OPTISOL CORNEAL STORAGE MEDIUM AND TRANSMISSION OF TREPONEMA-PALLIDUM

This study was conducted to provide experimental information on the pr obability of syphilis transmission resulting from corneal transplantat ion. To determine the effects of commonly employed corneal storage con ditions on the survival and infectivity of Treponema pallidum, T. pall idum subsp. pallidum (Nichols) was inoculated into OptiSol storage med ium or a T. pallidum survival medium at a concentration of 10(6)/ml an d incubated in cornea viewing chambers for 24 h at 4 degrees C. When i noculated intradermally into rabbits (0.1 ml per site), none of the 10 sites developed lesions from suspensions incubated in OptiSol in the presence or absence of 100 mu g/ml gentamicin; T. pallidum incubated i n the survival medium yielded lesions at one of 10 sites, whereas fres hly extracted organisms produced lesions at all 10 sites. In another s et of experiments, the infectivity of corneal tissue from rabbits inoc ulated intratesticularly with 2 x 10(7) T. pallidum 10 days earlier wa s determined. Corneas from five T. pallidum-infected rabbits were exci sed, extracted, and tested for infectivity either immediately after re moval or after 24-h storage in OptiSol. Recipient rabbits developed le sions at five of 50 intradermal sites when the corneas were neither st ored in OptiSol nor rinsed before extraction. Corneas from 10 donor ra bbits that were rinsed with phosphate-buffered saline to remove blood and aqueous humor before extraction did not yield lesions at any of 20 0 sites in the recipient animals. The results of this study indicate t hat retention of T. pallidum infectivity is poor under typical corneal storage conditions and that rabbit corneal tissue contains few, if an y, infectious T. pallidum organisms under the experimental conditions employed.