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One form of LCA, patients with LCA2 bearing a mutation in the RPE65 gene, has been successfully treated in clinical trials using gene therapy. The results of three early clinical trials were published in 2008 demonstrating the safety and efficacy of using adeno-associated virus to deliver gene therapy to restore vision in LCA patients. In all three clinical trials, patients recovered functional vision without apparent side-effects. These studies, which used adeno-associated virus, have spawned a number of new studies investigating gene therapy for human retinal disease.
The results of a phase 1 trial conducted by the University of Pennsylvania and Children’s Hospital of Philadelphia and published in 2009 showed sustained improvement in 12 subjects (ages 8 to 44) with RPE65-associated LCA after treatment with AAV2-hRPE65v2, a gene replacement therapy. Early intervention was associated with better results. In that study, patients were excluded based on the presence of particular antibodies to the vector AAV2 and treatment was only administered to one eye as a precaution. A 2010 study testing the effect of administration of AAV2-hRPE65v2 in both eyes in animals with antibodies present suggested that immune responses may not complicate use of the treatment in both eyes.
Eye Surgeon Dr. Al Maguire and gene therapy expert Dr. Jean Bennett developed the technique used by the Children's Hospital.
Dr. Sue Semple-Rowland at the University of Florida has recently restored sight in an avian model using gene therapy.
Treatment is usually unnecessary. In severe cases, surgery with a bilateral levator excision and frontalis brow suspension may be used.
Although treatment may be unnecessary, there may be social implications, especially in young children when venturing from a supportive home environment to a public environment (e.g., starting school). Continued support, including monitoring behavior and educating the child about his or her appearance as seen by others, is encouraged. Gradual or sudden withdrawal from interaction with others is a sign that may or may not be related to such behavior. Studies are being conducted to elucidate these implications.
Whether blindness is treatable depends upon the cause. Surgical intervention can be performed in PCG which is childhood glaucoma, usually starting early in childhood. Primary congenital glaucoma is caused by an abnormal drainage of the eye. However, surgical intervention is yet to prove effective.
Idebenone is a short-chain benzoquinone that interacts with the mitochondrial electron transport chain to enhance cellular respiration. When used in individuals with LHON, it is believed to allow electrons to bypass the dysfunctional complex I. Successful treatment using idebenone was initially reported in a small number of patients.
Two large-scale studies have demonstrated the benefits of idebenone. The Rescue of Hereditary Optic Disease Outpatient Study (RHODOS) evaluated the effects of idebenone in 85 patients with LHON who had lost vision within the prior five years. In this study, the group taking idebenone 900 mg per day for 24 weeks showed a slight improvement in visual acuity compared to the placebo group, though this difference was not statistically significant. Importantly, however, patients taking idebenone were protected from further vision loss, whereas the placebo group had a steady decline in visual acuity. Further, individuals taking idebenone demonstrated preservation of color vision and persistence of the effects of idebenone 30 months after discontinuing therapy. A retrospective analysis of 103 LHON patients by Carelli et al. builds upon these results. This study highlighted that 44 subjects who were treated with idebenone within one year of onset of vision loss had better outcomes, and, further, that these improvements with idebenone persisted for years.
Idebenone, combined with avoidance of smoke and limitation of alcohol intake, is the preferred standard treatment protocol for patients affected by LHON. Idebenone doses are prescribed to be taken spaced out throughout the day, rather than all at one time. For example, to achieve a dose of 900 mg per day, patients take 300 mg three times daily with meals. Idebenone is fat soluble, and may be taken with a moderate amount of dietary fat in each meal to promote absorption. It is recommended that patients on idebenone also take vitamin C 500 mg daily to keep idebenone in its reduced form, as it is most active in this state.
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.
Lucio's phenomenon is treated by anti-leprosy therapy (dapsone, rifampin, and clofazimine), optimal wound care, and treatment for bacteremia including antibiotics. In severe cases exchange transfusion may be helpful.
Disease progression may be slowed with immunosuppressives and other medications, and esophageal reflux, pulmonary hypertension and Raynaud phenomenon may benefit from symptomatic treatment. However, there is no cure for this disease as there is no cure for scleroderma in general.
Braille is a universal way to learn how to read and write, for the blind. A refreshable braille display is an assistive learning device that can help such children in school. Schools for the blind are a form of management, however the limitations of using studies done in such schools has been recognized. Children that are enrolled presently, usually, had developed blindness 5 or more years prior to enrollment, consequently not reflecting current possible causes. About 66% of children with visual impairment also have one other disability (comorbidity), be it, intellectual disabilities, cerebral palsy, or hearing loss. Eye care/screening for children within primary health care is important as catching ocular disease issues can lead to better outcomes.
Currently there is no effective therapy for dominant optic atrophy, and consequently, these patients are simply monitored for changes in vision by their eye-care professional. Children of patients should be screened regularly for visual changes related to dominant optic atrophy. Research is underway to further characterize the disease so that therapies may be developed.
Medications can be helpful for moderate or severe RP.
