Abstract:AIM: To determine the lowest concentration of trypan blue(TB)used to stain the anterior capsule satisfactorily and to evaluate the clinical significance of trypan-blue-assisted capsulorhexis in cataract surgery.
METHODS:Totally 60 cases(60 eyes)of mature age-related cataract, of which the cortex lentis cloudy degree was C4-C5 and the nucleus of the lens was N3, were randomly divided into three groups. Different concentrations of TB, 0.03%, 0.015%, 0.0075%, were used in staining groups respectively to stain the anterior capsule during cataract surgery. All cases were performed with manual small-incision cataract surgery by the same ophthalmologist. The staining effects, the success rate of continuous circular capsulorrhexis(CCC), the posterior capsule rupture and the state of the intraocular lens(IOL)were studied during the operation. The significant statistics was conducted between the groups. The density of corneal endothelial cells, intraocular pressure(IOP), inflammation in anterior chamber, corneal edema, staining of other intraocular structures were also observed at 1d, 1wk, 3mo postoperatively.
RESULTS: Trypan blue in concentrations as low as 0.015% stained the anterior capsule satisfactorily, allowing safe creation of a CCC. At concentrations of 0.03% and 0.015%, the success rate of CCC and the state of the intraocular lens(IOL)was significantly better than 0.0075% group, the difference was statistically significant(P<0.0083). The difference of posterior capsule rupture rates and the rate of lost corneal endothelial cells in three groups were not statistically significant(P>0.0083). The staining of CCC margin and side port disappeared in 1wk after surgery. Inflammation in anterior chamber of all cases was slight. There was not any evidence of residual stain in the anterior segment during the postoperative period. There was no corneal edema and intraocular pressure higher after 1wk.
CONCLUSION: Trypan blue staining of the anterior capsule is a safe and useful technique in cataract surgery, which can raise the success rate of cataract surgery. The 0.015% trypan blue staining, the lowest effective concentration, is strongly considered.
