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

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?

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.)

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.

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

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

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

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

Bar-on classification topography Type 5 Pathology of the iris

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

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.

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

Post 1 month

POST 6 MONTHS

Post 1 year No lost of line.

comparison

Type 2 Eccentric C.S.C.green

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

Type 3 Eccentric P.P.C.blue Pre-op;-3.00-3.00x180 b.c.v.a.-0.9

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

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

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

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.

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.

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.

Thank you for your attention