AAO Academy Online
IPoster: Ocular Microbial Flora in Contact Lens and Non-Contact Lens Wearers – Are They Symptomatic?
Purpose: To evaluate the microbial profile in Contact Lens (CL) wearers and non- Contact Lens wearers and to compare with symptomatic and asymptomatic contact lens wearers.
Methods: Contact lens wearers with minimum of one year of soft CL wear and controls with no history of any CL wear were included. Subjects went through preliminary examination followed by a comprehensive battery of clinical tests. At the end of all these test comfort rating using visual analogue scale of vision, comfort, dryness and redness were documented. Conjunctival swab, contact lens sample and lens case sample were collected for microbial assessment.
Results: A total of 24 contact lens wearers and 24 non contact lens wearers were included in the study. There was no growth of organism in conjunctival swab between CL and non-CL wearers, except for 2 subjects in each category with increased number of non pathogenic organism (Staphylococcus epidermidis). A positive growth of non-pathogenic organisms was observed in contact lens of 9 subjects. Pathogenic organisms were predominantly isolated from lens case (11/24 samples) than in CL (8/24 samples). The subjective comfort rating of dryness and the clinical findings of papillary roughness and meibomitis were higher in symptomatic than asymptomatic CL wearers which was found to be statistically significant (p < 0.05). Surprisingly only 5 samples from symptomatic and 9 samples from asymptomatic CL wearers were identified with pathogenic organisms. Pathogenic organisms namely Pseudomonas species and non pathogenic organism Staphylococcus epidermidis were identified in both symptomatic and asymptomatic group. Significant positive correlation (r=0.61, p=0.001) was found between years of lens wear and comfort with lenses and between hours of contact lens wear and with a positive growth of organisms in CL(r=0.44, p=0.02).
Conclusion(s): Both pathogenic and non pathogenic microorganisms were isolated in contact lens and lens case samples of a daily wear soft contact lens users. Both symptomatic and asymptomatic subjects showed presence of pathogenic organisms though only few subjects presented with positive clinical signs.
Rajeswari Mahadevan, PhD, FAAO
Dr. Rajeswari Mahadevan is the head of contact lens clinic at the Medical Research Foundation, Sankara Nethralaya, India. She is also an associate Professor at the Elite school of optometry and SN academy. She has been recently elected as the Asia pacific regional president for IACLE executive board.
She obtained her B.S.Optometry degree, the M.Phil degree in optometry specializing in the subject of contact lens and completed PhD from Elite School Of Optometry, Birla Institute of Technology and Science.
She has presented several scientific presentations in international and national conferences and has 20 peer reviewed publications. She has mentored 10 post graduate students since the year 1999. She is a mentor for 7 post graduate students currently. She has recently authored a book on “Trouble shooting and problem solving in contact lens practice.” She has authored a chapter on “Role of contact lens in different environment” in a book published on occupational optometry. She is the principal investigator for different clinical trials on contact lens at the Vision and Medical Research Foundation.