Optic disk reflectance was measured from 27 normal observers with their physiological lenses (aged 21-74 yr) and from two pseudophakic observers (aged 69 and 70 yr) with use of a Utrecht fundus reflection densitometer. Psychophysical heterochromatic flicker photometric luminance matches (10 degrees field) were obtained on the same group of the observers. A four-parameter model incorporating len...

Metastasis to the eye is rare, it can affect almost all ocular tissues. The association of metastasis to the optic nerve and lens dislocation in the same orbit is exceptional. We repport a 63 years old man presented with blindness due to a lens dislocation in the left eye. One month later, he presented a right hemiparesis. Brain magnetic resonance imaging (MRI) showing brain and intra orbital m...

Chimaeric mice were made by aggregating Pax6(-/-) and wild-type mouse embryos, in order to study the interaction between the optic vesicle and the prospective lens epithelium during early stages of eye development. Histological analysis of the distribution of homozygous mutant cells in the chimaeras showed that the cell-autonomous removal of Pax6(-/-) cells from the lens, shown previously at E1...

It has long been known that the early optic vesicle and cup are much concerned with the growth and differentiation of the lens in the vertebrate eye. Le Cron"2 first demonstrated this fact when he isolated the lens-forming cells in Amblystoma embryos at various early stages in development by merely removing the underlying optic anlage. His experiments showed that the longer the lens epithelium ...

Pitx3 is expressed in tissues fated to contribute to eye development, namely, neurula stage ectoderm and pre-chordal mesoderm, then presumptive lens ectoderm, placode, and finally lens. Pitx3 overexpression alters lens, optic cup, optic nerve, and diencephalon development. Many of the induced anomalies are attributable to midline deficits; however, as assessed by molecular markers, ectopic Pitx...

Since the beginning of the century the generally accepted scheme of eye/lens development has been that proposed by Spemann (1901) and later confirmed by numerous workers. According to this scheme the two presumptive components of the definitive eye, the optic cup and the lens, are spatially separated at the flat neural plate stage. They later come into apposition as a result of tissue movements...

Introduction: Among the components of the extracellular matrix (ECM) and basement membrane (BM), laminitis heterotrimeric glycoprotein (laminin) and collagen type IV are the most important. In a previous study we have examined the role of collagen type IV in the developing lens capsule. The present study aims to determine the appearance and distribution of laminin in the BM and ECM of lenses ...

The interactive events leading to lens formation and the developmental potentialities of the presumptive lens ectoderm were examined in vitro. The presumptive lens ectoderm of both mouse and chick embryos was capable of forming a lens even when isolated from the optic vesicle before the two tissues reach the stage of close association. This lens-forming bias can be released with favourable cult...

Pregnant rats were treated intraperitoneally with a single dose of methotrexate (MTX) 90 mg/kg on gestation day (GD) 13, and fetal eyeballs were examined time-dependently from GD 13.5 to 15.5. Throughout the experimental period, the inner plate of the ocular cup in the MTX group was significantly thinner than that in the control group. In the inner plate of the ocular cup on GD 15 and 15.5, whe...

The cell coats of the presumptive lens cells and the extracellular interface between the lens rudiment and optic vesicle were investigated in the chicken embryo throughout the period during which lens induction is presumed to take place. Histochemical methods showed that the cell coats contained both glycoproteins and glycosaminoglycans. Autoradiography after [H]glucosamine injection indicated ...