Observations on experimental pneumococcal infection of the rabbit's cornea and on their treatment with penicillin.

T'HE experimental production of infected lesions of the rabbit's cornea by intra-corneal inoculation of suspensions of pneumococci has been described by Ginsberg and Kaufman (1913) and by Robson and Scott (1943a, b). Cole, Hamilton-Paterson and Sorsby (1945) were unable to confirm the findings of Robson and Scott, although they used the same strain of pneumococcus. This divergence of results has not, as far as we know, been explained (Fraser, Robson, Scott and Scott, 1945; Sorsby, 1946). The present paper reports further observations on the lesions produced by intra-corneal inoculation of the same and other strains of pneumococci and on the effect of penicillin administered subconjunctivally on these lesions. It is by now well known that bacteriostatic concentrations of penicillin can be produced in the aqueous and cornea by subconjunctival injection of suitable doses (Andrews, 1947; Leopold and La Motte, 1945; Sorsby and Ungar, 1947; Struble and Bellows, 1944; von Sallmann, 1945). The present observations are directed to show whether this route of administration is in fact as well as in expectation therapeutically efficient, and if so, under what conditions.