The Impact of Non-Pharmacological Interventions on Visual Function, Ocular Health and Patient-Reported Outcomes in Parkinson’s Disease

Background/Objectives: Parkinson’s disease (PD) involves motor and non-motor im-pairments, including visual dysfunction related to retinal dopamine deficiency and mi-crovascular changes. Photobiomodulation (PBM) and aerobic exercise (AE) may offer neuroprotective and vascular benefits. This brief report presents findings from a ran-domised pilot trial comparing PBM, AE, and their combination on visual function, ocular health, and patient-reported outcomes in PD. Methods: Twenty participants with idio-pathic PD (mean age 76.1 ± 8.8 years; Hoehn & Yahr I–III) completed four 8-week in-terventions (PBM, AE, PBM + AE, sham), separated by 4-week washouts. PBM was ap-plied to the head, neck, and abdomen; AE followed a modified forced-rate protocol. Changes in ocular measures, including visual acuity (VA), contrast sensitivity, retinal nerve fibre layer (RNFL) thickness, choroidal thickness, retinal vascular perfusion, and questionnaires: 12-item Short Form Survey (SF-12), 39-item Parkinson’s Disease Ques-tionnaire (PDQ-39), and Falls Efficacy Scale–International (FES-I), were assessed pre- and post- intervention. Results: Seventeen participants completed all measurements. Non-pharmacological interventions resulted in improved VA (0.10 ± 0.02 to 0.02 ± 0.03, p = 0.01) and increased central retinal vascular perfusion (16.7 ± 1.4 % to 20.5 ± 1.6 %, p < 0.01) from pre- to post-study interventions. RNFL and choroidal thickness did not change significantly. Fear of falling decreased significantly (28.5 ± 2.4 to 22.7 ± 1.8, p < 0.01), while PDQ-39 and SF-12 scores were unchanged. Conclusions: PBM, alone or combined with AE, improved vision and retinal microvascular function and reduced fear of falling in individuals with PD, warranting larger-scale trials to further delineate independent and synergistic effects.