Immunofluorescence study of corneal wound healing after excimer laser anterior keratectomy in the monkey eye
D. S. Malley, R. F. Steinert, C. A. Puliafito and E. T. Dobi
Laser Research Laboratory, Massachusetts Eye and Ear Infirmary, Boston 02114.
We performed anterior keratectomies on six monkey eyes, four by excimer
laser large-area ablation at 193 nm and two by mechanical keratectomy.
Immunofluorescence was used to study the wound healing response
histopathologically. The distribution of fibrinogen, fibronectin, laminin,
collagen types III, IV, and VI, and keratan sulfate was determined at
postoperative intervals of 24 hours, 6 days, and 1 month. At 24 hours,
fibrinogen and fibronectin coated the ablated surface, but corneal
epithelial cells had not yet migrated over the wound. By 6 days and
persisting at 1 month, an epithelial ingrowth of seven to 10 layers, mild
stromal hypercellularity, and new collagen formation were present in the
repair region. At 1 month, fibrinogen, fibronectin, laminin, and type III
collagen were strongly detected in the repair region. Type VI collagen was
present in both normal and healed corneal stroma at all intervals, and type
IV collagen was present in Descemet's membrane only. Sulfated keratan
sulfate was absent from the newly synthesized collagen stroma at all
intervals. Slit-lamp photographs demonstrated corneal haze in the ablation
zone in all cases at 24 hours, persisting for 1 month. The fluorescence
patterns produced by excimer laser ablation and mechanical keratectomy were
qualitatively identical.
