Q&A: Sunir Garg, MD, shares insights on using chlorhexidine for anti-sepsis

Photo of Sunir Garg, MD, taken at Retina World Congress 2025

Sunir Garg, MD, a professor of ophthalmology at Wills Eye Hospital and partner with Mid-Atlantic Retina, discussed with Ophthalmology Times one significant challenge in ophthalmological procedures: patient discomfort during intravitreal injections caused by povidone iodine.

Note: The following conversation has been lightly edited for clarity.

Ophthalmology Times: Can you share more about the the challenges behind current anti-sepsis options for intravitreal injections?

Sunir Garg, MD: One of the things we've seen with our patients, is as much as they come in for their intravitreal injections, the thing that they hate about the most, besides the wait, is how irritated and burning a lot of their eyes are afterwards, and much of that's because of the povidone iodine. We know that povidone iodine is super important to reduce the risk of infection, and some patients have no problems with it, but some of my patients actually want to stop their treatment just because of all the discomfort that they have. Another antisepsis that's been used in medicine, and in many of our cases, is in the OR, that we can use when we're scrubbing before surgery, is chlorhexidine. There have been a number of papers over the past 10 years that have looked at chlorhexidine as antisepsis.

There's a couple of different formulations that are available. There's an alcohol based one, and this is used quite commonly in Canada. And there's a great paper by last year looking at it, but they found a higher rate of endophthalmitis. Because of the alcohol in the chlorhexidine, you don't want to put that on the cornea, so they were painting the quadrant, which might have skewed their results. Other people have been using chlorhexidine alcohol-free on the surface of the eye, and that works great. But the problem with that is, if you look at a chlorhexidine bottle, at least the big ones that are commercially available, one bottle has a 24 hour BUD, so once you open it, you're supposed to discard it. And at $100 a bottle, it just doesn't become cost effective. You can get it from a compounding pharmacy alcohol-free, but that's also patient specific, and $100 itself, so that doesn't work very well.

OT: What did your recent research involving chlorhexidine focus on?

Garg: We did a study looking at how stable the molecule is. We did this with a Professor of Pharmacy, and we use the same techniques that they [pharmacists] look at in terms of stability of the molecule at day 0, 1 week, and 30 days, using high performance liquid chromatography, turbidity and all these other things that they use. What we found is that the molecule, even at room temperature is identical at the end of 30 days as it is in the beginning, giving us confidence that if you take a big bottle of chlorhexidine and aliquot it and use it over the course of a month, it still retains the same characteristics as the original molecule, which makes it cost effective for our patients. It's still something that we're using more of. There's a bunch of people that are published on this, but I look forward to bigger and larger studies demonstrating that it's at least noninferior to povidone iodine.

OT: Can you share any firsthand experience of using chlorhexidine as an anti-sepsis measure in your practice?

Garg: For a lot of patients, this has been a game changer for them. Previous work, we've shown about half the patients have no discomfort at all with povidone iodine; you could dump acid on their eye [and] nothing bad would happen. But for the half that had discomfort, they had a lot more discomfort with povidone iodine than with a topical chloroexidine. And a few of my patients who really dreaded coming in actually haven't had much problems with it at all. I had one patient that I was seeing who I used chlorhexidine on – it was her first time getting it and I gave her an injection – she actually called us up later on that day, kind of mad because she thought we didn't give her the injection because she didn't have her typical pain, she didn't have the burning, and she could see just fine. So she thought we were trying to hoodwink her. It took us a long time to tell her that, no, we didn't hoodwink her, we gave her injection, and we just changed the antibiotic on her.