Interim Results of a Multicenter Trial with the New Electronic Subretinal Implant Alpha AMS in 15 Patients Blind from Inherited Retinal Degenerations.

We assessed the safety and efficacy of a technically advanced subretinal electronic implant, RETINA IMPLANT Alpha AMS, in end stage retinal degeneration in an interim analysis of two ongoing prospective clinical trials. The purpose of this article is to describe the interim functional results (efficacy). The subretinal visual prosthesis RETINA IMPLANT Alpha AMS (Retina Implant AG, Reutlingen, Germany) was implanted in 15 blind patients with hereditary retinal degenerations at four study sites with a follow-up period of 12 months (www.

Microarray analysis of retinal gene expression in Egr-1 knockout mice.

Purpose: We found earlier that 42 day-old Egr-1 knockout mice had longer eyes and a more myopic refractive error compared to their wild-types. To identify genes that could be responsible for the temporarily enhanced axial eye growth, a microarray analysis was performed in knockout and wild-type mice at the postnatal ages of 30 and 42 days.

Methods: The retinas of homozygous and wild-type Egr-1 knockout mice (Taconic, Ry, Denmark) were prepared for RNA isolation (RNeasy Mini Kit, Qiagen) at the age of 30 or 42 days, respectively (n=12 each).

Microarray analysis of retinal gene expression in chicks during imposed myopic defocus.

Purpose: The retina plays an important regulatory role in ocular growth. To screen for new retinal candidate genes that could be involved in the inhibition of ocular growth, we used chick microarrays to analyze the changes in retinal mRNA expression after myopic defocus was imposed by positive lens wear.

Methods: Four male white leghorn chicks, aged nine days, wore +6.

Relative axial myopia in Egr-1 (ZENK) knockout mice.

Purpose: Experiments in chickens have implicated the transcription factor ZENK (also known as Egr-1, NGFI-A, zif268, tis8, cef5, and Krox24) in the feedback mechanisms for visual control of axial eye growth and myopia development. ZENK is upregulated in retinal glucagon amacrine cells when axial eye growth is inhibited by positive spectacle lens wear and is downregulated when it is enhanced by negative spectacle lens wear, suggesting that ZENK may be linked to an inhibitory signal for axial eye growth. This study was undertaken to determine whether a Egr-1(-/-) knockout mouse mutant, lacking ZENK completely, has longer eyes and more myopic refraction, than do Egr-1(+/)(-) heterozygous and Egr-1(+/+) wild-type mice with near-identical genetic backgrounds.

Peripheral defocus does not necessarily affect central refractive development.

Purpose: Recent experiments in monkeys suggest that deprivation, imposed only in the periphery of the visual field, can induce foveal myopia. This raises the hypothesis that peripheral refractive errors imposed by the spectacle lens correction could influence foveal refractive development also in humans. We have tested this hypothesis in chicks.

Changes in scleral MMP-2, TIMP-2 and TGFbeta-2 mRNA expression after imposed myopic and hyperopic defocus in chickens.

Induction of myopia leads to a decreased glycosaminoglycan synthesis and smaller collagen fibrillar diameters, increased levels of gelatinase-A (MMP-2) and decreased amounts of tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the fibrous sclera of both chicks and tree shrews. Another factor found to be involved in altered eye growth is the transforming growth factor beta-2 (TGFbeta-2). The aim of the current study was to measure MMP-2, TIMP-2 and TGFbeta-2 mRNA expression changes separately in the two scleral layers of chicks, following myopic and hyperopic defocus.