Studies on human cataracts. I. Evaluation of techniques of human cataract preservation after extraction.

The effects of several media and temperatures on the features (i.e. classification) of human cataracts have been studied with the aim of defining those storage conditions that least alter the appearance of the cataract after extraction. It was found that distilled water, normal saline, TC 199 medium with extra bicarbonate and 5.5 mM glucose, and silicone oil at 4 degrees, 36 degrees, and 37 degrees C are all unsatisfactory for preserving cataracts for more than 1 hr. Normal saline and TC 199 medium with bicarbonate and glucose are satisfactory for period not exceeding 30 to 60 min at 4 degrees C. The best set of conditions, one that leads to no significant change in the appearance of the cataract, is storage in a small covered glass vial at 4 degrees C with no added fluid. In this moist chamber, no significant changes in cataract classification occurred during a 4 hr period. The effect of -20 degrees C for 15 min on the appearance of a nuclear cataract was negligible, and it was concluded that lenses so treated could be used for a correlation between the nuclear cataract's CCRG classification and its light scattering properties, as studied in Parts II and III.