Polyvinyl pyrrolidone (PVP) in cataract surgery.

Early reformation of the anterior chamber after intraocular surgery is of paramount importance, its absence or delay leading to peripheral anterior synechiae and aphakic glaucoma (Troncoso, 1933; Kronfeld and Grossman, 1941; McLean, I94I; Meyer and Sternberg, 1950). Selinger (1937) injected air after cataract operations to restore the normal curvature of the cornea. He concluded that air prevented blockage of the chamber angle by pressing on the iris hyaloid diaphragm and thus avoiding such postoperative complications as iris prolapse and secondary glaucoma. Barkan (195I) found that the intraocular pressure might rise after the injection of air, as air under pressure produced seclusion of the pupil. Lister (1957), in a case of irregular anterior chamber, withdrew air and introduced saline in its place with good results. Lytton (I963), while advocating the use of air, warned that the small air bubble might enter the posterior chamber and press the iris against the angle of the anterior chamber. Chacon Mendoza (I963) objected that air, being a foreign material, might lead to irritation and iris prolapse; he recommended the use of the patient's own aqueous, which could be removed before surgery and injected postoperatively. King and McTigue (I964) used polyvinyl pyrrolidone (PVP) in the anterior chamber after keratoplasty and glaucoma operations for the treatment of bullous keratopathy. In their own words: "Our use of PVP to replace aqueous after grafting and glaucoma was incidental. We had begun to use this method after Payran's trial, with the thought that it could be a treatment for bullous keratopathy". PVP, a synthetic polymer of vinylpyrrolidone (Figure), is a glistening white flaky substance, soluble in water, giving a clear to yellow viscous solution with pH 4-5 to 7-0. It is freely soluble in most organic substances and also in saline. Aqueous solutions are stable and can be sterilized by autoclaving.