MedicalResearch.com Interview with: Dr. Michael Kalloniatis School of Optometry and Vision Science, UNSW Australia, Sydney, New South Wales, Australia; Centre for Eye Health, Sydney, New South Wales, Australia; Medical Research: What are the main findings of the study? What was most surprising about the results? Dr. Kalloniatis: Normal mice given a single sildenafil treatment had a transient loss of visual function which recovered in two days. Carrier mice (mice which carry a single copy of a mutation that commonly causes recessive Retintis Pigmentosa) showed a supernormal visual response (a response much larger than the norm) to sildenafil which took two weeks to recover to normal. Carrier mice also showed an increase in an early marker for apoptosis (a protein which suggest cells may be preparing to die) suggesting sildenafil may cause retinal degeneration in these mice. (more…)