1. Different epithelial cleavage planes produced by various epikeratomes in Epi-LASIK Doh Lee, M.D., Ph.D. 1, Suk kyue Choi, M.D. 1, Jin Hyoung Kim, M.D. 1, Jae Bum Lee, M.D., Ph.D. 2, Hyo Myung Kim, M.D., Ph.D. 3, Hung Won Tchah M.D., Ph.D. 4, Tae Won Hahn, M.D., Ph.D. 5, Mee Joo, M.D. Ph.D. 6, Chang Il Ha, M.D. 1 Department of Ophthalmology, Ilsan Paik Hospital, College of Medicine, Inje University, Goyang, Korea 1 Younse Plus Eye Hospital, SungNam, Korea 2 Department of Ophthalmology, College of Medicine, Korea University, Seoul, Korea 3 Department of Ophthalmology, College of Medicine, Ulsan University, Seoul, Korea 4 Apgujung St. Mary’s Eye Center, Seoul, Korea 5 Department of Pathology, Ilsan Paik Hospital, College of Medicine, Inje University, Goyang, Korea 6

2. Purpose To determine the anatomic cleavage planes produced by various epikeratomes in Epi-LASIK I. Moria Epi-K Epikeratome  (Moria, Antony, France) II. Amadeus II Epikeratome  (Advanced Medical Optics, Santa Ana, CA, USA) III. Centurion SES Epikeratome  (Norwood Abbey Ltd., Melbourne, Australia)

3. Material & Method Sixteen eyes (8 patients) were included in this study Three epikeratomes were each used to collect four epithelial flaps from two patients in the Epi-LASIK procedure (n=12) Four epithelial flaps from two patients were also obtained by LASEK (n=4) Immunohistochemical staining monoclonal antibodies against Integrin ß1, Integrin ß4, Laminin 5, and Collagen type VII was performed

4. GroupSex(M/F)Age(years)Spherical EquivalentKeratometryPachymetry Group 1 (n=4)1/324.5 ± 2.6-4.34 ± 0.9143.75 ± 1.01548 ± 21 Group 2 (n=4)0/423.5 ± 2.5-3.16 ± 0.8343.14 ± 1.13532 ± 17 Group 3 (n=4)0/425.5 ± 4.0-4.25 ± 0.7944.19 ± 1.67542 ± 19 Group 4 (n=4)1/325.8 ± 2.8-3.25 ± 0.8643.64 ± 1.57532 ± 22 Material & Method Groups Group 1 : Moria Epi-K Epikeratome  Group 2 : Amadeus II Epikeratome  Group 3 : Centurion SES Epikeratome  Group 4 : LASEK

5. Results Immunohistochemical staining demonstrated expression of Integrin ß1 and Integrin ß4 in all epithelial flaps The expression of both Laminin 5 and Collagen type VII exhibited a linear or dotted pattern that differed based on the epikeratome used in Epi-LASIK. The expression of Laminin 5 and Collagen type VII exhibited a dotted pattern in the epithelial flaps obtained using LASEK

6. Results Immunohistochemical expression characteristicsa in epithelial flaps produced by various epikeratomes Integrin β1Integrin β4Laminin 5Collagen type VII Group No.Expression PatternExpressionPatternExpressionPattern 11yes, diffuse linear  yeslinearyeslinear and dotted (mixed) 2yes, diffuse linearyeslinearyeslinear and dotted (mixed) 3yes, diffuse linearyeslinear and dottedyeslinear and dotted (mixed) 4yes, diffuse linearyesdottedyes, focaldotted 25yes, diffuseyes, focallinearyes, focallinear, but focalyes, focallinear, but focal 6yes, diffuseyes, focallinearyes, focaldottednoNo 7yes, diffuse linearyesdottedyes, focaldotted 8yes, diffuse linearyeslinear and dottedyes, focaldotted 3 ９ yes, diffuse linearyeslinearyes, focallinear and dotted (mixed) 10yes, diffuse linearyeslinear, continuous and thickyeslinear, continuous and thick 11yes, diffuse linearyeslinear, continuous and thickyeslinear, continuous and thick 12yes, diffuse linearyeslinear, discontinuous and thickyeslinear, discontinuous and thick 413yes, diffuse linearyesdottedyes, focaldotted 14yes, diffuse linearyesdottedyes, focaldotted 15yes, diffuse linearyesdottedyes, focaldotted 16yes, diffuse linearyesdottedyes, focaldotted

7. Results Expression patterns of collagen type VII of epithelial flap ( immunochemical stain ) A. Dotted pattern B. Linear pattern C. Mixture of linear and dotted pattern

8. Results Immunochemical staining of Group 1 The staining of integrin ß1 is intercellular and pericellular in all epithelial cell layers of the epithelial flaps (A, B) The staining of integrin ß4 is found predominantly in the basal cell membrane of the epithelial flaps with linear pattern. The staining of laminin 5 is expressed by linear pattern and the staining of collagen type VII is expressed by mixed pattern (C, D)

9. Results Immunochemical staining of Group 2 The staining of integrin ß1 and integrin β4 is expressed by same pattern the epithelial flaps. But integrin β4 staining was focally present (A, B) The staining of Laminin 5 is expressed by dotted pattern and collagen type VII is not expressed at the same area (C, D)

10. Results Immunochemical staining of Group 3 The staining of integrin ß1 and integrin ß4 is expressed as like cases of other groups (A, B) The immunochemical stain of laminin 5 and collagen type VII is expressed linearly, continuously and thickly. In same area of epithelial flap, the stained area of Laminin 5 is located superiorly and the stained area of collage type VII is located inferiorly (C, D)

11. Immunochemical staining of Group 4 The staining of integrin ß1 and integrin ß4 is expressed as like cases of other groups (A, B) The immunochemical stain of laminin 5 and collagen type VII is expressed by dotted and focal pattern (C, D) Results

12. Conclusion Different epikeratomes may produce different cleavage planes and differences in the anatomical characteristics of the cleavage planes may influence the wound healing process after Epi-LASIK Repositioning of the epithelial flap appears to be ideal in Epi- LASIK using the Centurion SES Epikeratome  Discarding of the epithelial flap may be preferable in Epi-LASIK using the Amadeus II Epikeratome  However, because the role and fate of the basement membrane after Epi-LASIK are not yet known in detail, further investigations in a clinical setting or animal models are needed to elucidate the wound healing process after Epi-LASIK