Postoperative Dry Eye Syndrome In Smile Vs. Lasik: A Prospective Study
Published 2025 - 43rd Congress of the ESCRS
Reference: PP21.02 | Type: Free paper | DOI: 10.82333/jcry-tj84
Authors: Mohammed Mohammed Mahdy Tawfeek* 1 , Hanan Mohamed Abdel Hamid Ahmed 2 , Ashraf Bor'i 1 , Ahmed M. Nashaat Ali Rady 3
1Ophthalmology,Zagazig University,Zagazig,Egypt, 2Ophthalmology,General Organization Of Teaching Hospitals and Institutes (GOTHI), Mataria Teaching Hospital,Cairo,Egypt, 3Ophthalmology,Kazan Federal University,Cairo,Egypt
Purpose
To compare the incidence, severity, and duration of postoperative dry eye syndrome (DES) in patients undergoing Small Incision Lenticule Extraction (SMILE) vs. Laser-Assisted In Situ Keratomileusis (LASIK) in two separate patient groups.
Setting
This prospective, comparative study was conducted at NMC Royal hospital Sharjah . All procedures were performed by experienced refractive surgeons using the VisuMax femtosecond laser (Carl Zeiss Meditec, Germany) for SMILE and the EX500 excimer laser (Alcon, USA) for LASIK. Patients were recruited between 01/2024 and 06/2024 , with follow-up assessments conducted over six months
Methods
A total of 100 eyes from 100 patients were included, with 50 eyes undergoing SMILE and 50 eyes undergoing LASIK. Patients were matched for age, sex, and refractive error. Dry eye symptoms were assessed preoperatively and postoperatively at 1 day, 1 week, 1 month, 3 months, and 6 months using:
• Ocular Surface Disease Index (OSDI) questionnaire
• Schirmer’s test (tear production)
• Tear breakup time (TBUT)
• Corneal fluorescein staining (to assess epithelial damage)
Results
At 1 week postoperatively, the LASIK group had significantly lower Schirmer’s test values (mean 8.5 ± 2.1 mm vs. 12.3 ± 2.5 mm, p < 0.001) and shorter TBUT (6.2 ± 1.8 sec vs. 9.4 ± 2.3 sec, p < 0.01) compared to the SMILE group. Corneal fluorescein staining scores were higher in the LASIK group at 1 month (p = 0.002). By 3 months, dry eye symptoms improved in both groups, but LASIK patients continued to report more discomfort (OSDI score: 18.2 vs. 10.6, p = 0.03). At 6 months, 90% of SMILE patients were asymptomatic, while 20% of LASIK patients still reported mild dry eye symptoms.
Conclusions
SMILE results in significantly lower postoperative dry eye symptoms compared to LASIK, with better tear film stability, less corneal nerve disruption, and faster recovery. These findings suggest that SMILE may be a preferred choice for patients at higher risk of postoperative dry eye, such as those with pre-existing ocular surface disease or high screen time exposure. Further long-term studies on corneal nerve regeneration and patient quality of life are warranted.