Table 2. Corneal Subbasal Nerve Density and Keratocyte Density.

	Time after surgery
	preoperative	1 week	1 month	3 months	6 months
Corneal Subbasal Nerve Density (mean ± SD, µm/mm2)
SMILE	10875.7±3556.9	3331.1±2183.5	3265.6±2758.6	3944.0±3475.7	4941.2±3366.8
Decrease§		7608.3±576.6*	7642.1±564.6 *	6736.0±644.0*	5588.8±618.9*
FS-LASIK	9696.3±3085.6	70.7±229.4	398.9±871.2	1179.1±1920.2	3644.1±2848.1
Decrease§		9431.0±531.8†	9316.7±527.8†	8375.8±552.6†	5874.6±567.3†
△Decrease§		1822.7±784.4‡	1674.7±772.3‡	1639.8±847.3‡	285.8±838.4
Pre-IF keratocyte density (mean ± SD, cells/mm2)
SMILE	261.3±47.7	183.6±40.5	181.5±35.6	184.7±34.7	166.2±34.4
Decrease§		77.8±10.0*	81.2±9.9*	83.0±11.4*	96.1±10.5*
FS-LASIK	230±26.6	160.4±38.5	174.0±46.1	150.6±39.5	164.8±40.0
Decrease§		72.5±8.4†	57.6±8.3†	81.4±8.9†	71.9±9.0†
△Decrease§		−5.3±13.1	−23.6±12.9	−1.5±14.4	−24.2±13.8
Post-IF keratocyte density (mean ± SD, cells/mm2)
SMILE	209.5±40.0	107.4±31.6	112.0±31.1	123.3±42.8	107.7±29.4
Decrease§		102.3±8.2*	96.7±8.1*	85.4±9.3*	98.8±8.6*
FS-LASIK	221.2±28.6	147.8±33.0	138.2±30.3	135.1±30.0	120.7±29.8
Decrease§		72.2±6.9†	84.5±6.8†	85.7±7.3†	104.4±7.4†
△Decrease§		−30.1±10.7‡	−12.2±10.6	0.38±11.8	5.6±11.3

Pre-IF keratocyte density: pre interface keratocyte density.

Post-IF keratocyte density: post interface keratocyte density.

△Decrease, difference in the decreases between the two groups.

^* P<0.0001, significantly different from the preoperative values in the SMILE group.

^† P<0.0001, significantly different from the preoperative values in the FS-LASIK group.

^‡ P<0.05, significantly different decrease in the two groups.

^§estimated from the mixed model.