On the molecular biology of the vitreous in the aphakic eye.

The vitreous of aphakic and phakic eyes was assayed for hyaluronic acid. Intracapsular cataract extraction was regularly followed by decreased hyaluronic acid concentration and studies on the distribution of hyaluronic acid within the vitreous cavity showed that removal of the lens facilitates diffusion of hyaluronic acid into the anterior chamber. Based on these studies certain postoperative features of the aphakic eye are discussed. The instability of the vitreous gel, as reflected by rupture of the anterior vitreous face and an increased incidence of vitreous detachment supports the hypothesis of hyaluronic acid as a stabilizer of the gel. The decreased adhesion of the neural retina in the aphakic eye might be caused by the loss of hyaluronic acid. Normally the high concentration of hyaluronic acid adjacent to the retina contributes to the resistance of bulk flow of fluid into the subretinal space making it possible for the active transport system of the pigment epithelium to maintain a pressure drop across the neural retina. It is anticipated that saccades create currents in the fluid vitreous close to the eye wall after vitreous detachment. Model experiments showed that these currents were greatly enhanced, when the concentration of hyaluronic acid was lowered.