Characteristics of reversal optic cupping in adults glaucoma after reduction of intraocular pressure.

PURPOSE

According to Quigley's hypothesis the dense of 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 location to be involved in the characteristic glaucomatous optic nerve damage. To get clinical evidence for the hypothesis, the reversal of optic cup in adults glaucoma after reduction of intraocular pressure (IOP) was examined.

METHODS

The stereoscopic flicker comparison on with computerized image system was used to monitor the optic cup's changing, 2 serial superposed stereo pairs were displayed alternatively and rapidly and the changing parts appeared moving Under the stereoscopic observation, the changes of 3-dimension optic cup could be seen and the false positive phenomena caused by photographic angle variation, vascular pulsation could be differentiated from the characteristic change of the cup. Stereo fundus photographs were taken from 31 eyes with hypertension glaucoma before and after treatment of reduction of IOPs which was either diamox administration or trabeculectomy.

RESULTS

The result showed that the reversal of optic cups after reduction of IOPs were mostly asymmetrical, especially at the inferior and/or superior poles. By multiple stepwise regression, it is known that the amount of the change is only correlated with the initial elevated IOP.

CONCLUSIONS

The study indicated that it was the distortion and deformity of the lamina cribrosa leading to shearing stress that results in glaucomatous characteristic damage in structure and function. The individual tolerance of the lamina cribrosa to the high intraocular pressure and the locations of individual vulnerable at the optic nerve head are various.