Bacterial Contamination of The Wetting Solution in Cases of Soft Contact Lens

ABSTRACT

Soft contact lenses have become a popular modality for the cosmetic correction of refractive errors. Recent reports of bacterial corneal ulcer in cosmetic soft contact lens wearers prompted the evaluation of the possible sources of bacterial contamination which are wetting saline solution, soft contact lens case, concurrent conjunctivitis, lens surface abnormalities, inadequate temperature and duration of disinfection, poor hygiene in contact lens handling and aging of the lens. Of these factors, the authors considered that the wetting solution and cases of contact lens were most important sources. The extensive bacteriologic study and sensitivity test to antibiotics were done with 200 soft contact lens cases containing; wetting saline solution in 100 patients. The study showed that 149 cases containing wetting saline solution(74.5%) were contaminated with bacteria which serve as a possible source of corneal ulcers. Form 149 contaminated cases of soft contact lens, a total of 231 isolates were cultured. Of these 231 isolates, 32 isolates(13.9%) showed gram positive bacteria; 199 isolates(86.1%) gram negative bacteria. Major organisms were Enterobacter species(21.2%), Serratia marcescens(19.9%), pseudomonas species(17.7%), Adnetobacter calco var. antitrat(10.4%) and Bacillus subtilis(10.0%). Therofore, it should be emphasized that adequate and meticulous home disinfection of contact lens cases and wetting solution is done for prevention of bacterial contamination of soft contact lens.