Microbial keratitis is a rare but potentially severe sight-threatening condition, associated with societal burden, cost and morbidity. Compared with microbial keratitis without lens wear, the disease ...in contact lens wear is more common, occurs at an earlier age, has lower morbidity and is more often caused by Pseudomonas aeruginosa and Acanthamoeba spp. Resistance to common antibiotics is infrequent in contact lens-related isolates and there is little evidence to suggest increasing bacterial resistance over time. There is some evidence for increased reporting of cases of Acanthamoeba keratitis internationally. The incidence of contact lens-related microbial keratitis has remained stable over time. Rates vary with wear modality, with the lowest risk of severe disease in daily disposable and rigid gas permeable contact lens wear; however, there are limited studies in daily wear silicone hydrogel and in contemporary daily disposable contact lenses. Risk factors for contact lens-related microbial keratitis can be either modifiable or non-modifiable and interventions to reduce the risk of, or severity of disease may be prioritised based on the attributable risk. Key risk factors based on high attributable risk include any overnight wear, failing to wash and dry hands prior to handling lenses and poor storage case hygiene practice. The strong link between microbial keratitis and storage case hygiene and replacement suggests the relevance of microbial contamination of the storage case. Both risk factors and evidence-based strategies for limiting storage case contamination are presented, including storage case cleaning protocols and antimicrobial storage cases; however, it is unclear if such interventions can ultimately limit the rate or severity of microbial keratitis in daily wear. Emerging challenges include understanding and limiting the risk of infection associated with decorative or cosmetic contact lens wear, particularly in Asia, and in understanding the safety of contact lens modalities for myopia control in a paediatric population
TFOS DEWS II Definition and Classification Report Craig, Jennifer P.; Nichols, Kelly K.; Akpek, Esen K. ...
The ocular surface,
July 2017, 2017-Jul, 2017-07-00, 20170701, Letnik:
15, Številka:
3
Journal Article
Recenzirano
The goals of the TFOS DEWS II Definition and Classification Subcommittee were to create an evidence-based definition and a contemporary classification system for dry eye disease (DED). The new ...definition recognizes the multifactorial nature of dry eye as a disease where loss of homeostasis of the tear film is the central pathophysiological concept. Ocular symptoms, as a broader term that encompasses reports of discomfort or visual disturbance, feature in the definition and the key etiologies of tear film instability, hyperosmolarity, and ocular surface inflammation and damage were determined to be important for inclusion in the definition. In the light of new data, neurosensory abnormalities were also included in the definition for the first time. In the classification of DED, recent evidence supports a scheme based on the pathophysiology where aqueous deficient and evaporative dry eye exist as a continuum, such that elements of each are considered in diagnosis and management. Central to the scheme is a positive diagnosis of DED with signs and symptoms, and this is directed towards management to restore homeostasis. The scheme also allows consideration of various related manifestations, such as non-obvious disease involving ocular surface signs without related symptoms, including neurotrophic conditions where dysfunctional sensation exists, and cases where symptoms exist without demonstrable ocular surface signs, including neuropathic pain. This approach is not intended to override clinical assessment and judgment but should prove helpful in guiding clinical management and research.
Abstract Almost half the patients who undergo laser in situ keratomileusis (LASIK) experience dry eye following the procedure. However, the etiology of LASIK-induced dry eye is unclear. The purpose ...of this review is to examine and summarize the current evidence for the etiology of LASIK-induced dry eye, with a focus on ocular surface sensitivity and corneal innervation. Evidence suggests that the alteration of corneal nerves after LASIK is the most likely cause of the subjective symptoms of LASIK-induced dry eye, even though corneal sensitivity and the clinical indicators of dry eye return to apparently normal values within a year due to the partial recovery of the corneal nerve plexus. The hypothesis is explored that dry eye symptoms following LASIK may result from abnormal sensation due to LASIK-induced corneal neuropathy. Other factors, such as alterations in conjunctival goblet cell density, might also contribute to the symptoms and signs of LASIK-induced dry eye. Inter-relationships between nerve morphology, tear neuropeptide levels and dry eye require further investigation. A better understanding of this phenomenon may result in improved management of post-LASIK dry eye.
PURPOSE:To establish the risk factors, causative organisms, levels of antibiotic resistance, patient demographics, clinical presentations, and clinical outcomes of microbial keratitis at a tertiary ...hospital in Australia.
METHODS:Patients who had a corneal scraping for culture over a 5-year period were identified through the local microbiology database, and a retrospective audit of their medical records was carried out. Clinical information was gathered from medical records, and smear, culture, and antibiotic resistance results were from the microbiology database. An index of disease severity was calculated for each patient from scores for the magnitude of the epithelial defect and anterior-chamber reaction and the location of the lesion. Associations between risk factors for keratitis and variables such as patient demographics, causative organism and antibiotic resistance, disease severity, and outcome were analyzed by using analysis of variance and χ tests with appropriate correction for multiple comparisons.
