Posterior capsule opacification and neodymium:YAG laser capsulotomy rates with 2 microincision intraocular lenses: Four-year results

Influence of the CleaRing intraocular open capsule device on refractive predictability in cataract surgery

BACKGROUND

The marked improvement in cataract surgery and intraocular lens (IOL) quality has led to a decline in posterior capsular opacification (PCO) incidence; however, PCO remains a common complication of cataract surgery. The CleaRing intraocular capsule open device (IOCD) decreases PCO incidence. We aimed to investigate the influence of the CleaRing IOCD on refractive predictability in cataract surgery.

METHODS

We conducted this prospective pilot study at the Wolfson Medical Center, Holon, Israel. Ten eyes of patients who underwent cataract surgery and insertion of an IOL after IOCD implantation into the capsular bag were included. All patients completed 12 months of follow-up, including refraction, measurement of uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), slit-lamp biomicroscopy, and ultrasound biomicroscopy.

RESULTS

All the surgeries were uneventful, with no postoperative complications. The IOL was centred in the device and bag in all cases. The mean prediction error at 1 and 12 months postoperatively was +0.28 ± 0.32 D and +0.50 ± 0.32 D, respectively. The mean UDVA was 0.17 ± 0.13 and 0.15 ± 0.11 logMAR, and the mean CDVA was 0.04 ± 0.10 and 0.04 ± 0.06 logMAR, respectively. The manifest refractive cylinders at 12 months postoperatively were compatible with corneal astigmatism.

CONCLUSIONS

Implantation of the IOCD resulted in a slight, predicted, and stable hyperopic shift with a low standard deviation. The standard deviation of the prediction error demonstrated excellent refractive accuracy and predictability using the IOCD, which was as low as 0.32 D at the 12-month follow-up.

Centrifugally concentric ring-patterned drug-loaded polymeric coating as an intraocular lens surface modification for efficient prevention of posterior capsular opacification

Posterior capsular opacification (PCO) is the main postoperative complication after intraocular lens (IOL) implantation in cataract surgery, because of the proliferation of the residual lens epithelial cells (LECs) in the lens capsule. Drug-eluting IOLs, aimed to develop an in situ drug delivery device, are the promising concept in recent years. As IOLs are optical devices other than implants, the feasibility and applicability remain a challenge for drug-eluting coatings. In this investigation, a centrifugally concentric ring-patterned drug-loaded poly(lactide-co-glycolic acid) (PLGA) coating was designed and fabricated by the spin coating technique. The concentric ring-patterned morphologies and the drug loading and release properties were carefully investigated, and the spin coating parameters were optimized. A concentric annular coating with a thin center and thick periphery was obtained, which was particularly suitable for the surface modification of IOLs, as the visual pathway of the intraocular light transmission greatly requires good light transmittance of the IOLs. IOLs with the immunosuppressant cyclosporin A (CsA)-loaded coating (CsA @ PLGA) modification were then fabricated for PCO prevention. The in vitro LECs culture results showed that the CsA @ PLGA coating-modified IOLs significantly inhibited cell proliferation and induced cell death. Western blot analysis showed that the efficient cell inhibition behavior of CsA was due to the autophagy-mediated cell death pathway. The in vivo intraocular implantation results confirmed the desired PCO inhibition effect. Thus, the centrifugally concentric ring-patterned drug-loaded PLGA coating obtained by the spin coating technique provides a simple yet effective alternative of IOL modification for PCO prevention. STATEMENT OF SIGNIFICANCE: • Concentric ring-patterned polymer coating, specifically for drug-eluting IOL fabrication, was developed by the spin coating technique. • The immunosuppressant CsA inhibited LEC proliferation through the autophagy-mediated cell death pathway. • Concentric ring-patterned CsA-eluting IOLs exhibited reliable in vivo PCO prevention. • The drug-eluting IOLs fabricated by the simple and economical spin coating technique have a great potential in clinical translation.

The Protective Effect of Metformin Use on Early Nd:YAG Laser Capsulotomy

Purpose

To determine the effect of metformin on early Nd:YAG laser treatment for posterior capsule opacification (PCO) and to explore a molecular mechanism to explain a possible protective effect of metformin against PCO.

