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Though there is no treatment for Cone dystrophy, certain supplements may help in delaying the progression of the disease.
The beta-carotenoids, lutein and zeaxanthin, have been evidenced to reduce the risk of developing age related macular degeneration (AMD), and may therefore provide similar benefits to Cone dystrophy sufferers.
Consuming omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) has been correlated with a reduced progression of early AMD, and in conjunction with low glycemic index foods, with reduced progression of advanced AMD, and may therefore delay the progression of cone dystrophy.
Reis-Bücklers corneal dystrophy is not associated with any systemic conditions.
Treatment is aimed at managing the symptoms of the disease. A form of laser eye surgery named keratectomy may help with the superficial corneal scarring. In more severe cases, a partial or complete corneal transplantation may be considered. However, it is common for the dystrophy to recur within the grafted tissue.
Early stages may be asymptomatic and may not require any intervention. Initial treatment may include hypertonic eyedrops and ointment to reduce the corneal edema and may offer symptomatic improvement prior to surgical intervention.
Suboptimal vision caused by corneal dystrophy usually requires surgical intervention in the form of corneal transplantation. Penetrating keratoplasty, a common type of corneal transplantation, is commonly performed for extensive corneal dystrophy.
With penetrating keratoplasty (corneal transplant), the long-term results are good to excellent. Recent surgical improvements have been made which have increased the success rate for this procedure. However, recurrence of the disease in the donor graft may happen. Superficial corneal dystrophies do not need a penetrating keratoplasty as the deeper corneal tissue is unaffected, therefore a lamellar keratoplasty may be used instead.
Phototherapeutic keratectomy (PTK) can be used to excise or ablate the abnormal corneal tissue. Patients with superficial corneal opacities are suitable candidates for a this procedure.
Currently, there is no treatment for the disease. However, ophthalmologists recommend wearing sunglasses and hats outdoors and blue-light blocking glasses when exposed to artificial light sources, such as screens and lights. Tobacco smoke and second-hand smoke should be avoided. Animal studies also show that high doses of vitamin A can be detrimental by building up more lipofuscin toxin. Dietary non-supplemental vitamin A intake may not further the disease progression.
Clinical trials are being conducted with promising early results. The trials may one day lead to treatments that might halt, and possibly even reverse, the effects of Stargardt disease using stem cell therapy, gene therapy, or pharmacotherapy.
The Argus retinal prosthesis, an electronic retinal implant, was successfully fitted to a 67-year-old woman in Italy at the Careggi Hospital in 2016. The patient had a very advanced stage of Stargardt’s disease, and a total absence of peripheral and central visual fields.
Treatment modalities currently under clinical investigation include cell therapy, gene therapy and oral therapies.
Regarding cell therapy, Advanced Cell Technology, now called Ocata Therapeutics, has completed Phase I/II multicenter clinical trial using retinal cells derived from human embryonic stem cells (hESCs) to treat patients with Stargardt. After treating and collecting data on 18 patients, Advanced Cell was given approval to test its stem cell therapy on patients with 20/100 vision. In October 2014, the results of the Phase I/II clinical trial were published in "the Lancet".
Research at the preclinical (animal) stage include a new compound that can remove lipofuscin from retinal pigment epithelial cells.
Recurrence within a few years occurs in all patients following corneal transplantation. Soft contact lenses are effective in decreasing recurrences.
Corneal transplant is not needed except in very severe and late cases.
Light sensitivity may be overcome by wearing tinted glassess.
In case of corneal erosion, a doctor may prescribe eye drops and ointments to reduce the friction on the eroded cornea. In some cases, an eye patch may be used to immobilize the eyelids. With effective care, these erosions usually heal within three to seven days, although occasional sensations of pain may occur for the next six-to-eight weeks. As patients with LCD suffer with dry eyes as a result of erosion, a new technique involving the insertion of punctal plugs (both upper and lower) can reduce the amount of drops used a day, aiding ocular stability.
By about age 40, some people with lattice dystrophy will have scarring under the epithelium, resulting in a haze on the cornea that can greatly obscure vision. In this case, a corneal transplantation may be needed. There have been many cases in which teenage patients have had the procedure, which accounts for the change in severity of the condition from person to person.
Although people with lattice dystrophy have an excellent chance for a successful corneal transplantation, the disease may also arise in the donor cornea in as little as three years. In one study, about half of the transplant patients with lattice dystrophy had a recurrence of the disease between two and 26 years after the operation. Of these, 15 percent required a second corneal transplant. Early lattice and recurrent lattice arising in the donor cornea responds well to treatment with the excimer laser.
