Two-Step Transepithelial Photorefractive Keratectomy with WaveLight EX500 Platform for Adolescents and Adults with Low to Moderate Myopia: A 12-Month Comparative Evaluation

Figures & data

Table 1 Demographic Baselines of the Four Groups

Parameters	Mean ± SD
	Low Myopia (0 to −3.00 D)		Moderate Myopia (−3.01 to −6.00 D)
	Age <18	Age ≥18	Age <18	Age ≥18	P-value
Number of patients, N(%)	25(69.44)	11(30.56)	7(43.75)	9(56.25)	<0.001^a
Sex (%)
Male	25(100.00%)	7(63.64%)	7(100.00%)	4(44.44%)	<0.001^a
Female	0(0%)	4(36.36%)	0(0%)	5(55.56%)	<0.001^a
Age (years)	15.68±0.63	27.64±8.73	16.00±0.58	31.11±13.11	<0.001^b
(Range)	(14.00–17.00)	(18.00–45.00)	(15.00–17.00)	(18.00–58.00)

Notes: ^aFisher’s exact test; ^bKruskal–Wallis test.

Abbreviation: SD, standard deviation.

Table 2 Pre-Operative Baselines of the Four Groups

Parameters	Mean ± SD
	Low Myopia (0 to−3.00 D)		Moderate Myopia (−3.01 to−6.00 D)
	Age <18	Age ≥18	Age <18	Age ≥18	P-value
Number of eyes, N(%)	46(71.88)	18(28.12)	12(44.44)	15(55.56)	<0.001^a
UDVA (logMAR)	0.55±0.23	0.64±0.22	0.94±0.15	0.94±0.19	<0.001^b
CDVA (logMAR)	−0.08±0.04	−0.09±0.02	−0.08±0.04	−0.07±0.06	0.494^c
Sphere (D)	−1.59±0.59	−2.11±0.44	−3.69±0.63	−3.70±0.86	<0.001^c
Cylinder (D)	−0.28±0.39	−0.43±0.41	−0.35±0.38	−0.68±0.40	0.010^c
Spherical equivalent (D)	−1.75±0.52	−2.33±0.49	−3.86±0.64	−4.08±0.91	<0.001^c
Mean keratometric power (D)	43.75±1.21	44.67±1.10	43.01±0.73	43.31±1.79	0.002^b
Corneal thickness (µm)	540.70±29.22	531.56±30.68	571.42±12.49	526.40±40.59	0.001^b
Scotopic pupil size (mm.)	6.26±0.73	5.72±0.86	6.50±0.56	5.90±0.47	0.009^c

Notes: ^aFisher’s exact test; ^bAnalysis of variance test (ANOVA); ^cKruskal–Wallis test.

Abbreviations: SD, standard deviation; UDVA, uncorrected distance visual acuity; CDVA, corrected distance visual acuity; D, diopter.

Table 3 Post-Operative Efficacy, Safety and Visual Results of the Four Groups

Parameters	Mean ± SD
	Low Myopia (0 to −3.00 D)		Moderate Myopia (−3.01 to −6.00 D)
	Age <18	Age ≥18	Age <18	Age ≥18	P-value
UDVA (logMAR)
1 month	0.00±0.19	0.15±0.19	0.03±0.16	0.05±0.14	0.033^a
3 months	−0.05±0.13	0.06±0.19	−0.03±0.13	0.07±0.12	0.025^a
6 months	−0.06±0.12	0.04±0.17	−0.01±0.09	−0.07±0.11	0.309^a
1 year	−0.11±0.12	0.00±0.17	0.00±0.11	−0.05±0.07	0.015^a
Efficacy index
1 month	0.92±0.33	0.62±0.25	0.83±0.31	0.83±0.24	0.034^a
3 months	0.99±0.28	0.76±0.30	0.94±0.26	0.78±0.20	0.078^b
6 months	0.99±0.27	0.78±0.24	0.87±0.13	1.06±0.27	0.067^a
1 year	1.01±0.21	0.86±0.28	0.85±0.16	1.01±0.16	0.006^a
Safety index
1 month	1.02±0.23	0.89±0.11	0.94±0.19	0.92±0.13	0.129^a
3 months	1.08±0.18	0.93±0.17	1.01±0.16	1.03±0.83	0.035^a
6 months	1.06±0.19	0.93±0.10	1.01±0.16	1.06±0.27	0.174^a
1 year	1.07±0.22	0.90±0.60	1.05±0.25	1.03±0.28	0.206^a

Notes: Efficacy index = post-operative UDVA/pre-operative CDVA; Safety index = post-operative CDVA/pre-operative CDVA; ^aKruskal–Wallis test; ^bAnalysis of variance test (ANOVA).

Abbreviations: SD, standard deviation; UDVA, uncorrected distance visual acuity; CDVA, corrected distance visual acuity; D, diopter.

Figure 1 Post-operative spherical equivalent refractive accuracy at 12 months after TransPRK.

Figure 2 The trends of the mean refractive spherical equivalent (MRSE) of eyes after TransPRK at pre- and post-operation at 1, 3, 6 and 12 months.

Figure 3 Post-operative haze assessment at 3 months after TransPRK.

Table 4 Post-Operative Dry Eye Score and Night Visual Disturbance After TransPRK

Parameters	Mean ± SD
	Low Myopia (0 to −3.00 D)		Moderate Myopia (−3.01 to −6.00 D)		P-value
	Age <18	Age ≥18	Age <18	Age ≥18
Dry eye score (0–5)
1 month	1.33±0.99	1.29±1.20	1.11±1.36	1.89±1.27	0.514
3 months	1.10±1.05	1.67±1.21	1.44±1.42	2.11±1.54	0.103
6 months	0.49±0.89	1.07±1.14	0.33±1.00	1.22±2.17	0.048
1 year	0.61±1.24	0.56±0.93	0.67±1.32	2.00±2.24	0.304
Night visual disturbance (0–5)
1 month	0.63±0.99	1.37±1.78	0.56±0.88	0.67±0.71	0.438
3 months	0.35±0.83	1.11±1.63	0.67±1.00	0.44±0.73	0.060
6 months	0.18±0.49	0.30±0.54	0.00±0.00	0.22±0.67	0.304
1 year	0.24±0.56	0.37±0.69	0.00±0.00	0.22±0.67	0.352