Methods

We conducted: 1) a retrospective cohort study of patient eyes undergoing phacoemulsification at our institution; and 2) laboratory investigation of the effect of metformin on the behavior of lens epithelial cells in the context of an animal model for PCO. Population-averaged Cox proportional hazards modeling was used to estimate risk for time to Nd:YAG. For laboratory studies, expression of markers for epithelial-to-mesenchymal transition (EMT) implicated in PCO pathogenesis was measured in tissue culture and following extracapsular lens extraction in a mouse model.

Results

The rate of Nd:YAG laser capsulotomy was 13.1% among the 9798 eyes. Both metformin use and diabetes were protective factors for Nd:YAG laser capsulotomy in univariate analysis. However, in multivariable analysis with nondiabetics as the reference group, only metformin use among diabetics was significantly protective of Nd:YAG (hazard ratio: 0.68, 95% CI: 0.54–0.85, P = 0.0008), while eyes of patients with diabetes without metformin use did not significantly differ (P = 0.5026). Treatment of lens epithelial cells with metformin reduced the level of the EMT markers ⍺-SMA and pERK induced by TGF-β2. Similarly, metformin treatment reduced ⍺-SMA expression in lens epithelial cells following extracapsular lens extraction in a mouse model.

Conclusions

The protective effect of metformin against early Nd:YAG may relate to its ability to downregulate EMT in residual lens epithelial cells that otherwise trend toward myofibroblast development and PCO.

Uveal and capsular biocompatibility of a new hydrophobic acrylic microincision intraocular lens

PURPOSE

To evaluate uveal biocompatibility and capsular bag opacification of a new hydrophobic acrylic microincision intraocular lens (IOL) in comparison with a commercially available 1-piece hydrophobic acrylic IOL.

SETTING

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

DESIGN

Experimental study.

METHODS

Eight New Zealand rabbits underwent bilateral phacoemulsification and implantation of the preloaded Nanex multiSert IOL in one eye and a commercially available preloaded lens (AcrySof IQ in UltraSert, model AU00T0) in the contralateral eye. A slitlamp examination was performed weekly for 4 weeks. The rabbits were then killed humanely and their globes enucleated. Capsular bag opacification was assessed from the Miyake-Apple view, and the eyes were subjected to histopathologic evaluation.

RESULTS

Postoperative inflammatory reactions were similar between the test and control eyes in the 8 New Zealand rabbits. The mean postmortem central posterior capsule opacification (PCO) was 0.93 ± 0.73 in the test group and 1.19 ± 0.53 in the control group. The mean postmortem peripheral PCO was 1.75 ± 0.92 in the test group and 2.06 ± 0.77 in the control group. Central and peripheral PCO scores were not statistically different between the test and control groups (P = .41 and P = .35, respectively, 2-tailed t test: paired 2-sample for means).

CONCLUSIONS

A new 1-piece hydrophobic acrylic microincision IOL incorporating an ultraviolet-ozone treatment on the posterior surface performed similarly to a commercially available 1-piece hydrophobic acrylic IOL in terms of uveal and capsular biocompatibility in the rabbit model. To our knowledge, this is the first hydrophobic acrylic microincision IOL to demonstrate similar PCO performance when compared with a conventional, commercially available IOL.

Femtosecond laser induced nano-textured micropatterning to regulate cell functions on implanted biomaterials

Posterior capsular opacification (PCO) is the most common complication of cataract surgery. PCO is due to the proliferation, migration, and epithelial-to-mesenchymal transition of the residual lens epithelial cells (LECs) within the lens capsule. As surface topography influences cellular response, we investigated the effect of modulating the dimensions of periodic nano-textured patterns on the surface of an intraocular lens material to regulate lens epithelial cell functions such as cell adhesion, migration, orientation, and proliferation. Patterned poly(HEMA) samples were prepared by a femtosecond laser microfabrication, and the behaviors of human B-3 LECs were observed on groove/ridge patterns with widths varying from 5 to 40 µm. In the presence of ridge and groove patterns, the adherent cells elongated along the direction of the patterns, and f-actin of the cells was spread to a lesser extent on the nano-textured groove surfaces. Both single and collective cell migrations were significantly inhibited in the perpendicular direction of the patterns on the nano-textured micro-patterned samples. We also fabricated the patterns on the curved surface of a commercially available intraocular lens for in vivo evaluation. In vivo results showed that a patterned IOL could help suppress the progression of PCO by inhibiting cell migration from the edge to the center of the IOL. Our reports demonstrate that nano- and microscale topographical patterns on a biomaterial surface can regulate cellular behavior when it is implanted into animals.

