Altered spontaneous brain activity patterns in patients with diabetic retinopathy using amplitude of low-frequency fluctuation

Table 1 Demographics and clinical measurements by groups

Condition	DR	HC	t	P value
Male/female	10/14	10/14	N/A	> 0.99
Age (yr)	54.31 ± 5.96	53.08 ± 5.33	0.093	0.975
Weight (kg)	53.67 ± 9.64	59.86 ± 9.93	0.095	0.982
Handedness	24R	24R	N/A	> 0.99
Duration of DR (d)	253.18 ± 76.22	N/A	N/A	N/A
Best-corrected VA-right eye	0.19 ± 0.08	1.12 ± 0.36	-0.883	0.009
Best-corrected VA-left eye	0.22 ± 0.09	1.09 ± 0.42	-0.743	0.014
IOP-R (mmHG)	15.63 ± 2.93	17.56 ± 2.74	0.092	0.815
IOP-L (mmHG)	16.13 ± 2.32	16.54 ± 2.63	0.088	0.843

P < 0.05 independent t-tests comparing two groups. DR: Diabetic retinopathy; HC: Healthy control; N/A: Not applicable; R: Right; IOP: Intraocular pressure.

Table 2 Brain areas with significantly different amplitude of low-frequency fluctuation values between groups

Condition	L/R/B	Brain regions	MNI coordinates			BA	Peak voxels	t value	P value
			X	Y	Z
DRs > HCs
1	L	Cerebellum posterior lobe	-27	-72	-36	/	238	5.4338	< 0.001
2	R	Cerebellum posterior lobe	33	-57	-42	/	111	4.6875	< 0.001
3	R	Anterior cingulate	9	48	3	32	32	-4.4176	< 0.001
DRs < HCs
1	B	Calcarine	3	-66	21	/	46	-4.3494	< 0.001

P < 0.05, P < 0.001, independent t-test, P values between diabetic retinopathies and healthy controls. BA: Brodmann area; DR: Diabetic retinopathy; HC: Healthy control; MNI: Montreal Neurological Institute; L: Left; R: Right; B: Bilateral.

Table 3 Amplitude of low-frequency fluctuation method applied in ophthalmological diseases

Ref.	Disease	Brain areas
		PG > HG	PG < HG
Guo et al[46], 2010	High myopia	LCN; Thalamus; Cuneus	LOL; BFL; RIPL; RPL; RMTL
Li et al[14], 2014	Glaucoma	RPG	LPG; BMFG; BSFG; RP; RAG
Liu et al[13], 2018	Optic neuritis	LCPL; RCPL; RITG; LPG; RFG; LFG; LCF; LIPL; LC	RCPL; RCAL; RP; RIFG; RI;LMFG; LSTG; RSG; BAC;BP;RIPL
Xi et al[15], 2010	Strabismus	BT	POS
Liang et al[48], 2016	Amblyopia	BC; LMOG; LPG	BPC
Tan et al[47], 2016	Open-globe injury	LC; LMCC; BP
Pan et al[49], 2018	Acute eye pain	LPG; RPG; LC	LPG; RPG; LP

HG: Healthy group; PG: Patient group; LOL: Left occipital lobe; BFL: Bilateral frontal lobe; RIPL: Right inferior parietal lobule; RPL: Right parietal lobe; RMTL: Right middle temporal lobe; LCN: Left caudate nucleus; LPG: Left precentral gyrus; BMFG: Bilateral middle frontal gyrus; BSFG: Bilateral superior frontal gyrus; RP: Right precuneus; RAG: Right angular gyrus; RPG: Right precentral gyrus; LCPL: Left cerebellum posterior lobe; RCPL: Right cerebellum posterior lobe; RITG: Right inferior temporal gyrus; LPG: Left parahippocampal gyrus; RFG: Right fusiform gyrus; LFG: Left fusiform gyrus; LCF: Left calcarine fissure; LIPL: Left inferior parietal lobule; LC: Left cuneus; RCAL: Right cerebellum anterior lobe; RP: Right putamen; RIFG: Right inferior frontal gyrus; RI: Right insula; LMFG: Left medial frontal gyrus; LSTG: Left superior temporal gyrus; RSG: Right supramarginal gyrus; BAC: Bilateral anterior cingulate; BP: Bilateral precuneus; BCPL: Bilateral cerebellum posterior lobe; LAG: Left angular gyrus; BMG: Bilateral medialfrontal gyrus; BC: Bilateral calcarine; LMOG: Left middle occipital gyrus; LPG: Left postcentral gyrus; BPC: Bilateral precuneus cortex; LMCC: Left middle cingulum cortex; BP: Bilateral precuneus; RPG: Right parahippocampal gyrus; LPG: Left precentral gyrus; LC: Left caudate; RPG: Right precentral/postcentral gyrus; LP: Left precuneus; BT: Bilateral thalamus; POS: Parieto-occipital sulcus.