Interventions for preventing posterior capsule opacification.
BACKGROUND
Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. It can be treated by Nd:YAG laser capsulotomy, however, this may lead to other complications and laser treatment is not available in large parts of the developing world. Therefore, many studies try to find factors influencing the development of PCO.


OBJECTIVE
To summarise the effects of different interventions to inhibit PCO. These include modifications of surgical technique and intraocular lens (IOL) design, implantation of additional devices and pharmacological interventions.


METHODS
We searched CENTRAL, MEDLINE, EMBASE, LILACS in January 2007 and reference lists of identified trial reports.


METHODS
We included only prospective, randomised and controlled trials with a follow-up time of at least 12 months. Interventions included modifications in surgical technique explicitly to inhibit PCO, modifications in IOL design (material and geometry), implantation of additional devices, and pharmacological therapy, compared to each other, placebo or standard treatment.


METHODS
Data were extracted and entered into Review Manager. Visual acuity data, PCO score and YAG capsulotomy rates were compared and a meta-analysis was performed when possible.


RESULTS
Fifty three studies were included in the review. The review was divided into three parts. (1) Influence of IOL optic material on the development of PCO. Compared to other materials, the meta-analysis of the included studies showed a significantly higher PCO score (overall effect: 12.39 (95% confidence interval: 9.82 to 14.95), scale 0 to 100) and YAG rate (odds ratio: 8.37 (3.74 to 20.36)) only in hydrogel IOLs. (2) Influence of IOL optic design on the development of PCO. There was a significantly lower PCO score (-8.65 (-10.72 to -6.59), scale 0 to 100) and YAG rate (0.19 (0.11 to 0.35)) in sharp edged than in round edged IOLs, however, not between 1-piece and 3-piece IOLs. (3) Influence of surgical technique and drugs on the development of PCO. There was no significant difference between different types of intra-/postoperative anti-inflammatory treatment except for treatment with an immunotoxin (MDX-A) leading to a significantly lower PCO rate.


CONCLUSIONS
Due to the highly significant difference between round and sharp edge IOL optics, IOLs with sharp (posterior) optic edges should be preferred. There is no clear difference between optic materials, except for hydrogel IOLs, that showed more PCO than the other materials. The choice of postoperative anti-inflammatory treatment does not seem to influence PCO development.
Findl
O
O
Medical University of Vienna, Department of Ophthalmology, Allgemeines Krankenhaus Wien, Währinger Gürtel 18-20, Vienna, Austria, A-1090. oliver.findl@meduniwien.ac.at
Buehl
W
W
Bauer
P
P
Sycha
T
T
D002386:Cataract / Q000209:etiology*; D002387:Cataract Extraction / Q000009:adverse effects*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000009:adverse effects; D007903:Lens Capsule, Crystalline; D007910:Lenses, Intraocular / Q000009:adverse effects*; D018918:Phacoemulsification / Q000009:adverse effects; D019904:Polymethyl Methacrylate / Q000009:adverse effects; D016032:Randomized Controlled Trials as Topic
D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D019904:Polymethyl Methacrylate