Recent research by Krystel R. Huxlin and others on the relearning of complex visual motion following V1 damage has offered potentially promising treatments for individuals with acquired cortical blindness. These treatments focus on retraining and retuning certain intact pathways of the visual cortex which are more or less preserved in individuals who sustained damage to V1. Huxlin and others found that specific training focused on utilizing the "blind field" of individuals who had sustained V1 damage improved the patients ability to perceive simple and complex visual motion. This sort of relearning therapy may provide a good workaround for patients with acquired cortical blindness in order to better make sense of the visual environment. See also
Blindsight

References
Further reading
Books
Vighetto, A., & Krolak-Salmon, P. (2007). Cortical blindness. New York, NY: Cambridge University Press. Papers
Balliet, R., Blood, K. M., & Bach-y-Rita, P. (1985). Visual field rehabilitation in the cortically blind? : Journal of Neurology, Neurosurgery & Psychiatry Vol 48(11) Nov 1985, 1113-1124. Trevethan, C. T., & Sahraie, A. (2003). Spatial and temporal processing in a subject with cortical blindness following occipital surgery: Neuropsychologia Vol 41(10) 2003, 1296-1306. == External links ==
However, the intra-cellular thio-nucleotide metabolites of thioguanine (6-TGN) have longer half-lives and can therefore be measured after thioguanine is eliminated from the plasma. Thioguanine is catabolized (broken down) via two pathways. One route is through the deamination by the enzyme guanine deaminase to 6-thioxanthine, which has minimal anti-neoplastic activity, then by oxidation by xanthine oxidase of the thioxanthine to thiouric acid. This metabolic pathway is not dependent on the efficacy of xanthine oxidase, so that the inhibitor of xanthine oxidase, the drug allopurinol, does not block the breakdown of thioguanine, in contrast to its inhibition of the breakdown of the related thiopurine 6-mercaptopurine. The second pathway is the methylation of thioguanine to 2-amino-6-methylthiopurine, which is minimally effective as an anti-neoplastic and significantly less toxic than thioguanine. This pathway also is independent of the enzyme activity of xanthine oxidase. Mechanism of action
6-Thioguanine is a thio analogue of the naturally occurring purine base guanine. 6-thioguanine utilises the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) to be converted to 6-thioguanosine monophosphate (TGMP). High concentrations of TGMP may accumulate intracellularly and hamper the synthesis of guanine nucleotides via the enzyme Inosine monophosphate dehydrogenase (IMP dehydrogenase), leading to DNA mutations.TGMP is converted by phosphorylation to thioguanosine diphosphate (TGDP) and thioguanosine triphosphate (TGTP). Simultaneously deoxyribosyl analogs are formed, via the enzyme ribonucleotide reductase. The TGMP, TGDP and TGTP are collectively named 6-thioguanine nucleotides (6-TGN).