RESULTS:Two hundred fifty-three cases of microbial keratitis in 231 patients were included. Sixty percent of patients were men, and there was a bimodal distribution in the age of presentation. Common risk factors for keratitis were contact lens wear (53; 22%), ocular surface disease (45; 18%), ocular trauma (41; 16%), and prior ocular surgery (28; 11%). Gram stains were positive in 33%, with a sensitivity of 53% and specificity of 89%. Cultures of corneal scrapings were positive in 65% of cases, and Pseudomonas aeruginosa (44; 17%), coagulase-negative staphylococci (22; 9%), Staphylococcus aureus (19; 8%), and fungi (7; 3%) were commonly recovered. P. aeruginosa was more common than other culture results in contact lens-related cases (55% vs. 0%-23%; P < 0.001), and S. aureus was more common than other culture results in ocular surgery-related cases (29% vs. 0%-21%; P < 0.001). Patients with keratitis related to prior ocular surface disease had more severe keratitis at the time of scraping (P = 0.037). Cultures positive for Fusarium, P. aeruginosa, and other Gram-negative organisms had statistically significantly more severe keratitis at the time of scraping, whereas patients with negative cultures had milder keratitis (P = 0.030). Only 2% of all bacterial isolates were resistant to ciprofloxacin, 20% of Gram-positive isolates were resistant to cephalothin, and no Gram-negative isolates were resistant to gentamicin.
CONCLUSIONS:In this series, the most common risk factor for keratitis was contact lens wear and the most commonly isolated organism was P. aeruginosa.
To survey the demographics, risk factors, microbiology, and outcomes for infectious keratitis in Asia.
Prospective, nonrandomized clinical study.
Thirteen study centers and 30 sub-centers recruited ...consecutive subjects over 12-18 months, and performed standardized data collection. A microbiological protocol standardized the processing and reporting of all isolates. Treatment of the infectious keratitis was decided by the managing ophthalmologist. Subjects were observed for up to 6 months. Main outcome measures were final visual acuity and the need for surgery during infection.
A total of 6626 eyes of 6563 subjects were studied. The majority of subjects were male (n = 3992). Trauma (n = 2279, 34.7%) and contact lens wear (n = 704, 10.7%) were the commonest risk factors. Overall, bacterial keratitis was diagnosed in 2521 eyes (38.0%) and fungal keratitis in 2166 eyes (32.7%). Of the 2831 microorganisms isolated, the most common were Fusarium species (n = 518, 18.3%), Pseudomonas aeruginosa (n = 302, 10.7%), and Aspergillus flavus (n = 236, 8.3%). Cornea transplantation was performed in 628 eyes to manage ongoing infection, but 289 grafts (46%) had failed by the end of the study. Moderate visual impairment (Snellen vision less than 20/60) was documented in 3478 eyes (53.6%).
Demographic and risk factors for infection vary by country, but infections occur predominantly in male subjects and are frequently related to trauma. Overall, a similar percentage of bacterial and fungal infections were diagnosed in this study. Visual recovery after infectious keratitis is guarded, and corneal transplantation for active infection is associated with a high failure rate.
To establish risk factors for moderate and severe microbial keratitis among daily contact lens (CL) wearers in Australia.
A prospective, 12-month, population-based, case-control study.
New cases of ...moderate and severe microbial keratitis in daily wear CL users presenting in Australia over a 12-month period were identified through surveillance of all ophthalmic practitioners. Case detection was augmented by record audits at major ophthalmic centers. Controls were users of daily wear CLs in the community identified using a national telephone survey.
Cases and controls were interviewed by telephone to determine subject demographics and CL wear history. Multiple binary logistic regression was used to determine independent risk factors and univariate population attributable risk percentage (PAR%) was estimated for each risk factor.
Independent risk factors, relative risk (with 95% confidence intervals CIs), and PAR%.
There were 90 eligible moderate and severe cases related to daily wear of CLs reported during the study period. We identified 1090 community controls using daily wear CLs. Independent risk factors for moderate and severe keratitis while adjusting for age, gender, and lens material type included poor storage case hygiene 6.4× (95% CI, 1.9-21.8; PAR, 49%), infrequent storage case replacement 5.4× (95% CI, 1.5-18.9; PAR, 27%), solution type 7.2× (95% CI, 2.3-22.5; PAR, 35%), occasional overnight lens use (<1 night per week) 6.5× (95% CI, 1.3-31.7; PAR, 23%), high socioeconomic status 4.1× (95% CI, 1.2-14.4; PAR, 31%), and smoking 3.7× (95% CI, 1.1-12.8; PAR, 31%).
Moderate and severe microbial keratitis associated with daily use of CLs was independently associated with factors likely to cause contamination of CL storage cases (frequency of storage case replacement, hygiene, and solution type). Other factors included occasional overnight use of CLs, smoking, and socioeconomic class. Disease load may be considerably reduced by attention to modifiable risk factors related to CL storage case practice.
To establish the absolute risk of contact lens (CL)-related microbial keratitis, the incidence of vision loss and risk factors for disease.
A prospective, 12-month, population-based surveillance ...study.
