Abstract
Purpose: :
To identify healthy controls (HC) and patients affected by Parkinson Disease (PD) without co-morbidities for the development of a mathematical model of the fovea utilizing spectral domain optical coherence tomography. As PD patients are generally in their 60’s when diagnosed, finding HC and PD without concomitant pathology presents a challenge in this age group.
Methods: :
For comparing the results in PDs & HCs, strict Ophthalmological (OP) exclusion criteria were imposed: Visual Acuity (VA) <20/40, preclusion from dilation, recent history (Hx) of eye surgery or intravitreal injection (<90 days), Hx of glaucoma (Glc) or any degeneration (degn) of retinal tissue. Diabetic subjects were ineligible. Neurological (NEU) exclusion criteria were: Family Hx of PD, recent CVA (<2yrs), temporal arteritis, early onset PD (<40 yrs), PD non-responsive to Dopamine agonist therapy, PD with cognition changes, brain abnormalities suggestive of other cause for parkinsonism, & drug exposure, infection or repeated head trauma preceding PD. Subjects were screened by phone to reduce on-site exclusions (OSX); these "eliminated" (ELIM) subjects were not enrolled. Reasons for OSX & rate of ELIM vs OSX were reviewed for study efficiency.
Results: :
90 subjects volunteered to participate in the study (64PD, 26HC). Of these, 32%(29) were OSX or ELIM (34%(22)PD, 27%(7)HC). Of the 75 enrolled (52PD, 23HC), 16%(14) were OSX (16%(10)PD, 15%(4)HC). The 29 OSX+ELIM were primarily OP (90%(26)) (91%(20)PD, 86%(6)HC). More PDs were ELIM (19%(12)) than OSX (16%(10)); the reverse was true for HCs (12%(3) ELIM, 15% (4)OSX). Reasons for OP exclusion: Glc/optic neuropathy (9), macular (mac) drusen/ age-related mac degn (7), vascular events (4), vitreal-mac traction/ epiretinal membranes (4), nystagmus/ poor fixation (3), diabetes (3, all ELIM), myopic retinal degn (1), inflammatory retinal lesions (1), dilation hazard (1), reduced VA (1). Some subjects had >1 reason for OP exclusion. Tremors (NEU exclusion) precluded quality data collection in 2 PDs. 2 HC candidates were identified with early PD on neuro-screening (enrolled as PDs).
Conclusions: :
Eliminations via phone screening effectively reduced the amount of contact time invested with excludible subjects. Finding both PDs & age-matched HCs appropriate for studying retinal anatomy in a senior population presents a challenge. In the future, the most significant co-morbodities should be handled by using appropriate multivariate analysis for both HCs & patients suffering from neurodegenerative disorders.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • aging: visual performance • visual impairment: neuro-ophthalmological disease