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

Table 3 Comparisons for the nerve fiber length, nerve fiber density, nerve branch density, and R1 among four groups

Parameters	DEwDM	DEnDM	DMnDE	nDMnDE	Statistics
NFL [mm/mm2]	16.688 ± 4.782d	16.894 ± 4.855d	17.555 ± 5.236d	22.017 ± 3.369a,b,c	Tukey HSD test
NFD [num/mm2]	35.0 ± 9.4	37.5 ± 10.6	35.6 ± 11.3	41.3 ± 8.1	Tukey HSD test
NBD [num/mm2]	46.9 ± 23.1	51.3 ± 25.0	50.0 ± 23.1	60.6 ± 26.3	Tukey HSD test
R1 [ms]	12.0 ± 0.8b,c,d	11.2 ± 0.8a	11.3 ± 1.1a	10.6 ± 1.0a	Tamhane test

^aP < 0.05 versus diabetic dry eye syndrome (DES) group.

^bP < 0.05 versus non-diabetic DES group.

^cP < 0.05 versus diabetic without DES group.

^dP < 0.05 versus non-diabetic normal group.

All data are expressed as mean ± SD. NFL: Nerve fiber length; NFD: Nerve fiber density; NBD: Nerve branch density; R1, the R1 latency in blink reflex.