Applanation-Schiøtz disparity after retinal detachment surgery utilizing cryopexy

Previous reports of applanation-Schiøtz disparity following retinal detachment surgery involved patients whose detachments were treated with diathermy and scleral buckling. In 73 patients with retinal detachments treated by cryopexy and scleral buckling, applanation and Schiøtz pressures were measured before and after surgery. In the postoperative period, applanation tension values were significantly higher than Schiøtz values in the operated eyes only; the mean disparity was 6 mm Hg, with a range of 0 to 14 mm Hg. Sex, age, surgical aphakia, and length of time after surgery did not influence the data. Placement of the buckle, rather than extent of cryopexy, appeared to be the main factor in producing this disparity. Ophthalmologists who utilize the Schiøtz tonometer should be aware of the various conditions, including retinal detachment surgery, which produce low ocular rigidity.