Table 3 Comparison between 6 th generation Excimer platforms
From: Excimer laser 6th generation: state of the art and refractive surgical outcomes
Company | Schwind | Nidek | WaveLight |
|---|---|---|---|
Model | Amaris | Navex Quest | AllegrettoEye-Q |
Laser type | ArF | ArF | ArF |
Laser beam | Flying Spot | Slit scanning + variable spot-size scanner | Flying spot |
Beam profile | Super-Gaussian | Flat Top | Gaussian |
Pulse rate | 500-700 Hz | 6 scans/sec.60 Hz max | 400-700 HZ |
Pulse duration | 10 ns | 25 ns | 10 ns |
Peak fluence | 160 mJ/cm2 - 450 mJ/cm2 | 130 mJ/cm2 | 400 mJ/cm2 |
Beam size | 0.54 mm | 10 x2 mm scanning slit (1 mm for customized and hyperopia) | 0.68 mm |
Spot size (cornea) | 0.54 mm | 1.0 mm | 0.95 mm (1.2 mm) |
Optical zone (OZ) | 4 - 10 mm | 6.5 mm | 4.5 mm - 8 mm |
Ablation zone | Optimized | 8 mm | 9 mm |
Ablation profile | Aspheric (aberration free) | Munnerlyn with aspheric tansition zone | Aspheric (including Q-value) |
Transition zones adjustable | No | Yes | Yes |
Static Cyclo-Torsion | Yes | Yes | Pseudo, yes |
Dynamic Cyclo-Torsion | Yes | Yes (TEC = torsion error correction) | Pseudo, yes |
Cyclo-Torsion, Sampling Rate | 36 Hz | 30 Hz | NR |
Ablation depth per shot (cornea) | 0.42 μm - 0.68 μm | 0.32 μm | 0.65 μm |
Ablation volume per shot (cornea) | 110 pl -220 pl | 250 pl | N/A |
Ablation depth per diopter (6.5 mm OZ) | 16.4 μm | 15 μm | 15.3 μm |
Time per diopter (6.5 mm OZ) | <2.5 ms | 5 s | 3 s |
Ablation depth -5dpt/OZ = 6 mm | 65 μm (12 s) | 63 μm | 65 μm |
Eye tracking system | Active video tracking (SMI) | Active video tracking (SMI) | Active video tracking (SMI) |
Sampling rate | 1050 Hz | 1050 Hz | 400 Hz |
Eye tracker response time | <3 ms | 4 ms | 4 ms |
Cyclo-Torsion, Resolution | Static ±15° Dynamic ± 7° | NR | NR |
X-Y & Z-tracking | Active | Active | No |
Presbyopic treatment | No | Yes | No |
Online pachymetry | Yes - integrated | No | No |
Eye fixation | Green LED | Yes | LED |
Centration of pupil | Automatic, user defined | Manual | User defined |
Laserhead/Lasersource | Coherent | Lambda | TUI |
FluenceTest needed every: | 2 hours | NR | Before every treatment day |
Fluence & Calibration | Automatic and objective | Manual and subjective | Manual and subjective |
Capable of customized ablation | Yes | Yes | Yes |
Ocular wavefront | Yes | Yes | Yes |
Method used for wavefront | Hartmann - Shack | Yes | Tscherning Principle |
Topographic system | Corneal Wavefront Analyzer/CSO | Topographer retinoscopy | Yes Oculus |
Topgraphic link | Yes (Corneal wavefront) | Yes (OPD-scan) | Yes (topographic based on Zernike) |
Dimensions (LxWxH) | 264 × 144 × 136 cm(including patient bed) | 137 × 151.6 × 147 cm | 120 × 145 × 130 cm (without patient bed) |
Weight (without patient bed) | 550 kg | 650 kg | 265 kg (without bed and gas) patient bed 188 kg |
Website: last visited May 2014 | http://www.nidek-intl.com/products/ref_surgical/navex-quest.html | http://www.alconsurgical.com/wavelight-allegretto-wave-eye-q-laser.aspx |