Researchers have linked changes in patients’ tears with the pain that some people experience after laser procedures.
The new study, published in the American Chemical Society’s Journal of Proteome Research,1 suggests that shifts in the amounts of certain groups of proteins could one day identify people at risk of long-term pain after laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).
Pain is common in the initial days after the procedure, but sometimes it can persist longer. Researchers suspect such long-lasting pain may be related to changes in the environment immediately surrounding the corneal nerves, including in the tears that moisten the eye.
The research team, predominantly from Oregon Health and Science University, decided to comprehensively survey tear proteins in search of potential predictors of post-operative eye pain.
They recruited people having LASIK or PRK on both eyes at clinics in Portland, Oregon, and Miami. The team focussed its analysis on tears from 16 patients who reported a pain level of at least three out of 10, three months after surgery, and 32 patients who reported no post-operative pain after three months.
The researchers identified a collection of 2,748 proteins in tears from all the participants before surgery, the day after, and three months after surgery. When they compared protein profiles for the two groups of patients, they honed in on 83 proteins whose levels shifted up or down among the patients with post-operative pain. Using statistical tools, the researchers then tested whether individual proteins or sets of proteins could predict if eye-surgery patients would experience long-term pain.
The computer models using sets of three or four proteins appeared to be the most effective at predicting long-term discomfort. Such patterns of differences in proteins, the researchers said, could someday be used to evaluate patients’ risk of post-surgical eye pain and find new routes to treat it.2
References
- Harness BM, Chen S, Aicher SA, et al., Tear proteins altered in patients with persistent eye pain after refractive surgery: Biomarker candidate discovery. J. Proteome Res. 2024, 23, 7, 2629-2640. doi: 10.1021/acs.jproteome.4c00339.
- American Chemical Society, Predicting long-lasting pain from LASIK with tear proteins (media release, 9 July 2024), available at: eurekalert.org/news-releases/1050770 [accessed July 2024].