Bowman’s Layer and Epithelial Basement Membrane Restoring After Keratectomy in Hens

Abstract

Methods: : Sixteen adult lohmann classic hens (32 eyes) were used. A mechanical deepithelization was made in a pre-marked area of 7 mm of diameter. PRK was performed in a 5.0-mm diameter optical zone and received -5.00 D of treatment (63 µm) using a Summit excimer laser. Animals were allowed to heal for up to 6 months and euthanized in different time points (15, 30, 90 and 180 days). The pattern of basement membrane and Bowman’s layer restoration was studied by means of laminin expression with indirect immunofluorescence microscopy, Periodic Acid of Schiff (PAS), Massons Thicrome (MT) and Transmission Electronic Microscopy (TEM). In addition, expression of -SMA indicative of myofibroblast was evaluated by indirect immunofluorescence microscopy.

Results: : Presence of both full-restored basement membrane and presence of myofibroblast never were found together in any cornea and time point studied. In the peripheral areas, where tissue was not ablated, presence of basement membrane was found but myofibroblast were not observed. At one month, presence of new basement membrane was observed in an interrupted pattern in the center of the cornea where presence of both myofibroblast and new matrix deposits. At the third month the basement membrane appears full restored along with new matrix under the epithelium but myofibroblast were not observed already. Six months after surgery, both basement membrane and Bowman’s layer were seen full restored.

Keywords: cornea: epithelium • cornea: stroma and keratocytes • cell adhesions/cell junctions