[Radial keratotomy, corneal hydration and intraocular pressure. Experimental study]

Radial keratotomy reduces myopia by flattening the central cornea. The role of wound hydration, length and depth of incisions, intraocular pressure and general weakening of the cornea play a part in this process. The relative importance of these factors is not clear. We examined the effect of wound hydration on an 8 incision radial keratotomy (RK) procedure performed on cadaver eyes. The cornea was moistened with balanced salt solution. A mean change of 10 D was achieved after 30 minutes. The corneal dehydration induced by Dextran B was associated with a significant reduction (10 D) in RK induced corneal flattening. It would appear that the radial incision induced keratometric change is a preliminary result of wound hydration. Intraocular pressure within the physiological range had very minimal influence (< 1.5 D) on corneal flattening.