New cases of CL-related microbial keratitis presenting in Australia over a 12-month period were identified through surveillance of all ophthalmic practitioners (numerator). Case detection was augmented by records' audits at major ophthalmic centers. The denominator (number of wearers of different CL types in the community) was established using a national telephone survey of 35,914 individuals.
Cases and controls were interviewed by telephone to determine subject demographics and CL wear history. Visual outcomes were determined 6 months after the initial event. Annualized incidence and confidence intervals (CI) were estimated for different severities of disease and multivariable analysis was used in risk factor analysis.
Annualized incidence (with CI) of disease and vision loss by CL type and wear modality and identification of independent risk factors.
We identified 285 eligible cases of CL-related microbial keratitis and 1798 controls. In daily wear rigid gas-permeable CL wearers, the annualized incidence per 10,000 wearers was 1.2 (CI, 1.1-1.5); in daily wear soft CL wearers 1.9 (CI, 1.8-2.0); soft CL wearers (occasional overnight use) 2.2 (CI, 2.0-2.5); daily disposable CL wearers 2.0 (CI, 1.7-2.4); daily disposable CL wearers (occasional overnight use) 4.2 (CI, 3.1-6.6); daily wear silicone hydrogel CL wearers 11.9 (CI, 10.0-14.6); silicone hydrogel CL wearers (occasional overnight use) 5.5 (CI, 4.5-7.2); overnight wear soft CL wearers 19.5 (CI, 14.6-29.5) and in overnight wear of silicone hydrogel 25.4 (CI, 21.2-31.5). Loss of vision occurred in 0.6 per 10,000 wearers. Risk factors included overnight use, poor storage case hygiene, smoking, Internet purchase of CLs, <6 months wear experience, and higher socioeconomic class.
Incidence estimates for soft CL use were similar to those previously reported. New lens types have not reduced the incidence of disease. Overnight use of any CL is associated with a higher risk than daily use.
TFOS DEWS II Report Executive Summary Craig, Jennifer P.; Nelson, J. Daniel; Azar, Dimitri T. ...
The ocular surface,
October 2017, 2017-10-00, 20171001, Letnik:
15, Številka:
4
Journal Article
Recenzirano
Odprti dostop
This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The ...Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.TearFilm.org.
Infectious keratitis is a rare but potentially severe sight-threatening disease, associated with considerable societal burden, cost and morbidity. This review summarises the most recent evidence for ...the incidence, risk factors and impact of disease, all of which vary widely according to region, access to health care, socioeconomic and environmental factors, predisposing conditions and causative organisms. The frequency and societal impact of infectious keratitis are significantly higher in low-income countries. In non-viral infectious keratitis, bacterial causes predominate in most regions. Fungi, particularly linked with agricultural trauma, are more frequently associated with infectious keratitis in low-income regions, particularly in India and certain African countries. The disease impact is compounded by poverty and limited access to services and treatment. Early diagnosis, access to appropriate treatment, prophylaxis in ocular trauma, availability of eye protection, awareness of risk factors may be associated with reduced disease severity and vision loss. Evidence for the incidence and burden of disease is lacking in certain regions and well-designed epidemiological studies to identify independent risk factors for the disease and those associated with more severe outcomes may better identify causation and guide resource allocation and preventative strategies.
Objective
To compare fall incidence, and visual acuity and refractive status, before surgery and after first and second eye cataract surgery.
Design, setting
Prospective observational study in eight ...tertiary referral ophthalmology clinics in public hospitals in Sydney, Melbourne, and Perth.
Participants
People aged 65 years or more referred for bilateral age‐related cataract surgery during 2013–16, followed for maximum of 24 months after study entry or until six months after second eye surgery, whichever was shorter.
Main outcome measures
Primary outcome: age‐ and sex‐adjusted incidence of falls. Secondary outcomes: visual acuity and refractive error.
Results
The mean age of the 409 included participants was 75.4 years (SD, 5.4 years); 220 were women (54%). Age‐ and sex‐adjusted fall incidence prior to surgery was 1.17 (95% CI, 0.95–1.43) per year, 0.81 (95% CI, 0.63–1.04) per year after first eye surgery, and 0.41 (95% CI, 0.29–0.57) per year after second eye surgery. For the 118 participants who underwent second eye surgery and participated in all follow‐up visits, age‐ and sex‐adjusted incidence before (0.80 95% CI, 0.55–1.15 falls per year) and after first eye surgery (0.81 95% CI, 0.57–1.15 falls per year) was similar, but was lower after second eye surgery (0.32 95% CI 0.21–0.50 falls per year). Mean habitual binocular visual acuity (logMAR) was 0.32 (SD, 0.21) before surgery, 0.15 (SD, 0.17) after first eye surgery, and 0.07 (SD, 0.15) after second eye surgery.
Conclusions
First eye surgery substantially improves vision in older people with cataract, but second eye surgery is required to minimise fall incidence. Timely cataract surgery for both eyes not only optimises vision in older people with cataract, but also reduces their risk of injury from falls.
PDF
