Methods: This was an observational cross-sectional study using a convenience sampling method conducted in the OOC of Universiti Kebangsaan Malaysia Medical Center, Malaysia. The samples of POD bottles were divided into groups obtained after 14 days (T14) and after 30 days (T30) of use. The contamination rate at the dropper tip and in the residual contents was determined and the contaminating organisms were identified.
Results: A total of 140 of 149 extended-use POD bottles were included. The prevalence of contamination was 30%. There was a statistically significant difference in the rate of contamination between samples T14 and T30 (19% and 11%, respectively; p=0.046). Proparacaine and tropicamide showed higher contamination rates in the T14 samples (p=0.027 and p=0.497, respectively) than in the T30 samples. The site of contamination was higher at the dropper tip than in the residual contents (p>0.05). Coagulase-negative Staphylococcus species were the most frequently identified contaminants (89%).
Conclusion: The dropper tip was more contaminated than the residual contents, and coagulase-negative Staphylococcus species, which are common commensal flora of the ocular conjunctiva and skin, were the most frequently identified organisms.
DESIGN: A case-control study.
METHODS: This study received ethical approval (NMRR Research ID 23957) and informed consent was obtained from all participants. It involved 20 participants with 20 samples of pterygium and 20 samples of normal conjunctiva that were obtained from the same eye of each participant. All the participants underwent history taking, slit lamp examination, and pterygium excision surgery. Both samples underwent immunohistochemistry procedure. Pretreatment procedure was conducted using heat-induced epitope retrieval with PT link, subsequently followed by EnVision FLEX staining procedure and incubation with anti‒IL-17 antibody and anti‒IL-23 antibody. Slides were examined in high-power fields (400x) for both samples in 3 different fields. Total positive stained cell counts in all 3 fields with IL-17 and IL-23 between pterygium and normal conjunctiva were analyzed by using Wilcoxon signed rank test.
RESULTS: IL-17 positive cell counts for normal conjunctiva showed mean 196.10 ± 80.487 but for pterygium was 331.10 ± 108.416. As for IL-23, the mean for positive cell counts for normal conjunctiva was 62.10 ± 33.462 and IL-23 positive cell counts for pterygium showed mean 102.95 ± 41.378. Both IL-17 and IL-23 were significantly increased in pterygium compared with normal conjunctiva (P < 0.001).
CONCLUSIONS: Both IL-17 and IL-23 were found to be significantly higher in the pterygium group than in the normal conjunctiva group with P < 0.001 by Wilcoxon signed rank test.