NAAION & Sildenafil

Hi
Its about my mother who had been diagnosed with Severe Pulmonary Hypertension due to ASD (operated). She is taking Sildenafil Citrate tablets 50 mg, 3 times a day for the last 3 years and improved a lot. But 5 days back, she has developed sudden blurred vision in her left eye and it is not improving. I knew that Sildenafil citrate can cause NAAION. We took her to an ophthalmologist who is suspecting cataract.
My mother had blurred vision before and  it disappeared automatically after some days. However this time..it is more severe and troublesome. She has history of transient sensitivity to light with her left eye. Please advise us whether it could be NAAION. Should she stop taking sildenafil?
Mustofa from Bangladesh

[John C Hagan III, MD, FACS, FAAO]

The latest and largest studies done on sidenafil (sold in USA as Viagra) does not cause NAAION. The relation is coincidental in that the individuals that take viagra are older and this is the age group that has NAAION.

Pulomonary hypertension is a potentially fatal disease. Do not discontinue the medicine for fear of eye problems.

JCH MD