Prominent academics have expressed concern about the health of Charles Kao Kwan after it was reported that the internationally renowned pioneer of fibre-optic communications is suffering from Alzheimer's disease. Oriental Daily News yesterday quoted Professor Kao's wife, Wong May-wan, as saying that her 75-year-old husband had been diagnosed with the disease and his memory was fading. Born in Shanghai, Professor Kao graduated from the University of London in 1957. In 1963, he began experiments that culminated in the proof of a visionary concept - that strands of glass fibres thinner than human hair and cheaper to produce than fishing line could transmit near-limitless amounts of digitised data on pulses of laser light. In 1966, Professor Kao and another young engineer, George Hockham, published a landmark paper suggesting that an optical fibre could transmit laser signals with much reduced data loss if the glass strands were pure enough. Professor Kao served as vice-chancellor of the Chinese University of Hong Kong from 1987 to 1996. A spokeswoman for the university said it had maintained contact with Professor Kao since his retirement and was concerned about his condition. She declined to comment on the professor's health. Professor Kao could not be reached for comment yesterday. He was founding chairman of the board of governors of the ISF Academy, a private independent school in Pok Fu Lam, but quit the school's board in December. University of Science and Technology president Paul Chu Ching-wu, who has known Professor Kao for many years, said he had heard that the professor was unwell. Professor Chu said he held Professor Kao in the highest regard, not just for his scientific achievement but also because he took a keen interest in the education of Hong Kong's younger generations. Poon Chung-kwong, former president of Polytechnic University, said: 'I am obviously sad reading about this piece of news and wish him a speedy recovery.' Raymond Chang Chuen-chung, an expert in Alzheimer's disease at the University of Hong Kong, said the condition would first affect the patient's short-term memory. Dr Chang said patients gradually lose the ability to take care of themselves, and some might even develop depression as they witnessed the gradual deterioration of their abilities.