Enucleated human eyes were perfused via the anterior chamber at 25 mm Hg pressure with lens particles (whole lens homogenates) in one series of experiments and with soluble lens proteins from human cataractous lenses in another series. Adding 1% of a homogenate of a single cataractous lens to the anterior chamber induced a 68% decrease in outflow. Perfusion with HMW soluble lens proteins (1 mg/...

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...

The lens plays an important role in regulating the wavelengths of light that reach the retina. However, the evolutionary relationship between lens transmission and retinal sensitivity remains cloudy at best. We examined the relationship between lens transmission and opsin gene expression in a group of rapidly radiating cichlids from East Africa. Lens transmission was bimodal, either cutting off...

The effect of in vivo x-irradiation on rabbit lens permeability was studied by the Rb runout method. At 24 hours following x-irradiation of the lens the rate of Rb runout was found to be increased and reached a maximum at one week. Over the subsequent 2 weeks the rate of Rb runout decreased, although still remaining above normal. The increase in lens permeability preceded the appearance of lens...

In the absence of calcium, the penetration of sucrose and viannitol into the rat lens is increased, while that of inulin remains unchanged. The extracellular space of the lens, estimated with inulin, is 6 per cent of the wet iveight of the lens. The active accumulation of potassium and rubidium is 65 per cent of normal in the absence of calcium, while the uptake of a-aminoisobutyric acid (AIB) ...

Embryonic stem (ES) cells provide a potentially useful in vitro model for the study of in vivo tissue differentiation. We used mouse and human ES cells to investigate whether the lens regulatory genes Pax6 and Six3 could induce lens cell fate in vitro. To help assess the onset of lens differentiation, we derived a new mES cell line (Pax6-GFP mES) that expresses a GFP reporter under the control ...

Lens flexure and residual astigmatism were evaluated with rigid gas permeable (RGP) contact lenses made in low, medium, and high oxygen permeable (Dk) materials to determine if significant differences would be apparent as lens Dk was changed. Fourteen successful RGP contact lens wearers had their customary lens parameters, including lens thickness, held constant in duplicate pairs made in low (...

Phacoemulsification with foldable intraocular lens (IOL) implantation has several advantages because of smaller incision and sutureless technique. The visual recovery is usually fast and any surgically induced astigmatism can be kept at lowest. With increased number of trained phacosurgeons in Nepal, more phacosurgeries with foldable lens implantation are being done. Main purpose of this articl...

The importance of the large Maf transcription factor family has been investigated in lens development in the chick, Xenopus and mammals. Previously we reported that c-maf-deficient mice exhibit severe defects in lens fibre cells. Here, we report the roles of other large Mafs, MafA/L-Maf and MafB, during mouse lens development. MafA/L-Maf and MafB were expressed in lens epithelial cells and fibr...

Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design inno...