In a recent paper, "holes" were allegedly described in Bruch's membrane, and there has been speculation by the authors and others as to their significance. Utilizing both conventional histologic cross sections and flat preparations of the choroid, we find no evidence for the existence of such holes. Rather, it is clear that these apparent holes seen in flat preparations of the choroid are, in actuality, the lumina of the arterioles and venules supplying the choriocapillaris seen "end-on."
Friedman E, Strongin M. "Holes" in Bruch's Membrane. Arch Ophthalmol. 1971;85(3):280-282. doi:10.1001/archopht.1971.00990050282005