One example is a new surgical procedure to correct for cataracts , a condition in which the clear lens of the eye becomes so cloudy that vision is impaired. Vision can only be restored by surgical removal of the cataract. With the new procedure, a surgeon does not have to suture, or stitch, the incision. Instead, the eye's normal internal pressure pushes the edges of the severed tissue together and the incision heals naturally, a dramatic improvement over conventional cataract surgery, in which a surgeon had to make seven to 10 sutures to close an incision. Approximately one million cataract operations are performed each year in the United States.
Animal models are the key to present and future breakthroughs in research on eye diseases.
Lasers , for example, which have been successfully used in rabbits to treat eye tumors , are beginning to undergo human trials in order to remove eye tumors without cutting into the eye. Lasers are also being studied as instruments to reshape the cornea without scarring. Such a technique could potentially free millions of people from the need to wear corrective lenses. Retinal transplants, currently being performed on mice and other small animals, will soon be tried in primates, whose visual systems are similar to those of humans. Vision is perhaps the one of the five senses on which we rely most.