1. New corneal topography based procedure for kappa angle compensation in advanced surface ablation(A.S.A.)treatment.
Matsliah Taieb,M.D.,Igal Brikman,M.D.Ph.D ,Ariel Wender,M.D.,
Yariv Bar-on,optometrist.
American laser clinic ,Rishon le-zion
ISRAEL
E.S.C.R.S.WINTER SESSION MONACO 2006

2. purpose Which center to choose for the ablation zone?
To evaluate the effectiveness of perfectly centered eximer laser ablation based on computerized corneal topography in A.S.A.
Which center to choose for the ablation
zone?

3. Major corneal points & topography . classification
Physical pupil center(P.P.C.)
Corneal sighting center(C.S.C)
Maximal corneal power center (M.C.P.C)
Bar-on classification topography(B.C.T.)

4. BAR-ON CLASSIFICATION
TYPE 1:THE 3 CENTERS ARE ALIGNED
TYPE 2:ECCENTRIC C.S.C.
TYPE 3:ECCENTRIC P.P.C.
TYPE 4:ECCENTRIC M.C.P.C.
TYPE 5:PATHOLOGIC PUPIL.

5. Bar-on classification topography
Type 1
Centered p.p.c
Centered c.s.c.
Centered m.c.p.c.

6. Bar-on classification topography
Type 2
Eccentric c.s.c.
Centered p.p.c.
Centered m.c.p.c.

7. Bar-on classification topography
Type 3
Eccentric p.p.c.
Centered c.s.c.
Centered m.c.p.c.

8. Bar-on classification topography
Type 4
Eccentric m.c.p.c.
Centered p.p.c.
Centered c.s.c.

9. Bar-on classification topography
Type 5
Pathology of the iris

10. Prospective study Between december 2003 &march 2005
80 eyes of 40 consecutive patients
Bilateral same session A.S.A.;
Photo epithelial ablation
Photo refractive Keratectomy(p.r.k.)
Mitomycine application
Bandage contact lens
Wavelight Allegretto Excimer laser 200Hz
Oculus Keratograph

11. PATIENTS AGE BETWEEN:19 TO 55 years old REFRACTION RANGE-
SPH:+2.00dt to:-10.25dt
CYL:-0.25dt to:-4.50dt
CORRECTED CENTRATION FOR TYPE;2-3
-4,TYPE 5 WAS NOT INCLUDED.
RANGE OF SHIFT ON AXIS X:-150/+250
RANGE OF SHIFT ON AXIS Y:-200/+250
SHIFT OVER THAN 250 MICRONS:
TOPOGUIDED WAS INDICATED.

12. RESULTS FOLLOW -UP 1 YEAR HALOS ,NIGHT GLARE:NONE HAZE:1%
U.C.V.A:GAIN OR LOST LINES.

13. Post 1 month

14. POST 6 MONTHS

15. Post 1 year
No lost of line.

16. comparison

17. Type 2
Eccentric C.S.C.green

18. Irregular astigmatism TYPE 2
Pre-op;bcva-1.00
100X152;0.8
Post-op u.c.v.a;1.2
Residual +0.25
No halos
Very good night vision

19. Type 3
Eccentric P.P.C.blue
Pre-op; x180
b.c.v.a.-0.9

20. Example Type 3 Post-op 6 months u.c.v.a.;1.2 No halos No glare
Residual;plano

21. Post R.K.type 4 Type 4 Eccentric m.c.p.c.red Ref;+2.00-4.50x124
b.c.v.a.;0.6

22. example post-op 6 months u.n.c.v.a.:0.8 No glare No halos No haze
residual:+0.25-
0.75x90

23. DISCUSSION WE HAVE 2 GOALS: 1:Eccentric ablation prevention
2:Improved optical results
Bar-On CLASSIFICATION:
New CLINICAL TOOL for precise ablation
zone center CALCULATION.
Used in this clinical study for our A.S.A.
procedure but also for our LASIK treatments.

24. Seems to be a correlation between:
Discussion
Seems to be a correlation between:
1:eccentric types & relative amblyopia
2:standard procedure & relative amount of
eccentric ablation.

25. conclusion
Eccentric problems related to c.s.c.&p.p.c.& m.c.p.c. need to be considerated (Bar-on typology ).
Simple customized solution shift calculation
Could be a solution for relative amblyopia,
Allows smaller optical zone treatments
Under clinical & optical investigation
No complications related to lasik
All the bellow is already register as a patent.

26. Thank you for your attention