Table 2.

Refractive and tomographic changes after transepithelial CXL assisted by enhanced iontophoresis (n = 34 for each group)

	Group	Baseline	1 year		2 years		3 years		5 years
		Mean ± SD	Mean ± SD	p	Mean ± SD	p	Mean ± SD	p	Mean ± SD	p
UCVA	c-CXL	0.94 ± 0.29	0.94 ± 0.30	1.000	0.99 ± 0.34	0.428	0.96 ± 0.32	1.000	0.99 ± 0.33	0.378
	ei-CXL	0.97 ± 0.33	0.97 ± 0.34	1.000	1.01 ± 0.36	0.424	1.00 ± 0.35	0.703	1.02 ± 0.33	1.000
	p	0.371	0.424		0.388		0.252		0.546
BCVA	c-CXL	0.30 ± 0.08	0.30 ± 0.11	1.000	0.29 ± 0.11	1.000	0.31 ± 0.11	1.000	0.31 ± 0.08	1.000
	ei-CXL	0.30 ± 0.11	0.29 ± 0.99	1.000	0.29 ± 0.12	1.000	0.33 ± 0.12	1.000	0.33 ± 0.11	1.000
	p	0.898	0.789		0.902		0.528		0.581
Sphere, D	c-CXL	− 3.76 ± 2.25	− 3.15 ± 1.73	0.005	− 3.29 ± 1.82	0.002	− 3.32 ± 1.92	0.031	− 3.41 ± 1.90	0.062
	ei-CXL	− 3.76 ± 1.46	− 3.51 ± 1.32	0.029	− 3.54 ± 1.29	0.001	− 3.56 ± 1.25	0.016	− 3.71 ± 1.54	1.000
	p	0.984	0.256		0.416		0.430		0.328
Cylinder, D	c-CXL	− 3.87 ± 1.67	− 3.16 ± 1.46	0.005	− 3.13 ± 1.41	0.002	− 3.24 ± 1.39	0.035	− 3.28 ± 1.44	0.071
	ei-CXL	− 3.88 ± 1.91	− 3.21 ± 1.35	0.000	− 3.31 ± 1.43	0.000	− 3.52 ± 1.63	0.003	− 3.76 ± 1.94	1.000
	p	0.986	0.883		0.626		0.470		0.270
SE, D	c-CXL	− 5.70 ± 2.50	− 4.73 ± 1.88	0.001	− 4.86 ± 1.94	0.001	− 4.95 ± 2.09	0.005	− 5.05 ± 2.07	0.022
	ei-CXL	− 5.70 ± 1.67	− 5.12 ± 1.41	0.000	− 5.19 ± 1.43	0.000	− 5.32 ± 1.51	0.000	− 5.59 ± 1.84	1.000
	p	0.994	0.309		0.352		0.300		0.154
K1, D	c-CXL	48.27 ± 4.24	48.05 ± 4.20	0.060	48.15 ± 4.23	1.000	48.26 ± 4.45	1.000	48.29 ± 4.43	1.000
	ei-CXL	48.49 ± 5.21	48.30 ± 5.22	0.002	48.38 ± 5.28	0.076	48.48 ± 5.33	1.000	48.63 ± 5.51	1.000
	p	0.819	0.799		0.819		0.832		0.744
K2, D	c-CXL	52.68 ± 3.85	52.09 ± 3.81	< 0.001	52.14 ± 3.83	0.003	52.27 ± 3.99	0.177	52.32 ± 3.99	0.363
	ei-CXL	52.65 ± 5.38	52.09 ± 5.20	< 0.001	52.22 ± 5.08	0.001	52.37 ± 5.29	0.135	52.88 ± 5.78	1.000
	p	0.979	0.995		0.927		0.912		0.573
Kmax, D	c-CXL	58.37 ± 4.96	56.81 ± 4.04	0.020	56.78 ± 4.02	0.001	57.05 ± 4.82	0.048	57.46 ± 4.98	0.681
	ei-CXL	58.26 ± 5.78	56.94 ± 5.42	< 0.001	57.06 ± 5.60	< 0.001	57.30 ± 5.77	< 0.001	58.16 ± 6.28	1.000
	p	0.917	0.883		0.755		0.798		0.523
Minimal thickness, μm	c-CXL	430.8 ± 30.5	412.0 ± 31.2	< 0.001	421.5 ± 30.9	< 0.001	426.6 ± 31.6	0.006	427.2 ± 31.4	0.036
	ei-CXL	430.4 ± 28.6	416.5 ± 30.0	< 0.001	425.9 ± 27.9	< 0.001	429.7 ± 28.4	1.000	430.5 ± 29.6	1.000
	p	0.953	0.550		0.554		0.682		0.666
EC, cells/mm2	c-CXL	2666 ± 256	2650 ± 266	1.000	2654 ± 294	1.000	2628 ± 349	1.000	2604 ± 357	1.000
	ei-CXL	2697 ± 244	2688 ± 247	1.000	2681 ± 276	1.000	2634 ± 279	1.000	2664 ± 306	1.000
	p	0.611	0.488		0.677		0.934		0.420
IOP, mmHg	c-CXL	14.53 ± 2.00	14.59 ± 2.40	1.000	14.65 ± 2.84	1.000	14.62 ± 2.64	1.000	14.53 ± 2.50	1.000
	ei-CXL	14.56 ± 1.76	14.56 ± 3.08	1.000	14.50 ± 2.55	1.000	14.38 ± 2.81	1.000	14.71 ± 2.17	1.000
	p	0.955	0.963		0.837		0.756		0.767

UCVA uncorrected visual acuity, BCVA best-corrected visual acuity, SE spherical equivalent, EC endothelial cell, IOP intraocular ocular pressure