High doses of Viagra — a popular erectile-dysfunction medication — can cause irreverible damage to a person’s colour vision, a first-of-its-kind study suggests.Researchers from Mount Sinai Health System in the US based their study on a 31-year-old patient who arrived at an urgent care clinic complaining of red-tinted vision in both eyes that had not gone away in two days.He reported that his symptoms began shortly after taking a dose of liquid sildenafil citrate, sold under the brand name Viagra.Sildenafil citrate can cause visual disturbances with normal dosage, but symptoms typically resolve within 24 hours. The patient told doctors he had consumed much more than the recommended 50mg dose, and that symptoms began shortly after ingestion.The patient was then diagnosed with persistent retinal toxicity linked to the high dose of medication damaging the outer retina. His tinted vision has not improved more than a year after his initial diagnosis, despite various treatments.Researchers examined his retina for evidence of structural damage at the cellular level, something that had never been done before.They identified microscopic injury to the cones of the retina, the cells which are responsible for colour vision. The damage was similar to that seen in animal models of hereditary retinal disease such as retinitis pigmentosa or cone-rod dystrophy.”To actually see these types of structural changes was unexpected, but it explained the symptoms that the patient suffered from,” said Richard Rosen, Director of Retina Services at New York Eye and Ear Infirmary of Mount Sinai (NYEE). which adjusted for the age and sex of subjects, and, where appropriate, their medication use, to determine whether this difference was dissimilar in men and women.The study found that when comparing individuals with prediabetes to healthy subjects with normal glucose metabolism, the size of the difference in a number of cardiometabolic risk markers was greater in women than in men. men”>Women with prediabetes had a more elevated blood pressure, a more adverse difference in HDL (good) and LDL (bad) cholesterol, and more elevated levels of triglycerides (a type of fat) and markers of inflammation in the blood than prediabetic men.The authors stated that the major finding of this study is that there are already sex differences in cardiometabolic risk factors before the onset of T2D, to women’s disadvantage.They added, “Sex differences in some, not all, of the cardiometabolic risk factors, which were less favourable for the female sex (in individuals with T2D), were also observed in their association with prediabetes. This suggests that the cardiometabolic risk profile of women has deteriorated to a larger extent even before the onset of T2D, which needs to be confirmed by prospective studies.”
