For years, Dr Albert Yuen Wai-cheung has made the process of sex-change surgery slightly easier for patients, by performing all the operations himself. But he is about to retire, and with no doctor stepping forward as his successor, Yuen predicts his "one-stop" shop will be replaced by teams of surgeons. Yuen, 57, plans to retire in two years and none of his colleagues appear interested in taking over his practice. They were unwilling to specialise in the area, he said, so several doctors might be required, with different teams performing operations on men and women, as well as focusing only on a specific part of the procedure. "They think this kind of surgery is different. They may be thinking, 'There are many other surgeries to do, why do this?'" Yuen performs five to six sex- reassignment operations every year. He hoped the Hospital Authority would give more priority to these patients, as he believed the surgery was crucial for their overall well-being. "It is difficult for others to understand the psychological pressure [they face], how they want to appear as the opposite sex but are unable to. They are in agony. Without the surgery, they would have this pain for life," said Yuen, who has been performing the surgery since the 1980s. On Monday, the Court of Final Appeal ruled "W" - a man who had sex-reassignment surgery to become a woman - would be allowed to marry a man. Yuen said he was happy about the ruling as the rights of the people involved were being recognised, and he doubted the decision would affect the number of people seeking reassignment surgery. "They have to spend much time and pain in undergoing the surgery," he said. About one in every 300,000 people recognise themselves as having the sex opposite to that they were born with. In Hong Kong, people interested in having the procedure are required to first undertake a series of psychiatric assessments over two years. Yuen once rejected a prospective patient, thinking he was unsuitable. The man wanted to become a woman, but he did not wear women's clothes. Yuen suggested he should try it, and the next time he visited Yuen, he was wearing female clothing. But when Yuen saw him outside the consultation room, he had changed back into men's clothes. Yuen said there were guidelines stating that only those comfortable with appearing as the opposite sex were suitable for the surgery, as the urge should be natural and not forced.