Stereo optic disc photographs of 1,870 subjects with chronic open angle glaucoma (COAG), or a suspicion of glaucoma, were first reviewed in a masked fashion by the investigators to find optic nerve heads featuring the pure forms of the four types of glaucomatous appearance named by Geijssen and Greve (Fig. 7.1).
Only 123 optic disc photographs of the 1,870 could be classified as pure focal ischemic glaucoma (n = 38), myopic glaucoma (n = 37), senile sclerotic glaucoma (n = 24), and glaucoma with verifiable generalized enlargement of the optic cup (n = 24) and were available for study. Most discs could not be classified either because the very advanced glaucomatous damage could not be classified or because they had mixtures of more than one grouping. When there was any disagreement in disc classification between the investigators, the patients were not included in the study.

The following information was then collated from the clinical charts of the 123 patients: age; sex; race; ocular data including family history of glaucoma; visual acuity; visual field data; the highest untreated, recorded IOPs measured by applanation tonometry; and the mean of the three highest treated or untreated, recorded IOPs. The presence of migraine, cold hands/feet, vascular hypertension, ischemic heart disease, cerebral ischemic disease, hemodynamic crises, diabetes, and thyroid disease was noted, and drug and smoking histories were ascertained. The patients included those with COAG as well as those with normal-tension glaucoma (NTG).

The analysis showed the group of patients with myopic glaucoma was significantly younger than the groups with the other optic disc appearances. Patients with senile sclerotic glaucoma were significantly older than those with other optic disc appearances. There was a significant excess of men in the myopic glaucoma group and more women in the focal ischemic group. The level of IOP, both as the highest untreated recorded pressure and the mean of the three highest recorded pressures, was significantly greater in the group of eyes with generalized enlargement of the optic cup. The visual field defects were densest in the focal ischemic group in comparison with either senile sclerotic glaucoma or the group with evidence of generalized cup enlargement. A known family history of glaucoma was not significantly different between the groups.

Both a peripheral vasospastic response to temperature change and the subjective complaint of cold extremities were significantly more common in the focal ischemic group and significantly less common in the group with generalized cup enlargement. Migraine was also more prevalent in the focal ischemic group in comparison with the other groups. The overall mean vasospastic score for the focal ischemic group was significantly higher than in the other groups. There was a tendency for the vasospastic parameters to be more prevalent in the myopic glaucoma group.

Hypertension and ischemic heart disease were far more prevalent in the senile sclerotic group in comparison with the other groups. Diabetes and cerebral ischemic disease were also more common in the senile sclerotic group, but the differences were not statistically significant. The overall mean cardiovascular disease score was significantly higher in the senile sclerotic group when compared with the others. Thyroid disease (mainly hypothyroidism) was also found to be more prevalent in the senile sclerotic group.

It should be noted that patients who had verifiable evidence of a generalized neuroretinal rim diminution with increase of the overall cupping always had markedly elevated IOPs and statistically less evidence of vasospastic disease than the other groups. There may, of course, be other disc appearances yet to be recognized, which might manifest other risk factors that fail to be detected when an overall multifactorial disease such as glaucoma is studied without breaking it down by phenotypes.