Age at onset as stratifier in idiopathic Parkinson's disease - effect of ageing and polygenic risk score on clinical phenotypes.

Several phenotypic differences observed in Parkinson's disease (PD) patients have been linked to age at onset (AAO). We endeavoured to find out whether these differences are due to the ageing process itself by using a combined dataset of idiopathic PD (n = 430) and healthy controls (HC; n = 556) excluding carriers of known PD-linked genetic mutations in both groups. We found several significant effects of AAO on motor and non-motor symptoms in PD, but when comparing the effects of age on these symptoms with HC (using age at assessment, AAA), only positive associations of AAA with burden of motor symptoms and cognitive impairment were significantly different between PD vs HC. Furthermore, we explored a potential effect of polygenic risk score (PRS) on clinical phenotype and identified a significant inverse correlation of AAO and PRS in PD. No significant association between PRS and severity of clinical symptoms was found. We conclude that the observed non-motor phenotypic differences in PD based on AAO are largely driven by the ageing process itself and not by a specific profile of neurodegeneration linked to AAO in the idiopathic PD patients.

[The Fieldmaster-200 computer perimeter: a comparative, controlled clinical study of its sensitivity and specificity in glaucomatous field defects (author's transl)]. / Das Computer-Perimeter Fieldmaster-200. Eine vergleichende, kontrollierte klinische Studie zur Sensitivatät und Spezifität in der Glaukomperimetrie.

The central visual fields of 119 glaucomatous eyes (78 patients) were evaluated under controlled conditions using the Goldmann kinetic perimeter and the Fieldmaster-200 automatic supra-threshold computer perimeter. Where there were qualitative differences between the two instruments, the high-resolution program 61 of the Octopus computer perimeter was used as a reference system. Central visual fields of 101 eyes were also studied using the Octopus 31 program. The Fieldmaster-200 was found to be more sensitive than manual kinetic perimetry in identifying early glaucomatous visual field defects. However, the specificity of the Fieldmaster instrument was significantly lower than that of the Goldmann perimeter. Taking into account the perimetry of the total central visual field using the Octopus program 31, the Octopus itself was found to be the most sensitive of the three methods of detecting early visual field loss. Problems related to the specificity and supra-threshold perimetry that is not adapted to the eccentricity of the test stimulus, as the case with the Fieldmaster-200, are discussed.