BMC ophthalmology
Beyond motor recovery: subthalamic nucleus deep brain stimulation may improve blinking and dry eye symptoms without restoring tear film homeostasis in Parkinson's disease
By Hamzaoğlu EC, Hamzaoğlu V, Ateş U and 3 others.
Abstract
Purpose
To investigate the longitudinal effects of subthalamic nucleus deep brain stimulation (STN-DBS) on objective and subjective dry eye parameters in patients with Parkinson's disease (PD).
Methods
This retrospective observational study included 34 patients with advanced PD who underwent STN-DBS. Comprehensive ophthalmic examinations were performed were performed before surgery and at postoperative week 1, month 1, and month 4. Outcome measures included spontaneous blink rate, tear break-up time (TBUT), Schirmer I test, Oxford corneal staining score, and the Ocular Surface Disease Index (OSDI). Longitudinal changes were analyzed using generalized estimating equations (GEE).
Results
Spontaneous blink rate increased significantly over time, reaching statistical significance at postoperative month 4 compared with baseline (rate ratio 1.19, 95% CI 1.04-1.36; p = 0.014). OSDI scores showed progressive improvement throughout follow-up, with significantly lower scores at postoperative week 1 (p = 0.038), month 1 (p = 0.036), and month 4 (p = 0.002). In contrast, no significant longitudinal changes were observed in TBUT (p = 0.552), Schirmer I test results (p = 0.992) or Oxford corneal staining scores (p = 0.090).