A man pleaded not guilty to manslaughter charges Thursday in the case of a Casper man who died six days after being punched in the eye at a bar in January.

Ivall K. Sparks spoke clearly before a district court judge when he pleaded not guilty.

Mark Bretz, 50, died one week after being struck, a coroner testified in an earlier court session. The cause of death, he concluded, was blunt force trauma to the left eye.

Sparks, 42, hit Bretz in the early morning of Jan. 26 because Bretz made an obscene remark about his sister, he told police.

After being struck in the Evansville bar, Bretz took a cab to the Wyoming Medical Center where a doctor found his cornea was torn and his retina and lens were missing.

Bretz, a widower, was flown to a Colorado hospital the next day and died on Feb. 1.

The injury may not have been life threatening, Natrona County Chief Deputy Coroner Gary Hazen said during earlier testimony, but surgery was necessary because of the risk of infection from an open wound on the eye.

Bretz experienced bronchial spasms during surgery, a condition similar to a severe asthma attack, and after the surgery, he never regained consciousness.

Hazen said the punch did not cause a brain injury, but the doctor who performed the autopsy ruled out coincidental death, such as a heart attack.

Sparks pleaded guilty to assaulting Bretz before the Casper man died and began serving a 90-day prison sentence.

Sparks remained held late Thursday afternoon at the Natrona County Detention Center in lieu of $75,000 bond.

If convicted, Sparks could face up to 20 years in prison.

Contact city reporter Christine Robinson at (307) 266-0639 or christine.robinson@trib.com