Table 1.

Clinical and general demographics characteristics of all the participants.

Variables	All participants		p values	PD			p values
	HCs	PD, total		H-Y I stage	H-Y II stage	H-Y III stage
Number	427	397	–	131	146	120	–
Demographics
Age, y	61.50 ± 7.46	62.30 ± 7.68	0.128b	60.58 ± 7.28	62.51 ± 7.81	63.93 ± 7.63	0.002c
Age of onset	–	56.58 ± 7.96	–	55.83 ± 7.26	56.77 ± 7.59	57.18 ± 9.07	0.224d
Sex, (m/f)	219/208	192/205	0.401a	63/68	77/69	52/68	0.310a
Duration	–	5.72 ± 3.50	–	4.76 ± 3.03	5.73 ± 2.96	6.75 ± 4.24	< 0.001c
Assessment of motor symptoms, Mean (P25, P75)
Hoehn-Yahr	–	2 (1, 3)	–	–	–	–	–
MDS-UPDRS III	–	23 (15, 36)	–	14 (11, 24)	23.5(17, 34)	35 (24, 47)	< 0.001d
Assessment of non-motor symptoms, Mean (P25, P75)
MMSE	–	28 (25, 29)	–	28 (26, 30)	28 (25, 29)	27 (24, 29)	0.002d
RBDQ-HK	–	13 (3, 32)	–	8 (2, 21)	14 (3, 35)	21 (6, 37)	< 0.001d
ESS	–	6 (2, 12)	–	5 (2, 9)	7 (3, 12)	8 (3, 15)	0.033c
HRS	–	23 (12, 24)	–	24 (16, 24)	18 (12, 24)	22 (12, 24)	0.025c
HAMD	–	4 (0, 8)	–	2 (0, 7)	3 (0, 8)	5 (2, 10)	0.002c
Ophthalmologic parameters
IOP (mmHg)	15.63 ± 3.03	15.93 ± 2.75	0.140b	15.90 ± 2.76	15.87 ± 3.01	16.01 ± 2.43	0.918c
BCVA, Snellen	1.20 ± 0.25	1.19 ± 0.31	0.478d	1.22 ± 0.31	1.18 ± 0.29	1.17 ± 0.33	0.372c

Significant results appear in bold.

PD Parkinson’s Disease, HCs healthy controls, MDS-UPDRS III Movement Disorder Society-Unified Parkinson’s Disease Rating Scale III, P₂₅ 25% percentile, P₇₅ 75% percentile, y years, MMSE Mini-Mental State Examination, RBDQ-HK Rapid Eye Movement sleep behavior disorder (RBD) questionnaire-Hong Kong, ESS Epworth sleepiness scale, HRS Hyposmia Rating Scale, HAMD Hamilton rating scale for depression, IOP intraocular pressure, BCVA best-corrected visual acuity.

^aPearson’s χ2 test.

^bStudent’s t-test.

^cOne-way ANOVA.

^dNon-parametric test.