Rabbit corneas at two months, three months and four months after -9 diopters (D) photorefractive keratectomy (PRK). (A) At two months after -9D PRK, all the corneas had developed some clear areas called “lacunae” (arrows) within the confluent corneal haze in the excimer laser ablated zone (mag 25X). (B) At three months after -9D PRK, lacunae (arrows) had enlarged and began to coalesce in all corneas (mag 25X). (C) At four months after -9D PRK, corneal transparency was fully restored in all corneas (mag 25X). (D) At two months after -9D PRK, large numbers of α-SMA+ myofibroblasts (arrowheads) were present in the subepithelial stroma, although less than corneas at one month after PRK (mag 200X). (*) represents artifactual detachment of the epithelium from stroma that occurred during sectioning. (E) At three months after -9D PRK, there were few remaining α-SMA+ myofibroblast (arrowheads) in the subepithelial stroma within the excimer laser ablated zone (mag 200X). (F) At four months after -9D PRK, there were no remaining α-SMA+ myofibroblasts in the subepithelial stroma (mag 200X). (G) At two months after -9D PRK, transmission electron microscopy (TEM) of the excimer laser ablated zone showed areas of fully-regenerated EBM (arrows) with lamina lucida and lamina densa adjacent to areas without normal EBM (x) in all corneas at this time point (mag 23,000X). (H) At three months after -9D PRK, normal EBM (arrows) was regenerated in the excimer laser ablated zone in all corneas (mag 23,000X). (I) At four months after -9D PRK, normal EBM was regenerated in the excimer laser ablated zone in all corneas (mag 23,000X). (J) At 2 months after -9D PRK, large amounts of collagen type III (COL3, arrows) were detected in subepithelial stroma of the ablated zone of all corneas (mag 400X). The amount of COL3 in the subepithelial stroma appeared unchanged at three months (K) and four months (L) after -9D PRK (mag 400X). Blue is DAPI staining of cell nuclei; (e) epithelium; (s) stroma.