Bacterial profile of ocular infections: a systematic review

Background: Bacteria are the major contributor of ocular infections worldwide. Ocular infections, if left untreated, can damage the structures of the eye with possible blindness and visual impairments. This work was aimed to review the bacterial profile of ocular infections. Methods: Literature search was made in different electronic databases; the review was systematically made to get concrete findings. Results: As far as this review, Staphylococcus aureus, Coagulase negative Staphylococci, Streptococcus pneumoniae and Pseudomonas aeruginosa are the leading isolates in ocular infections. Frequent pathogens of the respective clinical diagnose include Staphylococci, Streptococcus pyogenes and Pseudomonas aeruginosa in blepharitis; Staphylococci, Streptococus pneumoniae, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli in Conjunctivitis; Staphylococci, P. aeruginosa and E. coli in dacryocystitis; Coagulase negative Staphylococci, Pseudomonas aeruginosa and Staphylococcus aureus in keratitis; Streptococcus viridians, Streptococcus pneumoniae and Coagulase negative Staphylococci in endophthalmitis diagnoses. Endogenous endophthalmitis is associated with Klebsiella pneumoniae whereas Coagulase negative Staphylococci and Bacillus spp. are common causes of post-operative and post- traumatic endophthalmitis. However, the predominant pathogens may not be exactly same in all areas of the world, in the United States for instance, Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae are the major causes of conjunctivitis. Conclusion: Gram positive bacteria are the major contributor of bacterial ocular infections. The distribution and proportion of bacterial isolates among clinical diagnoses varied but without exclusive anatomical restriction. To mitigate the burden of bacterial ocular infections, physicians should regard on risk reduction and comply with etiologic approach of diagnosis.