Trail-blazing retired U.S. Justice Sandra Day O'Connor reveals she has dementia

WASHINGTON, Oct 23 (Reuters) - Sandra Day O'Connor, the first woman to serve as a U.S. Supreme Court justice, announced on Tuesday that she has been diagnosed with dementia.

O'Connor, a centrist on the conservative-leaning court, was appointed by Republican former President Ronald Reagan in 1981 and retired in 2006.

"Some time ago, doctors diagnosed me with the beginning stages of dementia, probably Alzheimer's disease," O'Connor, 88, said in a letter issued by the court.

As a result of the diagnosis, O'Connor said she has withdrawn from public life.

"I will continue living in Phoenix, Arizona, surrounded by dear friends and family. While the final chapter of my life with dementia may be trying, nothing has diminished my gratitude and deep appreciation for the countless blessings in my life," O'Connor added.

O'Connor was the Supreme Court's first woman justice nearly two centuries after the Supreme Court was established in 1789 but her place in history went beyond breaking gender barriers.

Over time, she became the court's ideological center, casting key votes in cases on the most contentious issues of her era, including a ruling that helped preserve a woman's right to have an abortion and another upholding affirmative action - the use of racial preferences in student admissions - on college campuses.

When former President George W. Bush replaced her with conservative Justice Samuel Alito, the already conservative court moved further to the right.

"Justice O'Connor is of course a towering figure in the history of the United States and indeed the world," Chief Justice John Roberts said in a statement. "She broke down barriers for women in the legal profession to the betterment of that profession and the country as a whole."

(Reporting by Lawrence Hurley; Editing by Will Dunham)