One-Year Efficacy and Safety of Combined Photorefractive Keratectomy and Accelerated Corneal Collagen Cross-Linking after Intacs SK Intracorneal Ring Segment Implantation in Moderate Keratoconus
Table 1
Comparison of baseline patient characteristics in the three studies utilizing a two-stage surgical approach for the treatment of moderate keratoconus.
Current study
Al-Tuwairqi et al.
Lee et al.
Subject number (eyes)
30
41
23
Follow-up period
1 year
1 year
6 months
Surgical modality
ICRS type
Intacs SK
Keraring
Keraring
Excimer laser for transepithelial PRK
Schwind Amaris 1050
Schwind Amaris
Schwind Amaris 1050
Topographer type
Placido disk combined with Scheimpflug camera (Schwind Sirius)
Placido disk (Corneal Wavefront Analyzer, Schwind)
Placido disk (Keraton Scout, Optikon)
CXL
Accelerated (3 min at 30 mW/cm2)
Conventional (30 min at 3 mW/cm2)
Accelerated (6 min at 15 mW/cm2)
Preoperative measurements, mean or median (95% confidence intervals)
UDVA (logMAR)
0.8 (0.7 - 2)
0.74 (0.58 - 0.91)
0.85 (0.74 - 0.96)
CDVA (logMAR)
0.5 (0.4 - 0.6)
0.04 (0.00 - 0.08)
0.25 (0.18 - 0.32)
Spherical equivalent (D)
– 6.50 (– 8.75 to – 5.00)
– 3.03 (– 3.64 to – 2.42)
- 2.33 (– 3.24 to – 1.42)
Cylinder (D)
6.32 (5.17 - 7.46)
2.20 (1.75 - 2.65)
1.83 (1.27 - 2.39)
Steep K (D)
50.58 (49.15 - 52.00)
46.13 (45.49 - 46.77)
48.0 (46.5 - 49.5)
Mean K (D)
48.46 (47.25 - 49.67)
44.96 (44.40 - 45.52)
47.2 (45.9 - 48.5)
Maximum K (D)
58.5 (56.02 - 60.98)
NA
55.35 (53.10 - 57.60)
Thinnest corneal thickness (μm)
478 (464 - 491)
501.87 (492.23 - 511.51)
463.9 (451.4 - 476.4)
Coma aberration (μm)
2.339 (1.891 - 2.787)
1.08 (0.88 - 1.28)
2.47 (2.06 – 2.88)
Spherical aberration (μm)
– 0.115 (– 0.2 to – 0.02)
NA
0.15 (– 0.09 to 0.39)
RMS HOA (μm)
2.585 (2.117 - 3.054)
NA
2.87 (2.40 – 3.34)
[9]. [10]. median; others are means. Subjective refraction was utilized for comparison purposes in this table; objective refraction data by autorefraction are presented in the text. Subjective refraction. Central corneal thickness. ICRS, intrastromal corneal ring segment; PRK, photorefractive keratectomy; CXL, corneal collagen crosslinking; UDVA, uncorrected distance visual acuity; CDVA, corrected distance visual acuity; K, keratometry; RMS HOA, root mean square of higher-order aberrations; NA, not available.
