Vitreous changes after neodymium-YAG laser photodisruption.

We investigated physicochemical changes in the vitreous body after photodisruption with a Q-switched neodymium-YAG laser. In vivo proton nuclear magnetic resonance imaging techniques were employed to assess alterations in the vitreous of irradiated rabbit eyes. Measurements of proton relaxation times (T1 and T2), viscosity, and chromatographic spectra were made in vitro on irradiated bovine and rabbit vitreous, and circular dichroism measurements were used to study changes in an irradiated sodium hyaluronate solution. Statistically significant changes in T1, were observed immediately after irradiation, but the small magnitude and reversibility of those changes, combined with the fact that the other measurements detected no changes, suggest that neodymium-YAG laser photodisruption does not have a direct deleterious effect on the structural integrity of the normal vitreous body.