Figure 1

(A) Corneal topography axial map showing the extent of the cone (red area); (B) Corneal topography posterior elevation map showing the location of the cone (arrow head); (C) A schematic drawing of the cutting corneal central and peripheral pieces; (1C1) The cornea was divided into two halves; (1C2) Before embedding, the halve of the cornea was divided into two quarters and each quarter was further divided into equal triangle; (1C3) Each triangular piece was cut from the middle into two pieces; (1C4) the conical central part; and (1C5) wider peripheral part. Approximately less than 2 mm distance (red colour) from center point and approximately less than 1 mm distance (red colour) from the margin was used to cut semithin (0.5 µm) and ultrathin (70 nm) sections. (D) Light micrograph of keratoconus cornea showing non-scarred region (NSCR) with a normal Bowman’s layer (BW) and scarred region (SCR) with a break in BW; (E,F) Electron micrograph of non-scarred region (NSCR) shown in Figure A, a normal healthy BW, hemi-desmosome and stroma; (G) Electron micrograph of non-scarred region showing a healthy keratocyte; (H) At the posterior part of the non-scarred region, undulation of the lamellae was present just above the Descemet’s membrane; (I,J) Electron micrograph of scar region (SCR) shown in Figure A, showing break in BW and presence of collagen fibrils below epithelium; (K) Light micrograph of a very large scar region with a BW break; L) Electron micrograph of a large scar region (shown in Figure J), showing breaks in the BW and the presence of CF in the sub-epithelial region. E = Epithelium, BW = Bowman’s layer, BBW = Break in BW, H = Hemi-desmosomes, KR = Keratocyte, S = Stroma, SCR = Scar region, NSCR = Non-scar region.