Budget impact analysis of lens material on the posterior capsule opacification (PCO) as a complication after the cataract surgery

Background

Over 300,000 cataract operations are performed in Poland every year, and the most common, late complication of cataract removal surgery is posterior capsule opacification (PCO). The risk of PCO depends on the lens material. Hydrophobic acrylic lenses cause PCO less frequently as lymphatic endothelial cells show lower affinity for the surface of the lens made of silicone. The objective of this study is to assess the economic impact of using hydrophobic acrylic lenses compared to using hydrophilic acrylic lenses for cataract treatment in the Polish inpatient and outpatient settings.

Methods

A budget impact analysis (BIA) compared the economic outcomes associated with using hydrophobic acrylic lenses versus using hydrophilic lenses for patients undergoing cataract surgery. The BIA predicted annual expenses in the following scenarios: performing Nd:YAG to treat PCO within 2 and 3 years after implantation of hydrophobic or hydrophilic acrylic lenses for different lens structure. Data used to assess the frequency of PCO was determined in systematic literature review. Costs of current and predicted interventions were estimated based on average data from 19 Polish hospitals. Prices of health services were taken from official public tariff lists.

Results

The use of a hydrophobic lens significantly limits the number of complications after cataract surgery relative to a hydrophilic lens. As hydrophobic lenses have a higher unit price their use increases the cost of treatment which currently is not reflected by adequate difference in price of the service. Total annual National Health Fund (NHF) expenses for 3-year follow-up model range from 139.1 million EUR to 143.1 million EUR depending on the lens structure, due to the cost of complications.

Conclusions

BIA indicates the possibility of introducing surcharge for the use of hydrophobic lenses, which could increase the frequency of their use and reduce the number of complications after cataract surgery. It was estimated that total NHF expenses reach the minimum value for the surcharge at the level of 9 EUR. The surcharge of 14 EUR is the maximum value that does not increase the initial NHF expenses.

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.

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.

Nanotechnology for the Prevention and Treatment of Cataract

PURPOSE

The purpose of this article was to review recent advances in the applications of nanotechnology in cataract treatment and prevention strategies.

DESIGN

A literature review on the use of nanotechnology for the prevention and treatment of cataract was done.

METHODS

Research articles about nanotechnology-based treatments and prevention technologies for cataract were searched on Web of Science, and the most recent advances were reported.

RESULTS

Nonsteroid anti-inflammatory drugs, natural antioxidants, biologic and chemical chaperones, and chaperones such as molecules have found great application in preventing and treating cataracts. Current scientific research on new treatment strategies, which focuses on the biochemical basis of the disease, will likely result in new anticataract agents. However, none of the drug formulations will be approved for use unless efficient delivery is promised. Nanoparticle engineering together with biomimetic strategies enable the development of next-generation, more efficient, less complex, and personalized treatments.

CONCLUSIONS

The only currently available treatment for cataracts, surgical replacement of the opacified lens, is not an easily accessible option in developing countries. New treatment strategies based on topical drugs would enable treatment to reach massive populations facing the threat of blindness and more effectively deal with the postsurgical complications. Nanotechnology plays a key role in improving drug delivery systems with enhanced controlled release, targeted delivery, and bioavailability to overcome diffusion limitations in the eye.

Prospective Randomized Intraindividual Comparison of Posterior Capsule Opacification After Implantation of an IOL With and Without Heparin Surface Modification

PURPOSE

To compare posterior capsule opacification (PCO) of a hydrophobic acrylic heparin surface modified intraocular lens (HSM-IOL) and an uncoated IOL (UC-IOL) 1 year after implantation.

METHODS

One hundred two eyes of 51 patients underwent routine phacoemulsification with randomized implantation of a HSM-IOL in one eye (the HSM-IOL group) and a UC-IOL in the fellow eye (the UC-IOL group). Morphologic PCO evaluation was performed comparing digital photographs in retroillumination using the Evaluation of Posterior Capsule Opacification (EPCO) system, grading the density of the opacification from 0 to 4 (0 = none, 1 = minimal, 2 = mild, 3 = moderate, and 4 = severe). Distance visual acuities, subjective manifest refraction, pupil size, straylight measurements, flare in the anterior chamber using a laser flare meter, and contrast sensitivity were also evaluated.

