A UNIQUE ACHIASMATIC ANOMALY DETECTED IN NON-ALBINOS WITH MISROUTED RETINAL-FUGAL PROJECTIONS

In mammals with binocular vision, projections of retinal axons to prim ary retino-recipient nuclei establish a strict visuotopic and eye-segr egated arrangement. Normal primate visual pathway organization is char acterized by orderly hemiretina separation in which nasal - retinal ax ons cross at the optic chiasm and project to primary contralateral sub cortical and cortical structures while temporal-retinal fibres project ipsilaterally to corresponding visual structures. We report here, in two unrelated children, an unusual visual pathway malformation in whic h nasal - retinal cortical projections, unable to decussate due to the inborn absence of an optic chiasm, erroneously route ipsilaterally to visual projection targets. We have termed this newly documented achia smatic condition the non-decussating retinal-fugal fibre syndrome (Apk arian et al., Invest. Ophthalmol. Vis. Sci., 34, Suppl., 711, 1993).