To the Editor.
—In their provocative article in the June 1989 issue of the Archives, Ticho and Nesher1 arrive at a number of conclusions that contradict other reports. Some of these differences may be real; others, however, may result from problems in study design.First among the problems are the clinical techniques employed. The authors evaluated the stability of the optic nerve on the basis of "cup-disc ratios as observed by direct ophthalmoscopy." This is certainly not optimal for detecting mild to moderate progression. The monoscopic view of the disc does not provide the same information as a three-dimensional view, particularly as it relates to mild collapse of disc walls or slight reorientation of vessels. Furthermore, detection of such change requires a valid and reproducible method for comparing the appearance during the 10 or more years of follow-up. Stereoscopic disc photographs (preferably with a fixed base) provide "hard copy"
Sommer A. Trabeculoplasty: Results That Can Mislead!. Arch Ophthalmol. 1990;108(2):167. doi:10.1001/archopht.1990.01070040017009