Methodological quality of the review: Medium confidence
Author: Cheng J, Ye X, Wei R, Cai J, Li Y.
Region: China
Sector: Cataract surgery
Sub-sector: None specified
Type of cataract: Age-related cataract
Equity focus: None specified
Review type: Effectiveness review
Quantitative synthesis method: Meta-analysis
Qualitative synthesis methods: Not applicable
Background
Posterior capsular opacification (PCO) is a common complication after cataract surgery. Binding heparin to the polymethylmethacrylate (PMMA) surface appears to decrease foreign-body-induced inflammation by making the intraocular lens (IOL) more hydrophilic, and therefore it may play a role in reducing PCO.
Research objectives
To evaluate the efficacy of heparin-surface-modified (HSM) PMMA IOL in preventing PCO after cataract extraction.
Main findings
Authors included 12 randomized controlled trials which compared HSM PMMA IOL against PMMA IOL in the review.
Based on the meta-analysis, authors reported that the HSM PMMA IOL appears to be as effective as conventional unmodified PMMA IOL in preventing the formation of PCO and reducing the use of Nd:YAG laser capsulotomy.
Methodology
This review is based on a search of several databases including Cochrane Library, PUBMED, MEDLINE, EMBASE and Chinese Biomedical Database (CBM) (1966 to 2006). No language restriction was imposed and reference lists of relevant trials were reviewed. Titles and abstracts resulting from the searches as well as data collection of included trials were independently reviewed by authors.
Authors included randomized control trials comparing HSM PMMA IOL against unmodified PMMA IOL in post-operative cataract patients. Outcome measures included PCO rates and Nd:YAG laser capsulotomy rates after cataract surgery. The search words used to conduct the search included words in English such as: ‘heparin surface modified’, ‘heparin surface modification’, ‘heparin coated’ and ‘heparinized’; and words in Chinese including ‘Heparin’ and ‘IOL’. Authors did not report using any grading criteria to quality assess included studies, however, studies’ background information was provided.
Authors conducted a meta-analysis and a heterogeneity test using random effects models.
Applicability/external validity
Authors did not discuss the applicability/external validity of findings.
Geographic focus
Authors covered a range of countries in the review, including from China. However, they did not discuss it further.
Quality Assessment
Overall, medium confidence was attributed to the conclusions about the effects of this study. Although authors did not contact experts/authors as part of the search strategy, the literature search was thorough with no language or date restrictions. Methods used to screen studies and extract data of included studies were appropriately conducted, minimizing the risk of bias. However, methods used to analyse findings were unclear. There are also many influencing elements to the usage of YAG laser, which were not mentioned at all at the paper. The background of studies (for instance the surgeons, the method to grade PCO, etc.), were not given and analysed, which are very much related to happening of PCO. Nevertheless, overall authors acknowledged the limitations of the study.
Publication Details
Cheng J, Ye X, Wei R, Cai J, Li Y. Effect of heparin-surface-modified introcuolar lenses on posterior capsular opacification:meta-analysis of randomized clinical trial. Chin Ophtal Res. 2008;26(6):462-5.
© 2025 by Sightsavers, Inc., Business Address for all correspondence: One Boston Place, Suite 2600, Boston, MA 02108.
To make sure you have a great experience on our site, we’d like your consent to use cookies. These will collect anonymous statistics to personalise your experience.
You have the option to enable non-essential cookies, which will help us enhance your experience and improve our website.
These enable our site to work correctly, for example by storing page settings. You can disable these by changing your browser settings, but some parts of our website will not work as expected.
To improve our website, we’d like to collect anonymous data about how you use the site, such as which pages you read, the device you’re using, and whether your visit includes a donation. This is completely anonymous, and is never used to profile individual visitors.
To raise awareness about our work, we’d like to show you Sightsavers adverts as you browse the web. By accepting these cookies, our advertising partners may use anonymous information to show you our adverts on other websites you visit. If you do not enable advertising cookies, you will still see adverts on other websites, but they may be less relevant to you. For info, see the Google Ads privacy policy.