Topical fibronectin in an alkali burn model of corneal ulceration in rabbits
T. M. Phan, C. S. Foster, C. D. Shaw, L. M. Zagachin and R. B. Colvin
Hilles Immunology Laboratory, Massachusetts Eye and Ear Infirmary, Boston.
We studied the effect of topical fibronectin on epithelial wound healing
and ulceration in alkali-burned rabbit corneas. After the first 56 hours,
fibronectin accelerated complete surface reepithelialization to 4.3 +/- 2.3
days. Control alkali-burned corneas treated with phosphate-buffered saline
or albumin did not resurface for 6.7 +/- 3.7 days and 6.2 +/- 2.5 days,
respectively. When recurrent epithelial defects occurred, the time required
for healing was also significantly accelerated by fibronectin treatment.
Corneal ulceration developed in 25 of 28 and 15 of 18 saline and
albumin-treated control eyes, respectively; only nine of 18
fibronectin-treated eyes ultimately ulcerated. Immunohistologic studies
showed that the initially deposited fibronectin-fibrinogen matrix on the
surface of burned corneas had disintegrated by 72 to 96 hours after
wounding, corresponding clinically to the time of secondary epithelial
breakdown. A prominent fibronectin-fibrinogen matrix remained on the
surface of fibronectin-treated corneas, presumably aiding surface
reepithelialization and decreasing corneal ulceration.
