Beyond motor recovery: subthalamic nucleus deep brain stimulation may improve blinking and dry eye symptoms without restoring tear film homeostasis in Parkinson's disease.
6 affiliations
- 1Department of Ophthalmology, Mersin City Training and Research Hospital, Mersin, Türkiye, Türkiye. [email protected].
- 2Department of Neurosurgery, Mersin City Training and Research Hospital, Mersin, Türkiye.
- 3Department of Neurology, Mersin City Training and Research Hospital, Mersin, Türkiye.
- 4Department of Psychiatry, Mersin City Training and Research Hospital, Mersin, Türkiye.
- 5Department of Anatomy, Gaziantep University, Gaziantep, Türkiye.
- 6Department of Ophthalmology, Mersin City Training and Research Hospital, Mersin, Türkiye, Türkiye.
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).Conclusions
STN-DBS was associated with increased spontaneous blinking and significant improvement in subjective dry eye symptoms in patients with PD, whereas objective measures of tear film stability, tear production, and ocular surface integrity remained unchanged during short-term follow-up. These findings may suggest that the ocular benefits of STN-DBS may be mediated primarily through modulation of central neural mechanisms governing blink regulation and symptom perception rather than restoration of peripheral tear film homeostasis. Continued ophthalmic evaluation and conventional dry eye management remain important following STN-DBS.
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BibTeX
@article{hamzaoglu2026beyond,
title = {{Beyond motor recovery: subthalamic nucleus deep brain stimulation may improve blinking and dry eye symptoms without restoring tear film homeostasis in Parkinson's disease.}},
author = {Ebru Cömert Hamzaoğlu and Vural Hamzaoğlu and Uzay Ateş and Ayten Yüksek and Orhan Beger and Emin Serbülent Güclü},
journal = {BMC ophthalmology},
year = {2026},
month = oct,
doi = {10.1186/s12886-026-05474-5},
url = {https://europepmc.org/article/MED/42919269},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Beyond motor recovery: subthalamic nucleus deep brain stimulation may improve blinking and dry eye symptoms without restoring tear film homeostasis in Parkinson's disease.
AU - Ebru Cömert Hamzaoğlu
AU - Vural Hamzaoğlu
AU - Uzay Ateş
AU - Ayten Yüksek
AU - Orhan Beger
AU - Emin Serbülent Güclü
PY - 2026
DA - 2026/10/21
JO - BMC ophthalmology
DO - 10.1186/s12886-026-05474-5
UR - https://europepmc.org/article/MED/42919269
AB - 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).Conclusions STN-DBS was associated with increased spontaneous blinking and significant improvement in subjective dry eye symptoms in patients with PD, whereas objective measures of tear film stability, tear production, and ocular surface integrity remained unchanged during short-term follow-up. These findings may suggest that the ocular benefits of STN-DBS may be mediated primarily through modulation of central neural mechanisms governing blink regulation and symptom perception rather than restoration of peripheral tear film homeostasis. Continued ophthalmic evaluation and conventional dry eye management remain important following STN-DBS.
SN - 1471-2415
ER -