Confocal scanning laser ophthalmoscope imaging superimpose two or three kinds of lasers to obtain images of different layers of retina, and then synthesize a pseudo-color fundus image by computer. Confocal scanning laser ophthalmoscope is widely used in outpatient fundus pre-examination and epidemiological screening of large samples due to its features of non-mydriatic, fast imaging, simple operation and high degree of patient cooperation. It has good clinical and scientific application value in the diagnosis and treatment of a variety of fundus diseases. Because of there is still a lack of unified standards for laser fundus photos in China, it is necessary to correctly identify the common fundus lesions in confocal scanning laser ophthalmoscope and to summarize and popularize the method of reading the photos in layers. In addition, we should give full play to the its advantage of layering and locating, and reasonably choose the combination of OCT, OCT angiography, FFA, ICGA, ultrasonography, so as to maximize its clinical application value and help clinical diagnosis.
ObjectiveTo observe the imaging characteristics of optical coherence tomography angiography (OCTA) and the changes of choroidal capillary density (CCD) in the eyes of patients with high myopia choroidal neovascularization (mCNV). MethodsA case-control study. From January 2018 to October 2020, 50 cases of mCNV patients with 50 eyes (mCNV group) were included in the study. There were 18 males and 32 females; their age was 42.11±11.66 years old. Fifty eyes of 50 patients with normal fundus with matching myopia refractive power (≥6.00 D) were selected as the simple high myopia group, and 50 normal volunteers (refractive power －0.25-0.25 D) while 50 eyes were selected as the normal control group. There was no statistically significant difference in age (F=0.028) and gender composition ratio (χ2=0.136) among the three groups of patients (P＞0.05); the difference in best corrected visual acuity was statistically significant (F=14.762, P=0.004). Compared with mCNV group and pure high myopia group, the refractive index (t=－0.273) and axial length (t=0.312) of the examined eyes were not statistically significant (P＞0.05). OCTA instrument was used to measure the CCD in the macular area of the examined eye. Analysis of variance was used for comparison of measurement data among the three groups; χ2 test was used for comparison of categorical variables. The paired t test was performed to compare the CCD of the mCNV patient's eye and the contralateral eye. ResultsAmong the 50 eyes in the mCNV group, Ⅰ, Ⅱ, and mixed choroidal neovascularization (CNV) were 12 (24%, 12/50), 34 (68%, 34/50), and 4 (8%, 4/50) eyes, respectively. Corresponding to the OCTA cross-sectional image of the lesion, there was a clear “flower cluster”-like strong blood flow signal. Among them, the focal shape, the filament shape, and the group net shape were 6 (12%, 6/50), 8 (11%, 8/50), and 36 (72%, 36/50) eyes, respectively. The CCD of the eyes in the mCNV group, the pure high myopia group, and the normal control group were (57.39±3.24)%, (59.33±2.23)%, and (61.87±1.62)%, respectively. The CCD of the eyes in the mCNV group was significantly lower than that of the simple high myopia group (P=0.030) and the normal control group (P＜0.001). The CCD of the affected eye and the contralateral eye in the mCNV group were (57.39±3.24)% and (59.82±3.94)%, respectively; there was no statistically significant difference between the CCD of the affected eye and the contralateral eye (t=－0.496, P=0.100). The CCDs of eyes with Ⅰ, Ⅱ and mixed CNV were (57.38±3.31)%, (57.39±2.83)%, and (57.36±4.21)%, respectively. There were no statistically significant differences in CCD (F=1.476), age (F=0.274), sex ratio (χ2=0.825), and diopter (F=0.348) in different CNV types (P＞0.05). ConclusionThe mCNV is mostly type Ⅱ, and OCTA has a "bloom" appearance of abnormal reticular blood vessels; the CCD is significantly reduced, and it is bilateral.