STREPTOCOCCUS MITIS/ORALIS CORNEAL ULCER AFTER CORNEAL TRANSPLANTATION

Streptococcus mitis/oralis corneal ulcer occurred in a case of corneal transplantation reducing vision to hand movements close to face in the right eye. Treatment with 5% vancomycin eye drops led to healing of corneal ulcer followed by scar formation. Fresh corneal graft transplanted after three months resulted in clear graft well opposed to the host cornea accompanied with visual acquity of 6/24 and -2 170° refractive correction. While viridans Streptococci have been implicated in corneal infections, this is the first case of S. mitis/oralis corneal ulcer of its kind. S. mitis/oralis is expanding in pathogenicity crossing the barriers of commensalism to cause opportunistic infection in susceptible hosts. It is difficult to identify and differentiate it to species level through conventional, molecular and mass spectrometry due to limitations of phenotypic expression, genotypic sequence and spectra databases. Both penicillin and high level gentamicin resistance has been reported. S. mitis/oralis can lead to permanent corneal scarring leading to loss of vision and consequent corneal transplantation thereby mandating a high index of suspicion and prudence in attributing causality to initiate early treatment to preserve vision in cases of corneal ulcers.