Phototherapeutic keratectomy (PTK) using [Excimer laser] can restore and preserve useful visual function for a significant period of time in patients with anterior corneal dystrophies.
Phototherapeutic keratectomy (PTK) done by an ophthalmologist can restore and preserve useful visual function for a significant period of time in patients with anterior corneal dystrophies including EBMD.
Different corneal dystrophies are caused by mutations in the CHST6, KRT3, KRT12, PIP5K3, SLC4A11, TACSTD2, TGFBI, and UBIAD1 genes. Mutations in TGFBI which encodes "transforming growth factor beta induced" cause several forms of corneal dystrophies including granular corneal dystrophy, lattice corneal dystrophy, epithelial basement membrane dystrophy, Reis-Bucklers corneal dystrophy, and Thiel–Behnke dystrophy.
Corneal dystrophies may have a simple autosomal dominant, autosomal recessive or rarely X-linked recessive Mendelian mode of inheritance:
Non-surgical treatments of FCED may be used to treat symptoms of early disease. Medical management includes topical hypertonic saline, the use of a hairdryer to dehydrate the precorneal tear film, and therapeutic soft contact lenses. Hypertonic saline draws water out of the cornea through osmosis. When using a hairdryer, the patient is instructed to hold it at an arm's length or directed across the face on a cold setting, to dry out the epithelial blisters. This can be done two or three times a day. Definitive treatment, however, (especially with increased corneal edema) is surgical in the form of corneal transplantation. The most common types of surgery for FCED are Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK), which account for over half of corneal transplants in the United States.
More speculative future directions in the treatment of FED include in-vitro expansion of human corneal endothelial cells for transplantation, artificial corneas (keratoprosthesis) and genetic modification. Surgery where the central diseased endothelium is stripped off but not replaced with donor tissue, with subsequent Rho-Associated Kinase (ROCK) inhibition of endothelial cell division may offer a viable medical treatment.
A greater understanding of FED pathophysiology may assist in the future with the development of treatments to prevent progression of disease. Although much progress has been made in the research and treatment of FED, many questions remain to be answered. The exact causes of illness, the prediction of disease progression and delivery of an accurate prognosis, methods of prevention and effective nonsurgical treatment are all the subject of inquiries that necessitate an answer.
Increased attention must be given to research that can address the most basic questions of how the disease develops: what are the biomolecular pathways implicated in disease, and what genetic or environmental factors contribute to its progression? In addition to shaping our understanding of FED, identification of these factors would be essential for the prevention and management of this condition.
Cell based therapies using bone marrow stem cells as well as retinal pigment epithelial transplantation are being studied. A number of trials have occurred in humans with encouraging results.
Supplements that include lutein and zeaxanthin may slow down the worsening of AMD. They have, however, not been shown to prevent the disease. There is not enough evidence to determine if statins have a role in preventing or slowing the progression of AMD. Antiangiogenic steroids such as anecortave acetate and triamcinolone acetonide have shown no evidence in preventing visual loss in people with neovascular AMD.
Vitelliform macular dystrophy or vitelliform dystrophy is an irregular autosomal dominant eye disorder which can cause progressive vision loss. This disorder affects the retina, specifically cells in a small area near the center of the retina called the macula. The macula is responsible for sharp central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. The condition is characterized by yellow (or orange), slightly elevated, round structures similar to the yolk (Latin "vitellus") of an egg.
A cone dystrophy is an inherited ocular disorder characterized by the loss of cone cells, the photoreceptors responsible for both central and color vision.
Posterior Polymorphous Corneal Dystrophy (PPCD; sometimes also "Schlichting dystrophy") is a type of corneal dystrophy, characterised by changes in Descemet's membrane and endothelial layer. Symptoms mainly consist of decreased vision due to corneal edema. In some cases they are present from birth, other patients are asymptomatic. Histopathological analysis shows that the cells of endothelium have some characteristics of epithelial cells and have become multilayered. The disease was first described in 1916 by Koeppe as "keratitis bullosa interna".
PPCD type 2 is linked to the mutations in COL8A2, and PPCD type 3 mutations in ZEB1 gene, but the underlying genetic disturbance in PPCD type 1 is unknown.