The Effect of Capsulotomy Shape on Intraocular Light-Scattering after Nd:YAG Laser Capsulotomy

Purpose

To investigate the effects of capsulotomy shape on the visual acuity and visual quality after neodymium: yttrium aluminum garnet laser capsulotomy.

Methods

In this study, a total of 42 eyes from 35 patients with posterior capsule opacification were divided into the circular and cruciate groups. The corrected distance visual acuity (CDVA), objective scatter index (OSI), modulation transfer function cutoff (MTF cutoff), Strehl ratio, and Optical Quality Analysis System values at contrasts of 100%, 20%, and 9% (OV-100, OV-20, and OV-9) were measured at precapsulotomy and 1 week and 1 month postcapsulotomy. The pseudophakic dysphotopsia questionnaire (PDQ) was used to evaluate the subjects' satisfaction with treatment.

Results

OSI values were significantly higher in the cruciate group than in the circular group at 1 week and 1 month after capsulotomy (P=0.013 and P < 0.001). No significant difference was found in the OSI values between the two groups before capsulotomy (t = 0.52; P=0.61). The decrease in OSI was higher in the circular group than in the cruciate group at 1 week and 1 month after capsulotomy (P=0.036 and P=0.019). No significant differences were found in the Strehl ratio, MTF cutoff, CDVA, OV-100, OV-20, and OV-9 between the two groups at 1 week and 1 month after capsulotomy (P > 0.05). The PDQ results showed that patients with circular-shaped capsulotomy complained less with intolerance of bright lights than those with cruciate-shaped capsulotomy.

Conclusions

Circular-shaped capsulotomy can induce less intraocular light scattering and increase patient satisfaction.

Impact of primary posterior capsulorhexis on regeneratory after-cataract and YAG laser rates with an acrylic micro-incision intraocular lens with plate haptics: 1-year and 3-year results

PURPOSE

To evaluate the posterior capsule opacification (PCO) and YAG laser capsulotomy (YAG-LCT) rates with a plate-haptic acrylic micro-incision intraocular lens (IOL) and the impact of primary posterior capsulorhexis.

METHODS

A total of 97 patients scheduled for immediate sequential bilateral cataract surgery underwent a randomized, prospective intraindividual comparison with the ZEISS Asphina 409MV plate-haptic acrylic IOL with the eyes receiving an additional primary posterior capsulorhexis (PPCR) or not. YAG-LCT and PCO rates were evaluated at 1 and 3 years. Three-year PCO rates were calculated with a 3-scenario method for eyes that underwent YAG-LCT between 1 and 3 years.

RESULTS

A total of 56 patients were seen at 1 year, and 57 at 3 years. For the eyes without and with PPCR, YAG-LCT rates were 14.3% and 0% at 1 year, and 59.7% and 3.5% at 3 years, respectively. Opacification rates at 1 year were 0.55 ± 0.99 and 0.05 ± 0.21 for the central 2-mm optic zone. A total of 42 patients completed both the 1- and 3-year follow-up. Three-year opacification rates for the group without PPCR were 1.99 ± 2.20, 2.26 ± 2.66 and 3.66 ± 3.61 for the central 2-mm zone and 2.57 ± 2.07, 3.13 ± 3.03 and 4.09 ± 3.34 for the 4.5-mm zone for the best, extrapolated and worst-case scenarios, respectively.

CONCLUSION

The ZEISS Asphina 409MV plate-haptic acrylic IOL exhibited unusually high YAG-LCT and PCO rates with standard in-the-bag implantation. PPCR was safe and effective in preventing central opacification and the need for YAG laser treatment.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of the Neodymium-doped Yttrium Aluminum Garnet Capsulotomy Rate with Viscoimplantation and the Hydroimplantation Intraocular Lens Technique

PURPOSE

To investigate the rate of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy in the hydroimplantation intraocular lens (IOL) technique.

METHODS

This retrospective study was comprised of 6,192 eyes in 3,790 patients who underwent surgery from January 2013 to September 2017 and then were followed up for at least 1 year. The eyes of these patients were divided into two groups: either viscoimplantation or hydroimplantation. The follow-up examinations were carried out on the 1st day, 4th day, 1st month, and 3 months to 1 year postoperatively. The Nd:YAG capsulotomy rates were evaluated by the different IOL implantation techniques and IOL materials.

