phacoemulsification surgery.

SETTING

Single center.

DESIGN

Prospective nonrandomized comparative study.

METHODS

Patients receiving phacoemulsification were included. Consecutive eligible patients alternately underwent either removal of RLFs on the posterior capsule using capsular polish after irrigation and aspiration, and before intraocular lens (IOL) implantation, or RLF removal using a fluid-jet technique after IOL implantation. Posterior capsular images were used to quantify RLFs. Visual parameters were evaluated at 1 day, 1 week, and 1 year postoperatively. The proportion of capsule occupied by posterior capsule opacification (PCO) (area %) and incidence of protocol-driven laser posterior capsulotomy were recorded at 1 year in masked fashion.

RESULTS

Seven hundred forty eyes were allocated to polishing (n = 370) or fluid-jet technique (n = 370). Polishing required 70.4 ± 17.5 seconds and fluid-jet 32.2 ± 9.9 seconds (P ≤ 0.001). Compared with the polishing group, capsular area occupied by RLFs in the fluid-jet group was significantly smaller (3.5% vs 0.5%, P = .031) at the end of surgery. One day postoperatively, the fluid-jet group had more desirable corrected distance visual acuity, objective scattering index, and Strehl ratio (all P < .05). PCO area percentage did not differ between groups (6.5% vs 4.5%, P = .252) 1 year postoperatively, but incidence of posterior capsulotomy was lower in the fluid-jet group (3.2% vs 0.8%, P = .019).

CONCLUSIONS

Fluid-jet removed RLFs effectively and had lower incidence of postoperative capsulotomy than capsular polishing.

Research Progress of Drug Prophylaxis for Lens Capsule Opacification after Cataract Surgery

Phacoemulsification combined with intraocular lens (IOL) implantation is the international standard operation procedure for cataract and has been generalized worldwide. However, lens capsule opacification, one of the common complications after cataract surgery, impacts the recovery of patients' visual function to a large extent. Lens capsule opacification has two types, anterior capsule opacification (ACO) and posterior capsule opacification (PCO), according to the location. There is not an accepted approach to treat ACO. Nd : YAG laser capsulotomy, the common treatment of PCO, can effectively improve the vision, but may cause a series of complications and is inappropriate for children who are too young to cooperate with this treatment. It is generally known that the responses of lens epithelial cells (LECs) after cataract surgery, including cell proliferation, migration, and epithelial-mesenchymal transition (EMT), play a key role in the pathogenesis of lens capsule opacification. Scholars found that substantial drugs can reduce the occurrence of lens capsule opacification by inhibiting, clearing, or killing LECs, and made great efforts as well as innovations on the exploration of drug species or modes of administration. This article is a systematic interpretation and elaboration about how to prevent lens capsule opacification after cataract surgery via different drugs.

Osmotically induced removal of lens epithelial cells to prevent PCO after pediatric cataract surgery: Pilot study to assess feasibility

PURPOSE

Development of an osmotic-shock technique to remove human lens epithelial cells (LECs) as a preventive measure to address posterior capsule opacification (PCO) after pediatric cataract surgery.

SETTING

Department of Genetics, UCL Institute of Ophthalmology, London, England, and Department of Ophthalmology, Ruijin Hospital, Jiao Tong University, Shanghai, China.

DESIGN

Laboratory study.

METHODS

Various tissue preparations of human LECs (cultured on coverslips/collagen-coated membrane inserts, human lens capsule biopsies, and lens organ cultured PCO models) were subjected to a single or incremental hyperosmotic shock (NaCl, 350-4000 mOsm/L) in the presence of inhibitors of the Na+-K+-2Cl- cotransporter (NKCC) (to disable the regulatory volume increase [RVI] process). The integrity of the cell monolayer was determined by phase-contrast microscopy, viability assays, and measurement of transepithelial resistance.

RESULTS

Hyperosmotic shock (400 mOsm/L) caused rapid cell shrinkage (<5 minutes) in all the LEC models studied. In the absence of the NKCC inhibitor, the shrunk cells gradually returned to their original cell volume and architecture over time, while still exposed to the hyperosmotic shock. However, inhibition of the RVI process disabled the ability for restoration of cell volume leading to persistent cell shrinkage, subsequently resulting in cell detachment from the underlying support medium.

CONCLUSION

Hyperosmotic shock in the presence of inhibitors of the RVI process was effective in rapidly detaching LECs from their basement membranes. This technique could potentially facilitate removal of residual LECs left on the lens capsule after cataract surgery, thus decreasing or eliminating the risk for aggressive cell proliferation and the development of PCO.

Prevention of posterior capsule opacification through intracapsular hydrogen peroxide or distilled water treatment in human donor tissue

In order to determine whether posterior capsule opacification after cataract surgery, could be delayed or inhibited through the application of hydrogen peroxide (H₂O₂) or distilled water (H₂Od),we extracted lens capsules from 25 human donor eye globes. Samples were treated for 5 min with either 30 mM H₂O₂ or H₂Od or used as controls, and cultured for one month, during which dark field and tilt illumination photos were taken. These were used to observe and quantify, time until cellular growth and confluence on the posterior capsule. After culture, histological sections were stained for H&E, α-SMA, Ki-67 and vimentin and evaluated. We prevented cellular growth in 50% of H₂Od and 58% H₂O₂ of treated samples. The overall prevention of cell growth compared to cultured controls was significant for both treatments while there was no significant difference between them. In the cases where cellular growth was not prevented, both treatments significantly delay cellular growth. Until day 28 none of the treated samples of either type that had shown growth reached total confluence. All cultured controls reached total confluence before treated samples (median = day 11.5). Also, histologically, there was a clear morphological difference between cultured controls and treated samples.

