A commonly used contact lens solution has been withdrawn from sale amid concerns linking it to eye infections.
The solution keeps the eyes moist
Manufacturers Bausch & Lomb acted after a rise in Fusarium infections among users of its ReNu MoistureLoc solution in Hong Kong, Singapore and the US.
The reason for this rise is not yet known, but the company has been unable to rule out the possibility that the product is to blame.
The UK regulatory authority advised users to stop using the product.
Initial investigations have not revealed any problems with contamination of the product.
Ronald Zarrella, chief executive officer of Bausch & Lomb, said: "After an extensive investigation involving thousands of tests, millions of dollars and collaboration with government agencies, health authorities and independent experts, there is no evidence of product contamination, tampering, counterfeiting or sterility failure.
"That leads us to conclude that some aspect of the MoistureLoc formula may be increasing the relative risk of Fusarium infection in unusual circumstances."
The Medicines and Healthcare products Regulatory Authority (MHRA) has advised users to dispose of any remaining stocks of the solution, and to exchange the empty bottle for an alternative lens care solution at the point of sale.
The MHRA stressed this was a precautionary measure, and that there have been no reports of Fusarium eye infection in the UK.
Fusarium infections cause inflammation of the cornea, the front part of the eye.
Symptoms include redness, blurry vision, discharge, swelling, tearing, pain and increased sensitivity to light.
In severe cases it can cause permanent blindness.