Table 2.

Arden colour vision test in retinopathy

Test results	Mild retinopathy	Advanced retinopathy	Normals
Protan axis “abnormal”	8	3	6
Protan axis “normal”	29	1	45
	Sensitivity 22%	Sensitivity 75%	Specificity 88%
Tritan axis “abnormal”	22	4	17
Tritan axis “normal”	15	0	34
	Sensitivity 60%	Sensitivity 100%	Specificity 67%
Acquired colour defect	[3]	1	3
No acquired colour defect	[31]		44
	[Sensitivity 10%]*	*	Specificity 94%

Sensitivity and specificity of the computerised Arden colour test to screen for chloroquine retinopathy.

*Cannot be assessed validly due to the low patient number.