Are Viagra and Cialis dangerous for the optic nerve?

A study published in the British Journal of Ophthalmology seems to confirm the link, also mentioned last summer by the American Food and Drug Administration (FDA), between the use of medication for impotence and a particular eye complication known as 'NAION', 'Non-arteritic Anterior Ischemic Optic Neurophathy'.

It is a fairly rare disorder but it can cause a very marked reduction in vision acuity. The data gathered from 76 patients, half with NAION and half with no eye problems, showed that the patients who had had a heart attack were 10 times more likely to have eye complications if they had taken sildenafil (an active ingredient in Viagra) or tadalafil (an active ingredient in Cialis) before damage to the optic nerve had been diagnosed. A similar relationship, although less significant from a statistical point of view, was shown in patients with high blood pressure.

Other NAION risk factors are arterial hypertension, diabetes mellitus, hypercholesterolemia, and vascular disorders. This is why, according to a statement made to the Corriere della Sera by professor Nicola Orzatesi, director of the ophthalmology clinic at the University of Milan, before including medication for impotence amongst the risk factors, it would be a good idea to corroborate the potential relationship through appropriate and controlled clinical studies carried out on a larger number of patients. In any case, Orzatesi concluded, 'it is important to bear in mind that, as with any medication, these should only be taken under strict medical control'.

(Source: Corriere Salute)