Special Senses
Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard in Toxicologic Pathology, 2018
Corneal deposits often consist of mineral. Some deposits are a feature of corneal dystrophy, but others may be due to other causes (Peiffer et al. 1994; Taradach et al. 1981). Corneal dystrophy is a spontaneous, noninflammatory, bilateral corneal change that occurs in several laboratory animals (Moore et al. 1987; Port and Dodd 1983; Shibuya et al. 2001). Microscopically, the finding consists of mineralized deposits along the corneal epithelial basement membrane (Bruner et al. 1992; Carlton and Render 1991a; Hoffman et al. 1983; Losco and Troup 1988). A high spontaneous incidence of corneal mineralization has been reported in Wistar Hannover rats, being greater in males compared to females, with a hypothesis proposed that in response to mineralization, keratocytes become active to play an important role in responding to the mineralized substance (Hashimoto et al. 2013). Mineralized deposits in the cornea adjacent to the palpebral fissure are referred to clinically as band keratopathy.
Lysosomal, sterol and lipid disorders
Steve Hannigan in Inherited Metabolic Diseases: A Guide to 100 Conditions, 2018
Symptoms of Anderson-Fabry disease usually appear during childhood or adolescence. However, in some cases the onset has been reported to be delayed until the third decade. The early clinical features include a dark bluish-red rash (angioker-atoma), commonly seen in the bathing trunk area, umbilicus and the mucous membranes of the mouth, decreased sweating (hypohydrosis), and gastrointestinal manifestations such as alternating constipation and diarrhoea, abdominal pain and bloating. Slit-lamp examination of the eyes reveals haziness of the cornea (corneal dystrophy or cornea verticillata), which does not afect vision. Cataracts and tortuosity of the blood vessels in the retina can also be present. There are usually episodes of severe burning pain, known as acroparaesthesiae, in the hands and feet and sometimes in the arms and legs. Patients with Anderson-Fabry disease may also suffer from a sudden onset of sharp tingling pains in their fingers or toes, or experience acute abdominal pain, which is sometimes mistaken for an acute abdominal problem such as appendicitis. These episodes of sudden-onset pain are called Fabry crises. They may last for a few minutes but can sometimes last for days. They are usually brought on by fatigue, exercise, stress, fever or variations in temperature, and are often not relieved by standard painkillers. In addition, afected individuals may be intolerant of heat, which may lead to nausea, light-headedness, headaches and general weakness. Children with Anderson-Fabry disease often experience tiredness and lethargy, which afects their daily activities and school performance, and these symptoms are worsened by decreased sweating.
Ocular media
Fiona Rowe in Visual Fields via the Visual Pathway, 2016
One of the most common pathologies is that of cataract which causes a reduction of sensitivity across the central visual field (Figure 4.4). With corneal dystrophy the marked corneal opacity typically causes a pronounced generalised depression of sensitivity in the central field (Figure 4.5). In general, anterior opacities typically result in general reduction of sensitivity (because of scattered light) whereas posterior opacities result in more localised visual field defects (due to shadow effects).
Phototherapeutic Keratectomy in Macular and Granular Dystrophy: Two-year Results
Published in Seminars in Ophthalmology, 2020
Burcu Kemer Atik, Yusuf Yildirim, Orcun Sonmez, Gulsah Gumus, Burcin Kepez Yildiz, Alper Agca
Corneal dystrophies are a group of diseases with bilateral, progressive, non-inflammatory, and genetic transmission.1–3 Granular and macular corneal dystrophies are in the group of stromal corneal dystrophies and are characterized by corneal opacification.1,2 Granular corneal dystrophy is characterized by amorphous hyaline deposits in the stromal layer of the cornea, and shows autosomal dominant inheritance.1,4 Macular corneal dystrophy shows autosomal recessive genetic transition, and abnormal proteoglycan synthesis is the main mechanism in its pathogenesis.1,2,4 In both granular and macular dystrophy, abnormal corneal deposits diminish corneal transparency and this leads to decreased visual acuity. Penetrating keratoplasty, deep anterior lamellar keratoplasty, or phototherapeutic keratectomy (PTK) may be preferred in the treatment of corneal opacifications.1–4
Unilateral posterior polymorphous corneal dystrophy due to a novel ZEB1 gene mutation in a Korean girl
Published in Ophthalmic Genetics, 2022
Chae Yeon Lee, Ja-Hyun Jang, Gyule Han, Tae-Young Chung, Dong Hui Lim
The child in this case report revealed a likely pathogenic variant in the ZEB1 gene and her clinical manifestation was consistent with PPCD3. In 2010, Nguyen et al. reported a novel change in exon 5 of ZEB1 (c.672delA) that resulted in clinical phenotype in a family with PPCD (6,7). Since then, many studies on ZEB1 have been conducted. ZEB1 is thought to be responsible for up to 50% of PPCD cases (7,8). Although the exact mechanism which induces corneal dystrophy is not fully elucidated, ZEB1 binds to a promoter of the COL4A3 gene and, when ZEB1 is mutated, the expression of the COL4A3 protein is altered, which may provoke the endothelial cells to manifest a different phenotype. Furthermore, the ZEB1 protein has been implicated in many other metabolic pathways, including epithelial–mesenchymal transition (9). There has been retrocorneal membrane growth observed when interventions like surgery or trauma were performed in patients with this gene mutation and the frequency of guttata expression was higher. In addition to corneal disease, an association with metabolic diseases such as obesity or inguinal hernia has also been reported (10).
Assessment of incorporation of the International Committee for Classification of Corneal Dystrophies (IC3D) in literature
Published in Ophthalmic Genetics, 2020
Saif Aldeen AlRyalat, Bahaa Al-Din Jaber
The present study sheds a light on the adoption of the recently issued nomenclature for corneal dystrophy, which has important clinical and practical implications. Most dystrophies have multiple names and eponyms that are used in the literature, some of which may be misleading, and naming Schnyder corneal dystrophy as a “crystalline” dystrophy is an example. The adoption of this change was well implemented in the literature, as 80.95% of publications used the new name “Schnyder corneal dystrophy”. This change in nomenclature emphasized on the possibility of diagnosing this dystrophy without the presence of crystals (5). On the other hand, granular corneal dystrophy type 2 was the least used among the approved nomenclature, as Avellino dystrophy alone was used in almost half of the publications. The main limitation of the current study is that cases of corneal dystrophy may be published in languages other than English, which were not covered in the current study.
Related Knowledge Centers
- Cornea
- Lipid
- Cholesterol
- Ophthalmology
- Tgfbi
- Epithelial Basement Membrane Dystrophy
- Subepithelial Mucinous Corneal Dystrophy
- Lisch Epithelial Corneal Dystrophy
- Lattice Corneal Dystrophy
- Granular Corneal Dystrophy