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A total of 37 eyes from 22 patients with BCD (8 males and 14 females), who were diagnosed by genetic examinations, and 37 eyes from 22 healthy subjects (8 males and 14 females) were included in the analysis. However, 7 eyes from 7 patients had to be excluded due to the inability to obtain sufficient quality scans. The mean age was 40.6 ± 11.2 years (range: 26–66 years) for patients with BCD and 40.8 ± 11.6 years (range: 24–65 years) for healthy subjects (P = 0.958). BCVA was also noted to be 0.6 ± 0.9 and 0.0 ± 0.0 logMAR in the BCD and control groups, respectively (P < 0.001). All subjects were Chinese and did not have glaucoma or systemic disease, with normal intraocular pressure (IOP) levels.
RPC densities of 13 eyes from 7 Stage 2 patients with BCD (2 males and 5 females) and 24 eyes from 15 Stage 3 patients with BCD (6 males and 9 females) were compared. The mean age was 43.571 ± 11.631 years for Stage 2 patients with BCD and 39.267 ± 11.094 years for Stage 3 patients with BCD (P = 0.413).
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RPC densities of the whole image, inside disk region, peripapillary region, superior-hemi region, inferior-hemi region and the S, N, I, and T quadrants were 45.9% ± 3.6%, 38.8% ± 6.3%, 49.1% ± 4.7%, 49.1% ± 5.3%, 49.2% ± 4.5%, 48.7% ± 6.8%, 51.2% ± 5.7%, 53.1% ± 6.2%, and 44.8% ± 4.4%, respectively, in the BCD group and 50.7% ± 3.0%, 49.2% ± 6.1%, 54.1% ± 3.0%, 54.6% ± 3.0%, 53.6% ± 3.4%, 57.1% ± 3.6%, 57.7% ± 3.3%, 56.5% ± 4.1%, and 47.7% ± 4.7%, respectively, in the control group (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P = 0.006, and P = 0.008, respectively). Meanwhile RPC densities in the NS, NI, IN, IT, TI, TS, ST, and SN sectors of the peripapillary region were 46.0% ± 6.1%, 43.1% ± 4.9%, 48.3% ± 6.4%, 55.0% ± 6.2%, 52.3% ± 6.8%, 53.8% ± 6.3%, 50.3% ± 7.0%, and 47.3% ± 7.6%, respectively, in the BCD group and 49.3% ± 5.0%, 45.8% ± 5.0%, 55.1% ± 3.8%, 60.9% ± 3.8%, 55.2% ± 4.8%, 57.5% ± 4.7%, 59.7% ± 3.5%, and 55.0% ± 4.4%, respectively in the control group (P = 0.012, P = 0.022, P < 0.001, P < 0.001, P = 0.036, P = 0.005, P < 0.001, and P < 0.001, respectively). Overall, the RPC density was significantly lower in the BCD group than in the control group (Table 1).
Variables BCDs (n = 22) Controls (n = 22) P value* Sex (male/female) 8/14 8/14 − Age 40.636 ± 11.176 40.818 ± 11.583 − Eye (right/left) 18/19 18/19 − Signal strength 6.054 ± 1.699 8.405 ± 0.985 < 0.001 RPC vessel density (%) Whole image 45.935 ± 3.609 50.695 ± 2.989 < 0.001 Superior-Hemi 49.054 ± 5.375 54.622 ± 3.076 < 0.001 Inferior-Hemi 49.135 ± 4.492 53.647 ± 3.393 < 0.001 Superior 48.676 ± 6.836 57.081 ± 3.631 < 0.001 Inferior 51.297 ± 5.739 57.703 ± 3.290 < 0.001 Tempo 53.054 ± 6.200 56.514 ± 4.134 0.006 Nasal 44.811 ± 4.427 47.703 ± 4.701 0.008 Inside Disk 38.800 ± 6.281 49.162 ± 6.135 < 0.001 Peripapillary 49.119 ± 4.692 54.149 ± 3.014 < 0.001 Nasal Superior 45.954 ± 6.108 49.292 ± 5.015 0.012 Nasal Inferior 43.146 ± 4.902 45.841 ± 5.006 0.022 Inferior Nasal 48.300 ± 6.372 55.076 ± 3.802 < 0.001 Inferior Tempo 54.997 ± 6.216 60.930 ± 3.822 < 0.001 Tempo Inferior 52.268 ± 6.787 55.208 ± 4.860 0.036 Tempo Superior 53.751 ± 6.339 57.532 ± 4.680 0.005 Superior Tempo 50.278 ± 7.057 59.722 ± 3.482 < 0.001 Superior Nasal 47.311 ± 7.603 55.024 ± 4.376 < 0.001 Note. *Analyzed using Student's t-test. RPC: radial peripapillary capillary; BCD: Bietti crystalline dystrophy. Table 1. Demographic characteristics and the data of RPC density between the BCD and control groups