RESULTS

The mean total EPCO score was slightly higher in the HSM-IOL group (0.50 ± 0.45) compared to the UC-IOL group (0.45 ± 0.46), but did not reach statistical significance. No statistically significant differences were found in the other main outcome parameters (straylight measurement, distance visual acuities, flare in the anterior chamber, and mesopic and photopic contrast sensitivity) when comparing both IOLs.

CONCLUSION

Although the HSM-IOL showed decreased flare 1 day postoperatively, no statistically significant differences regarding PCO were found 1 year postoperatively.

Surface modification of intraocular lenses with hyaluronic acid and lysozyme for the prevention of endophthalmitis and posterior capsule opacification

Posterior capsule opacification is one of the complications of cataract surgery caused by the adhesion and reproduction of residual human lens epithelial cells (HLECs) on the posterior capsule.

Types of intraocular lenses for cataract surgery in eyes with uveitis

BACKGROUND

Cataract formation often occurs in people with uveitis. It is unclear which intraocular lens (IOL) type is optimal for use in cataract surgery for eyes with uveitis.

OBJECTIVES

To summarize the effects of different IOLs on visual acuity, other visual outcomes, and quality of life in people with uveitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2013), EMBASE (January 1980 to August 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to August 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 14 August 2013. We also performed forward and backward searching using the Science Citation Index and the reference lists of the included studies, respectively, in August 2013.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing hydrophobic or hydrophilic acrylic, silicone, or poly(methyl methacrylate) (PMMA) IOLs with or without heparin-surface modification (HSM), with each other, or with no treatment in adults with uveitis, for any indication, undergoing cataract surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Two review authors screened the search results and for included studies, assessed the risk of bias and extracted data independently. We contacted study investigators for additional information. We did not perform a meta-analysis due to variability in reporting and follow-up intervals for the primary and secondary outcomes of interest.

MAIN RESULTS

We included four RCTs involving 216 participants (range of 2 to 140 participants with uveitic cataract per trial) and comparing up to four types of IOLs. The largest study was an international study with centers in Brazil, Egypt, Finland, France, Japan, the Netherlands, Slovak Republic, Spain, and the USA; two studies were conducted in Germany and one in Saudi Arabia. There was substantial heterogeneity with respect to the ages of participants and etiologies of uveitis within and across studies. The length of follow-up among the studies ranged from 1 to 24 months after cataract surgery. The studies were at low risk of selection bias, but two of the four studies did not employ masking and only one study included all randomized participants in the final analyses. The funding source was disclosed by investigators of the largest study (professional society) and not reported by the other three. Due to heterogeneity in lens types evaluated and outcomes reported among the trials, we did not combine data in a meta-analysis.In the largest study (140 participants), the study eye of each participant was randomized to receive one of four types of IOLs: hydrophobic acrylic, silicone, HSM PMMA, or unmodified PMMA. Proportions of participants with one or more Snellen lines of visual improvement were similar among the four treatment groups at one year' follow-up: 45 of 48 (94%) in the hydrophobic acrylic IOL group, 39 of 44 (89%) in the silicone IOL group, 18 of 22 (82%) in the HSM PMMA IOL group, and 22 of 26 (85%) in the unmodified PMMA IOL group. When comparing hydrophobic acrylic IOLs with silicone IOLs, the risk ratio (RR) was 1.06 (95% confidence interval (CI) 0.93 to 1.20). At one year' follow-up, fewer eyes randomized to hydrophobic acrylic IOLs developed posterior synechiae when compared with eyes receiving silicone IOLs (RR 0.18, 95% CI 0.04 to 0.79); the effects between these groups were less certain with respect to developing posterior capsule opacification (PCO) (RR 0.74, 95% CI 0.41 to 1.37), corneal edema (RR 0.49, 95% CI 0.22 to 1.12), cystoid macular edema (RR 0.10, 95% CI 0.01 to 1.84), or mild IOL decentration (RR 0.92, 95% CI 0.06 to 14.22).Two intra-individual studies also compared HSM PMMA IOLs with unmodified PMMA IOLs at three or six months of follow-up. These studies, including a combined total of 16 participants with uveitis, were insufficiently powered to detect differences in outcomes among eyes of people with uveitis randomized to receive HSM PMMA IOLs when compared with fellow eyes receiving unmodified PMMA IOLs.In the fourth study (60 participants), the study eye of each participant was randomized to receive a hydrophobic or hydrophilic acrylic IOL. At three months, there were no statistical or clinical differences between hydrophobic and hydrophilic acrylic IOL types in the proportions of participants with two or more Snellen lines of visual improvement (RR 1.03, 95% CI 0.87 to 1.22). There were similar rates in the development of PCO between hydrophobic or hydrophilic acrylic IOLs at six months' follow-up (RR 1.00, 95% CI 0.80 to 1.25). The effect of the lenses on posterior synechiae was uncertain at six months' follow-up (RR 0.50, 95% CI 0.05 to 5.22).None of the included studies reported quality of life outcomes.

