Popis: |
The region of the macula, and especially the fovea, is so consistently free of retinal blood vessels that any large blood vessel in that region is looked on as a definite anomaly. Numerous anatomists 1 who have studied the circulation of this region have shown that it is supplied and drained almost entirely through capillaries. In fact, injected specimens of the retina have demonstrated that the fovea centralis itself is devoid even of capillaries. The choriocapillaris, on the other hand, is thicker in this area than elsewhere. Because the number of cases in which retinal blood vessels of large caliber cross the macula are so few, they deserve to be mentioned when they do occur. The earliest case that I could find was reported in 1868 by Mauthner. 2 He mentioned only 1 case in which he saw a vein of a large caliber unaccompanied by an artery going directly |