Gelatinous drop-like corneal dystrophy, also known as amyloid corneal dystrophy, is a rare form of corneal dystrophy. The disease was described by Nakaizumi as early as 1914.
Granular corneal dystrophy is a slowly progressive corneal dystrophy that most often begins in early childhood.
Granular corneal dystrophy has two types:
- Granular corneal dystrophy type I , also corneal dystrophy Groenouw type I, is a rare form of human corneal dystrophy. It was first described by German ophthalmologist Arthur Groenouw in 1890.
- Granular corneal dystrophy type II, also called Avellino corneal dystrophy or combined granular-lattice corneal dystrophy is also a rare form of corneal dystrophy. The disorder was first described by Folberg et al. in 1988. The name Avellino corneal dystrophy comes from the first four patients in the original study each tracing their family origin to the Italian province of Avellino.
Posterior amorphous corneal dystrophy (PACD) is a rare form of corneal dystrophy. It is not yet linked to any chromosomal locus. The first report describing this dystrophy dates back to 1977.
Congenital stromal corneal dystrophy (CSCD), also called Witschel dystrophy, is an extremely rare, autosomal dominant form of corneal dystrophy. Only 4 families have been reported to have the disease by 2009. The main features of the disease are numerous opaque flaky or feathery areas of clouding in the stroma that multiply with age and eventually preclude visibility of the endothelium. Strabismus or primary open angle glaucoma was noted in some of the patients. Thickness of the cornea stays the same, Descemet's membrane and endothelium are relatively unaffected, but the fibrills of collagen that constitute stromal lamellae are reduced in diameter and lamellae themselves are packed significantly more tightly.
Epithelial basement membrane dystrophy (EBMD), also known as map-dot-fingerprint dystrophy and Cogans's microcystic dystrophy, is a disorder of the eye that can cause pain and dryness.
It is sometimes included in the group of corneal dystrophies. It diverges from the formal definition of corneal dystrophy in being in most cases non-familial. It also has a fluctuating course, while for a typical corneal dystrophy the course is progressive. When it is considered part of this group, it is the most common type of corneal dystrophy.
Controversies exist around eliminating this disorder from breeding Collies. Some veterinarians advocate only breeding dogs with no evidence of disease, but this would eliminate a large portion of potential breeding stock. Because of this, others recommend only breeding mildly affected dogs, but this would never completely eradicate the condition. Also, mild cases of choroidal hypoplasia may become pigmented and therefore undiagnosable by the age of three to seven months. If puppies are not checked for CEA before this happens, they may be mistaken for normal and bred as such. Checking for CEA by seven weeks of age can eliminate this possibility. Diagnosis is also difficult in dogs with coats of dilute color because lack of pigment in the choroid of these animals can be confused with choroidal hypoplasia. Also, because of the lack of choroidal pigment, mild choroidal hypoplasia is difficult to see, and therefore cases of CEA may be missed.
Until recently, the only way to know if a dog was a carrier was for it to produce an affected puppy. However, a genetic test for CEA became available at the beginning of 2005, developed by the Baker Institute for Animal Health, Cornell University, and administered through OptiGen. The test can determine whether a dog is affected, a carrier, or clear, and is therefore a useful tool in determining a particular dog's suitability for breeding.
Subepithelial mucinous corneal dystrophy (SMCD) is a rare form of corneal dystrophy. It was first described in 1993 by Feder et al. Anterior to Bowman layer, deposits of glycosaminoglycan were detected and identified as chondroitin-4-sulfate and dermatan sulfate.
CNV is conventionally treated with intravitreal injections of angiogenesis inhibitors (also known as "anti-VEGF" drugs) to control neovascularization and reduce the area of fluid below the retinal pigment epithelium. Angiogenesis inhibitors include pegaptanib, ranibizumab and bevacizumab (known by a variety of trade names, such as Macugen, Avastin or Lucentis). These inhibitors slow or stop the formation of new blood vessels (angiogenesis), typically by binding to or deactivating the transmission of vascular endothelial growth factor ('VEGF'), a signal protein produced by cells to stimulate formation of new blood vessels. The effectiveness of angiogenesis inhibitors has been shown to significantly improve visual prognosis with CNV, the recurrence rate for these neovascular areas remains high.
CNV may also be treated with photodynamic therapy coupled with a photosensitive drug such as verteporfin (Visudyne). The drug is given intravenously. It is then activated in the eye by a laser light. The drug destroys the new blood vessels, and prevents any new vessels forming by forming thrombi.