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).
Rubella Virus Infections
Sunit K. Singh, Daniel Růžek in Neuroviral Infections, 2013
The typical cataracts and pigmentary retinopathy seen in CRS were described by Gregg in 1941. The cataracts may consist of a central dense pearly white opacity (Figure 17.5e) or may be total with a more uniform density throughout the lens. Bilateral cataracts are found in about 50% of affected infants; they are usually present at birth but may not be visible until several weeks later. Cataracts, which are often accompanied by microphthalmia (Figure 17.6 a,b), are a useful marker for surveillance of CRS (Bloom et al. 2005; WHO 1999; Vijayalakshmi et al. 2007). Retinopathy is found in about 50% of affected infants. Hyperpigmented and hypopigmented areas of the retina give it a “salt and pepper” appearance, which can be a useful diagnostic indicator of CRS; however, because it does not cause any visual defects, it may not be suspected. Retinopathy is due to a defect in pigmentation and usually involves the macular areas. Glaucoma is less frequently observed than cataract. Other symptoms are pupil rigidity, cloudy cornea, corneal opacity, microcornea, iris hypoplasia, optic atrophy, anophthalmos, chronic uveitis, corneal hydrops, choroidal neovascularization, and keratoconus (Arnold et al. 1994; Vijayalakshmi et al. 2007). Some of these ocular abnormalities may occur later in life (see below).
Nutrition
Jan de Boer, Marcel Dubouloz in Handbook of Disaster Medicine, 2020
Severe vitamin A deficiency causes xerophthalmia, blindness and death. Clinical eye signs include: poor vision in dim light, dryness of conjunctiva or cornea, foamy material on the conjunctiva, or clouding of the cornea itself. These signs may appear after several months of an inadequate diet, or following acute or prolonged infections, particularly measles and diarrhoea. Mild/moderate vitamin A deficiency increases young-child mortality rates by about 20%. Clinical assessment reveals signs only in a very small proportion of subjects in populations affected by vitamin A deficiency and large numbers of children must be examined if this is the method of assessment used. Biochemical assessment is by the modified relative dose response (MRDR), which detects mild and moderate deficiency5.
Ocular Surface Disease in Glaucoma Patients
Published in Current Eye Research, 2023
Christina Scelfo, Reem H. ElSheikh, Muhammad M. Shamim, Javaneh Abbasian, Alireza Ghaffarieh, Abdelrahman M. Elhusseiny
Dry eye disease includes either evaporative tear loss or aqueous insufficiency. Other causes of dry eye include meibomian gland dysfunction (MGD) and blepharitis.21 All three conditions can lead to ocular surface disease which manifests in several tissues of both the eyelids and anterior segment including the lid margin, meibomian glands, conjunctiva, and cornea.7 Patients may present with subjective symptoms such as dryness, burning, foreign body sensation, and photophobia or objective symptoms such as tearing, injection, and decreased vision.21,22 Prior studies have shown that symptoms on instillation or between doses correlate with patient dissatisfaction.10 This could lead to non-compliance and contribute to treatment failure.18
Novel Cytokine Multiplex Assay for Tear Fluid Analysis in Sjogren’s Syndrome
Published in Ocular Immunology and Inflammation, 2021
Bernd Willems, Louis Tong, Tue Dang Thi Minh, Ngoc Dong Pham, Xuan Hiep Nguyen, Markus Zumbansen
The autoimmune disease Sjögren’s syndrome (SS) induces a relatively severe form of dry eye syndrome (DES), also called keratoconjunctivitis sicca (KCS). It is characterized by a lack of tear secretion or tear instability, as well as an increase in inflammation in the tear fluid and peri-ocular glands such as the lacrimal glands, meibomian glands and the conjunctival mucosa including the goblet cells. The SS affects 0.3–0.5% of the adult western population.1,2 Women are nine times more likely to be affected than men1. When cells of the patient´s immune system wrongly recognize lacrimal and salivary gland cells as foreign entities, the resulting chronic inflammation leads to gland dysfunction which results not only in dry eyes but also dry mouth and dryness of skin. There could be various degrees of ocular manifestations ranging from eye irritation and redness to chronic inflammation and scarring of the cornea.3–5
Drugs of abuse and ocular effects
Published in Clinical and Experimental Optometry, 2021
Valérie Proulx, Benoit Tousignant
There are also commonly reported associations between the use of cocaine and corneal problems. This drug is known for its anaesthetic effect on the cornea, which can lead to decreased blinking and toxic effects to the corneal epithelium, from devitalisation of the corneal nerves or decreased epithelial integrity. Cocaine fumes or smoke may cause increased pruritus of the eye and lead to mechanical corneal trauma. When this condition is related to smoking crack cocaine, it is sometimes reported as ‘crack eye syndrome’.39,40 One study shows that after ten years of stopping cocaine, corneal nerves may still show abnormalities.41 All these effects on the cornea may lead to commonly reported conditions such as decreased corneal nerve sensitivity, microbial or fungal keratitis (with or without severe corneal ulceration), chronic dry eye from reduced tear production.39–47 There are also recurrent reports of neurotrophic keratopathy and a case of corneal perforation leading to anterior staphyloma.48
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