Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Dec 2010
Selective activation of the prostaglandin E2 circuit in chronic injury-induced pathologic angiogenesis.
Cyclooxygenase (COX)-derived prostaglandin E(2) (PGE(2)) is a prevalent and established mediator of inflammation and pain in numerous tissues and diseases. Distribution and expression of the four PGE(2) receptors (EP1-EP4) can dictate whether PGE(2) exerts an anti-inflammatory or a proinflammatory and/or a proangiogenic effect. The role and mechanism of endogenous PGE(2) in the cornea, and the regulation of EP expression during a dynamic and complex inflammatory/reparative response remain to be clearly defined. ⋯ These findings place the corneal PGE(2) circuit as an endogenous mediator of inflammatory neovascularization rather than general inflammation and demonstrate that chronic inflammation selectively regulates this circuit at the level of biosynthetic enzyme and receptor expression.
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Invest. Ophthalmol. Vis. Sci. · Sep 2010
Selective changes in human corneal sensation associated with herpes simplex virus keratitis.
To determine corneal sensitivity to selective mechanical, chemical, and thermal (heat and cold) stimulation in patients with a history of herpes simplex virus (HSV) keratitis. ⋯ In eyes that had had HSV keratitis, corneal sensitivity to mechanical forces and heat was significantly impaired, suggesting that axonal damage and/or altered expression of membrane ion channels involved in transduction and membrane excitability affects primarily the mechano- and polymodal nociceptor terminals. Corneal cold-sensitive terminals remain largely unaffected.
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Invest. Ophthalmol. Vis. Sci. · Aug 2010
Use of single-vision distance spectacles improves landing control during step descent in well-adapted multifocal lens-wearers.
Epidemiologic research has shown that multifocal spectacle wearers (bifocal and progressive addition lenses [PALs]) are more than twice as likely to fall than are nonmultifocal spectacle wearers, with this risk further increasing when negotiating stairs. The present study investigated whether step and stair descent safety is improved by using single-vision distance lenses. ⋯ Use of single-vision distance spectacles led to improvements in landing control, consistent with individuals' being more certain regarding the precise height of the lower floor level. This enhanced control was attributed to having a view of the foot, step edge, and immediate floor area that was not blurred, magnified, or doubled and that did not suffer from image jump or peripheral distortions. These findings provide further evidence that use of single-vision distance lenses in everyday locomotion may be advantageous for elderly multifocal wearers who have a high risk of falling.
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Invest. Ophthalmol. Vis. Sci. · Aug 2010
ABCA4 and ROM1: implications for modification of the PRPH2-associated macular dystrophy phenotype.
To identify the causative mutation leading to autosomal dominant macular dystrophy, cone dystrophy, and cone-rod dystrophy in a five-generation family and to explain the high intrafamilial phenotypic variation by identifying possible modifier genes. ⋯ Features of a PRPH2-associated phenotype might be modulated by additional mutations in other genes (in this family ABCA4 and/or ROM1) accounting for intrafamilial variability and resulting in a cumulative effect worsening the phenotype. Families showing a variable macular dystrophy phenotype caused by mutations in PRPH2 should be tested for additional mutations in ABCA4 and ROM1, as they may alter the progression of the PRPH2 phenotype. This testing will influence genetic counseling, as patients with additional mutations may be confronted with a faster progression of visual loss.