Retina and optic nerve of eyes enucleated due to an iris ring melanoma or a malignant melanoma of the ciliary body were studied to investigate the correlation between corpora amylacea count and glaucoma stages. Ten eyes from ten patients [age: 62.3 +/- 13.0 (mean +/- SD); range 43-84 years] were used for the present study. Eight eyes had shown elevated intraocular pressure readings preoperatively. The corpora amylacea count was correlated with histomorphometric changes of the intra- and parapapillary region. The corpora amylacea count of the retinal ganglion cells decreased significantly with increased histological ratio of cup to disc, decreased retinal nerve fiber layer thickness, and increased optic cup depth. There was no significant correlation between the corpora amylacea count of the bipolar cells and each histomorphometric datum. These results suggest that the corpora amylacea of the retinal ganglion cells decrease in number with advancing histological changes of secondary glaucoma.