Visual and Refractive Long-Term Outcomes Following Standard Cross-Linking in Progressive Keratoconus Management

Figures & data

Table 1 Summary of S-CXL Preoperative and Postoperative Visual, Topographic and Refractive Data Analysis

Parameters	Preoperative Mean ± SD Median [Range]	Postoperative 12th Month Mean ± SD Median [Range]	Postoperative 24th Month Mean ± SD Median [Range]	Postoperative 36th Month Mean ± SD Median [Range]	Postoperative 60th Month Mean ± SD Median [Range]	Difference (Post-Pre) Mean ± SD [95% CI]	P value Within Subject (Time)	P value Between Subject (Surgeon)
Visual Outcomes:
Mean UDVA (logMAR)	1.34±0.29 1.3 [0.78:1.78]	1.10±0.26 1.12 [0.30:1.78]	1.06±0.27 1.12 [0.30:1.78]	1.05±0.28 1.12 [0.22:1.78]	0.99±0.32 1.00 [0.10:1.78]	−0.34±0.32 [0.90:1.08]	<0.0001	0.77
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001 P6<0.0001, P7<0.0001
Mean CDVA (logMAR)	0.74±0.23 0.78 [0.30:1.12]	0.55±0.20 0.60 [0.18:1.22]	0.51±0.19 0.52 [0.18:1.22]	0.51±0.20 0.52 [0.18:1.22]	0.50±0.22 0.52 [0.18:1.22]	−0.24±0.20 [−0.30:-0.19]	<0.0001	0.56
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001, P6<0.0001, P7<0.0001
Topographic Outcomes:
Mean k1 reading	46.66±1.19 46.75 [42.75:49.5]	45.52±1.50 45.75 [40.25:49.5]	45.49±1.55 45.5 [40.25:49.5]	45.53±1.58 45.75 [40.25:49.5]	45.57±1.65 45.75 [40.5:49.25]	−1.09±1.31 [−1.46:-0.71]	<0.0001	0.76
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5
Mean k2 reading	50.87±1.73 51 [46:55.5]	49.39±1.73 49 [45.25:52.75]	49.25±1.81 49 [45:52.75]	49.20±1.83 49 [45:53]	49.11±1.86 49 [45:5.]	−1.76±1.56 [−2.20:-1.30]	<0.0001	0.80
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001, P6<0.0001, P7<0.0001, P9=0.005, P10=0.009
Mean K max	51.95±1.90 52.25 [46.5:58.82]	51.15±2.03 51.5 [45.8:58.7]	50.64±1.86 51 [45.5:57.5]	50.27±1.92 50.11 [45.75:57.7]	50.19±1.96 50 [45.8:59.93]	−1.77±1.77 [−2.26:-1.27]	<0.0001	0.85
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001, P6=0.001 1, P7=0.001
Mean K reading average (D)	48.77±1.27 48.88 [44.63:51.5]	47.46±1.47 47.5 [43:50.63]	47.37±1.52 47.5 [42.88:50.5]	47.36±1.55 47.5 [42.88:50.63]	47.34±1.60 47.5 [43:50.75]	−1.42±1.39 [−1.82:-1.02]	<0.0001	0.21
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001
Mean corneal thickness at thinnest location, (µm)	437.73±18.65 436 [400:485]	430.18±20.20 428 [389:480]	427.29±21.13 428 [365:478]	424.31±21.99 425 [338:475]	420.67±22.73 421 [319:470]	−17.06±11.90 [−20.75:-10.07]	<0.0001	0.71
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001, P6<0.0001, P7<0.0001, P8<0.0001, P9=0.03
Coma aberrations	3.08±1.92 2.52 [0.24:10.56]	2.79±1.66 2.02 [0.24:8.25]	2.71±1.63 1.99 [0.13:7.90]	2.68±1.52 1.95 [0.14:7.35]	2.69±1.50 1.79 [0.13:7.24]	−0.39±0.48 [−0.94:-0.61]	<0.0001	0.61
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001, P6<0.0001, P7<0.0001, P8=0.01, P9<0.0001
Q value	−0.55±0.66 0.62 [−1.55:1.57]	−0.39±0.60 0.27 [−1.02:1.25]	−0.27±0.64 –0.10 [−1.23:1.35]	−0.24±0.71 –0.21 [−1.33:1.45]	−0.32±0.71 –0.35 [−1.5:1.50]	0.23±0.19 [−0.61:-0.11]	<0.0001	0.52
P1=0.001, P2<0.0001, P3<0.0001, P4<0.0001, P5<0.0001, P6<0.0001, P7<0.0001, P8=0.02, P9<0.0001, P10=0.04
Refractive Outcomes:
Mean spherical component	−5.52±3.11 –4.75 [−15.5:-1.25]	−4.71±2.58 –4.25 [−10.25:-0.5]	−4.55±2.50 –4.25 [−10:-0.5]	−4.47±2.46 –4.25 [−9.75:-0.5]	−4.27±2.40 –4 [−9.5:-0.5]	1.25±1.33 [0.87:1.63]	<0.0001	0.35
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5=0.04, P6=0.001, P7<0.0001, P8=0.001, P9<0.0001, P10<0.0001
Mean cylindrical component	−4.78±1.61 –4.75 [−8.25:-1.5]	−4.43±1.63 –4.25 [−8:-1.25]	−4.37±1.62 –4.25 [−8:-1.25]	−4.32±1.61 –4.25 [−7.75:-1.25]	−4.17±1.67 –4 [−8.25:-1.25]	0.60±0.57 [0.44:0.77]	<0.0001	0.33
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5=0.06, P6<0.0001, P7<0.0001, P8=0.02, P9<0.0001, P10=0.002
Mean SE	−7.90±3.14 –7.38 [−18.5:-2.38]	−6.92±2.61 –6.63 [−13:-1.38]	−6.74±2.54 –6.5 [−12.63:-1.38]	−6.63±2.49 –6.5 [−12.63:-1.25]	−6.35±2.49 –6.13 [−12.25:-1.13]	1.55±1.47 [1.13:1.97]	<0.0001	0.42
P1<0.0001, P2<0.0001, P3<0.0001, P4<0.0001, P5=0.02, P6<0.0001, P7<0.0001, P8<0.0001, P9<0.0001, P10<0.0001

Notes: P1 compared pre with 12 ms, P2 compared pre with 24 ms, P3 compared pre with 36 ms, P4 compared pre with 60 ms, P5 compared 12 ms with 24 ms, P6 compared 12ms with 36 ms, P7 compared 12ms with 60 ms, P8 compared 24ms with 36 ms, P9 compared 24ms with 60 ms, P10 compared 36ms with 60 ms.

Figure 1 The standard graphs of the visual and refractive outcomes: (A) the cumulative logMAR visual acuity; (B) the change in CDVA; (C) the attempted versus achieved postoperative SE refraction in a scatterplot; (D) the refractive accuracy of SE; (E) the refractive cylinder; (F) the refractive stability of SE; (G) the refractive stability of cylindrical component and (H) the refractive stability of spherical component.

Figure 2 The relationship graphs of topographic and refractive outcomes: (A) K readings relationships; (B) spherical, cylindrical and SE components relationships.