AAO 2024: Optimal pupil size reduction percentage for near vision improvement in presbyopia

Jennifer Loh, MD, shared insights from on her presentation at the American Academy of Ophthalmology meeting in Chicago on the effects of CSF-1, which is the lowest effective concentration of pilocarpine approved in the United States.

This transcript has been lightly edited for clarity.

Jennifer Loh, MD: Hi. My name is Jennifer Loh, and I'm from Miami, Florida, in private practice. I had the honor today of presenting a paper at the American Academy of Ophthalmology in Chicago on the effects of CSF-1, which is the lowest effective concentration of pilocarpine approved in the United States. In our paper, we looked at the mean reduction in pupil size attributed to CSF-1, and also its improvement of near visual acuity. Patients used the drop for 15 days. We measured endpoints at day 1, day 8, and day 15. We found throughout the study that there was a mean reduction in pupil size of 30 percent at all measured time points. And this also corresponded with an improvement in near visual acuity of greater than 3 lines without a loss of distance visual acuity. And this is important because we've come to understand that it's, for a presbyopic drop to function well, it needs to improve near vision without affecting distance vision and with minimal side effects. What was also interesting in our study was we found that patients near vision actually improved, especially from day 1 through day 8, and this was thought to be attributed to neuro-adaptation, which we also find in patients with multifocal contact lenses, or multifocal IOLs placed during cataract surgery, and this is thought, again due to the patients learning how to adapt to their new, near-vision focal point. Other papers have also shown that a reduction in pupil size for about 30 percent is important to help reduce the symptoms of presbyopia, and we found that a pupil size between 2 to 3 millimeters is very beneficial to achieve this effect. In our paper, the adverse events were mild. There were no serious adverse events. The most common one reported was a headache. Yeah, I think that, I mean, I think the fact that, patients near visual acuity improved over those few days that were analyzed, I think, was important. Also in the paper, on between day 8 and day 15, we changed the second dose. So, the dosing for Qlosi or CSF-1 is BID, but it's not really BID When you think BID, you think Q12 hours. This was not done that way. In the study, it was dose 1, like the initial dose, and then the first 2 time points were dose 2 hours later. Between day 8 and day 15, though, we looked at dosing after 3 hours from the initial dose, and this was done to look at, to see if we could extend the duration of effect of Qlosi to get to that closer to 8 hours, which is considered probably an ideal time range that patients want. They want to use the drop and have 8 hours of near vision. So that was not mandated by the FDA, but we looked at it in order to see, again, if we could kind of achieve a longer duration. So instead of dosing it 2 hours after the first dose, it was dosed at 3 hours, and that did seem to help. I think. What was also interesting, you could really see the correlation in pupil size. As the pupil that, you know, we measured every hour for those, those 8-hour time periods, as the pupil got bigger, you definitely saw that drop in your vision. So there's certainly a correlation there. And I don't know, I think it was just a really interesting study. We also looked at low luminance, so there was a filter placed over the visual acuity screen that patients had to read, that was to simulate dim vision, and patients did not lose the distance vision. So I think that was also really important, and there might have been some neuro-adaptation to that too, and that was more reassuring to show that probably using Qlosi would not reduce patient's vision at night.