Risk factors for postvitrectomy fibrin formation

A complication of vitrectomy (removal of a portion of the vitreous, a jelly-like substance located behind the lens of the eye) may be the formation of intraocular fibrin (a stringy insoluble protein, and product of the clotting process). Formation of a fibrin membrane on the pupil may cause a form of glaucoma, and fibrin in the vitreous or on the retina can contract, causing retinal detachment. The incidence and risk factors for postvitrectomy intraocular fibrin formation have not been determined. To determine the incidence of this complication and identify patients at risk, 194 patients undergoing vitrectomy were studied. Indications for vitrectomy included retinal detachment, proliferative disease, vitreous hemorrhage, macular pucker, and trauma. Intraocular fibrin formation occurred in 62 patients (32 percent); of these, 24 patients developed severe fibrin formation. Preoperative factors found to be predictive of severe fibrin formation were: severe flare in the anterior chamber (in front of the iris), an indication of breakdown of the blood-aqueous barrier: a scleral buckle from previous retinal detachment surgery; and poor vision preoperatively. An anterior epiretinal membrane dissection during surgery was also associated with fibrin formation. These results may be helpful in determining methods of preventing postvitrectomy fibrin formation. (Consumer Summary produced by Reliance Medical Information, Inc.)