The effect of cataract surgery on the blood--aqueous barrier.

Orally-administered fluorescein was used as a quantitative test of the blood-aqueous barrier in a group of patients who had undergone cataract extraction and intraocular lens implantation in one eye. There was no statistically significant difference in the concentration of fluorescein in the anterior chamber between the aphakic or pseudophakic eye and the control eye of the total group of 46 patients. Eyes with an intracapsular cataract extraction with medallion suture implant lens, however, had a significantly lower concentration of fluorescein in the anterior chamber as compared to the control eye. This difference is probably due to loss of fluorescein into the vitreous by mixing and diffusion. In eyes with an intact posterior capsule, the time course of anterior chamber fluorescence in the aphakic eye is more comparable to that of the phakic eye. In such eyes the blood-aqueous barrier seems to remain normal long after cataract extraction and intraocular lens implantation.