[Aplasia and hypoplasia of the optic nerve. Comparison of 2 cases]. / Aplasia ed ipoplasia del nervo ottico. Comparazione di due casi.

Hypoplasia and aplasia of the optic nerve are congenital anomalies characterized respectively by a marked volume reduction (very small papilla, often identifiable only as a rosy-yellowish area from which the retinal vessels emerge) and by the absence of the optic disk (absence of the nerve and mainly of its vessels) and of the visual functions. These anomalies are often associated with malformations of the central nervous system and of the ocular structures. The defects originate in the embryonal period due to the arrested development of the mesodermal component towards the head of the optic nerve. The aim of this study is to try to interpret the different clinical manifestations of the disease by observing two cases (a female and a male) with a clinical picture of aplasia and hypoplasia of the optic nerve respectively. Both cases presented the following clinical characteristics: developmental defects of the optic nerve, severe microcephaly, positive IgG antibodies against CMV. The association of the optic nerve defect with microcephaly is due to the embryogenic origin of the optic vescicle by prosencephalon. The resulting clinical picture is probably the outcome of an interfering process that the authors have presumed in CMV intrauterine infection, after having excluded the most frequent teratogenic agents (maternal diabetes, tabagism, intake of alcohol ad drugs). Moreover, the different degree of ocular involvement and the different time of onset of the intrauterine pathogenic insult in the two cases could account for the different clinical pictures.

A retrospective study of ocular side effects in children undergoing bone marrow transplantation.

Bone marrow transplantation (BMT) is recognized as a successful treatment for malignant and non-malignant hematological diseases. Thanks to transplantation, the number of long-term survivors has risen and with the improved prognosis a problem of ocular side effects has arisen. We carried out a retrospective study to determine the incidence and etiopathogenesis of ocular complications in a series of young patients undergoing BMT. One hundred children (62 males and 38 females) with a mean age of 7.12 (+/- 3.3) years at the time of BMT (autologous in 66 cases, allogenic in 34) were followed for a mean of 4.2 years (range 2-9). The conditioning regimens preceding BMT induced cytoreductive chemotherapy alone (47 cases) or associated with total body irradiation (TBI) (53 cases) in three or six fractions for a total dose of 10-12 Gy. We examined every child before BMT and subsequently every six months. We did not include patients with ocular complications due to the primary disease. Thirty-three children showed several complications after BMT: 17 had subcapsular posterior cataract in both eyes and eight had tear hyposecretion; one had dramatic fungal panuveitis, four had hemorrhagic complications and five optic disk edema. TBI was significantly associated with the development of subcapsular posterior cataract.