Univariable comparison of clinical and ocular characteristics among circular gamma (c-Gamma), temporal gamma (t-Gamma) and inferior gamma zone (i-Gamma)
| i-Gamma (n=67) | t-Gamma (n=86) | c-Gamma (n=17) | Comparison among three groups* | Comparison between two groups | |||
| i-Gamma versus t-Gamma | i-Gamma versus c-Gamma | t-Gamma versus c-Gamma | |||||
| Age (years） | 60±6.3 | 61.0±7.8 | 68.7±9.3 | 0.003 | 0.37 | 0.002 | <0.001 |
| Sex (male/%) | 29/43.3 | 56/65.1 | 8/47.1 | 0.021 | 0.007 | 0.779 | 0.161 |
| Axial length (mm) | 24.2±1.4 | 24.7±1.4 | 26.3±1.3 | <0.001 | 0.04 | <0.001 | 0.001 |
| Refractive error (diopter) | −2.4±2.6 | −3.0±3.2 | −5.8±3.9 | <0.001 | 0.16 | <0.001 | 0.002 |
| IOP (mm Hg) | 14.9±2.9 | 15.3±2.8 | 14.0±2.9 | 0.24 | 0.48 | 0.24 | 0.093 |
| BMO area (mm2) | 2.4±0.4 | 2.4±0.5 | 3.2±1.0 | 0.01 | 0.97 | 0.006 | 0.006 |
| Disc-fovea angle (°) | 8.9±4.1 | 6.3±3.4 | 10.7±4.0 | <0.001 | <0.001 | 0.23 | 0.001 |
| PCT (μm) | 125±30 | 126±42 | 92±20 | <0.001 | 0.77 | <0.001 | <0.001 |
| LC depth (μm) | 455±78 | 439±107 | 417±123 | 0.33 | 0.27 | 0.24 | 0.46 |
| PPSA 7–1 (°) | 6.1±6.1 | 6.3±5.5 | 18.1±7.0 | <0.001 | 0.79 | <0.001 | <0.001 |
| PPSA 8–2 (°) | 6.6±4.8 | 6.0±5.8 | 17.1±8.1 | <0.001 | 0.51 | <0.001 | <0.001 |
| PPSA 9–3 (°)† | 6.9±6.3 | 6.1±5.8 | 18.1±8.1 | <0.001 | 0.39 | <0.001 | <0.001 |
| PPSA 10–4 (°) | 6.5±6.5 | 7.0±5.1 | 24.4±8.9 | <0.001 | 0.59 | <0.001 | <0.001 |
| PPSA 11–5 (°) | 5.8±7.0 | 6.7±6.6 | 21.7±9.6 | <0.001 | 0.42 | <0.001 | <0.001 |
| PPSA 6–12 (°)‡ | 4.7±6.6 | 6.3±6.4 | 20.0±8.6 | <0.001 | 0.13 | <0.001 | <0.001 |
| Mean PPSA (°) | 6.1±5.5 | 6.4±4.9 | 19.9±7.2 | <0.001 | 0.69 | <0.001 | <0.001 |
| Gamma zone width (μm) | 308±164 | 301±185 | 618±226 | <0.001 | 0.8 | <0.001 | <0.001 |
PPSA 7–1 represents the PPSA at the scan starting from 7 o’clock to 1 o’clock. Similar for PPSA 8–2, 9–3, 10–4, 11–5 and 6–12.
*For comparison among eyes with i-Gamma, t-Gamma and c-Gamma, one-way ANOVA was used for the continuous variables while χ2 test was used for the categorical variables.
†The PPSA 9–3 is the horizontal PPSA.
‡The PPSA 6–12 is the vertical PPSA.
ANOVA, analysis of variance; BMO, Bruch’s membrane opening; IOP, intraocular pressure; LC, lamina cribrosa; PCT, peripapillary choroidal thickness; PPSA, peripapillary scleral angle.