Terms such as "primary open angle glaucoma" and "chronic open angle glaucoma" are used to include both exfoliation glaucoma and POAG and some studies fail even to consider the disorder (11). This approach, is inappropriate since exfoliation glaucoma and POAG are different entities. Clinical and morphological evidence supports the view that exfoliation glaucoma is a true secondary open-angle glaucoma. The balance of ultrastructural evidence is in favour of exfoliation glaucoma developing due to an accumulation of exfoliation material and pigment within the outflow system of the affected eye. Clinically, exfoliation glaucoma has a number of specific attributes which distinguish it from POAG. It has a worse prognosis than POAG for medical therapy and ALT, but this may not apply in the case of prompt surgical intervention.