A doctor treating Alex Zanardi has admitted the former F1 driver's vision could be affected by his hand-cycling crash.

Italian Zanardi, who lost his legs in a 2001 Champ Car crash, is still in a coma with serious facial and head injuries in the Santa Maria alle Scotte di Siena in Italy.

We reported on Wednesday that the 53-year-old could lose his eyesight.

"We have asked an ophthalmologist for advice," said head of emergency medicine Dr Sabino Scolletta.

And one of the first emergency specialists to treat Zanardi, Dr Robusto Biagioni, said: "Without treatment, Zanardi would only have had minutes to live.

"My colleagues found him deeply unconscious, with brief moments of unrest. He moved his arms and shouted incoherently.

"His face was marked by broken bones and what worried us most at the start was a very bad right eye injury. It was also clear that he had broken his skull," Dr Biagioni added.

But for Zanardi's fans, he gives some hope.

"I have seen worse injuries in my career and these patients recovered, often contrary to our forecasts. We cannot give up hope for Alex Zanardi.

"He is a model athlete and everyone knows how strong his will to survive and his determination are."

Finally, the hospital said it has been advised by Zanardi's family that no further medical updates will be provided "until there are significant changes in his state of health".