• Angle closure glaucoma is a well-known complication of scleral buckling and it is of particular interest when it occurs in eyes with previously normal angles. Forward rotation of the ciliary body about the scleral spur has been postulated as one possible mechanism for such angle closure. Large buckles were used in macaque rhesus monkeys and histopathologic examination indicated rotation of the ciliary body about the scleral spur as the cause of angle closure. Pupillary block was not present and large choroidal detachments were not needed to produce the observed closure. The exaggerated buckles used do not allow these monkeys to serve as a clinical model and great caution is stressed in making clinical extrapolations.