RESULTS

The mean follow-up duration of the patients was in the viscoimplantation group 14.85 ± 2.43 and 15.05 ± 1.93 months in the hydroimplantation group. The Nd:YAG capsulotomy rate was significantly lower in the hydroimplantation group compared with the viscoimplantation group for the entire hydrophilic IOL model (p < 0.001). In addition, the Nd:YAG rate was lower in the hydroimplantation group that used a hydrophilic IOL than it was in the viscoimplantation group, which used a hydrophobic IOL.

CONCLUSIONS

The hydroimplantation technique reduced the Nd:YAG capsulotomy rate.

Retrospective Analyses of Potential Risk Factors for Posterior Capsule Opacification after Cataract Surgery

PURPOSE

To evaluate the potential risk factors of posterior capsule opacification (PCO) after cataract surgery.

METHODS

Data on PCO patients diagnosed from September 2015 to May 2017 were obtained from the Department of Ophthalmology at Qingdao Municipal Hospital, Qingdao, China. The factors associated with PCO were assessed using Pearson's χ2 test for univariate analyses and logistic regression for multivariate analyses.

RESULTS

Eyes (652) from 550 patients were enrolled in this study. All patients were diagnosed with PCO/non-PCO and had <3 years of follow-up after surgery. The numbers of PCO and non-PCO were 108 eyes and 544 eyes, respectively. Statistically significant associations with PCO were found for age at the time of surgery (χ2 = 78.504; p < 0.001), diabetes (χ2 = 4.829; p=0.028), immune diseases (χ2 = 4.234; p=0.004), high myopia (χ2 = 5.753; p=0.016), lens nucleus hardness (χ2 = 11.046; p=0.026), surgery type (χ2 = 11.354; p=0.001), a history of vitrectomy (χ2 = 4.212; p=0.004), ocular inflammation (χ2 = 6.01; p=0.009), and the intraocular lens (IOL) type (χ2 = 8.696; p=0.003). Multivariable data analyses using logistic regression analyses of the variables showed that age at the time of surgery <60 years, diabetes, lens nucleus hardness of III-V, extracapsular cataract extraction (ECCE), postvitrectomy, and hydrophilic IOLs were significant independent risk factors associated with PCO.

CONCLUSIONS

Age <60 years, diabetes, lens nucleus hardness of III-V, ECCE, postvitrectomy, and a hydrophilic IOL were significantly associated with the formation of PCO. Estimation of the incidence of and risk factors for PCO should help in patients counseling and in the design of treatment protocols to reduce or prevent its development.

Further Enhancement of Intraocular Open-Capsule Devices for Prevention of Posterior Capsule Opacification

Purpose

We improve the intraocular open-capsule devices (IOCD) for the prevention of posterior capsule opacification (PCO).

Methods

A total of 45 New Zealand rabbit eyes were divided into six similar groups after crystalline lens evacuation. Each group was implanted with a hydrophilic intraocular lens (IOL) and a hydrophilic IOCD of different designs. In the first experiment (Part A), a square design ring with and without large apertures was compared to a round design ring without apertures. In the second experiment (Part B), a square design ring with large apertures was compared to square design IOCDs with small apertures of high and low density. PCO and Soemmering's ring were evaluated clinically, by the Miyake Apple view, and histologically. The results were compared to a control group of eyes implanted with a hydrophilic IOL only.

Results

All devices showed significant prevention of PCO and Soemmering's ring compared to the control group. Part A: the square design with apertures had the lowest level of peripheral lens epithelial cells proliferation (protrusions). Part B: modifying the size and density of the apertures had no influence on those protrusions.

Conclusions

The IOCD significantly reduced the rate of PCO and its precursor, Soemmering's ring. The rings with the square edges and apertures produced the best results. The study was underpowered to determine the influence of the apertures design.

Translational Relevance

The IOCD has the potential to prevent up to 80% of the PCO cases; the most common complication after cataract surgery. The design of the ring is important for its success.

Comparison of hydrophobic and hydrophilic intraocular lens in preventing posterior capsule opacification after cataract surgery: An updated meta-analysis

BACKGROUND

Posterior capsular opacification (PCO) is a common long-term complication of cataract surgery. Intraocular lens design and material have been implicated in influencing the development of PCO. This study evaluated the association of hydrophobic and hydrophilic intraocular lenses on preventing PCO.

METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until August 3, 2016, using the following search terms: cataract, posterior capsule opacification, and intraocular lens. Eligible studies included randomized controlled trials (RCTs), retrospective, and cohort studies.