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RPC densities of the whole image, inside disk region, peripapillary region, superior-hemi region, inferior-hemi region, and the S, N, I, and T quadrants were 48.5% ± 2.8%, 38.5% ± 7.8%, 53.7% ± 3.0%, 53.5% ± 3.3%, 52.8% ± 3.2%, 55.0% ± 5.1%, 56.3% ± 3.3%, 54.9% ± 4.4%, and 48.1% ± 2.7%, respectively, in the Stage 2 patients with BCD and 44.6% ± 3.3%, 40.0% ± 5.5%, 54.4% ± 3.0%, 46.7% ± 4.7%, 47.1% ± 3.8%, 45.3% ± 5.0%, 48.6% ± 5.0%, 52.0% ± 6.8%, and 43.0% ± 4.2%, respectively, in the Stage 3 patients with BCD (P = 0.001, P =0.817, P = 0.491, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P = 0.181, and P < 0.001). Meanwhile, RPC densities in the NS, NI, IN, IT, TI, TS, ST, and SN sectors of the peripapillary region were 49.6% ± 3.9%, 46.3% ± 4.1%, 53.7% ± 3.3%, 59.9% ± 3.5%, 54.0% ± 5.3%, 55.6% ± 4.0%, 56.1% ± 5.0%, and 54.1% ± 6.1%, respectively, in the Stage 2 patients with BCD and 44.0% ± 6.2%, 41.5% ± 4.5%, 45.4% ± 5.8%, 52.4% ± 5.8%, 51.3% ± 7.4%, 52.7% ± 7.2%, 47.1% ± 6.0%, and 43.6% ± 5.5%, respectively, in the Stage 3 patients with BCD (P = 0.006, P = 0.003, P < 0.001, P < 0.001, P = 0.261, P = 0.186, P < 0.001, and P < 0.001).
There were no significant differences in the RPC density of the tempo, inside Disk, Peripapillary, tempo Inferior, and tempo Superior regions between Stage 2 and Stage 3 subgroup. In contrast, the other areas showed significantly lower RPC densities in the Stage 3 subgroup than in the Stage 2 subgroup (Table 2).
Variables Stage 2 (n = 7) Stage 3 (n = 15) P value* Sex (male/female) 2/5 6/9 − Age 43.571 ± 11.631 39.267 ± 11.094 0.413 Eye (right/left) 7/6 11/13 − Signal strength 6.000 ± 1.581 6.083 ± 1.791 0.889 RPC vessel density (%) Whole image 48.454 ± 2.805 44.571 ± 3.279 0.001 Superior-Hemi 53.462 ± 3.332 46.667 ± 4.743 < 0.001 Inferior-Hemi 52.846 ± 3.158 47.125 ± 3.791 < 0.001 Superior 55.000 ± 5.066 45.250 ± 4.989 < 0.001 Inferior 56.308 ± 3.308 48.583 ± 4.986 < 0.001 Tempo 54.923 ± 4.425 52.042 ± 6.849 0.181 Nasal 48.077 ± 2.660 43.042 ± 4.206 < 0.001 Inside Disk 38.469 ± 7.804 39.979 ± 5.467 0.817 Peripapillary 53.677 ± 3.042 54.404 ± 3.031 0.491 Nasal Superior 49.592 ± 3.936 43.983 ± 6.227 0.006 Nasal Inferior 46.269 ± 4.117 41.454 ± 4.503 0.003 Inferior Nasal 53.715 ± 3.325 45.367 ± 5.677 < 0.001 Inferior Tempo 59.885 ± 3.469 52.350 ± 5.777 < 0.001 Tempo Inferior 53.992 ± 5.291 51.333 ± 7.409 0.261 Tempo Superior 55.639 ± 4.026 52.729 ± 7.165 0.186 Superior Tempo 56.077 ± 4.958 47.138 ± 5.980 < 0.001 Superior Nasal 54.108 ± 6.111 43.629 ± 5.545 < 0.001 Note. *Analyzed using Student's t-test. RPC: radial peripapillary capillary. Table 2. Demographic characteristics and the data of RPC density between the Stage 2 and Stage 3 subgroup
B-scan showed that the signals of the RPE, ellipsoid zone layer, and part of the retinal outer nuclear layer around the optic disk in BCD were lost. Moreover, the outer plexus, inner nuclear, inner plexus, and ganglion cell layers were disordered. As a result, the retina of advanced patients with BCD was atrophied and thinned.
Analysis of Radial Peripapillary Capillary Density in Patients with Bietti Crystalline Dystrophy by Optical Coherence Tomography Angiography
doi: 10.3967/bes2022.015
- Received Date: 2021-03-09
- Accepted Date: 2021-09-14
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Key words:
- Bietti crystalline dystrophy /
- Optical coherence tomography angiography /
- Radial peripapillary capillary
Abstract:
Citation: | ZHANG Sheng Juan, WANG Li Fei, XIAO Zhe, LIU Zhi Qiang, XING Chen, LI Qian, SUN Hui Jing, YANG Zan Zhang, LYU Li Na, PENG Xiao Yan. Analysis of Radial Peripapillary Capillary Density in Patients with Bietti Crystalline Dystrophy by Optical Coherence Tomography Angiography[J]. Biomedical and Environmental Sciences, 2022, 35(2): 107-114. doi: 10.3967/bes2022.015 |