Transforming growth factor β (TGF-β) plays an important role in anterior segment wound healing, by controlling the cell proliferation and differentiation, angiogenesis, extracellular matrix composition and mediating the immunosuppres-sive properties of the aqueous humor. The present study was undertaken to clarify the possible changes of aqueous humor TGF- β1 levels after excimer laser photoablation. Twenty-eight New Zealand rabbits were divided into four groups of 7 rabbits each. Group 1 served as control, the central 7 mm of corneal epithelium was removed in groups 2, 3 and 4. We performed 50-µm corneal photoablation in group 3, and 100-µm ablation in group 4. After 48 h we measured the TGF- β1 levels of the aqueous humor by ELISA method. The mean TGF- β1 value of the aqueous humor was found to be 162.94 ± 13.73 pg/ml in the control group. Mechanical deepithelialization did not change the TGF- β1 0.05), but the TGF-β1 levels of the 100-µm photoablated group were found to be significantly higher than those of both the control group and 50-µm photoablated group (p < 0.05). Many factors and cytokines may induce corneal haze and myopic regression after excimer laser photoablation; our study demonstrated that TGF- β1 is one of these factors and there is a positive correlation between the depth of corneal photoablation and aqueous TGF- β1