The value of no-touch isolation technique for resection of cancer. The eye as a model.

The role of the no-touch technique was examined using retinoblastoma and primary choroidal malignant melanoma of the eye as a model. Choroidal invasion, tumor friability, and tumor vascularity are important factors that render these two tumors susceptible to metastasis secondary to intraorgan pressure increases. Animal studies on no-touch enucleation procedures show that increased intraocular pressure during enucleation decreases survival rates considerably providing the tumor has invaded the choroid but has not yet metastasized. This "critical stage" correlates well with earlier data on the no-touch technique studied in noneye models. In humans, standard enucleations create intraocular pressures measured up to 500 mm Hg. The no-touch technique is applicable to the therapy of retinoblastoma and primary choroidal malignant melanomas, but long-term clinical studies are needed to establish the true benefit.