Evaluation of used eye drop containers for microbial contamination in outpatient department of tertiary care teaching hospital

Abstract

Background: Contaminated eyedrops are considered as serious risk factor for many iatrogenic ocular infections. Apart from the risk of infection, microbial contamination may alter the pH of the solution thereby reducing the efficacy of drugs. Presently many preservatives are added to these eye drops preparations to extend the duration of use. Hence authors aimed this study to find the contamination rates in such eye drop preparations.Methods: This was a prospective observational research conducted at Ophthalmology OPD, of tertiary care teaching hospital for the period of 2 months. Total fifty five used eyedrops were collected.Results: Authors found that 25.45% of the collected eye drops were contaminated with various organisms, viz. E. coli (10.90%), Staphylococcus aureus (9.09%), Pseudomonas aerugenosa (1.81%), Bacillus subtilis (1.81%) and Candida albicans (1.81%). Among various eyedrops, mydriatic (60%) eyedrops had the highest rate of contamination. We also found that, different preservatives in the eye drops were presents with different level of microbial contamination.Conclusions: The present study showed that there is a definite co-occurrence between eyedrop contamination and ocular infections irrespective of preservatives. This research raises a concern about questionable efficacy of preservatives.

Comparison of Preservatives Efficacy of Benzalkonium Chloride, Thimerosal and Benzyl Alcohol in Eye Drop Products Containing Chloramphenicol

“…In fact, the eye drops's shelf-life is determined by the preservatives themselves, rather than the main components. Expired eyedrop mean loss of preservative potency to protect the eye drops from microbial contamination [42]. Therefore, preservatives must fulfill certain requirement such as; compatibility with other components in the eye drops, non-toxic and must be efficient during the entire of use.…”

Highlighting the Microbial Contamination of the Dropper Tip and Cap of In-Use Eye Drops, the Associated Contributory Factors, and the Risk of Infection: A Past-30-Years Literature Review

“…The sterility of eye drops should be, ideally, secured throughout the manufacturing process and the supply chain and maintained for the recommended duration of use, from opening to handling by the end user [ 10 , 11 ]. A literature review showed that the microbial contamination rate of preserved and preservative-free eye drops varied from 2.3 to 73% [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. The most important point was that fungal and bacterial microorganisms were cultured from the dropper tip, cap, and contents of eye drops [ 20 , 22 , 26 , 39 , 43 , 46 ,…”

“…Bacteria from the human commensal flora were the predominant isolated microorganisms [ 17 , 18 , 21 , 22 , 26 , 30 , 34 , 41 , 43 , 46 , 49 ], logically, since the contamination occurred after the bottle was opened. Limited growth of pathogenic bacteria and airborne environmental bacterial and fungal spores were also reported [ 15 , 24 , 29 , 34 , 43 , 50 ].…”

“…A literature review showed a limited number of studies that examined in-depth the link between ocular infection and the microbial contamination of eye drops. Microbial contamination was documented when used by patients at home and by healthcare professionals (HCP) in private clinics, in inpatient and outpatient settings, and in the operating room (OR) [ 15 , 17 , 18 , 19 , 36 , 37 , 39 , 41 , 43 , 49 ]. Numerous studies have reported inconsistent findings attributable to contributory factors [ 15 , 17 , 18 , 19 , 21 , 23 , 24 , 37 , 46 , 47 , 49 , 50 ].…”

“…Microbial contamination was documented when used by patients at home and by healthcare professionals (HCP) in private clinics, in inpatient and outpatient settings, and in the operating room (OR) [ 15 , 17 , 18 , 19 , 36 , 37 , 39 , 41 , 43 , 49 ]. Numerous studies have reported inconsistent findings attributable to contributory factors [ 15 , 17 , 18 , 19 , 21 , 23 , 24 , 37 , 46 , 47 , 49 , 50 ]. The handleability of eye drops may pose an important risk of microbial contamination [ 10 ].…”