[The effect of viscoelastic substances on postsurgical blood aqueous barrier]

A postsurgical flare was evaluated with a flare-cell meter and the effect of residual viscoelastic substances on the blood aqueous barrier function was studied. The materials consisted of 100 eyes undergoing extracapsular cataract extraction and posterior chamber lens implantation using sodium hyaluronate products (Healon:Pharmacia and Opegan:Santen). The molecular weight is 1.9-3.6 million daltons in Healon and 0.9-1.2 million daltons in Opegan. According to the aqueous warm current on the 1st postoperative day, the eyes were divided into two groups; the poor current group and the normal current group. The poor current group consisted of 13 eyes had static aqueous current, probably due to residual viscoelastic substances from the clinical findings, namely a little pain, foggy general corneal edema and spontaneous recovery of the warm current without specific administrations of antibiotics. Eyes with poor current were recognized in 18% (11/62) among cases with Healon and 5% (2/38) in case with Opegan. Flare values of the poor current group were higher in 7 eyes than the highest of the normal current group on the 1st postoperative day. After the 2nd postoperative day, the median flare value of the poor current group was higher than that of the normal current group. The difference was statistically significant throughout the first week (p less than 0.02). The cell number was also higher in the poor current group on the 1st and 2nd postoperative day (p less than 0.02). These findings suggest that the residual viscoelastic materials may increase the breakdown of blood-aqueous barrier and/or interfere the barrier recovery.