COMPARISON OF VARIOUS LASER PROCEDURES FOR GLASSES REMOVAL

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

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

6

Flap Complications,
Flap Displacement

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

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

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