Effect of dopaminergic therapy on lacrimation in Parkinson's disease

The prevalence of dry eye syndrome (DES) in Parkinson's disease (PD) reaches 87% and leads to impaired quality of life in many patients.Objective: to evaluate the lacrimal function and the effect of dopaminergic therapy in patients with PD.Material and methods: 43 patients with stage II–III PD according to Hoehn and Yahr (H&Y) receiving therapy with levodopa (n=17), amantadines (n=13) and dopamine receptor agonists (ADR) (n=28) were assessed using Schirmer's test (to estimate tear flow), sialometry, Unified Parkinson's Disease Rating Scale (UPDRSI-IV), Schwab and England Activities of Daily Living scale (Sch&En), the Parkinson’s Disease Questionnaire Summary Index (PDQ-39), the Mini Mental State Examination Scale (MMSE), the Non-Motor Symptom Questionnaire (NMSQ), the American Urological Association Symptom Scale (AUA), the Gastrointestinal Symptom Rating Scale (GSRS), the Bristol Stool Form Scale (BSFS).Results. Lacrimal insufficiency was found in 49% of patients. It occurred more frequently (χ2=9.546; p=0.003) in patients taking amantadine and correlated with the daily dose of amantadine (r-S=-0.359). It did not depend on the intake of ADR and levodopa and their doses but correlated with the UPDRS-IV score (r-S= -0.463), namely with the presence and duration of OFF-periods. Lacrimal insufficiency correlated with the Sch&En score (r-S=0.321) and non-motor parameters: UPDRSI (r-S =-0.302), NMSQ (r-S=-0.435), constipation domain of the GSRS (r-S=-0.362), BSFS (r-S=0.363). It was not related to age, gender, stage and duration of PD, motor symptoms of parkinsonism (assessed during the ON-phase) and was not related to salivation (although it was reduced in 39.5% of patients).Conclusion. Lacrimal insufficiency is observed in half of patients with stage II–III PD; it is related to the presence and duration of OFF-periods, the severity of other autonomic disorders and the use of amantadines, suggesting the role of dopamine dysregulation, neurodegeneration of autonomic centers and anticholinergic therapy in the development of DES in PD.