Accelerated Epithelium-Off Corneal Collagen Cross-Linking For Keratoconus: 12-Month Results

Figures & data

Figure 1 Preoperative topometric map of a keratoconus patient showing keratometric values, corneal thickness, and keratoconus indices.

Figure 2 Preoperative aberration map showing all corneal aberrations of the same patient in Figure 1.

Table 1 Visual, Refractive, And Keratometric Changes Before And After Acc CXL

	Preoperative	Postoperative	Difference Of Means	P Value
UCVA	0.32±0.06	0.38±0.04	0.06	0.01*
BCVA	0.77±0.02	0.81±0.02	0.04	0.02*
MRSE	−7.22±3.85	−6.30±3.52	0.92	0.13
Corneal astigmatism	−4.43±2.27	−3.25±2.43	1.18	0.03*
K1	47.18± 3.95	46.77±4.22	0.41	0.002*
K2	50.93± 5.19	50.31±5.34	0.62	0.0001*
Kmax	56.04±7.75	54.47±8.38	1.57	0.029*

Note: *Significant P-value.

Abbreviations: UCVA, uncorrected visual acuity; BCVA, best-corrected visual acuity; MRSE, manifest refraction spherical equivalent; K1, flat meridian; K2, steep meridian; Kmax, maximum k reading.

Table 2 Corneal Thickness And Corneal Volume Pre- And Post-CXL

	Preoperative	Postoperative	Difference	P-Value
Apex thickness	464±33.3	454.02±34.97	9.98	0.0001*
Thinnest location	455.25±33.59	444.87±35.25	10.38	0.0001*
Corneal volume	57.97±3.51	56.91±2.77	1.06	0.001*

Note: *Significant P-value.

Table 3 Keratoconus Indices Pre- And Post-CXL

	Range	Mean ±SD	Difference	P-Value
IVA
Preoperative	0.15–1.75	0.56±0.31	0.03	0.022*
Postoperative	0.038–0.102	0.53±0.28
ISV
Preoperative	29.00–161.00	68.55±32.73	3.63	0.002*
Postoperative	18.00–169.00	64.92±33.69
IHA
Preoperative	0.80–60.50	20.47±16.25	−3.45	0.248
Postoperative	18.00–74.10	23.92±21.08
IHD
Preoperative	0.01–0.24	0.080±0.053	0.003	0.500
Postoperative	0.01–0.25	0.077±0.058
KI
Preoperative	1.02–1.42	1.15±0.09	0.01	0.047*
Postoperative	0.009–0.0310	1.14±0.09

Note: *Significant P-value.

Abbreviations: IVA, index of vertical asymmetry; ISV, index of surface variance; IHA, index of height asymmetry; IHD, index of highest decentration; KI, keratoconus index.

Table 4 Higher Order Aberrations Pre- And Post-CXL

	Range	Mean ±SD	Difference	P-Value
Total aberrations
Preoperative	1.54–22.86	7.783±4.997	0.446	0.127
Postoperative	1.73–21.56	7.337±5.049
HOA
Preoperative	0.31–10.45	2.135±1.767	0.377	0.131
Postoperative	0.56–5.84	1.758±1.181
Spherical aberrations
Preoperative	−3.84–0.82	−0.616±0.923	−0.106	0.017*
Postoperative	-3.99–0.81	–0.510±0.989
Horizontal coma
Preoperative	−0.54–0.73	0.095±0.256	0.008	0.665
Postoperative	-0.70–0.75	0.087±0.266
Vertical coma
Preoperative	−0.41–0.42	−0.010±0.170	0.009	0.04*
Postoperative	-0.32–0.41	–0.001±0.126
Trefoil
Preoperative	−0.16–0.33	0.023±0.103	0.017	0.025*
Postoperative	-0.95–0.47	–0.006±0.018

Note: *Significant P-value.

Abbreviation: HOA, higher order aberrations.

Figure 3 Topometric map of the same patient 1 year after CXL. It shows improvements in Kmax and keratoconus indices with decreased corneal thickness.

Figure 4 One-year postoperative aberration map showing improvement in most of the studied aberrations when compared with Figure 2.