Updated from 2:56 p.m. EDT

Shares of

VISX

(EYE) - Get Report

were among the best-performing health and pharmaceutical stocks Wednesday, rising 34.6% after the company agreed to be acquired by

Advanced Medical Optics

( AVO) for $1.27 billion in cash and stock.

The deal for VISX, a maker of systems for laser vision correction, values each share at $26.52, a 47% premium to Tuesday's closing price of $18.10. Shareholders will receive 0.552 shares of Advanced Medical and $3.50 in cash for each VISX share they own. The combination of the two companies will create the largest refractive surgical business in the world. Advanced Medical Optics expects the deal, which is expected to close during the first quarter of 2005, to be neutral to 2005 pro forma earnings results. Shares of VISX traded up $6.26 to $24.36. Advanced Medical Optics traded down $3.64, or about 9%, to $38.80.

Dendreon

(DNDN)

fell 10.9% after the company posted a third-quarter loss that was wider than expected. The biotechnology company reported a loss of 38 cents a share on sales of $69,000. Analysts polled by Thomson First Call were expecting a loss of 33 cents a share on sales of $160,000. A year ago the company posted a loss of 35 cents a share on sales of $1.8 million. Shares traded down $1.41 to $11.57.

Shares of

Ligand Pharmaceuticals

(LGND) - Get Report

fell 10.1% after the company posted third-quarter earnings and sales results that fell significantly below expectations. The drug discovery company posted a loss of 9 cents a share on sales of $49.5 million. Analysts were expecting a loss of 1 cent a share on sales of $59.8 million. Looking ahead, the company forecast 2004 earnings of 3 cents to 9 cents a share on sales of $216 million to $231 million. Shares traded down 96 cents to $8.55.

Hologic

(HOLX) - Get Report

rose 15.4% after it posted fourth-quarter earnings and sales well above expectations. The diagnostic imaging systems provider earned 24 cents a share on sales of $63.9 million. Analysts were expecting earnings of 19 cents a share on sales of $59.6 million. Strong sales of the company's Selenia full field digital mammography systems contributed to the solid fourth-quarter results. Shares traded up $3.01 to $22.62.

Shares of

Wilson Greatbatch Technologies

(GB)

fell 2.1% after the company posted third-quarter results, narrowed its 2004 sales expectations, and lowered its 2005 sales guidance. During the third quarter the medical device components maker posted a profit of 14 cents a share on sales of $45.2 million. Analysts were expecting a profit of 7 cents a share on sales of $45.8 million.

Looking ahead, the company now expects earnings of 64 cents to 68 cents a share on sales of $195 million to $200 million. Previously, Wilson Greatbatch expected earnings of 50 cents to 57 cents a share on sales of $195 million to $205 million. For 2005, it forecast sales of $200 million to $220 million, down from its previous guidance of $207 million to $230 million. Analysts are looking for 2004 earnings of 74 cents a share on sales of $199.4 million and 2005 earnings of 94 cents a share on sales of $212.1 million. Shares traded down 41 cents to $19.51.

Other health care volume movers included

Pfizer

(PFE) - Get Report

, down 52 cents to $27.47;

Merck

(MRK) - Get Report

, up 41 cents to $26.41;

Mylan Labs

(MYL) - Get Report

, up 42 cents to $17.37;

Teva Pharmaceutical

(TEVA) - Get Report

, up 55 cents to $25.98; and

Amgen

(AMGN) - Get Report

, down 48 cents to $59.34.