Highlight
1. Postoperative ocular pain after LASIK and PRK follows distinct trajectories: no pain, transient postoperative pain, and prolonged pain lasting several months.
2. Prolonged ocular pain is significantly more frequent after PRK compared to LASIK.
3. Baseline factors such as preoperative use of lubricating drops, chronic low back pain, and higher dry eye symptom burden are associated with increased risk of prolonged postoperative ocular pain.
4. Unexpectedly, corneal staining observed at 6 months post-surgery correlates with a lower risk of prolonged pain, suggesting complex ocular surface dynamics after surgery.
Study Background
Refractive surgery, including laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK), is widely performed to correct ametropia, offering patients improved uncorrected visual acuity. Despite their overall safety, postoperative ocular discomfort remains a common and impactful complication, varying widely among patients. Persistent ocular pain and discomfort can impair quality of life and visual function, yet longitudinal characterization of symptom trajectories and their predictors remains inadequately defined. Understanding individual postoperative symptom patterns could enable more individualized patient counseling, risk stratification, and optimized perioperative management.
Study Design
This prospective, multicenter cohort study was conducted at two academic ophthalmology centers in the United States between April 2021 and July 2025. The study enrolled adults aged 18 or older scheduled for bilateral LASIK or PRK. Exclusion criteria were pregnancy, corneal abnormalities (such as scarring or ectasia), prior corneal surgery, and ocular conditions known to affect ocular pain perception (e.g., glaucoma, herpetic eye disease).
Participants underwent assessments preoperatively and at postoperative day 1 (POD 1), postoperative month 3 (POM 3), and postoperative month 6 (POM 6). The primary outcome was ocular pain intensity measured by the numerical rating scale (NRS, range 0-10) at each time point. Clinically relevant pain was defined as an NRS score of 3 or greater. The symptom trajectories were categorized based on the presence or absence of clinically significant pain across time points.
Baseline variables assessed included demographics, clinical history, surgical factors, and ocular surface status, including the 5-Item Dry Eye Questionnaire (DEQ-5) score, lubricating eye drop usage, and presence of corneal staining.
Key Findings
The cohort comprised 326 individuals (mean age 34.3 years; 60.1% female) with complete pain data. The analysis revealed heterogeneous postoperative ocular pain trajectories:
- 28.8% showed no clinically significant pain at any time point.
- 43.9% reported clinically relevant pain limited to POD 1 only, resolving by month 3.
- 18.1% exhibited prolonged pain that persisted or recurred at POM 3 or POM 6.
- The remaining participants had uncommon or mixed pain trajectories.
Multivariable logistic regression identified key factors independently associated with prolonged postoperative ocular pain: undergoing PRK (versus LASIK) conferred a 2.7-fold higher odds (OR 2.73; 95% CI, 1.29–5.77), presumably reflecting greater initial epithelial trauma inherent in PRK. Preoperative use of lubricating drops, suggesting pre-existing ocular surface dryness or discomfort, was associated with increased risk (OR 2.41; 95% CI, 1.17–4.96). Notably, participants with chronic low back pain, a recognized neuropathic pain comorbidity, had higher odds of prolonged ocular pain (OR 2.45; 95% CI, 1.14–5.25), indicating potential shared pain sensitization pathways. Higher baseline ocular symptom burden measured via DEQ-5 was also predictive (OR 1.11 per unit increase; 95% CI, 1.01–1.22).
Interestingly, study findings revealed that corneal staining observed at 6 months post-surgery was inversely associated with prolonged pain risk (OR 0.79; 95% CI, 0.64–0.97). This counterintuitive result may reflect complex ocular surface healing dynamics or differential patient responsiveness to post-surgical inflammation.
Expert Commentary
The identification of distinct postoperative ocular pain trajectories following refractive surgery underscores the heterogeneous recovery experiences of patients. That PRK is associated with prolonged pain aligns with clinical intuition since the procedure removes the corneal epithelium, causing more prolonged nerve exposure and regeneration compared to the flap-based LASIK.
Preoperative ocular surface symptoms and systemic chronic pain conditions have emerged as important predictors, emphasizing a biopsychosocial dimension of ocular pain after surgery. Clinicians should consider screening for these factors and counsel patients accordingly regarding their postoperative symptom expectations.
The protective association of corneal staining with prolonged pain is intriguing and warrants further mechanistic study; it may suggest that certain ocular surface inflammatory markers prompt more effective healing or symptomatic relief strategies.
Limitations include potential selection bias in a surgical candidate population and the subjective nature of pain scoring. Moreover, while the study extended to 6 months postoperatively, longer-term outcomes remain to be elucidated.
Conclusion
This prospective cohort study furnishes a nuanced longitudinal characterization of ocular pain symptom trajectories after LASIK and PRK, linking prolonged postoperative discomfort with surgery type and baseline ocular and systemic factors. The findings advocate for a tailored, trajectory-based approach to patient counseling and management, potentially improving perioperative interventions to mitigate prolonged ocular pain and enhance recovery quality. Further research is needed to validate these trajectories and explore targeted therapeutic strategies, including preoperative optimization of ocular surface health and addressing systemic pain comorbidities.
Funding and ClinicalTrials.gov
The study was supported by academic funding sources affiliated with the participating ophthalmology centers. Clinical trial details are registered under the respective institutional protocols.
References
Kang S, Betz JD, Locatelli EVT, et al. Ocular Symptoms After Refractive Surgery. JAMA Ophthalmol. 2026 Jul 9. PMID: 42424051.
Weinstock RJ, Craig JP. Risk factors and management of postoperative ocular pain in refractive surgery. Curr Opin Ophthalmol. 2023;34(1):33-40.
Rosenthal P, Borsook D. The corneal pain system: A neuroscience perspective for ophthalmologists. J Cataract Refract Surg. 2016;42(10):1410-1426.
Galor A, Levitt RC, Felix ER, et al. Neuropathic ocular pain: an important yet underevaluated feature of dry eye. Eye (Lond). 2015;29(3):301-312.