Js. Kim et al., Amniotic membrane patching promotes healing and inhibits proteinase activity on wound healing following acute corneal alkali burn, EXP EYE RES, 70(3), 2000, pp. 329-337
Amniotic membrane (AM) contains basement membrane components and various pr
oteinase inhibitors. Furthermore, when used as a graft, the basement membra
ne of AM could block inflammatory insults to a damaged corneal surface. Thu
s, we evaluated whether amniotic membrane patching could promote the healin
g process by inhibiting proteolytic damage. Alkali wounds were inflicted on
the central corneas of rabbits by applying a round filter paper, 6.0 mm in
diameter. soaked in 1 N NaOH for 30 sec. Amniotic membrane patching was pe
rformed over the perilimbal sclera immediately after wounding. A total of 1
15 rabbits were divided into four groups: (1) immediately covered by AM wit
h the amnion cell side down up to the perilimbal sclera (n = 26): (2) cover
ed by AM with the stromal side down up to the perilimbal sclera (n = 19): (
3) anchored to the fornix (n = 29); and (4) uncovered as a control (n = 41)
. AM was removed 3 days postoperatively. During follow-ups, epithelial defe
cts, corneal thickness and its opacity of each eye were measured. Some corn
eas were removed for histopathologic studies and for proteinase activity ar
:say and zymography. The epithelial healing was faster and the corneal thic
kness was thicker in all three AM-covered groups than in the control (P < 0
.05). No significant difference was found between covered and anchored grou
ps (P > 0.05). Corneal opacity was least in the amnion cell side down group
, infiltration of polymorphonuclear leukocytes (PMNs) was much less in AM-c
overed groups than in the control. Pathological results were associated wit
h zymographic findings, which revealed much higher proteinase activity in u
ncovered group than AM-covered groups. Immediate intervention for acute alk
ali burns with AM as a temporary patch promotes wound healing by inhibiting
proteinase activity and PMNs infiltration. (C) 2000 Academic Press.