Changes in corneal nerve morphology and function in patients with dry eyes having type 2 diabetes

Table 4 Demographics and examination findings of the dry eye patients grouped by Schirmer test with or without type 2 diabetes mellitus

Parameters	DEwDM		P value	DEnDM		P value	DEwDM versus DEnDM P value
	Schirmer test ≤ 5 mm	Schirmer test > 5 mm		Schirmer test ≤ 5 mm	Schirmer test > 5 mm		Schirmer test ≤ 5 mm	Schirmer test > 5 mm
Number [N]	39	17		24	9
Age [yr ± SEM]	57.1 ± 8.5	57.9 ± 7.2	0.707	53.5 ± 11.7	49.1 ± 9.0	0.323	0.164	0.011
Gender			0.686			0.122a	0.632b	0.026a
Male [N (%)]	23 (59.0)	11 (64.7)		8 (33.3)	6 (66.7)
Female [N (%)]	16 (41.0)	6 (35.3)		16 (66.7)	3 (33.3)
Blood glucose [mmol/L ± SEM]	8.8 ± 3.6	8.9 ± 5.0	0.893	NA	NA	NA
	13.5 ± 6.8	9.5 ± 7.4	0.054	NA	NA	NA
HbA1c [% ± SEM]	8.1 ± 1.8	8.1 ± 2.5	0.995	NA	NA	NA
BUT [s ± SEM]	4.3 ± 2.9	3.1 ± 1.0	0.105	5.6 ± 4.3	3.2 ± 1.3	0.114	0.153	0.856
Schirmer test [mm ± SEM]	2.1 ± 1.7	9.9 ± 3.1	0.000	1.9 ± 1.5	8.7 ± 2.5	0.000	0.590	0.319
NFL [mm/mm2 ± SEM]	16.671 ± 4.749	16.727 ± 5.006	0.968	17.036 ± 4.691	16.514 ± 5.549	0.788	0.767	0.922
NFD [num/mm2 ± SEM]	32.4 ± 9.7	30.1 ± 11.7	0.310	35.7 ± 8.3	34.7 ± 16.3	0.429	0.072	0.039
NBD [num/mm2 ± SEM]	52.1 ± 22.9	55.5 ± 30.9	0.241	65.6 ± 23.7	49.3 ± 22.2	0.019	0.031	0.104
R1 [ms ± SEM]	12.1 ± 0.9	11.8 ± 0.6	0.406	11.1 ± 0.8	11.5 ± 0.9	0.288	0.000	0.215

^aP value from exact probability test.

^bP value from Chi-squared test with continuity correction.

BUT: Tear film break-up time; HbA1c: Hemoglobin A1C; OSDI: Ocular surface disease index; Schirmer: Schirmer I test; NA: Not available; NFL: Nerve fiber length; NFD: Nerve fiber density; NBD: Nerve branch density; R1: The R1 latency in blink reflex.