RESULTS

Eleven studies were included in the study with a total of 889 eyes/patients. The overall analysis revealed that hydrophobic intraocular lenses were associated with lower Nd:YAG laser capsulotomy rates than hydrophilic lenses [odds ratio (OR) = 0.38, 95% confidence interval (95% CI) = 0.16-0.91, P = .029]. Hydrophobic intraocular lenses were also associated with lower subjective PCO score (diff. in means: -1.32, 95% CI = -2.39 to -0.25, P = .015) and estimated PCO score (diff. in means: -2.23; 95% CI, -3.80 to -0.68, P = .005) as compared with hydrophilic lenses. Objective PCO score was similar between lens types. (diff. in means: -0.075; 95% CI, -0.18 to 0.035; P = .182). Pooled analysis found that visual acuity was similar between hydrophobic and hydrophilic intraocular lenses (diff. in means: -0.016; 95% CI, -0.041 to 0.009, P = .208).

CONCLUSION

In general, PCO scores and the rate of Nd:YAG laser capsulotomy were influenced by intraocular lens biomaterial. Lens made of hydrophobic biomaterial were overall superior in lowering the PCO score and the Nd:YAG laser capsulotomy rate, but not visual acuity.

Postoperative posterior capsular striae and the posterior capsular opacification in patients implanted with two types of intraocular lens material

AIM

To evaluate the incidence of postoperative posterior capsular striae (PCS) and its influence on posterior capsular opacification (PCO) in patients implanted with two types of lens material.

SETTING

Tertiary eye care center in central rural India.

STUDY DESIGN

A prospective, observational, nonrandomized study.

MATERIALS AND METHODS

The study included 1247 patients having age-related cataract scheduled for removal by phacoemulsification technique and implantation of hydrophilic or hydrophobic intraocular lens (IOL). Demographic profile, nuclear grading, axial length, and IOL power were noted. Details of PCS were noted on the 1st postoperative day in patients with clear cornea. Postoperative follow-up was ensured to study the status of PCS and development of PCO.

RESULTS

The overall incidence of PCS was 19.8% (247 out of 1247 eyes). Out of 1247 patients, 641 patients (51.4%) had hydrophilic IOL implantation and 201 eyes had PCS (31.4%) and 606 patients (48.6%) had hydrophobic IOL implantation and 46 eyes had PCS (7.6%), P = 0.04. Three and more striae were seen in 119 eyes (119/641, 18.6%) in hydrophilic group and 4 eyes (4/606, 0.66%) in hydrophobic group. Sixty-two eyes (62/201, 30.9%) in hydrophilic group with multiple PCS were reported with persistent striae after 6 months of surgery. Two eyes in hydrophobic group had persistent striae even after 3 years of follow-up. Evaluation of PCO score of the hydrophilic group was 0.6 whereas of the hydrophobic group was 0.1 (P = 0.04). Ten patients of the hydrophilic group only required neodymium-doped yttrium aluminum garnet (ND: YAG) laser capsulotomy.

CONCLUSION

The incidence of PCS was higher in hydrophilic than hydrophobic IOLs. Multiple PCS persisting in patients beyond 6 months after operation should be followed up for early development of PCO, particularly in patients implanted with hydrophilic IOL.

Posterior Capsule Opacification 9 Years after Phacoemulsification with a Hydrophobic and a Hydrophilic Intraocular Lens

Purpose

To compare the development of posterior capsule opacification (PCO) and survival rate without capsulotomy after implantation of a hydrophobic or hydrophilic acrylic intraocular lens (IOL) at the 9-year postoperative follow-up.

Methods

One of 3 experienced cataract surgeons performed standard phacoemulsification in one eye of 120 patients with cataract. The patients were randomized to implantation of either a hydrophobic acrylic IOL or a hydrophilic acrylic IOL. Both IOLs had sharp posterior edges. Retroillumination images of PCO were obtained with a fundus camera 9 years postoperatively and analyzed semiobjectively using POCOman computer software.

Results

Seventy-eight of the 120 patients completed the 9-year follow-up examination. Patients implanted with the hydrophilic IOL had significantly (p<0.001) more and denser PCO. The survival rate without Nd:YAG capsulotomy was significantly higher (p<0.001) in eyes with the hydrophobic IOL.

Conclusions

After 9 years, more and denser PCO developed in eyes with the hydrophilic IOL than the hydrophobic IOL. The survival rate without the need for capsulotomy was higher in eyes with the hydrophobic IOL.