An ophthalmic treatment device , comprising: a treatment beam generation unit that is arranged to generate a treatment beam; a beam delivery unit that is arranged to configure a light path along which the treatment beam generated by the treatment beam generation unit radiates to a treatment area positioned at a fundus; a monitoring unit comprising an Optical Coherent Tomography, OCT, device and that is arranged to: radiate a detecting beam to the treatment area; and detect, by using Z-scan and without using separate B-scan, state information of the treatment area, in which the treatment beam is radiated, based on interference information of the detecting beam scattered or reflected from the treatment area, wherein only state information corresponding to a predetermined depth region of an entire depth region of the fundus is detected as the state information based on the interference information without processing the entire depth region of the fundus, wherein the predetermined depth region encompasses a retinal pigment epithelial (RPE) cell layer within the treatment area and an adjacent area; and a control unit that is arranged to control operation of the treatment beam generation unit based on the state information of the treatment area detected in the monitoring unit . a treatment beam generation unit that is arranged to generate a treatment beam; a beam delivery unit that is arranged to configure a light path along which the treatment beam generated by the treatment beam generation unit radiates to a treatment area positioned at a fundus; a monitoring unit comprising an Optical Coherent Tomography, OCT, device and that is arranged to: radiate a detecting beam to the treatment area; and detect, by using Z-scan and without using separate B-scan, state information of the treatment area, in which the treatment beam is radiated, based on interference information of the detecting beam scattered or reflected from the treatment area, wherein only state information corresponding to a predetermined depth region of an entire depth region of the fundus is detected as the state information based on the interference information without processing the entire depth region of the fundus, wherein the predetermined depth region encompasses a retinal pigment epithelial (RPE) cell layer within the treatment area and an adjacent area; and radiate a detecting beam to the treatment area; and detect, by using Z-scan and without using separate B-scan, state information of the treatment area, in which the treatment beam is radiated, based on interference information of the detecting beam scattered or reflected from the treatment area, wherein only state information corresponding to a predetermined depth region of an entire depth region of the fundus is detected as the state information based on the interference information without processing the entire depth region of the fundus, wherein the predetermined depth region encompasses a retinal pigment epithelial (RPE) cell layer within the treatment area and an adjacent area; and a control unit that is arranged to control operation of the treatment beam generation unit based on the state information of the treatment area detected in the monitoring unit . <EOS>