[A case of congenital retinoschisis in a 34-week gestation female infant].

At age one month a female infant was referred for a fundus examination because she was delivered after a 34-week gestation and her birth weight was 1908 g. Fundus examination revealed a brown granular pigmentary deposition surrounding the foveola in the macular region and a large highly ballooning retinoschisis occupying almost the lower half of the fundus in each eye. There was slight hemorrhage in the vitreous body and the retinoschisis cavity, and no retinal hole. The anterior border of the retinoschisis did not extend to the ora serrata. The almost negative ERG response showed an abnormal b-wave amplitude. Over the course of about one year, the vitreous hemorrhage developed and cleared. The ballooning feature of the retinoschisis also developed and disappeared. On examination of the infant's family her father and elder sister had no abnormal findings but her mother had chorioretinal degeneration with macular yellow pigmentary deposition, visual defect and negative ERG. These abnormal findings of her mother were suggested to have been derived from congenital retinoschisis. Therefore, this is a very rare case because of the different hereditary form, the common sex-linked recessive inheritance, the 34-week gestation and female infant.