AUTHORS' CONCLUSIONS

Based on the trials identified in this review, there is uncertainty as to which type of IOL provides the best visual and clinical outcomes in people with uveitis undergoing cataract surgery. The studies were small, not all lens materials were compared in all studies, and not all lens materials were available in all study sites. Evidence of a superior effect of hydrophobic acrylic lenses over silicone lenses, specifically for posterior synechiae outcomes comes from a single study at a high risk of performance and detection bias. However, due to small sample sizes and heterogeneity in outcome reporting, we found insufficient information to assess these and other types of IOL materials for cataract surgery for eyes with uveitis.

[Alkylphosphocholines inhibit lens epithelial cell proliferation and attachment]

BACKGROUND

Posterior capsule opacification (PCO) is one of the major concerns in modern cataract surgery. Ten years after successful surgery, Nd:YAG capsulotomy is required in up to 42% of patients with an acrylic sharp-edged intraocular lens (IOL). Some accommodative and multifocal IOLs display even higher capsulotomy rates. Pharmacologic prophylaxis with alkylphosphocholines (APCs) could be a novel option in PCO prevention.

METHODS

The human lens epithelial cell line HLE-B3 served as an in-vitro model. After incubation with APCs in different concentrations (0.01, 0.1, and 1 mM), the trypan blue exclusion assay and the live/dead test were performed at serum concentrations of only 5%. Cell proliferation was assessed with the MTT test. Evaluation of cell attachment was done with fibronectin- and laminin-coated wells.

RESULTS

APCs can inhibit the proliferation of human lens epithelial cells in the presence of only 5% serum in a dose-dependent manner. Proliferation inhibition of 60% and attachment inhibition of about 50% were reached at concentrations of 0.1 µM.

CONCLUSION

APCs inhibit proliferation and attachment of human lens epithelial cells in nontoxic concentrations in vitro. The substance can be applied topically, and an intraoperative application for pharmacologic PCO prophylaxis is feasible.

Alkylphosphocholines as a potential pharmacologic prophylaxis for posterior capsule opacification

PURPOSE

To evaluate the effect of alkylphosphocholines (APCs) on human lens epithelial cell (LEC) proliferation, attachment, and migration in a well-established in vitro model.

SETTING

Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.

METHODS

The immortalized human LEC line HLE-B3 was incubated for 24 hours with APC in different concentrations in the presence of Eagle's modified essential medium supplemented with fetal calf serum under standard cell-culture conditions. The trypan blue exclusion test and live-dead assay were performed to exclude toxic concentrations. To determine cell proliferation, cells were incubated with APCs at the maximum slope of the growth curve for 24 hours before the tetrazolium dye-reduction assay (MTT test) was performed. After cells were seeded on coated 24-well plates, incubated with APCs, and rinsed with phosphate-buffered saline, cell attachment was assessed by the MTT test. Migration was determined by a modified Boyden chamber method after incubation of LECs with APCs.

RESULTS

Alkylphosphocholines were effective inhibitors of human LEC proliferation, attachment, and migration at nontoxic concentrations in vitro. The 50% inhibitory concentration was close to 0.1 mM. An APC concentration of 1.0 mM accounted for the following: inhibition of cell proliferation of more than 80%, reduction in cell attachment to 66.5%, and inhibition of cell migration of more than 90%. All effects were dose dependent. No toxic effects were detected compared with controls.

CONCLUSIONS

Alkylphosphocholines might have the potential for topical application as a single-dose agent to prevent posterior capsule opacification formation. However, further studies are needed before a clinical application can be considered.