The following is a summary of “Topical Antiseptics in Minimizing Ocular Surface Bacterial Load Before Ophthalmic Surgery: A Randomized Controlled Trial,” published in the January 2024 issue of Ophthalmology by Romano et al.
Researchers conducted a retrospective study to assess the efficacy of two commercially available ophthalmic antiseptic formulations, 0.6% povidone-iodine (PVI) and 0.02% chlorhexidine (CLX), in reducing bacterial load on the ocular surface before surgery.
They involved 70 adult patients scheduled for intraocular surgery (phacoemulsification), who were randomly assigned to receive either 0.6% PVI four times daily for three days (group A) or 0.02% CLX four times daily for three days (group B) before surgery in their index eye. The untreated eye served as a control. Conjunctival swabs were collected from both eyes before (T0) and after (T1) the treatment regimen. Microbial DNA quantification was performed using real-time polymerase chain reaction (PCR) analysis. The Mick algorithm was employed to compare the abundance of each genus/genera against the distribution of abundances from the reference. At T1, patients completed a questionnaire to assess therapy-induced symptoms. The primary outcome measured was the reduction in bacterial DNA at T1 (microbial load) compared to the control group, expressed as the mean number of real-time PCR cycle times (CTs). Secondary outcomes included taxonomic composition, differential abundance, and therapy-induced ocular symptoms.
The results showed that the T0-T1 difference in CT was significant in group B (mean [95% CI]: 0.99 [0.33], P<.001) but not in group A (mean [95% CI]: 0.26 [0.15], P=.09). Taxonomic composition, alpha, and beta diversity remained consistent at all time points in both groups. The rate of patients reporting therapy-induced ocular symptoms and the mean discomfort grade were higher in group A compared to group B (97% vs 26% and 4.97 ± 2.48 vs. 0.66 ± 1.53).
Investigators concluded that CLX 0.02% is more effective than PVI 0.6% in reducing ocular surface bacteria while maintaining bacterial diversity and causing less discomfort.
Source: ajo.com/article/S0002-9394(24)00010-2/fulltext