Inexpensive stereoscopic CCRG camera for lens/cataract photography in vitro.

In 1978 the American Cooperative Cataract Research Group (CCRG) adopted a stereoscopic camera system for photographing human cataracts in vitro based upon a Zeiss OPMI 1 operating microscope (Carl Zeiss, Inc.; Oberkochen, West Germany). Photographs obtained with this system were used to classify human cataractous change according to the standardized CCRG protocol. Classification data correlated with laboratory data furthered the attempt to define the biochemical or biophysical basis for specific types of cataractous change. Presently, the high cost of this camera (exceeding $20,000) precludes its use by many laboratories wishing to do human lens research. This study describes an inexpensive (less than $2,200) alternative camera for this type of photography. Adjacent frames on the film strip constitute stereo pairs which can be viewed in a modified stereo viewer. In the original CCRG camera both members of a stereo pair were included in the same frame. The quality of the stereo images obtained with this new system nearly equals that with the original Zeiss system. It is hoped that this inexpensive system will allow more scientists to participate in CCRG-related research and increase the supply of intracapsularly extracted cataracts available to all collaborating CCRG scientists.