AIR/FLUID-DROPPING TECHNIQUE FOR INTRACAPSULAR DISTILLED WATER APPLICATION: A Vitrectomy Approach for Selective Targeting of Lens Epithelial Cells

PURPOSE

We describe a simplified technique of intracapsular distilled water application for targeting lens epithelial cells using vitrectomy approach of fluid-air exchange and to evaluate the reliability and safety of this technique.

METHODS

Consecutive patients with cataract were randomly assigned to treatment group and control group. After the nucleus removal and cortical aspiration, the space of anterior chamber and capsular bag were maintained with continuous infusion of sterile air by using fluid-air exchange technique through side-port incision. Distilled water was dropped into the capsular bag using a specially designed syringe. A concave air-fluid surface (a physical phenomenon) insured the contact of distilled water with the inner surface of the capsule without overflowing from the bag. The distilled water remained in place for 3 minutes and was then removed by the syringe.

RESULTS

No intraoperative surgical complication was observed, and no damage to adjacent intraocular structures was observed during the postoperative follow-up. There was no statistical difference of corneal endothelial cell loss between the treatment group and the control group. Histological study confirmed damage to the lens epithelial cells from anterior capsular specimens treated by the technique.

CONCLUSION

The simplified technique using vitrectomy approach is safe and specific for targeting lens epithelial cells without associated complications.

Current Status of IOL implantation in pediatric eyes: an update

INTRODUCTION

Pediatric cataracts are a huge problem worldwide, and with improving techniques and technology, the surgical treatment and postoperative visual rehabilitation are improving. Despite intraocular lenses(IOLs) being the standard of care for adult cataract surgery, this issue is still somewhat controversial, particularly in young children and infants due to lack of unequivocal evidence. This review therefore summarises the findings from recent studies on the aspect of IOL implantation in pediatric eyes. Areas covered: An extensive literature search was undertaken for published articles on congenital/developmental pediatric cataracts, and IOL implantation, where literature pertinent to traumatic and subluxated cataracts was not included in the review. Pubmed was used for literature search, and keywords entered were : pediatric, cataract surgery, intraocular lens, persistent fetal vasculature, outcomes, complications, visual performance with intraocular lenses. Expert commentary: Recent literature supports IOL implantation in most cases of congenital / developmental pediatric cataracts, and it seems like the way forward. However, the jury is still out on IOL implantation in infants, particularly in bilateral cataracts. Thus, surgeons must be extremely cautious in planning primary IOL implantation in infant eyes, and if they do perform IOL implantation, rigorous followup is mandatory.

Prevention of posterior capsular opacification

Posterior capsular opacification (PCO) is a common complication of cataract surgery. The development of PCO is due to a combination of the processes of proliferation, migration, and transdifferentiation of residual lens epithelial cells (LECs) on the lens capsule. In the past decades, various forms of PCO prevention have been examined, including adjustments of techniques and intraocular lens materials, pharmacological treatments, and prevention by interfering with biological processes in LECs. The only method so far that seems effective is the implantation of an intraocular lens with sharp edged optics to mechanically prevent PCO formation. In this review, current knowledge of the prevention of PCO will be described. We illustrate the biological pathways underlying PCO formation and the various approaches to interfere with the biological processes to prevent PCO. In this type of prevention, the use of nanotechnological advances can play a role.

Pediatric cataract: challenges and future directions

Cataract is a significant cause of visual disability in the pediatric population worldwide and can significantly impact the neurobiological development of a child. Early diagnosis and prompt surgical intervention is critical to prevent irreversible amblyopia. Thorough ocular evaluation, including the onset, duration, and morphology of a cataract, is essential to determine the timing for surgical intervention. Detailed assessment of the general health of the child, preferably in conjunction with a pediatrician, is helpful to rule out any associated systemic condition. Although pediatric cataracts have a diverse etiology, with the majority being idiopathic, genetic counseling and molecular testing should be undertaken with the help of a genetic counselor and/or geneticist in cases of hereditary cataracts. Advancement in surgical techniques and methods of optical rehabilitation has substantially improved the functional and anatomic outcomes of pediatric cataract surgeries in recent years. However, the phenomenon of refractive growth and the process of emmetropization have continued to puzzle pediatric ophthalmologists and highlight the need for future prospective studies. Posterior capsule opacification and secondary glaucoma are still the major postoperative complications necessitating long-term surveillance in children undergoing cataract surgery early in life. Successful management of pediatric cataracts depends on individualized care and experienced teamwork. We reviewed the etiology, preoperative evaluation including biometry, choice of intraocular lens, surgical techniques, and recent developments in the field of childhood cataract.