Comparison of MacKay-Marg, Goldmann, and Perkins Tonometers in Abnormal Corneas

Intraocular pressure was determined manometrically in owl monkey eyes with normal and edematous corneas. The pressure was measured with Perkins hand held, Goldmann, and MacKay Marg tonometers to compare relative accuracy. At manometric levels of 20, 30, and 40 mm Hg, a statistically significant difference in readings was found between normal and edematous corneas with use of the Perkins and Goldmann applanators, whereas no such difference was found with the MacKay Marg tonometer. The MacKay Marg tonometer most closely approximated the true intraocular pressure in edematous corneas.