Optimal Concentration of hEGF for Epithelial Healing in Experimental Corneal Alkali Wounds

PURPOSE: An optimal concentration of hEGF to enhance epithelial healing was determined in the rabbit eyes after alkali wounds. METHODS: Alkali-injured corneas (=5.5 mm, 1N NaOH, 60s) were treated with 0 (control), 2, 5, 10, and 50microgram/ml hEGF 3 times per day. The measurement of epithelial healing rate, transmission electron microscopy and immunohistochemical observation were performed after 7 days treatment. RESULTS: No significant difference was observed in the rates of epithelial healing between control and each hEGF-treated group. Among the tested concentrations, 5microgram/ml hEGF induced the most active proliferation of basal cells and 50microgram/ml hEGF remarkably produced a vascular ingrowth to the central wound area. The number of epithelial layers was increased by hEGF in a concentration-dependent manner. CONCLUSIONS: A low concentration of hEGF may selectively enhance epithelial healing without inducing corneal neovascularization. The optimal concentration of hEGF for the stimulation of basal cell proliferation appears to be 5 microgram/ml in rabbit corneal alkali wounds.

Effects of 0.1% Dexamethasone on Experimental corneal Epithelial Healing Following Alkali Wounds

The effect of topical steroid on corneal alkali wound has been controversial due to a complexity of its mechanism and a risk of ulceration and perforation. In this study, the effect of topical 0,1% dexamethasone on corneal epithelial wound healing following alkali burn was evaluated quantitatively. 22 eyes wounded by alkali burn out of 22 white rabbits were divided into 3 groups ; A group treated with topical 0.1% dexamethasone for eight weeks, B grouptreated with topical 0.1% dexamethasone for the first one week followed by another seven weeks without treatment, C group with no treatment served as a control. The area of corneal epithelial defect was examined at 6, 18, 30, 42 hours following corneal alkali wound for initial wound healing and examined every other day from 4 days to 48 days following corneal alkali wound for late wound healing. In this study, it was found that topical 0.1% dexamethasone delayed corneal epithelial healing following corneal alkali burn in both stage of initial and late wound healing.

The Therapeutic Effect of Topically Applied 1% Sodium Hyaluronic Acid(Na-HA) on Corneal Alkali Burn

The effects of topically applied 1% Na-HA on corneal epithelial healing and visual outcomes were evaluated in 15 eyes of 12 corneal alkali-burned patients. 1 % Na-HA (Healon, Pharmacia, Sweden) together with antibiotics(Tarivid eye oint, Japan) in the treatment group and antibiotics ointment alone in the control group were given four times a day for the first one week and then antibiotics were used in both groups. For the assessment of the initial epitheilal healing, the eyes were examined at about 8 to 12 hours intervals during the first week. Individual epithelial healing rates were calculated by a linear regresion analysis from the epithelial defect areas. The best corrected visual acuity was compared between two groups. Initial epithelial healing rates were 0.81+/-0.53(mm2/hour) in the 1% Na-HA treated group and 0.40+/-0.21(mm2/hour) in the control group, respectively. A progressive improvement of visual acuity was observed in the 1% Na-HA treated group, while no change of vision was found in the control group. This clinical study suggests that topical application of 1 % Na-HA in combination with topical antibiotics could be considered for the management of corneal alkali wound.