Contact Lens-related Infectious Keratitis Research Articles

Epidemiology, Microbiology, and Genetics of Contact Lens-Related and Non-Contact Lens-Related Infectious Keratitis.

Infectious keratitis is a rare but severe condition associated with a range of ocular and systemic predisposing conditions, including ocular trauma, prior surgery, surface disease, and contact lens (CL) wear. This review explores the epidemiology of infectious keratitis, specifically the differences in disease incidence and risk factors, causative organism profile and virulence characteristics and host microbiome, genetics, gene expression, proteomics, and metabolomic characteristics in CL-related and non-CL-related diseases. Differences exist in the epidemiology, demographics, causative organisms, and their virulence characteristics in CL-related and non-CL-related diseases, and there is less evidence to support differences between these groups of individuals in the ocular surface microbiome, genetics, and pathways of disease. Genetic variations, however, in the host immune profile are implicated in both the onset and severity of infectious keratitis in CL and non-CL wearers. As technologies in metabolomics, proteomics, and genomics improved to be better able to process small-volume samples from the ocular surface, there will be improved understanding of the interplay between the CL, ocular surface, host immune profile, and the microbial environment. This may result in a more personalized approach in the management of disease to reduce disease severity.

Contact Lenses and Infectious Keratitis

We review the evolution of contact lenses, risk factors for contact lens-related infectious keratitis, and updates on management. Infectious keratitis is still a devastating complication of contact lens use, with improper lens hygiene and use as significant risk factors. Cosmetic contact lenses have become popular among the younger generations. They can be obtained online without a doctor’s prescription or supervision, leading to an increased risk of serious infection. Topical antibiotics remain the best treatment for bacterial keratitis, but resistance to fourth-generation fluoroquinolones has increased. Fungal ulcers fare worse than bacterial ulcers, with no new commercially available topical treatments since topical natamycin. Despite the well-established link between water exposure of contact lenses and development of Acanthamoeba keratitis, patients still regularly expose their lenses to tap water. Corneal cross-linking, new methods for antimicrobial drug delivery, and novel antimicrobial targets represent the next frontiers in the treatment of infectious keratitis. Contact lens-related infectious keratitis remains a serious cause of ocular morbidity, with the rates of atypical causative organisms (Acanthamoeba and fungus) on the rise. Strategies for risk reduction include prevention through patient education; collaboration with industry to develop novel antimicrobials, lens materials, and care system products; and reporting of infections and illegal sale of contact lenses to regulatory agencies such as the United States Food and Drug Administration (FDA) and the Federal Trade Commission (FTC).

Acanthamoeba and Fusarium interactions: A possible problem in keratitis

The incidence of Acanthamoeba and Fusarium species has increased in contact lens-related infectious keratitis. They share several environments and cases of co-infection have been reported. The interaction between the amoebae and other microorganisms may result in significant changes for both, like increased virulence in mammalian hosts. In this study, we evaluated the interaction of three Acanthamoeba castellanii strains with Fusarium conidia and the possible implications on keratitis. F. conidia were internalized by A. castellanii strains and were able to germinate inside the amoebae. The co-culture with the live amoebae, as well as the amoebal culture supernatant and lysate, increased the fungal growth significantly. Moreover, live F. solani and its culture supernatant enhanced the survival of amoebae, but in a different way in each amoebal strain. The encystment of the A. castellanii strain re-isolated from rat lung was increased by the fungus. These results show that A. castellanii and F. solani interaction may have an important influence on survival of both, and specially indicate a possible effect on virulence characteristics of these microorganisms. These data suggest that the A. castellanii–F. solani interaction may cause severe impacts on keratitis.

Risk Factors and Microbiological Features of Patients Hospitalized for Microbial Keratitis

We conducted a retrospective, cross-sectional study to analyze predisposing factors, clinical features, and microbiological characteristics of patients with microbial keratitis hospitalized over 10 years.The medical records of 558 patients who were diagnosed with microbial keratitis and admitted to Chang Gung Memorial Hospital (CGMH), a referral center in Taiwan, from January 1, 2003 to December 31, 2012 were reviewed. Demographics, predisposing factors, isolated organisms, treatment, and hospital stay were recorded. Yearly trends were tested using a linear-by-linear association.Contact lens wear was the most common predisposing factor (31.4%), followed by ocular and systemic diseases (26.3%) and trauma (23.5%). Contact lens-related infectious keratitis increased year by year (P = 0.011). Pseudomonas aeruginosa was the most commonly isolated organism (28%), followed by fungi (17.6%) and coagulase-negative Staphylococcus (5.4%). Except for Serratia marcescens, the identified organisms did not change over 10 years. Most bacterial infections were controlled using antimicrobial treatment, but more than half of patients with fungal keratitis required surgical interventions. The mean hospital stay was 13.7 ± 11.5 days. Previous ocular surgery, large ulcer size, nontuberculous myycobacteris infection, and surgery during admission were related to prolonged hospital stay.In Taiwan, contact lens-related pseudomonal keratitis remained the most common cause of microbial keratitis in patients hospitalized from 2003 to 2012.

