Chemical eye injury is accompanied by decrease in the antioxidant protection system as well as activation of the free radical lipid peroxidation. To the best of our knowledge, no studies have been done on the effect of Malaysian honey on the eye.
In this study, the honey treatment is noted to be as good as the conventional treatment in treating the conjunctival hyperemia, corneal edema and epithelial healing due to alkali chemical injury. In a study by Alio et al  antioxidant topical treatment with Dimethythiourea has been found to be efficient in reducing inflammatory reactions during acute corneal inflammation.
Hallberg and his colleagues  suggested that free radicals delay the corneal epithelial wound healing in rabbits. This was evidenced by improvement in the epithelial defect in diabetic rats treated with Trolox antioxidant when compared with that of untreated diabetic rats. However the corneal epithelial wound induced was only 3 mm. This current study revealed that the honey treated group is as good as the conventional treated group in the healing process of corneal epithelial defect.
In the histolopathological evaluation, there was only mild corneal infiltration by PMN in all the rabbits. This shows that the honey treatment has the anti-inflammatory component comparable to that of the conventional treatment. Our results are supported by the study by Öztürk et al . In that study the degree of inflammatory cell infiltration was significantly lower in the group treated with topical dexamethasone and also the one treated with Propolis. However the strength of the NaOH used was 1 N and the exposure time was only 30 seconds. They also noted no statistically significant difference between those two groups as in this study. As a conclusion, they agreed that Propolis has an anti-inflammatory component comparable to dexamethasone in chemical corneal injury.
Study by Pfister et al  demonstrated that daily subcutaneous injection of ascorbic acid had significantly raised the plasma ascorbic acid level greater than that of the control. Moreover the level of ascorbic acid in the aqueous humour has increased as well. However the groups treated with topical ascorbic acid showed higher levels of ascorbic acid. This explains that the transport of parenteral ascorbic acid had slower access to cross the blood-aqueous barrier.
Pfister's study showed increment in the mean level of ascorbic acid in the aqueous humour with 35 seconds of chemical burn exposure with 1 N NaOH . However the increment in the ascorbic acid level was noted to be less than his previous study in 1977 where the chemical injury was induced with an exposure of 20 seconds . The characteristic of antioxidant activity of ascorbic acid is measured as total antioxidant status.
In this current study, the concentration of NaOH used was 2 N and the exposure time was 60 seconds. The concentration of total antioxidant status was noted to be higher in the honey treated group when compared with the conventional treated group in the aqueous humour and serum. However the total antioxidant status in the vitreous humour was lower in the honey treated group. But those results were statistically not significant.
Total antioxidant activity in the aqueous humour, vitreous humour and retina was noted to be higher in the groups treated with oral antioxidants and topical anti-inflammatory drugs when compared with the control group where only topical anti-inflammatory drugs were given. This denotes that oral supplement can increase the antioxidant capacity in eye tissues of rabbits .
In the same study, the concentration of MDA in the aqueous humour, vitreous humour and retina has also been explored. As expected, the MDA concentration was lower in the groups treated with oral antioxidants, post induction of alkali chemical injury . The concentration of MDA and total antioxidant status were inversely related i.e. if the concentration of the MDA is high, the total antioxidant status will be less and vice versa.
In this current study, the concentration of MDA was inversely related when compared between the two groups. For example if the total antioxidant status of aqueous humour is more in the honey treated group, the concentration of MDA will be less in this group when compared with that of the conventional group. The lower value of lipid peroxidation products in honey treated group clearly denotes the protective role of honey as an antioxidant against the oxidative stress induced by the alkali chemical injury. This correlates with the study by Gakhramanov . However the method of chemical eye injury induced in that study was not mentioned.
Schramm and colleagues  have concluded that oral administration of honey can increase the plasma antioxidant level. In their study, honey fed at 1.5 gm/kg body weight found to raise the plasma antioxidant level. Oxidative stress was not induced in their study. In this current study, the honey treated group showed higher plasma antioxidant level than the conventional group. However the dose was only 1.0 gm/kg and the oxidative stress was induced by means of alkali chemical injury.
In this study, we found that there was no clinical sign of infection with the absence of eye discharge in all of the eyes with alkali chemical injury in honey treated group as well as in conventional treated group. Although honey has a high content of sugar but it has a low content of water, together with acidity property . These characteristics will prevent microbial growth. Honey also will generate hydrogen peroxide when diluted [30, 31] and this hydrogen peroxide is the major contributor to the antimicrobial activity [30, 32].