Exploring Potential of Nanocarriers for Therapy of Mycotic Keratitis
Mahendra Rai, Marcelo Luís Occhiutto in Mycotic Keratitis, 2019
Keratitis, a general term for eye condition in which the cornea (dome shaped transparent window in front of the eye) becomes inflamed, is a painful inflammatory condition which causes problems with vision and makes the eye more sensitive to light (Shukla et al. 2008, Srigyan et al. 2017). The non-infectious keratitis can be caused by wearing contact lenses for too long, dry eyes, an allergic reaction to cosmetics or pollution, injury to the cornea due to foreign objects lodged in the eye, exposure to intense sunlight, vitamin A deficiency, etc. However, the infectious or microbial keratitis includes ocular infections that can be caused by a range of non-viral pathogens. The causative organisms include bacteria, protists (e.g., Acanthamoeba), and fungi (yeasts, molds and microsporidia) (Srinivasan et al. 2008, Barnes et al. 2014). In most countries with a tropical climate fungi are the important causative organism of keratitis and account for nearly 40% of all isolates from corneal ulcer cases (Kredics et al. 2015).
The cornea
Mary E. Shaw, Agnes Lee in Ophthalmic Nursing, 2018
Acanthamoeba keratitis is usually associated with a history of improper cleaning of contact lenses, using homemade sodium chloride solution to clean the lenses, and swimming in fresh water or a swimming pool while contact lenses are worn. Keratitis typically begins with a foreign-body sensation followed by pain, tearing, photophobia, blepharospasm and blurred vision. Patients may have periods of symptom remission with a waxing and waning course. The condition is very painful as the organism has a predilection for the corneal nerves – radial perineuritis and a ring-shaped infiltrate are findings which would strongly suggest Acanthamoeba keratitis. Early diagnosis and treatment are paramount for improving outcomes. A high index of suspicion is needed to make the diagnosis, especially in the early stages. The earliest clue to this infection is a dendriform pattern noted on the epithelium of the cornea. Identification of Acanthamoeba consist of culture on a buffered charcoal yeast extract or with non-nutrient agar overlaid with organisms such as Escherichia coli, polymerase chain reaction of biopsy specimens and scanning confocal corneal microscopy. If corneal specimens are unremarkable, consider culturing the contact lenses and saline solution for Acanthamoeba (Kerr 2014).
Herpes Simplex Virus Infections in Immunocompromised Patients
Marie Studahl, Paola Cinque, Tomas Bergström in Herpes Simplex Viruses, 2017
The diagnosis of keratitis can be established by opthalmologic evaluation. A diagnosis of etiology, or HSV subtyping is achieved by virus culture or PCR on tissue or fluid obtained by corneal scraping, anterior chamber aspirate, or biopsy. Recommended treatment does not differ from that of HSV keratitis occurring in immunocompetent patients and must be aggressive and initiated promptly to prevent further complications. The medical treatment of choice of epithelial keratitis is topical trifluridine. Vidarabine 3% ointment five times/day may also be effective. Use of oral aciclovir is debated, as it has been shown that oral administration did not prevent active herpes lesions of the corneal epithelium from moving deeper into the stroma (98). In cases of frequently recurrent disease, oral aciclovir, valaciclovir or famciclovir may be administered to suppress the risk of recurrence (9).
Reports of New and Recurrent Keratitis following mRNA-based COVID-19 Vaccination
Published in Ocular Immunology and Inflammation, 2023
Paras P. Shah, Yoav Glidai, Richard Braunstein, Matthew Gorski, Jung Lee, Farihah Anwar, Amelia Schrier, Jules Winokur, Anne S. Steiner
Keratitis is an inflammatory condition of the cornea that can be characterized by pain, tearing, blurry vision, inflammation, and even loss of vision.17 Although its etiology is multifaceted, it is most commonly caused by infectious and non-infectious inflammatory conditions. Of these, infectious keratitis is the leading cause of corneal blindness and the fourth leading cause of overall blindness globally, representing an annual incidence of up to 799 per 100,000 population-year.5,18 Within the umbrella of infectious keratitis, HSV keratitis is the most common, affecting an estimated 500,000 people in the United States at any given time.19 Adequate work-up to identify the causative organism is crucial to guiding treatment; the gold standard remains culture, although other techniques such as in vivo confocal microscopy have also emerged.5
Infectious Keratitis Caused by Rare and Emerging Micro-Organisms
Published in Current Eye Research, 2020
Pranita Sahay, Siddhi Goel, Ritu Nagpal, Prafulla K. Maharana, Rajesh Sinha, Tushar Agarwal, Namrata Sharma, Jeewan S. Titiyal
Kocuria spp. is a coagulase-negative gram-positive coccus that rarely causes keratitis and canaliculitis.16,17 Keratitis is usually seen in eyes with compromised ocular surface or immunocompromised patient. Clinical presentation is variable with a severe course and poor outcome in the majority of the cases. The identification of this species is done by culture reports, mass spectroscopy and gene analysis. It forms 2–3 mm whitish, small, round, raised, convex colonies, which develops a yellowish pigmentation on prolonged incubation in blood agar.16Kocuria spp. is often misdiagnosed as coagulase-negative staphylococcus. It is sensitive to vancomycin, cephalosporin, and few fluoroquinolones. Usually, these cases are severe at presentation requiring surgical intervention.16
Kocuria Endophthalmitis: Clinical Spectrum and Long-term Outcomes
Published in Ocular Immunology and Inflammation, 2022
Gabriela P. Amadeo-Oreggioni, Grecia Y. Ortiz-Ramirez, Pablo Baquero-Ospina, Guillermo Salcedo-Villanueva, Jorge Jans Fromow-Guerra, Raul Velez-Montoya
The current case series expands the work by Dave et al and includes a detailed description of the clinical presentation and follow-up of 6 cases of Kocuria endophthalmitis.5 Although all patients were considered immunocompetent in our series, two patients had a history of longstanding diabetes mellitus, and all were significantly older than patients in the series by Dave et al at the time of endophthalmitis diagnosis (31 ± 17.4 vs. 60.5 ± 15.5).5 It is important to note that even though all patients reported severe pain, red eye, and poor visual acuity, the majority had keratitis-associated infections; therefore, this association should be taken with caution. Nevertheless, a more severe presentation than expected or a slightly longer time to onset should raise the suspicion level of Kocuria endophthalmitis in cases in which a CNS is the expected pathogen. This diagnosis should also be part of the differential diagnosis in cases of endophthalmitis associated with any form of keratitis, corneal ulcers, or penetrating keratoplasties.
Related Knowledge Centers
- Cornea
- Eye
- Herpes Simplex Virus
- Inflammation
- Photophobia
- Red Eye
- Nummular Keratitis
- Interstitial Keratitis
- Neurotrophic Keratitis
- Herpes Simplex Keratitis