Corneal Thinning after Contact Lens-related Infective Keratitis

ABSTRACT Purpose To describe two cases of contact lens-related infectious keratitis with secondary corneal thinning. Material and methods Case reports and review of the literature. Results The first case is of a 13-year-old girl, contact lens user, admitted for acute corneal infection in her right eye (OD). Seven years after treatment, she presented with corneal thinning and flattening with uncorrected distance visual acuity of 20/30 OD; thinnest value was 363 µm in OD and 513 µm in the left eye (OS). The second case is a 22-year-old male, cosmetic contact lens user, first presented with severe keratitis in OD. One year after treatment, the eye was quiet with moderate corneal opacity; corneal thickness was 228 µm OD and 561 µm OS. Ectasia was identified due to the protrusion and steepening with an irregular curvature pattern. Rigid gas permeable (RGP) contact lens fitting enabled visual acuity of 20/25 OD. Conclusion Corneal melt with secondary stromal loss and thinning may lead or not to secondary ectasia. Visual rehabilitation is possible with RGP contact lenses despite corneal opacity. The risk of infectious keratitis among contact lenses users should be considered. How to cite this article Almeida R, Rodrigues F, Santos M, Siqueira R, Contarini P, Salgado-Borges J, Ambrosio R Jr. Corneal Thinning after Contact Lens-related Infective Keratitis. Int J Kerat Ect Cor Dis 2014;3(2):95-98.

Corneal Cross-Linking as Supplementary Treatment Option in Melting Keratitis: A Case Series

Corneal melting represents a serious condition that can result in corneal perforation and loss of vision. Treatment options include topical and systemic immunosuppression, cyanoacrylate gluing, and emergency keratoplasty, depending on the underlying disease and the stage of corneal melt. Recently, corneal cross-linking (CXL) has emerged as an additional treatment option. The present study evaluates whether CXL induces a clinical improvement in melting keratitis not responding to conventional treatment. Six patients undergoing CXL for corneal melting of variable origin (including bacterial, fungal and Acanthamoeba keratitis) were reviewed retrospectively. Treatment parameters included riboflavin application following UV irradiation with a wavelength of 370 nm and an irradiance of 3 mW/cm2 for 30 minutes. Four patients with corneal melting due to contact lens-related infectious keratitis showed healing without any need for further interventions up to date. In two patients, CXL stabilized the melting cornea and facilitated additional surgical procedures. By stabilizing corneal collagen fibres, CXL seems to represent an effective option to re-establish corneal integrity in the event of pending perforations. In established perforations, CXL facilitates further emergency procedures by stiffening the tissue.

Lentilles de contact et risques infectieux, aspects réglementaires

Contact lens-related infectious keratitis is a potentially sight-threatening complication. Bacterial keratitis, mostly due to Gram-negative bacteria, is associated with poor lens hygiene, overnight wear, and contaminated lens care solutions. Contamination of the lens storage case may cause fungal keratitis. Acanthamoeba infection is related to the use of tap water or swimming while wearing soft lenses. Viruses are of less concern among contact lens wearers. Possible transmission of Creutzfeldt-Jakob disease by multi-patient trial lenses must be taken in account. To minimize these risk factors, regulations are applied at various levels: CE marking of contact lenses and care products as they are medical devices; contact lens fitting only by health care professionals; distribution of contact lenses by opticians and lens care solutions by opticians and pharmacists; hygienic management of trial lenses following official recommendations. Contact lens-related keratitis must be reported to health care Authorities.

Contact Lens-related Infectious Keratitis

Infectious keratitis is the most serious complication of contact lens use. Virtually all contact lens wearers are at risk. Initial therapy consists of frequent broad-spectrum fortified antibiotic drops after appropriate laboratory workup. Pseudomonas and Acanthamoeba species are the most important causes of contact lens-associated ulcers. Acanthamoeba keratitis produces significant ocular morbidity, and treatment is not always effective. Recent studies have provided new insights regarding the incidence, risk factors, and pathogenesis of contact lens-related infectious keratitis. Extended-wear soft contact lens wearers are at greatest risk. With our present understanding of the pathogenesis and risk factors of contact lens-related infectious keratitis, daily-wear schedules are strongly advised. Even under the best of lens care conditions, infectious keratitis may still occur. It is therefore imperative that patients be informed to remove their lenses and seek medical evaluation if any discomfort develops.

Contact lens-related infectious keratitis

Infectious keratitis is the most serious complication of contact lens use. Virtually all contact lens wearers are at risk. Initial therapy consists of frequent broad-spectrum fortified antibiotic drops after appropriate laboratory workup. Pseudomonas and Acanthamoeba species are the most important causes of contact lens-associated ulcers. Acanthamoeba keratitis produces significant ocular morbidity, and treatment is not always effective. Recent studies have provided new insights regarding the incidence, risk factors, and pathogenesis of contact lens-related infectious keratitis. Extended-wear soft contact lens wearers are at greatest risk. With our present understanding of the pathogenesis and risk factors of contact lens-related infectious keratitis, daily-wear schedules are strongly advised. Even under the best of lens care conditions, infectious keratitis may still occur. It is therefore imperative that patients be informed to remove their lenses and seek medical evaluation if any discomfort develops.