[Histochemical investigation of acid mucopolysaccharides in corneal wound healing of lamellar corneal grafts].

Histochemical investigations were carried out in a series of toluidine blue preparations of pH 3.8-5.2 of unfixed frozen corneal sections of lamellar keratoplasties in rabbit eyes to show alterations in the pattern of acid mucopolysaccharides during wound healing. The metachromasia in lamellar auto- and homokeratoplasties is mainly reduced in the region of the vertical host-graft junction. When using virgin silk the zone of reduced metachromasia in the vertical junction is broader compared with a 9/0-Nylon suture. The metachromasia of the lamellar transplant becomes normal in autokeratoplasties (Table 1) after a fortnight and in homokeratoplasties after 3 weeks; otherwise the metachromasia during the wound healing shows no significant difference in auto- and homokeratoplasties. The normal pattern of mucopolysaccharides in the corneal stroma does not return in the vertical host-graft junction, but this scar becomes smaller over a period of time (Fig. 3, 4, 5). There are no significant alterations of metachromasia found in the horizontal host-graft junction during wound healing between 1 day and 6 months, but starting from the 7th day after the lamellar keratoplsty using PAS-stain a small more PAS-intensive coloured line in the horizontal host-graft junction which is still there 6 months after the operation (Fig. 1, 2). When the 9/0 Nylon suture remains for 3 months, corneal vascularisation develops predominantly in the horizontal junction between host and lamellar graft. The graft becomes cloudy and the metachromasia remains reduced as long as 9 months after the suture has been removed (Table 2).