Pfizer officials say they have found no sign of increased blindness risk in men taking its drug Viagra.

Pfizer staff have reviewed all reports of eye-related events since the drug has been on the market, according to a news release from the pharmaceutical company.

"There is no evidence that Viagra causes blindness or any other serious ocular condition," says Joseph Feczko, MD, in the news release. Feczko is Pfizer's chief medical officer.

Pfizer is a WebMD sponsor.

Read Web MD's "Rare Reports of Vision Loss With Viagra."

Rare Vision Problem

"Men taking Viagra are at no greater risk for blindness than men of similar age and health not taking the medicine," says Feczko.

That includes a rare vision problem called nonarteritic anterior ischemic optic neuropathy (NAION), says Feczko. NAION is a painless swelling of the optic nerve that causes a rapid reduction in vision.

A journal report earlier this yearnoted NAION in 14 Viagra users.Most had other health problems or structural eye problems that raised their risk of NAION. None of the men in the study went blind, although their vision loss was permanent and reportedly started within 24-36 hours of taking Viagra.

Read Web MD's "Viagra Label May Note Rare Vision Problems."

Pfizer: No Evidence Seen in More Than 27 Million Users

"After more than 10 years of rigorous clinical study and worldwide safety monitoring of a medicine used by more than 27 million men, there is no evidence to suggest a link between Viagra and blindness or other serious ocular events," says Feczko.

"In addition, several studies specifically looking into the effect of Viagra in the eye by Pfizer as well as independent ophthalmologic experts found Viagra to have no serious adverse effects on the eye," he says.

Read Web MD's "Young Men Lead Surge in Viagra Use."

Pfizer, FDA Discussing Label Changes

According to Pfizer's statement, the company is still talking to the FDA about changing Viagra's label to reflect rare vision problems in men who have used the drug.

The update would reflect rare reports of NAION in some men who have used the drug.

However, the FDA concluded that no causal relationship between Viagra and NAION has been established, says Pfizer.

Talks between Pfizer and the FDA were first reported in May.

Read Web MD's "Pills for Erectile Dysfunction: Cialis, Viagra, and Levitra."

Label Changes for Other ED Drugs?

Other erectile dysfunction drugs may also update their labels.

"It is Pfizer's understanding that the FDA has asked that similar information be included in the labels of all oral ED (erectile dysfunction) medicines," the company's statement reads.

Patients should consult their doctors about using Viagra and follow the drug's prescribing information, as with any other medicine, says Pfizer.

Visit WebMD's Erectile Dysfunction Health Center

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: News release, Pfizer. WebMD Medical News: "Rare Reports of Vision Loss With Viagra." WebMD Medical News: "Viagra Label May Note Rare Vision Problems."