Relationship of basal iridectomy to shallow chamber following cataract extraction.

A STUDY CONDUCTED at the University of Oregon Medical School since 1950 revealed that shallowing of the anterior chamber after cataract extraction was an uncommon, but sometimes serious, complication which developed under several circumstances. In patients observed prior to 1951, the anterior chamber occasionally did not reform during the first twenty-four hours after surgery. In those eyes a wound leak usually was demonstrable. In 1951, we began to use a limbus-based flap of conjunctiva and Tenon's capsule to bury a half-lap type of limbal incision which had been closed with multiple catgut sutures (Figure 1). This technique virtually eliminated failure of reformation of the anterior chamber and epithelial ingrowth,' but it did not prevent a second type of shallow chamber which most commonly developed without a demonstrable wound leak seven to twenty-one days postoperatively. In 1957, Weisel and 12 described what we thought were the important clinical features of this second type of shallow anterior chamber (Table 1). It was associated with hypotony, choroidal separation, posterior vitreous detachment with forward displacement, and adherence of an intact vitreous face to the pupil and iris opening. The resultant vitreous obstruction to the flow of aqueous from the posterior into the anterior chamber contributed to the shallow chamber. This viewpoint was not widely accepted because the prevalent concept then was that pupillary obstruction would have to be associated with elevated tension. We felt that, in those eyes, there was hypotony, rather than glaucoma, because the formation of aqueous wvas decreased. Chandler and Maumenee have provided evidence to stupport this concept.:' *Froimi the Tolhn E Weeks Inistittute of Ophthalmology, University of Oregon Medical School.