The barrier function in extracapsular cataract surgery.

The distribution of fluorescein between the anterior chamber and the anterior vitreous was measured in two groups of patients after oral administration: group I, extracapsular cataract extraction (ECCE) patients with intact capsule and posterior chamber intraocular lens (PC IOL) (n = 12); group II, intracapsular cataract extraction (ICCE) patients with anterior chamber IOL (AC IOL) (n = 13). The fluorescein concentrations were measured by fluorophotometry and the penetration ratios were calculated. The penetration of fluorescein into the anterior vitreous was significantly less in the ECCE group (group I, penetration ratio = 2.03 +/- 1.00 X 10(-3) min-1; group II, penetration ratio = 5.99 +/- 4.89, X 10(-3) min-1, P less than 0.01). The authors concluded that in ECCE versus ICCE a significantly smaller proportion of fluorescein is found in the anterior vitreous relative to the aqueous after passage through the blood-aqueous barrier. This suggests a barrier to posterior movement of other molecules that may initially gain access to the eye in the anterior segment (e.g., prostaglandins).