This time, important structures, such as the cornea, iris, scleral spur, and trabecular meshwork of the anterior segment angle were successfully imaged in all subjects of the anterior segment angle and the SCs could be determined in 95.9% of them. The location and shape of SC in our study coincide with the histological result.21 This high success rate might be contributed to several reasons. Firstly, the system adopts a light source of 1310 nm, which has a better penetration and SNR than the 870 nm one for the image of the anterior segment of human eye. Consequently, high-quality images can be obtained. Secondly, a horizontal mechanical structure was introduced to the system, where patients can be examined just laying in bed, and thereby reducing the influence of body shaking during the examination. This design not only increases the “comfort level” to improve the patients’ cooperation, allowing the old POAGs to keep the eye position steady during imaging, but also gives the operators more time to search SC, so as to increase the success rate of the imaging. Besides, we have carefully calibrated the axial and transverse scan ranges at first, which eliminates the measurement error caused by the refractive index. Finally, the system can realize video-level data acquisition, data processing, and display by using a GPU. The real-time observations of the anterior segment of the eyes came true. Operators can observe the sectional structure easily. There are still six positions from six eyes, in which SC can not be distinguished clearly. The first might be the age. Previous research indicated that the sclera become thicker with the ageing process. Moreover, the sclera is thickest at corneoscleral limbus, where SC is located. This might reduce the penetration of scanning light in elder subjects. Two undiscerning SCs are from eyes of the oldest two subjects in the normal group (71 and 74 years old), though there is no significant statistical difference between the ages of these two subject and other normal (Mann-Whitney Test , ). The other reason might be the pathological damage of POAG. The SCs might have collapsed due to the prolonged elevation of IOP. Histological research indicated that the collapsing of SC in POAG eyes is not uncommon. Also in the histo-study, it was found that the SC in some POAG eyes was difficult to discern.7 So, we deduced the absence of the SC on the OCT image might be the result of the collapsing of SC.