Altered spontaneous brain activity in patients with diabetic optic neuropathy: A resting-state functional magnetic resonance imaging study using regional homogeneity

Table 1 Basic information of participants in the study

Condition	DON	HCs	t	P value1
Male/female	10/12	10/12	N/A	> 0.99
Age (years)	54.74 ± 5.98	53.02 ± 5.12	0.274	0.914
Weight (kg)	65.32 ± 7.52	62.12 ± 8.57	0.197	0.943
Handedness	22R	22R	N/A	> 0.99
Duration of DON (days)	56.76 ± 5.26	N/A	N/A	N/A
Best-corrected VA-left eye	0.35 ± 0.22	1.05 ± 0.25	-3.581	0.014
Best-corrected VA-right eye	0.26 ± 0.19	1.05 ± 0.15	-3.127	0.011
Latency (ms)-right of the VEP	121.01 ± 10.64	101.23 ± 5.42	3.291	0.002
Amplitude (UV)-right of the VEP	6.96 ± 2.15	13.29 ± 1.84	-8.021	0.003
Latency (ms)-left of the VEP	110.42 ± 7.48	100.76 ± 3.29	5.597	0.012
Amplitude (UV)-left of the VEP	10.26 ± 3.34	16.24 ± 2.65	-3.018	0.005

¹Independent t-tests (P < 0.05). DON: Diabetic optic neuropathy; HCs: Healthy controls; N/A: Not applicable; VA: Visual acuity; VEP: Visual evoked potential.

Table 2 Brain regions with significant differences in regional homogeneity between the healthy control and diabetic optic neuropathy groups

ReHo	DON group and HCs				MNI coordinates
	Brain areas	BA	Peak t-values	Voxels	X	Y	Z
DON < HCs
1	RMFG	45	4.4606	185	39	36	9
2	LAC	32	4.6582	195	-9	30	24
3	SFG/LFSO	48	4.0066	214	-30	36	15

Statistical threshold set at voxels with P < 0.05 for multiple comparisons using Gaussian random-field theory (z > 2.3, P < 0.05, cluster size, > 40, AlphaSim-corrected). ReHo: Regional homogeneity; DON: Diabetic optic neuropathy; HCs: Healthy controls; BA: Brodmann area; MNI: Montreal Neurological Institute; RMFG: Right middle frontal gyrus; LAC: Left anterior cingulate; SFG: Superior frontal gyrus; LFSO: Left frontal superior orbital gyrus.

Table 3 Application of regional homogeneity method in ophthalmologic and neurogenic diseases

	Ref.	Year	Disease
Ophthalmologic diseases	Song et al[13]	2014	Glaucoma
	Chen et al[38]	2017	Primary angle-closure glaucomas
	Huang et al[12]	2017	Retinal detachment
	Guo et al[11]	2019	Neuromyelitis optica
	Wang et al[39]	2019	High-tension glaucoma
	Shi et al[40]	2019	Constant exotropia
	Yang et al[17]	2019	Strabismus amblyopia
	Liao et al[41]	2019	Diabetic retinopathy
	Lu et al[42]	2020	Anisometropic amblyopia
	Guo et al[7]	2020	Nonarteritic anterior ischemic optic neuropathy
Neurogenic diseases	Dai et al[14]	2012	Sleep disorders
	Li et al[15]	2016	Parkinson disease
	Russo et al[43]	2020	Bipolar mania and depression

Table 4 Brain region alternation and its potential impact

Brain region	Experimental result	Brain function	Anticipated results
Middle frontal gyrus	DONs < HCs	Contingency awareness and executive attention	Dysfunction of cognitive activities
Anterior cingulate	DONs < HCs	Cognition and emotion	Depression and anxiety
Superior frontal gyrus/frontal superior orbital gyrus	DONs < HCs	Visual transmission and emotional expression	Impaired visual function

DONs: Diabetic optic neuropathy patients; HCs: Healthy controls.