Describes the procedure of ReLEx smile, and illustrates why it is likely to replace excimer laser LASIK over time. For more details, visit www.newvisionindia.com

1. ENTER RELEX-GOODBYE
EXCIMER
Dr. Rupal Shah
Clinical Director, New Vision Laser Centers, India
www.drrupalshahlasik.com

2. EXCIMER LASER
 Technology has been around since at least 20
years
 Stable Technology
 Excellent results (>95% of all eyes are within +/-
0.5D)
 Ability to customize treatments
 High Patient Awareness and Acceptance

3. CONVENTIONAL LASIK
 Mechanical Microkeratome to create a hinged flap
 Flap is lifted to one side and excimer laser ablation
is carried out
 In excimer Laser ablation a lens is ablated from the
cornea, equivalent to the correction achieved
 Lens material is removed in the shape of a gas
plume from the corneal surface

4. FEMTOSECOND LASER
 Wellestablished Safety Profile for making
LASIK Flaps
 Several Advantages
 “Locked In” Flap
 Fully Sterile
 Tight control of Flap thickness
 Thin Flaps possible
 More Predictability and better complication profile relative
to mechanical microkeratome flaps
 Preferred choice for making LASIK flaps

5. RELEX
 Uses only the femtosecond laser for completing the
entire LASIK procedure
 No need for an excimer laser
 Possible only with the VisuMax Laser from Carl Zeiss
 Two Procedures
 FLEx=Femtosecond Lenticule Extraction
 SMILE-Small Incision Lenticule Extraction

6. Surgical steps of the ReLeX Procedure
1
2
3

7. WHY RELEX?

8. STABILITY OF THE LASER
 Excimer Laser is a gas based laser. Even after
many improvements, it is not as stable as a fiber
based femtosecond laser
 In a study we did, our MEL 80 excimer laser
required about six interventions in the year
ended February 2011 (including gas bottle
changes)
 Our VisuMax Femtosecond Laser required only
two interventions (of which one was for software
upgradation)

9. CORNEAL RESHAPING WITHOUT
ABLATION
 An excimer laser performs photoablation
 The photoablation rate increases linearly with
fluence beyond a certain threshold
 Excimer Laser fluence and photoablation rate
gets influenced by various factors –corneal
hydration levels, humidity levels, the presence of
organic vapors, the depth of ablation
 This results in a scatter, especially for the
treatment of high myopia

10. RELEX
 Uses cutting instead of ablation
 A binary process instead of linear
 Much less influence of any external factors
 Reflected in the tremendous accuracy achieved,
even in the first 1500-2000 eyes treated
worldwide
 Results are especially interesting for high
myopia, a group in which excimer lasers don’t
fare as well

11. RESULTS OF REFRACTIVE
CORRECTION USING RELEX WITH A
500 KHZ VISUMAX
month (eyes)
97% 98%
100% 94%
1 m (410) 3 m (377)
95%
90% 6 m (261) 1 y (64)
80%
70%
60%
50%
40%
30%
CZM-Application Pujara
20%
10%
2% 2% 1% 1%
1% 1% 1% 2% 3% 1% 1% 0%
0%
0%
-2
-1
+1
+2
,5
0
to
to
to
to
+-
01
51
01
51
,
,
-0
,
,
-1
+0
+1
Refractive outcome - Percentage within Attempted

12. SCATTER PLOT OF RELEX WITH A
500 KHZ LASER (AT 3 MONTHS)
Achieved [D] Scatter: Attempted vs. Achieved SEQ 'PREDICTABILITY' 377 eyes
15
14
13 overcorrected
12
11
10
9
8
7
y = 0.99x + 0.02
6
R2 = 0.98
5
4
3
undercorrected
2
CZM-Application Pujara
1
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Attempted delta SR equiv. [D]

13. RESULTS OF RELEX FOR HIGH
MYOPIA (>-5D UPTO -10D)

14. RELEX AND INFLAMMATION
 Total amount of energy input into the eye with
ReLEx is less than with Femto LASIK
 Results in less inflammation and higher stability
of the treatment

15. RELEX-STABILITY AFTER TREATMENT
WITH A 500 KHZ LASER
1.00 -0.02 -0.02
-0.03 -0.03
0.00
pre op 1m 3m 6m 1y
-1.00
-2.00
-3.00
-4.43
-4.00
CZM-Application Pujara
-5.00
-6.00
422 410 377 261
64
-7.00
Achieved Correction SEQ over Time 'STABILITY'

16. STABILITY AFTER RELEX FOR THE
TREATMENT OF HIGH MYOPIA (>-
5D)
1.00
0.07 0.08 0.06
0.14
0.00
pre op 1w 1m 3m 6m
-1.00
-2.00
-3.00
-4.00
-5.00
-6.00
-6.41
-7.00
123 118 113 83 43
-8.00
Time

17. POTENTIAL FOR MINIMALLY
INVASIVE TREATMENT
 One can easily remove the lenticule from a 3 mm
incision. We are working on techniques to reduce
this to less than 1.5 mm

18. VIDEO

19. SMALL INCISIONS
 No risk of flap displacements (There is a cap.
There is no flap!!!)
 Small Incision results in minimal cutting of
corneal nerves – less dry eyes, smaller reduction
in corneal sensitivity
 Less discomfort for the patient for a smaller
period
 Possible better biomechanical stability relative to
Femto-LASIK

20. INDUCTION OF ABERRATIONS
 Excimer lasers suffer from peripheral fluence
loss
 Fresnel reflection losses at a high angle of incidence
 Increase in spot size in the periphery
 Leads to an increase in spherical aberrations
 Minimized by newer ablation profiles
 However, with ReLEx, this problem is essentially
not there
 Should lead to less induction of spherical aberration
 In our study, there was an induction of less than 0.12
microns of spherical aberration (5 mm pupil)

21. WORKFLOW IMPROVEMENTS
 No need to change stations
 No need to keep placing and removing the
speculum
 In a study we conducted,
 SMILE (2 Eyes) took an average of 12.9 minutes
 Femto LASIK (2 Eyes) took an average of 21 minutes
 At our volume, doing ReLEx on all patients
would result in a net saving of 120 hours a year,
or half an hour every working day

22. PATIENT ACCEPTANCE
 Patients really like the idea of a flap less
procedure without the pain and slow visual
recovery of surface procedures
 In my experience, ReLEx is an easier “sell” to
patients than Femto-LASIK

23. COSTS
 Only one laser needed instead of 2
 Capital cost is reduced by nearly 50%
 Consumables of only one laser
 Maintenance contract of only one laser

24. SO WHEN IS AN EXCIMER NEEDED
 Wavefront Guided Procedures (< 5% of a normal
refractive practice)
 Retreatments (< 1% in ReLEx procedures- In
over 1000 eyes treated, I have actually retreated
only 3 eyes)
 Hyperopia (Latest results of ReLEx for
Hyperopia are quite encouraging)

25. GOODBYE EXCIMER
Enter ReLEx
drrupalshahlasik.com