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Concept: Corneal ulcer

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There is increasing interest in fitting children with soft contact lenses. This review collates data from a range of studies to estimate the incidence of complications, specifically corneal infiltrative events and microbial keratitis, in patients under the age of 18 years.

Concepts: The Age, Cornea, Orthokeratology, Contact lens, Keratitis, Corneal ulcer, Bausch & Lomb

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PURPOSE: To compare the equivalence of moxifloxacin 0.5% with a combination of fortified cefazolin sodium 5% and tobramycin sulfate 1.3% eye drops in the treatment of moderate bacterial corneal ulcers. DESIGN: Randomized, controlled, equivalence clinical trial. PARTICIPANTS AND CONTROLS: Microbiologically proven cases of bacterial corneal ulcers were enrolled in the study and were allocated randomly to 1 of the 2 treatment groups. INTERVENTION: Group A was given combination therapy (fortified cefazolin sodium 5% and tobramycin sulfate) and group B was given monotherapy (moxifloxacin 0.5%). MAIN OUTCOME MEASURES: The primary outcome variable for the study was percentage of the ulcers healed at 3 months. The secondary outcome variables were best-corrected visual acuity and resolution of infiltrates. RESULTS: Of a total of 224 patients with bacterial keratitis, 114 patients were randomized to group A, whereas 110 patients were randomized to group B. The mean ± standard deviation ulcer size in groups A and B were 4.2±2 and 4.41±1.5 mm, respectively. The prevalence of coagulase-negative Staphylococcus (40.9% in group A and 48.2% in group B) was similar in both the study groups. A complete resolution of keratitis and healing of ulcers occurred in 90 patients (81.8%) in group A and 88 patients (81.4%) in group B at 3 months. The observed percentage of healing at 3 months was less than the equivalence margin of 20%. Worsening of ulcer was seen in 18.2% cases in group A and in 18.5% cases in group B. Mean time to epithelialization was similar, and there was no significant difference in the 2 groups (P = 0.065). No serious events attributable to therapy were reported. CONCLUSIONS: Corneal healing using 0.5% moxifloxacin monotherapy is equivalent to that of combination therapy using fortified cefazolin and tobramycin in the treatment of moderate bacterial corneal ulcers. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Concepts: Clinical trial, Wound healing, Collagen, Randomized controlled trial, Staphylococcus, Arithmetic mean, Standard deviation, Corneal ulcer

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Abstract Aim: To compare collared silicone punctal plugs to intracanalicular SmartPlugs for the treatment of moderate to severe dry eye. Materials and methods: In this prospective, randomized, single blind, clinical study, 30 patients (60 eyes) who had been diagnosed with moderate to severe dry eye syndrome were enrolled. Study group I (n = 30 eyes) received collared silicone punctal plugs and group II (n = 30 eyes) received intracanalicular SmartPlugs. Data for the Schirmer I test, tear break-up time, vital staining, subjective symptoms and frequency of artificial tear application were recorded at baseline and 3 months after punctal occlusion. Results: There was no statistical significant difference for these values between group I and II. Conclusions: Although published data show free flow with irrigation and probing after SmartPlug insertion, the clinical effect in the treatment of dry eye appears to be the equally well to collared silicone punctal plugs. It seems likely that difference of design and localization between the treatment groups were of minor importance concerning impeding of natural and supplemental moisture.

Concepts: Clinical trial, Statistical significance, Eye, Ophthalmology, Sjögren's syndrome, Tears, Corneal ulcer, Keratoconjunctivitis sicca

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Abstract Purpose: The aim of this study was to determine the normal inter-day and intra-day variations in tear film osmolarity and the tear fluorescein clearance test (T-FCT) in healthy subjects. Methods: Tear samples from 24 young, healthy adults were collected from 11:00 AM to 1:00 PM (midday) and 5:00 PM to 7:00 PM (evening) on three non-consecutive days. Tear osmolarity measurement and the T-FCT were performed to assess the basal values and inter-day and intra-day variations of the test results. A freezing point depression osmometer was used to analyze the tear osmolarity, and the T-FCT was performed using a fluorophotometer. Results: The mean osmolarity value was 270 ± 4.4 mOsm/l and the mean T-FCT result was 2.97 ± 0.17 fluorescence arbitrary units. The inter-day or intra-day tear osmolarity values did not differ significantly. The T-FCT results varied significantly during the day, with significantly (p = 0.0004) higher results in the evening; no significant differences were found in the inter-day analysis. Conclusions: Tear osmolarity was unaffected by intra-day variations; however, the T-FCT showed an inter-day variation, which indicated that the time of day when the test is performed must be considered when it is used to evaluate the diagnosis of dry eye disease, disease progression or therapeutic effectiveness.

Concepts: Eye, Tears, Corneal ulcer, Melting point, Keratoconjunctivitis sicca, Freezing-point depression, Eye disease, 12-hour clock

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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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Meibomian gland dysfunction (MGD) is the most frequent cause of dry eye disease (DED). Eyelid inflammation, microbial growth, associated skin disorders as well as potentially severe corneal complications culminate to make MGD a complex multifactorial disorder. It is probable that MGD is a heterogeneous condition arising from any combination of the following five separate pathophysiological mechanisms: eyelid inflammation, conjunctival inflammation, corneal damage, microbiological changes and DED resulting from tear film instability. The pathogenesis of both MGD and DED can be described in terms of a ‘vicious circle’: the underlying pathophysiological mechanisms of DED and MGD interact, resulting in a double vicious circle. The MGD vicious circle is self-stimulated by microbiological changes, which results in increased melting temperature of meibum and subsequent meibomian gland blockage, reinforcing the vicious circle of MGD. Meibomian gland blockage, dropout and inflammation directly link the two vicious circles. MGD-associated tear film instability provides an entry point into the vicious circle of DED and leads to hyperosmolarity and inflammation, which are both a cause and consequence of DED. Here we propose a new pathophysiological scheme for MGD in order to better identify the pathological mechanisms involved and to allow more efficient targeting of therapeutics. Through better understanding of this scheme, MGD may gain true disease status rather than being viewed as a mere dysfunction.

Concepts: Immune system, Eye, Cornea, Tears, Corneal ulcer, Keratoconjunctivitis sicca, Meibomian gland, Eye disease

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Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled) skull shape, the presence of a nasal fold (wrinkle), and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not), or if a previous diagnosis of corneal ulcer(s) was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%), small breed dogs (mean± SE weight: 11.4±1.1 kg), with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio <0.5) were twenty times more likely to be affected than non-brachycephalic dogs. A 10% increase in relative eyelid aperture width more than tripled the ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare.

Concepts: Eye, Fluorescein, Contact lens, Dog, Dog breed, Corneal ulcer, Conformation, Gray Wolf

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To determine if the number of emergency department (ED) rechecks, persistent fluorescein uptake, ophthalmology referrals, or complications would be affected by the prescription of topical tetracaine for pain relief from simple corneal abrasions (SCAs).

Concepts: Hospital, Observational study, Ophthalmology, Fluorescein, Corneal ulcer, Dublin, Abrasion, Corneal abrasion

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Acanthamoeba keratitis is a severe, often sight threatening, corneal infection which in Western countries is predominantly seen in daily wear of contact lenses. This review aims to summarise the pathobiology and epidemiology of contact lens-related Acanthamoeba keratitis, and to present strategies for prevention, particularly with respect to modifiable risk factors in contact lens wear.

Concepts: Cornea, Lens, Contact lens, Contact lenses, Keratitis, Corrective lens, Corneal ulcer, Bausch & Lomb