SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Keratitis

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ABSTRACT:: Contact lens-associated corneal infiltrative events (CIEs) are presumed sterile events that have complicated contact lens wear for more than 30 years. There is consistent evidence that silicone hydrogel soft contact lenses increase CIE risk by twofold compared with low Dk hydrogel materials. The incidence of CIEs during silicone hydrogel extended wear ranges from 2% to 6% for symptomatic events and from 6% to 25% when asymptomatic events are included. For daily wear, with silicone hydrogels, the incidence of CIEs ranges from 2% to 3% for symptomatic events and from 7% to 20% when asymptomatic events are included. Despite the increased rate of CIEs with silicone hydrogels, the benefits of these lenses largely outweigh this risk for many patients. Most risk factors for CIEs observed with silicone hydrogels are consistent with CIE risk factors reported earlier with hydrogel lenses, such as bacterial bioburden on lens surfaces, and young age among others. Limiting the transfer of bacterial bioburden from the skin to lenses, lens cases and eventually to the eye is an obvious step forward for the prevention of CIEs across all lens types.

Concepts: Epidemiology, Eye, Cornea, Lens, Contact lens, Contact lenses, Keratitis, Corrective lens

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To review an Acanthamoeba keratitis case series for the documented extracorneal spread of the amoeba.

Concepts: Keratitis, Acanthamoeba, Amoebozoa, Amoeboid, Amoeba

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To report the observation of prolonged reepithelialization after photorefractive keratectomy (PRK) associated with the use of besifloxacin 0.6% (Besivance; Bausch & Lomb, Rochester, NY) underneath bandage contact lenses (BCLs) placed during surgery.

Concepts: Cornea, Contact lens, Keratitis, Photorefractive keratectomy, Rochester, New York, Bausch & Lomb, Bausch & Lomb Place, Mount Hope Cemetery, Rochester

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Mini-scleral lenses are an increasingly popular contact lens modality; however, there are relatively few reports regarding the unique aspects of their fitting and potential complications. We report a complication of mini-scleral lens wear in a 44-year-old female patient using the lenses for keratoconus. Her mini-scleral contact lenses were non-fenestrated and fitted to vault over the cornea and seal at the periphery. The patient presented with an acute red eye (non-ulcerative keratitis), characterised by unilateral severe conjunctival and limbal hyperaemia, corneal infiltration and pain. Refitting the lens to increase the corneal vault clearance did not prevent recurrence of the keratitis, some five months later. Successful prevention of further episodes of the acute red eye was achieved through improved patient compliance with lens cleaning, disinfection and lens case procedures. Lens hygiene may be particularly important for mini-scleral lenses with a sealed fitting.

Concepts: Eye, Cornea, Lens, Orthokeratology, Contact lens, Contact lenses, Keratitis, Keratoconus

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Ophthalmic herpes simplex viral keratitis (HSVK) is responsible for a range of ocular manifestations from superficial epithelial disease to stromal keratitis and endotheliitis. The Herpetic Eye Disease Study (HEDS) has guided the management of herpetic eye disease for almost twenty years, but newer medications such as valacyclovir are now available and are considered to have better bioavailability than acyclovir. In this review, we examine the existing evidence on the pathogenesis of different HSVK disease modalities and the role of oral and topically administered antiviral drugs in the treatment of herpes simplex viral keratitis.

Concepts: Virus, Antiviral drug, Herpes simplex, Antibiotic, Antivirals, Keratitis, Conjunctivitis, Valaciclovir

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A 76 year old male presents with a corneal perforation in a phthisical eye. Definitive treatment in the form of an evisceration was delayed by 38 days. During this period a bandage contact lens prevented extrusion of ocular contents through an enlarging corneal perforation. This case demonstrates that a bandage contact lens can be effective in the immediate management of large corneal perforations whilst awaiting urgent definitive treatment.

Concepts: Eye, Cornea, Lens, Orthokeratology, Contact lens, Keratitis, Corneal ulcer

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To evaluate the safety and efficacy of topical recombinant human nerve growth factor (rhNGF) for treating moderate-to-severe neurotrophic keratitis (NK), a rare degenerative corneal disease resulting from impaired corneal innervation.

Concepts: Cornea, Nerve, Contact lens, Keratitis, Nerve growth factor

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The primary side effects associated with 0.1% brimonidine tartrate (BT) ophthalmic solution with sodium chlorite are allergic conjunctivitis, blepharitis, and conjunctival hyperemia. However, cornea-related side effects are rare. In this study, we report 2 similar cases in which corneal neovascularization, corneal infiltration, and corneal opacity developed after BT eye-drop use.

Concepts: Eye, Ophthalmology, Keratitis, Conjunctiva, Conjunctivitis, Allergic conjunctivitis, Brimonidine, Blepharitis

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Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, despite our advances in antimicrobial chemotherapy and supportive care. In part, this is due to an incomplete understanding of the pathogenesis and pathophysiology of the disease, diagnostic delays and problems associated with chemotherapeutic interventions. In view of the devastating nature of this disease, here we present our current understanding of Acanthamoeba keratitis and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be potential targets for improved diagnosis, therapeutic interventions and/or for the development of preventative measures. Novel molecular approaches such as proteomics, RNAi and a consensus in the diagnostic approaches for a suspected case of Acanthamoeba keratitis are proposed and reviewed based on data which have been compiled after years of working on this amoebic organism using many different techniques and listening to many experts in this field at conferences, workshops and international meetings. Altogether, this review may serve as the milestone for developing an effective solution for the prevention, control and treatment of Acanthamoeba infections.

Concepts: Immune system, Infectious disease, Infection, Cornea, Contact lens, Keratitis, Acanthamoeba, Amoeboid

9

Fusarium keratitis is a destructive eye infection that is difficult to treat and which results in poor outcome. In the tropical and subtropical areas the infection is relatively common and associated with trauma or chronic eye diseases. However, in recent years, an increased incidence has been reported in temperate climate regions. At the German National Reference Center, we observed a steady increase in case numbers since 2014. Here, we present the first German case series of eye infections with Fusarium spp. We identified Fusarium isolates from the eye or eye-related material from 22 patients in 2014 and 2015. Thirteen isolates belonged to the Fusarium solani species complex (FSSC), 6 belonged to the Fusarium oxysporum species complex (FOSC) and three to the Fusarium fujikori species complex (FFSC). FSSC was isolated in 13 of 15 (85 %) definite infections and FOSC in 3 of 4 (75 %) definite contaminations. Furthermore, diagnosis from contact lens swabs or culture of contact lens solution turned out to be highly unreliable. FSSC isolates differed from FOSC and FFSC by distinctly higher minimal inhibitory concentration (MIC) for terbinafine. Outcome was often adverse with 10 patients requiring keratoplasty or enucleation. The use of natamycin as the most effective agent in keratitis caused by filamentous fungi was rare in Germany, possibly due to restricted availability. Keratitis caused by Fusarium spp. (usually FSSC) appears to be a relevant clinical problem in Germany with the use of contact lenses as the predominant risk factor and an adverse outcome.

Concepts: Species, Climate, Fusarium, Eye, Cornea, Ophthalmology, Contact lens, Keratitis