Table 1.

Summary of all the study subjects.

	Ungradable	Gradable	$P$ value
Training and primary validation dataset
No. of SDOCT volumes	1353	4246	—
No. of subjects	260	549	—
Gender (male/female)	139/121	229/320	0.002
Age, years ($\text{mean}\pm \mathrm{SD}$)	$63.2\pm 15.8$	$57.0\pm 17.1$	0.003
No. of eyes	402	1077	—
Eye (right/left)	222/180	533/544	0.050
External validation dataset 1 (PWH)
No. of SDOCT volumes	181	530	—
No. of subjects	80	227	—
Gender (male/female)	50/30	102/125	0.009
Age, years ($\text{mean}\pm \mathrm{SD}$)	$73.6\pm 10.5$	$68.3\pm 11.9$	0.367
No. of eyes	122	387	—
Eye (right/left)	60/62	204/183	0.497
External validation dataset 2 (TMEC)
No. of SDOCT volumes	60	238	—
No. of subjects	42	158	—
Age, years ($\text{mean}\pm \mathrm{SD}$)	$61.7\pm 14.5$	$60.7\pm 12.4$	0.177
Gender (male/female)	23/19	77/81	0.603
No. of eyes	60	234	—
Eye (right/left)	35/25	114/120	0.185

Note: OCT, optical coherence tomography; SD, standard deviation.

Unpaired $t$-test for numerical data and chi-square test for categorical data were used for comparison between ungradable and gradable groups. All the hypotheses tested were two-sided, and $p$-value <0.05 were considered to be significant which were values in bold.