There are many types of congenital stationary night blindness (CSNB) with normal fundi. Precise information on their pathogenesis can be useful for molecular biological study. We classified Schubert-Bornschein type CSNB into two types: complete and incomplete. It has been proven that these two are different clinical entities. The complete type shows no rod b-wave, and STR with normal rod a-wave on ERG, indicating that the defect lies in the rod on-bipolar cell. Cone driven ERG recorded with long flash stimuli (photopic long flash ERG) shows extremely reduced b-wave (on) with large d-wave (off), similar to the monkey ERG blocked by APB, including cone on-biopolar cell dysfunction as well. These results suggest that complete type CSNB has an "off-retina". Incomplete CSNB showed normal rod b-wave near the threshold with abnormal STR, suggesting that the rod on -bipolar cell was functioning well. The photopic long flash ERG showed small a-wave, relatively larg b-wave (on), and small d-wave (off), which resembles the monkey ERG blocked by KYN. That is, incomplete CSNB has normal rod and cone on-bipolar cells with abnormal cone off-bipolar cells, suggesting an "on-retina". The ERG findings in the mGluR6 knockout mouse are similar to those of complete type CSNB, and are useful for molecular biologic study of CSNB.
|Number of pages||2|
|Journal||Folia Ophthalmologica Japonica|
|Publication status||Published - 1996|
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