Relatives of a Tucson eye surgeon who disappeared during a Swiss skiing trip more than two weeks ago have given up hope that he's alive and are planning a memorial service.

Douglas J. Symes, a 43-year-old ophthalmologist, was with some 90 skiers who crossed the Swiss border on March 13 from Courmayeur, Italy, to the Zermatt resort to ski the Matterhorn.

Symes was seen about 2:30 p.m. skiing alone on the mountain.

At 4 p.m., other skiers on the trip organized by Morningstar Ski Tours of Tucson boarded a bus for the return trip to their Courmayeur hotel, but Symes was not with them.

Swiss and Italian authorities, using the Alpine ski patrol, dogs and helicopters, searched the area from March 17 through March 21 before abandoning their effort.

It is believed Symes likely fell into a deep crevasse on the Matterhorn.

''We know he couldn't have survived more than two or three days,'' said Symes' sister, Sue Goodwin of Raleigh, N.C.

Larry Hutter, a Tucson real estate broker who was Symes' roommate on the trip, said his friend may have made a mistake.

''I am convinced his body is still on the mountain,'' Hutter said. ''He was an expert skier, but he was skiing ... in an unfamiliar area." She said her sister, Terri Symes, of Columbus, Ohio, even flew in a search helicopter.

Symes, who is single, left Tucson on March 9 and planned to return by March 16, according to a cheerful message left in Italian on his telephone answering machine.

At the request of a reporter, Roma Cafe chef Gino Marinelli translated the message.

''The message says, 'I'm going over there to ski, eat and shop 'til I die' - or drop, depending on how you want to interpret it. But he said die,'' Marinelli said.