Corneal nerve regeneration and ocular surface restoration following treatment with autologous serum eye drops in patients with paralytic lagophthalmos and neurotrophic keratitis

Purpose: To investigate the effect of 20% autologous serum eye drops (ASED) in improving ocular surface condition and promoting corneal nerve regeneration in patients with Paralytic Lagophthalmos (PL) and Neurotrophic Keratitis (NK). Methods: This prospective study included 11 patients with unilateral NK and PL treated with 20% ASED for 2 months. Ocular surface assessment included Schirmer I test, non-invasive tear film break-up time (NIBUT), Oxford staining score, Ocular Surface Disease Index (OSDI) and corneal esthesiometry. In vivo confocal microscopy (IVCM) was used to quantify changes in corneal subbasal nerve plexus, evaluating corneal nerve fiber length (CNFL), nerve fiber density (CNFD), and nerve branch density (CNBD). Pre- and post-treatment values were compared. Results: Ten patients completed the study. ASED treatment significantly improved Schirmer I values (mean: 10.3 ± 4.7 mm to 19.7 ± 12.1 mm; p = 0.041), OSDI scores (21.1 ± 12.9 to 17.0 ± 10.0; p = 0.009), and corneal sensitivity readings (central esthesiometry: 3.4 ± 1.9 mm to 5.0 ± 1.2 mm; p = 0.005). IVCM revealed significant increases in CNFL (11.1 ± 6.4 to 14.7 ± 7.3 mm/mm²; p = 0.006) and CNFD (23.1 ± 13.2 to 33.8 ± 11.9 fibers/mm²; p = 0.012). One patient discontinued treatment due to ocular discomfort. Conclusion: Topical 20% ASED improved both functional and structural parameters in patients with PL and NK, suggesting neuroregenerative potential. These findings support the use of ASED as a therapeutic option in complex ocular surface disease, with IVCM as a valuable tool for monitoring nerve recovery.