Editor,—I read with interest the article by Koet al,1 in which the authors describe their findings on the morphology of the circle of Zinn–Haller (CZH) obtained with fluorescein angiography. It was not mentioned in the article that by using scanning laser Doppler flowmetry, a non-invasive clinical method, CZH can also be clearly identified.2 Like Ko et al, the authors we found CZH easily visible in healthy myopic eyes within the temporal peripapillary area, especially if peripapillary atrophy was present.2 Using Heidelberg retina flowmeter images focused on the retinal surface, the temporal part of CZH was seen even in …