What has Uma Thurman done to her face?

Los Angeles - Actress Uma Thurman has a new look that had the media abuzz after she appeared at the New York premiere of her new miniseries, The Slap, on Monday.

"What has Uma done to her face?" blared a headline in The Daily Mail, which said her "suspiciously smooth forehead and puffy face along with an extremely tight smile" leave her almost unrecognisable.

"Uma Thurman pulls a Renee Zellweger," went another headline in a reference to the shock the Jerry Maguire actress gave when she debuted a dramatically altered face last October.

Was it her bare-faced make-up, some in the media debated, noting that Thurman's angular facial features appeared to have smoothed out.

Indeed, she wore just a shimmer on her eyelids, bright red lips and slicked-back hair in a departure from her usual look of wavy tresses and dark eyeliner. And her complexion glowed.

Although Internet observers noted with approval that she could have been trying out the daring no-mascara trend, her look set off the inevitable speculation about plastic surgery.

Surgeons interviewed by the New York Daily News were divided as to whether she really went under the knife.

Some of her fans reacted with horror. "Uma Thurman used to be beautiful... but then, did that to her face," wrote a reader on the Hollywood Life website.

On Gawker.com, one critic compared her face to that of actress Tilda Swinton, known for her minimalistic look.

Thurman's glamorous transformation was remarkable as just two weeks ago, she was at a New York event, looking casual with tousled hair.

At the NBCUniversal Press Tour last month, she wore her hair straight with a fringe and smoky eye make-up.

But like Zellweger, Thurman, 44, had her supporters. One of them, Time magazine writer Daniel D'Addario pointed to the similarities shared by the Kill Bill actress and Zellweger, 45.

He wrote: "They were both hugely in-demand actresses after breakout roles in the 1990s through wide acclaim in the early 2000s. In the subsequent years, by choice or due to realities of the market, both Zellweger and Thurman worked less and less. Will comebacks be allowed by the public again or must every star over 40 have remained consistently in the public eye, so that their ageing process comes little by little rather than all at once?"

The Slap, also starring Thandie Newton, Peter Sarsgaard and Melissa George, is a remake of an Australian series, based on the book by Christos Tsiolkas about the events that come after a man at a barbecue slaps a boy for misbehaving.