Failure of the cortical capillaris to nourish the outer retinal layers at the macula may be significant."[12] The therapy he used anticipates the use today of multivitamins in ARMD patients. A logical therapy since the problems arise from malnutrition, Ridley used multivitamin therapy, returned them to a normal diet and then noted improvement in the prisoners' condition. The Burma theatre of war permitted the first large population study of individuals with nutritional amblyopia: a total of over 500 within his region of whom about 200 he personally examined and treated.[12]