THE EFFECT OF INTRAVITREAL INJECTION OF ATROPINE ON THE PROLIFERATIONOF SCLERAL CHONDROCYTE IN-VIVO

Atropine was found to be effective in arresting the progression of myo pia. However, the actual mechanism is still unclear. Thus, we tried to investigate the in vivo effect of atropine on the proliferation of sc leral chondrocytes in chicks of form-deprivation myopia. Twenty chicks were equally divided into 4 groups which included intravitreal inject ion of normal saline (IVN), IVN with goggling (IVNG), intravitreal inj ection of atropine (1%) (IVA), and IVA with goggling (IVAG) groups. In travenous injection of bromodeoxyuridine (BrdU) (30 mg/kg) from subaxi llary vein was performed 2 hours before being sacrificed. The eyeballs were then fixed in 10% neutral-buffered formalin at 4 degrees C. Stan dard BrdU immunohistochemical staining was performed. The BrdU labelin g index was obtained from the average of positive labelings of BrdU in scleral chondrocytes for every 100 counting cells in posterior poles and anterior scleral margins by two experienced technicians. The BrdU index on the anterior scleral margin of the NAG group was less than th at of the IVNG group. The index on the anterior scleral margin of the IVNG group was higher than the NN group. Although the index on the pos terior poles of the IVNG group was also higher than the IVN group, it was statistically not different. Also, no statistical difference was f ound between IVN and IVA on the anterior scleral margins or posterior poles. The index was significantly different on the anterior scleral m argins, but not on the posterior pole among each group. Therefore, int ravitreal injection of atropine could inhibit the proliferation of cho ndrocytes on the anterior margins of sclera, but not the posterior pol es in form-deprivation myopia.