Nerve Atrophy (nerve + atrophy)

Distribution by Scientific Domains

Kinds of Nerve Atrophy

  • optic nerve atrophy

  • Selected Abstracts

    Erythropoietic protoporphyria with eye complications

    Hiromi TSUBOI
    ABSTRACT We herein report a case of erythropoietic protoporphyria (EPP) complicated by a decrease in eyesight that occurred in a Japanese male. An ophthalmologist initially thought that the eyesight loss might be the result of idiopathic optic nerve atrophy due to a vascular obstruction in the fundus. There are no previous reports of EPP cases with eye complications. However, an eye abnormality has been reported in an animal model of protoporphyria after long-term, low-level exposure to blue light. As a result, in our case, it is therefore possible that a relationship may have existed between EPP and the onset of eye complications. [source]

    2224: Oxygenation of the human retina

    Purpose Partial pressure of oxygen in the optic nerve and retina is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The PO2 is autoregulated and moderate changes in intraocular pressure, blood pressure or tissue oxygen consumption do not affect the retinal and optic nerve oxygen tension. Methods If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. Medical intervention can affect optic nerve PO2. Lowering the intraocular pressure tends to increase the optic nerve PO2, even though this effect may be masked by the autoregulation when the optic nerve PO2 and perfusion pressure is in the normal range. Results Carbonic anhydrase inhibitors increase retinal PO2 through a mechanism of vasodilatation and lowering of the intraocular pressure. Carbonic anhydrase inhibition reduces the removal of CO2 from the tissue and the CO2 accumulation induces vasodilatation resulting in increased blood flow and improved oxygen supply. This effect is inhibited by indomethacin but not other cyclo-oxygenase inhibitors. Conclusion Carbonic anhydrase inhibitors increase retinal blood flow and increase oxygen delivery. Glaucoma drugs and glaucoma surgery lower intraocular pressure, increase ocular perfusion pressure and blood flow. Demand of oxygen by retinal cells may be reduced through apoptosis and tissue atrophy, as well as active destruction of tissue by laser photocoagulation. [source]

    PCR identification of Rhizobium radiobacter in post-operative endophthalmitis

    V VINH
    Purpose: To present 2 cases of PCR identification of Rhizobium radiobacter in post-operative endophthalmitis. Methods: Microbiological identification was carried out using samples from aqueous humor and/or vitreous. Conventional cultures were performed using a Brain Heart Infusion broth. We used broad-range eubacterial PCR amplification followed by direct sequencing. Results: In both cases, Rhizobium radiobacter was identified using eubacterial PCR and cultures of vitreous from vitreous tap. An 81-year-old female presented an endophthalmitis 4 weeks after an cataract surgery. Inflammation and infection were controlled after 2 intravitreal antibiotic injections and the final visual acuity was of 20/24 at the one-year follow-up exam. A 75-year-old male who underwent a cataract surgery presented an endophthalmitis 9 days after. This patient was treated by 3 intravitreal antibiotic injections and a vitrectomy. The 6-month follow-up exam showed an optic nerve atrophy with a poor visual outcome (20/120). Both patients had an initial marked anterior chamber inflammation with a hypopyon and a severe retinal vasculitis was observed in the second case. Conclusions: Rhizobium radiobacter is a rare pathogen involved in postoperative endophthalmitis. As it is an environmental soil organism, we may assume that the patient's exposure to outdoor environnement and moist soil remains the source of this organism. This gram negative rod is resistant to vancomycin and have an intermediate resistance to most antibiotics used to treat post-operative endophthalmitis. PCR allows a swifter bacterial identification than do cultures and may help choose the most efficient antibiotics. [source]

    Ocular complications at the limits of viability

    ACTA PAEDIATRICA, Issue 3 2007
    Ferdinand Pulzer
    Abstract Aim: To evaluate the incidence of retinopathy of prematurity (ROP) and other ocular morbidities in extremely premature infants. Methods: A retrospective analysis of the prevalence and nature of ocular abnormalities in a cohort of 22 extremely pre-term infants born <25 + 0 weeks of estimated gestational age (GA) was performed. Results: The children were grouped according to the observed disorder: 13 out of 22 (59%) neonates with mild ophthalmologic findings (ROP , stage II) [Group 1], 5 out of 22 (23%) infants with ROP stage III or more (Group 2) and 4 out of 22 (18%) neonates with severe ocular morbidity (congenital cataract, microphthalmia, partial optic nerve atrophy and corneal perforation due to an ulcer with lens protrusion), partly combined with ROP , stage III (three of four). One child of 22 (5%) needed laser therapy. Out of 22 admitted infants, 20 (91%) were discharged alive. Conclusion: The high rate of ocular morbidity besides ROP in extremely pre-term infants is noteworthy. Mechanisms influencing the postnatal development of the eye, especially their relation to the grade of prematurity and neonatological therapeutical strategies, require further investigations. [source]