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

Summary 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 patients (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 essentially vascular pathology and should, therefore, be differentiated from chronic open angle glaucoma.