[Characteristics of reversed optic cupping in glaucoma after reduction of intraocular pressure]

Quigley's hypothesis indicates that the dense connective tissue is the least and the pores of the lamina cribrosa are the largest at the superior and inferior poles of the lamina cribrosa, therefore they are the most vulnerable locations to be involved by the characteristic glaucomatous optic nerve damage. To get clinical evidences of the hypothesis, the reversal or contraction of glaucomatous optic cup after reduction of intraocular pressure (IOP) was examined (The change is primarily caused by intraocular hypertension--induced distortion and posterior ectasia of the lamina cribrosa which moves forward reversely, leading to dilated optic cup contraction.). The method of examination was a stereoscopic flicker comparison with a computerized image system, alternatively displaying superposed 2 serial stereo pairs rapidly and the changing part presenting jumping appearance. Under stereoscopic observations, the changes of 3-dimension optic cup end be seen and the false positive phenomena caused by photographic angle variation, vascular pulsation, etc. can be differentiated from the characteristic changes of the cup. Stereo fundus photographs were taken from 31 eyes with high intraocular pressures before and after treatment for reduction of IOPs which was either diamox administration or trabeculectomy. The results show that the reversal of optic cups after reduction of IOPs are mostly asymmetrical, especially at the superior and/or inferior poles. By multiple stepwise regression, it is known that the amount of the change is only correlated with the initial IOP.(ABSTRACT TRUNCATED AT 250 WORDS)