The histopathologic effects of cryopexy on the retinal vasculature of the dog were studied. Ranges of cryopexy considered therapeutic were used, and the vessels were examined in retinal whole mounts prepared by trypsin digestion. Cryosurgical applications of -30 C to -40 C for one to three seconds produced necrosis of retinal capillaries, first apparent three days following treatment. Pigment deposition and hypercellularity were noted in the venules, while the arterioles remained relatively unaffected.
Wood LW, Watzke RC. Effects of Cryopexy Upon the Retinal Vasculature. Arch Ophthalmol. 1969;81(2):254-258. doi:10.1001/archopht.1969.00990010256019