Minimizing the risk of endophthalmitis: Study on PVI and PHMB in ophthalmic surgery

(Image Credit: AdobeStock/Siniehina)

A new study¹ from the Department of Ophthalmology, University Hospital, Martin-Luther-University Halle-Wittenberg, Halle, Germany, that considered the effects of 2 very commonly used antiseptic agents used preoperatively, found that corneal and conjunctival epithelial cell lines are highly sensitive to povidone-iodine (PVI) and polyhexanide (PHMB). However, the investigators led by first authors Sabine Foja, MD, and Joana Heinzelmann, PhD, reported that no significant alterations were found in intact tissue-specific corneal epithelial constructs or porcine corneas.

Based on their results, the authors believe that PVI and PHMB are not associated with postoperative ocular irritation.

The authors conducted the study because of the serious implications of postoperative development of endophthalmitis, which can result in visual loss or loss of the eye. “In an effort to minimize the risk of endophthalmitis after ophthalmic surgery, prophylactic steps are necessary to reduce the number of microorganisms. Therefore, PVI and PHMB as alternative agents are used in the preoperatively and perioperatively to minimize the quantity of microorganisms on the ocular surface,” the authors commented.

The investigators cited previous evaluations of the 2 antiseptic agents. A large study of more than 13,000 patients showed that PHMB was effective against microbes, with a resulting incidence of endophthalmitis comparable to that of PVI reported previously.² The authors of the large study also found that PHMB The authors summarized that PHMB irritated the ocular surface to a lesser degree, thus eliminating some pain and discomfort that occurs with PVI. However, preoperatively, PHMB requires a longer exposure time than PVI.

Results of toxicity assessment

In the study under discussion to identify possible toxic effects of the 2 antiseptic agents on wound healing, the authors exposed human telomerase-immortalized corneal epithelial (hTCEpi) cells and human telomerase-immortalized conjunctival epithelial (hCjE) cells to 1% and 5% PVI or 0.04% PHMB for different periods. They also evaluated the toxicity in a human tissue-specific corneal epithelial construct and porcine eye culture model.

They reported that high cytotoxicity was associated with PVI and PHMB in the hTCEpi and hCjE in monolayer cell culture models, regardless of the incubation time concentrations of the agents. However, after hTCEpi cell differentiation into a tissue-specific corneal epithelial construct, the expressions of cPARP1, an early marker of cell death, or Ki67, a proliferation marker of cancer, did not change.

The investigators also found that wound healing in the porcine cornea was not significantly affected by incubation with these antiseptics.

They concluded that corneal and conjunctival epithelial cell lines are very sensitive to PVI and PHMB, but no significant alterations were found in intact tissue-specific corneal epithelial constructs or porcine corneas. “Therefore,” they commented, “we could not identify PVI and PHMB as reasons for postoperative eye irritation.”

References:

1. Foja S, Heinzelmann J, Viestenz A, et al. Evaluation of the possible influence of povidone iodine (PVI) solution and polyhexanide (PHMB) on wound healing in corneal epithelial regeneration. J Clin Med. 2024;13:588; https://doi.org/10.3390/ jcm13020588

2. Ristau, T.; Kirchhof, B.; Fauser, S. Antisepsis with polyhexanide is effective against endophthalmitis after intravitreal injections. Acta Ophthalmol. 2014;92:e494–e496; https://doi.org/10.1111/aos.12347.