Shares in Optos yesterday surged more than 9% after the Scottish eyecare specialist and rising technology star almost quadrupled its interim pre-tax profits and said its expansion projections were back on track.

Shares in Optos yesterday surged more than 9% after the Scottish eyecare specialist and rising technology star almost quadrupled its interim pre-tax profits and said its expansion projections were back on track.

The Dunfermline-based firm unveiled pre-tax profits of $1.8m (£916,000) for the six months to the end of March, compared with $500,000 for the same period last year.

At the same time, revenue was up 22% to $48.9m, with the biggest rise occurring in North America.

Optos shares yesterday climbed more than 14% in early trading, but then settled back to a rise of 9.03%, or 13.5p, to 161.5p although it still reversed a recent dip.

The company's eye-testing machines produce a high-resolution image of the retina in a single capture, allowing identification and prevention of eye disease, such as retinal detachment and age-related degeneration, at a very early stage.

Under its business model, Optos retains ownership of the expensive P200 machines and charges for each test.

Thomas Butts, the com pany's US-born chief executive, yesterday told The Herald that Optos was addressing a largely uptapped global market worth up to £4bn.

"Our core market is prim ary care in North America, that is to say optomologists, and that market alone consists of 24,000 identifiable practices and 165 million eye exams each year," he said.

"That market is worth $2bn to $3bn annually.

"On top of that, we've recently launched machines for the secondary, or ophthalmic, market, which we believe to be worth another $600m, as well as machines for the medical market, such as surgery, worth around $250m." Butts also said the company had recently invested in Europe and had seen significant growth in Germany.

However, North America still accounted for the bulk of revenue, rising some 20% to $45.8m, while Europe climbed 44% to $3.1m.

The company noted that during the latter part of the first half its devices were taken up by Wal-Mart in its Advanced Instrument Programme for the retail group's in-store optometrist at 2250 outlets.

Butts said: "We are on track to generate 20% to 25% revenue growth and maintain a contract renewal rate in excess of 85% at the full year.

"We're very happy with these results and the overall profitability, which means our margins are improving.

"We're also very pleased Douglas Anderson, founder of Optos, recently won the Inventor of the Year."

The company was founded by Anderson in 1992 to help his then five-year-old son, Leif, who had become blind in one eye after a detached retina was detected too late.

Anderson, who was then head of an Edinburgh design company, asked his colleagues to design the device that has become Optos's core product because his son hated lengthy eye examinations.

Earlier this year, Optos was named by the European Commission and European Patent Office as European Inventor of the Year 2008.

Anderson received the award in Ljubljana, Slovenia.