Type 2 diabetes complicated by dry eye syndrome: Analysis of dry eye symptoms, corneal neuropathy, and influencing factors

Table 1 Comparison of dry eye syndrome-related index scores

	SPEED score	NIBUT (second)	SIt (mm)	FLS score
DES group (n = 27)	14.19 ± 2.75a,b	6.70 ± 1.46a,b	7.63 ± 1.45a,b	1.93 ± 0.78a
Non-DES group (n = 54)	5.22 ± 1.13a	10.20 ± 1.84a	10.67 ± 1.53a	1.89 ± 1.11a
Control group (n = 50)	4.32 ± 1.19	12.04 ± 1.48	12.16 ± 1.30	0.42 ± 0.50
F	368.6	91.56	103.5	46.51
P value	< 0.0001	< 0.0001	< 0.0001	< 0.0001

^aP < 0.05 vs control group.

^bP < 0.05 vs non-dry eye syndrome group.

One-way analysis of variance (ANOVA) for multi-group comparisons and independent-sample t-tests for between-group comparisons. DES: Dry eye syndrome; SPEED: Standard patient evaluation of eye dryness; NIBUT: Non-invasive tear film breakup time; SIt: Schirmer I test; FLS: Fluorescein staining test.

Table 2 Blood glucose levels of three groups

	FBG (mmol/L)	HbA1c (%)
DES group (n = 27)	9.06 ± 2.06a,b	7.11 ± 0.74a,b
Non-DES group (n = 54)	7.77 ± 1.29a	6.72 ± 0.59a
Control group (n = 50)	5.02 ± 0.55	5.11 ± 0.57
F	103.0	126.4
P value	< 0.0001	< 0.0001

^aP < 0.05 vs control group.

^bP < 0.05 vs non-dry eye syndrome group.

One-way analysis of variance (ANOVA) for multi-group comparisons and independent-sample t-tests for between-group comparisons. DES: Dry eye syndrome; FBG: Fasting blood glucose; HbA1c: Glycated hemoglobin.

Table 3 Comparison of corneal neuropathy parameters

	Nerve density (μm/mm2)	Main nerve length (μm)	Number of main nerves (pieces)	Main nerve tortuosity (%)
DES group (n = 27)	884.23 ± 25.09	565.41 ± 36.08	2.11 ± 0.42	1.17 ± 0.04
Non-DES group (n = 54)	7944.76 ± 231.55	1388.74 ± 55.89	5.94 ± 1.52	1.11 ± 0.05
t value	157.5	69.53	12.80	5.544
P value	< 0.0001	< 0.0001	< 0.0001	< 0.0001

Independent-sample t-tests for between-group comparisons. DES: Dry eye syndrome.

Table 4 Univariate analysis of risk factors for dry eye syndrome, n (%)

	DES group (n = 27)	Non-DES group (n = 54)	χ2/t	P value
Sex			0.225	0.635
Male	13 (48.1)	23 (42.6)
Female	14 (51.9)	31 (57.4)
Age (years)	59.59 ± 3.49	5.80 ± 3.01	3.739	0.0003
Duration of diabetes (year)	7.74 ± 2.18	5.29 ± 1.64	5.641	< 0.0001
Hypertension			0.105	0.747
Yes	11 (40.7)	20 (37.0)
No	16 (59.3)	34 (63.0)
Lacrimal gland dysfunction			12.501	0.0004
Yes	18 (66.7)	14 (25.9)
No	9 (33.3)	40 (74.1)
Insufficient insulin secretion			6.488	0.011
Yes	21 (77.8)	26 (48.1)
No	6 (22.2)	28 (51.9)
Disease awareness level			4.365	0.037
Low	15 (55.6)	17 (31.5)
High	12 (44.4)	37 (68.5)
Medication compliance			5.625	0.018
Good	10 (37.0)	35 (64.8)
Poor	17 (63.0)	19 (35.2)

Independent-sample t-tests and χ² test for between-group comparisons. DES: Dry eye syndrome.

Table 5 Multivariate analysis of risk factors for dry eye syndrome in type 2 diabetes patients

Variable	Assignment	β	SE	Wald	P value	HR	95%CI
Age	Continuous variable	0.347	0.152	5.192	0.023	1.415	1.050-1.907
Duration of diabetes	Continuous variable	0.721	0.298	5.859	0.015	2.057	1.147-3.689
Lacrimal gland dysfunction	0 = no, 1 = yes	2.134	1.027	4.317	0.038	8.450	1.129-63.262
Insufficient insulin secretion	0 = no, 1 = yes	2.269	1.123	4.086	0.043	9.673	1.072-87.319
Disease awareness level	0 = high, 1 = low	0.720	1.010	0.509	0.476	2.005	0.284-14.864
Medication compliance	0 = good, 1 = poor.	0.397	0.911	0.190	0.663	1.487	0.249-8.874
FBG	Continuous variable	0.815	0.298	7.482	0.006	2.259	1.260-4.049
HbA1c	Continuous variable	1.396	0.698	4.006	0.045	4.041	1.029-15.862
Constant	-	-45.302	13.712	10.916	0.001	0.000	-

Binary logistic analysis was used. FBG: Fasting blood glucose; HbA1c: Glycated hemoglobin.