LASER TYPES |
Excimer Laser PRK |
Conventional LASIK Micro-keratome |
Femto-LASIK |
Small Incision Lenticule Extraction (SMILE) |
Trans epithelial surface treatment (TEST) |
|
Pre-Op Patient Selection |
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1 |
Suitability for Various Spectacle Numbers |
For Low to Moderate Numbers |
For all Low to High Numbers |
For all Low to High Numbers |
Moderate suitability only. Can not correct Low -0.5 or any plus numbers |
High suitability. Can correct Very Low -0.5 to Very High Numbers |
2 |
Suitability for Thin Cornea |
Yes |
No |
No |
Moderate but causes more corneal tissue loss |
Maximum safety & accuracy |
3 |
Suitability for previously Operated Lasik or Repeat |
Yes (conditional) |
Yes (conditional) |
Yes (conditional) |
No |
Yes |
4 |
Safety for High Risk Jobs & Contact Sports |
High |
Moderate |
Moderate |
High |
Highest |
5 |
Multifocal Number Correction after age 40 |
No |
Possible |
Possible |
No |
Possible |
Operative Conditions |
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6 |
Flap Complications, |
No Flap |
1 in 100 eyes |
1 in 250 eyes |
Flapless so no flap complication |
Flapless so no flap complication |
7 |
Corneal Cut |
No |
Nearly 300 degrees/ 20 mm |
Nearly 300 degrees/ 20 mm |
Nearly 45 degrees/ 2 to 3 mm |
No Cut |
8 |
Splitting or separation of Corneal Layers |
No |
Yes |
Yes |
Yes |
No |
9 |
Microkeratome Blade Complications |
No |
Yes |
No |
No |
No |
10 |
Advanced Astigmatism Cylinder Cyclotorsion & Wavefront Treatment for axis & better contrast |
No |
Yes |
Yes |
Not Possible so Less Accurate Cylinder Axis Alignment |
Yes |
11 |
Permanent Mark on Cornea |
Moderate |
Cut Mark Visible |
Cut mark visible |
Cut mark visible |
No mark, so safer for medical test |
12 |
Incomplete Lenticule Extraction Complication |
No |
No |
No |
Yes |
No |
13 |
Corneal Bowman's Layer Wrinkles Complication |
No |
Yes |
Yes |
Yes |
No |
14 |
Gas Bubble Breakthrough Complication |
No |
No |
Yes |
Yes |
No |
15 |
Maintenance of Corneal Architecture |
Some Compromise |
Some Compromise |
Some Compromise |
Less Compromise |
Least or no Compromise |
Post-Operative Consideration |
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16 |
Pain after the procedure |
Intense for 48 hours |
Discomfort for a few hours |
Discomfort for a few hours |
Mild Discomfort for a few hours |
Mild to moderate |
17 |
Vision Recovery |
Poor for 3-4 days, recovers gradually over a few weeks |
Quick ( 12 to 24 hours ) |
Quick ( 24 hours ) |
24-48 hrs, Moderate |
72 hrs,Slow but very safe and end result is same or better |
18 |
Corneal Haze |
Moderate |
No |
No |
Minimal,transient |
Rare (MMC) |
19 |
Enhancement in case of residual power |
Difficult |
Possible |
Possible |
Not Possible have to convert to LASIK or PRK |
Possible |
20 |
Dry Eyes after Laser |
Mild |
Mild to moderate |
Mild to moderate |
Mild or none |
Mild or none |
21 |
Return to Routine Activities |
7 to 10 days |
1 day |
1 day |
1 day |
3 days |
22 |
Night Glare and Large Pupil Problems |
Moderate(if haze) |
Mild |
Mild |
Mild |
Least or none as large Optic zone |
23 |
Restrictions on Swimming |
2 Months |
1 Months |
1 Months |
1 Week |
2 weeks |
24 |
Steroid Eye Drops |
8 to 10 weeks |
3 Weeks |
3 Weeks |
2 to 3 Weeks |
4 weeks (optional) |
Conclusion |
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25 |
Overall Safety |
Safe |
Fairly Safe |
Safer |
More Safe |
Safest |
26 |
Accuracy |
0.25 microns |
0.25 microns |
0.25 microns |
4.0 microns error |
0.25 microns |
27 |
Glasses Number Correction Accuracy |
+ /- 0.02 Diopter but regression |
+/- 0.02 Diopters |
+/- 0.02 Diopters |
+/- 0.33 to 0.66 Diopters error |
+/- 0.02 Diopters |
28 |
Keratoconus & Corneal Ectasia Risk |
Low |
Moderate |
Moderate |
Low to Moderate |
Least |
29 |
Long term Results |
Average |
Very Good |
Very Good |
Under Investigation |
Extremely Good |
30 |
US - FDA APPROVED |
Yes |
Yes |
Yes |
Limited Approval |
Yes |