CORNEAL NERVE REGENERATION AND TEAR-FILM STABILITY AFTER TRANSPKR VERSUS FEMTO-LASIK: A PROSPECTIVE COMPARATIVE STUDY
Published 2026 - 30th ESCRS Winter Meeting
Reference: PP01.12 | Type: Presented Poster & Poster | DOI: 10.82333/gdk0-1p48
Authors: Ghita Halfi* 1 , louai serghini 1 , siham chariba 1 , abdallah elhassan 1
1speciality hospital,rabat ,Morocco
Purpose
To compare subbasal corneal nerve regeneration and ocular surface recovery after transepithelial photorefractive keratectomy (TransPRK) versus femtosecond laser-assisted LASIK (FS-LASIK) using in vivo confocal microscopy (IVCM) and non-invasive tear film measurements.
Setting
Prospective, study conducted at a refractive surgery center , between January 2024 and September 2025.
Methods
A prospective, single-center, comparative cohort study including 90 eyes of 90 patients (45 TransPRK, 45 FS-LASIK).
Inclusion criteria: myopia −1.50 to −6.50 D, age 20–40 years, central pachymetry ≥ 500 µm, OSDI < 20 preoperatively.
Exclusion criteria: suspected keratoconus, history of ocular surgery, ocular surface disease, chronic topical treatment.
Assessments: IVCM (Nerve Fiber Density — NFD, Nerve Fiber Length — NFL, tortuosity), NIBUT (non-invasive tear break-up time), Schirmer I, OSDI, visual acuity.
Time points: preoperative, 1 month, 3 months, 6 months, 12 months.
Results
At 1 month, NFD was significantly reduced in both groups, but the reduction was more pronounced after TransPRK (median decrease −55% vs −38% for FS-LASIK, p < 0.001).
At 6 months, partial recovery: TransPRK 72% of baseline vs FS-LASIK 88% (p = 0.009). Initially, NIBUT was reduced in both groups (preop 13.2 ± 3.1 s → 1 month: TransPRK 7.6 ± 2.5 s, FS-LASIK 9.4 ± 2.6 s, p < 0.01 between groups).
There was a strong correlation between NFD and NIBUT recovery at 6 months (r = 0.71, p < 0.001). Multivariate regression showed that the change in NFD was an independent predictor of NIBUT at 6 months (β = 0.64, p < 0.001) after adjustment.
No ectasia or serious complications occurred during follow-up.
Conclusion
TransPRK results in more pronounced subbasal denervation and slower nerve recovery than FS-LASIK, leading to delayed functional tear film recovery. Quantitative confocal microscopy (NFD, NFL) is a useful biomarker for predicting the recovery of tear film stability after refractive surgery.