Multifocal Visual Evoked Potentials Reveal Normal Optic Nerve Projections in Human Carriers of Oculocutaneous Albinism Type 1a

Abstract

The absence of evidence for projection abnormalities in human OCA1a carriers contrasts with the previously reported evidence for abnormalities in cat-carriers of tyrosinase-related albinism. This discrepancy suggests that animal models of albinism may not provide a match to human albinism.

Prediction of higher visual function in macular degeneration with multifocal electroretinogram and multifocal visual evoked potential

“…MfERGs are routinely obtained upon flash stimulation . In contrast, the optimal stimulus for mfVEPs are circular checkerboard patterns, i.e. a stimulus requiring higher spatial resolution than local flashes.…”

Visual Pathways in Humans With Ephrin-B1 Deficiency Associated With the Cranio-Fronto-Nasal Syndrome

“…61 It must be noted that, while pattern-onset stimulation is mandatory for conventional misrouting VEPs, 30,37 for mfVEPs to pattern-onset and pattern-reversal stimulation similar accuracies were determined previously for the differentiation of normal and abnormal response lateralizations. 34,35 This is likely related to the finding of similar wave shapes in mfVEPs to pattern-reversal and pattern-onset stimulation, 61 which is in contrast to cVEPs.…”

“…Therefore, the cortical responses in controls are asymmetrical leading to sizable interhemispherical mfVEPs, which, as for the misrouting cVEPs, do not depend in their polarity on the eye stimulated, which contrasts to albinism. [34][35][36] Procedure. The recording and analysis procedures for cVEPs and mfVEPs followed procedures described earlier.…”

“…This paradigm serves as a clinical routine tool for the detection of misrouting of the optic nerves 33 and can also be combined with mfVEPs to identify localized optic nerve misroutings. [34][35][36] Enhanced crossing of the optic nerves has long been considered as a pathognomonic sign of albinism. As a consequence, the misrouting VEP has since served as an important diagnostic in the detection of albinism as the cause of ocular symptoms specified above.…”

“…As a consequence, the misrouting VEP has since served as an important diagnostic in the detection of albinism as the cause of ocular symptoms specified above. In fact, the abnormality is absent in human carriers of albinism 34,35,37 and patients without albinism, but with some ocular symptoms observed in albinism, such as foveal hypoplasia, 38 dissociated vertical deviation and missing stereopsis, [39][40][41] and congenital nystagmus. 42,43 Further, normal projections were observed in patients with unilateral anophthalmia or severe microphthalmia 22 and in patients with generalized lateralization abnormalities (i.e., situs inversus in the Kartagener syndrome, and in primary ciliary dyskinesia in general).…”