Lower-dose pilocarpine does not affect ciliary muscle thickness

Mark Dunbar, OD, of the Bascom Palmer Eye Institute, spoke with Optometry 360 about his presentation at SECO 2026. The study found that low-dose pilocarpine had minimal to no effect on ciliary muscle thickness. Six months after the commercial release of Qlosi, there have been no documented cases of retinal tears or retinal detachments.

Mark Dunbar, OD:

Hi everybody. My name is Mark Dunbar. I practice at the Bascom Palmer Eye Institute in Miami, Florida. I am here on behalf of Optometry 360 regarding the poster that I have done at SECO.

As you know, Qlosi is now commercially available for the treatment of near vision correction for people with presbyopia. As you may know, Qlosi is one of the newer pilocarpine drugs. The concentration of Qlosi is about 0.4%. As you know, one of the concerns with using pilocarpine is really the risk of retinal tears and retinal detachments. Vuity, of course, was the first presbyopia drug that was FDA-approved. It really sailed through clinical trials with no adverse events.

As we’ve talked about, one of the concerns with any pilocarpine drug is this risk of developing retinal detachments. That really comes about because of the mechanism of action. With pilocarpine, you get contraction of the ciliary muscle. Obviously, you get myosis and the nice pinhole effect, but more concerning is contraction of the ciliary muscle. When that happens, of course, forward movement of the vitreous. What we saw with Vuity was a significant number of patients went on to develop retinal tears and retinal detachments.

Orasis, of course, was very concerned about this with their commercial release of Qlosi, which as I said, contains 0.4% pilocarpine. Really the question was, do we get that same kind of effect on the ciliary muscle with a lower concentration of pilocarpine than we do with a higher concentration of pilocarpine? Again, and the idea was if we don’t really get that same kind of effect with pilocarpine with a lower concentration, do we limit or reduce the risk of retinal tears and retinal detachments?

Orasis set out to really answer that question. They reached out to Bascom Palmer where I work. As you may not know, we apparently have the only OCT device that can measure ciliary muscle thickness. We looked at 10 patients using low-dose pilocarpine 0.0.4% pilo. We used 2% pilocarpine, and then we looked at really just a balanced salt solution; 10 patients, each of them given either the balanced salt solution, given the Qlosi low-dose pilocarpine or the 2% pilocarpine. We measured ciliary muscle thicknesses and measured them at different locations.

Interestingly, what we found was that the 0.4% pilocarpine was almost identical in terms of ciliary muscle thickness to the balanced salt solution. Whereas with the 2% pilocarpine, we got a significant increase in ciliary muscle thickness. The hypothesis that they set out to explore was true that there is a dose dependency on ciliary muscle thickness, that low-dose pilocarpine really had minimal to no effect on ciliary muscle thickness. Again, thinking big picture, if we have worries or concerns about using Qlosi and a potential risk of pilocarpine, what we’re seeing is essentially no change in ciliary muscle thickness.

Again, we may not see the same forward rotation of the vitreous. Again, that would essentially reduce or eliminate the risk of developing retinal detachments. The fact is, so far, I think it’s been about 6 months since we’ve had the commercial release of Qlosi. We really haven’t had any documented cases of retinal tears or retinal detachments, unlike what we saw with Vuity.