One of the leading causes of blindness in New Zealand and other developed countries is a "wet" form of age-related macular degeneration.
The condition can be rapidly progressive if untreated and results from the growth of abnormal blood vessels behind the macula. This is a small area at the back of the eye that allows fine details to be seen clearly.
A new macular degeneration drug called Lucentis received United States Food and Drug Administration approval in 2006.
This offered new hope for many people who once faced certain blindness, stopping and in many cases reversing at least some vision loss in most people.
But a closely related drug, called Avastin, has also been shown to be a highly effective and much cheaper alternative for people with this condition, many eye doctors say.
However, Avastin is FDA approved only for treatment of colon and other cancers and, as an alternative, doctors in many parts of the world have been using Avastin as an off-label treatment.
Since 2005, more than 300 eye patients, most of them with advanced macular degeneration, have been treated with Avastin in Dunedin, doctors say.
Prof Anthony Molteno, who heads the University of Otago ophthalmology section and is an eye specialist at Dunedin Hospital, said about 1000 Avastin injections had been administered to eye patients in the city.
"It's not miraculous but it has made an enormous difference for the good for these people."
By mid-2008, 312 Dunedin patients had been treated, including about 270 patients with macular degeneration.
Vision was improved in 35% of the patients, remained the same for about 30%, with the rest experiencing some deterioration, but at a much reduced rate.
The overall outcome had been "brilliant", offering new hope for many patients who otherwise faced a tragic loss of sight, he said.
In a letter sent out last week, Roche Products (New Zealand) Ltd offered medical professionals "important new safety information" about off-label use of Avastin.
Roche had been made aware of two "clusters" in Canada with a total of 25 spontaneously reported cases of eye inflammation and other adverse eye-related symptoms in patients after off-label use, the letter said.
Approached for comment, Prof Molteno said such symptoms had not been reported in Dunedin.
Stuart Knight, Roche's Auckland-based sales and marketing director, denied that Roche was applying pressure to have the off-label use reduced or stopped in New Zealand.
"We do, however, have a professional and ethical obligation to ensure that medical specialists and all other relevant stakeholders are aware that Avastin has not been formally studied in this setting, and is not registered by Medsafe [a Ministry of Health regulatory authority] for this use," Mr Knight said.
He said the Roche drug safety team had sent out a "dear-doctor letter", to alert key prescribers to potential safety issues.
Roche had been informed about reports of eye inflammation originating from one specific lot of Avastin administered intra-vitreally.
It was important to stress that a "causal relationship between Avastin and these cases of eye infections had not been established."
