Chronic open angle glaucoma and low tension glaucoma: endothelin-1 levels in plasma and aqueous humour

The authors evaluated the possible variations of endothelin-1 (ET-1) levels in plasma and aqueous humour in patients suffering from chronic open angle glaucoma (COAG) and low tension glaucoma (LTG). Radioimmunoassay was used to assess the level of ET-1 in plasma and aqueous humour in two groups of patients with COAG and LTG. The ET-1 plasma level was higher in LTG cases (2.950 +/- 0.211 pg/ml vs 1.770 +/- 0.211 pg/ml; p < 0.001), whereas the aqueous humour ET-1 level was higher in the COAG pati ents (4.100 +/- 0.330 pg/ml vs 3.890 +/- 0.292 pg/ml; p < 0.008). The data collected indicated that low tension glaucoma must be considered as an esse ntially vascular pathology and should, therefore, be differentiated from ch ronic open angle glaucoma.