- Vasodilators – calcium channel blockers, such as the dihydropyridines nifedipine or amlodipine, preferably slow release preparations – are often first line treatment. They have the common side effects of headache, flushing, and ankle edema; but these are not typically of sufficient severity to require cessation of treatment. The limited evidence available shows that calcium channel blockers are only slightly effective in reducing how often the attacks happen. Peoples whose RP is secondary to erythromelalgia often cannot use vasodilators for therapy as they trigger 'flares' causing the extremities to become burning red due to there being too much blood.
- People with severe RP prone to ulceration or large artery thrombotic events may be prescribed aspirin.
- Sympatholytic agents, such as the alpha-adrenergic blocker prazosin, may provide temporary relief.
- Losartan can, and topical nitrates may, reduce the severity and frequency of attacks, and the phosphodiesterase inhibitors sildenafil and tadalafil may reduce their severity.
- Angiotensin receptor blockers or ACE inhibitors may aid blood flow to the fingers, and there is some evidence that angiotensin receptor blockers (often losartan) reduce frequency and severity of attacks, and possibly better than nifedipine.
- The prostaglandin iloprost is used to manage critical ischemia and pulmonary hypertension in RP, and the endothelin receptor antagonist bosentan is used to manage severe pulmonary hypertension and prevent finger ulcers in scleroderma.
- Statins have a protective effect on blood vessels, and SSRIs such as fluoxetine may help RP symptoms but the data is weak.
Evidence does not support the use of alternative medicine, including acupuncture and laser therapy.
Genetic tests and related research are currently being performed at Centogene AG in Rostock, Germany; John and Marcia Carver Nonprofit Genetic Testing Laboratory in Iowa City, IA; GENESIS Center for Medical Genetics in Poznan, Poland; Miraca Genetics Laboratories in Houston, TX; Asper Biotech in Tartu, Estonia; CGC Genetics in Porto, Portugal; CEN4GEN Institute for Genomics and Molecular Diagnostics in Edmonton, Canada; and Reference Laboratory Genetics - Barcelona, Spain.
Given the unknown nature of MES, treatments have been largely dependent on an individual basis. Treatments can vary from being as little as self-reassurance to pharmaceutical medications.
Medications can be helpful, such as antipsychotics, benzodiazepines or antiepileptics, but there is very limited evidence for this. Some case studies have found that switching to a prednisolone steroid after a betamethasone steroid which caused MES helped alleviate hallucinations or the use of the acetylcholinesterase inhibitor, Donepezil, have also found that it successfully treated an individual's MES. However, because of the heterogeneous etiology, these methods cannot be applied as general treatment.
Other than treatment by medicinal means, individuals have also successfully alleviated musical hallucinations by cochlear implants, listening to different songs via an external source, or by attempting to block them through mental effort, depending on how severe their condition is.
Patients with optic disc drusen should be monitored periodically for ophthalmoscopy, Snellen acuity, contrast sensitivity, color vision, intraocular pressure and threshold visual fields. For those with visual field defects optical coherence tomography has been recommended for follow up of nerve fiber layer thickness. Associated conditions such as angioid streaks and retinitis pigmentosa should be screened for. Both the severity of optic disc drusen and the degree of intraocular pressure elevation have been associated with visual field loss. There is no widely accepted treatment for ODD, although some clinicians will prescribe eye drops designed to decrease the intra-ocular pressure and theoretically relieve mechanical stress on fibers of the optic disc. Rarely choroidal neovascular membranes may develop adjacent to the optic disc threatening bleeding and retinal scarring. Laser treatment or photodynamic therapy or other evolving therapies may prevent this complication.
There is no current cure. The only way to treat this disease is by treating symptoms. Commonly patients are prescribed immunosuppressive drugs. Another route would be to take collagen regulation drugs.
Those experiencing amaurosis are usually advised to consult a physician immediately as any form of vision loss, even if temporary, is a symptom that may indicate the presence of a serious ocular or systemic problem.
Mees' lines or Aldrich–Mees' lines, also called leukonychia striata, are white lines of discoloration across the nails of the fingers and toes (leukonychia).
Without a known family history of LHON the diagnosis usually requires a neuro-ophthalmological evaluation and blood testing for mitochondrial DNA assessment. It is important to exclude other possible causes of vision loss and important associated syndromes such as heart electrical conduction system abnormalities. The prognosis for those affected left untreated is almost always that of continued significant visual loss in both eyes. Regular corrected visual acuity and perimetry checks are advised for follow up of affected individuals. There is beneficial treatment available for some cases of this disease especially for early onset disease. Also, experimental treatment protocols are in progress. Genetic counselling should be offered. Health and lifestyle choices should be reassessed particularly in light of toxic and nutritional theories of gene expression. Vision aides assistance and work rehabilitation should be used to assist in maintaining employment.
For those who are carriers of a LHON mutation, preclinical markers may be used to monitor progress. For example, fundus photography can monitor nerve fiber layer swelling. Optical coherence tomography can be used for more detailed study of retinal nerve fiber layer thickness. Red green color vision testing may detect losses. Contrast sensitivity may be diminished. There could be an abnormal electroretinogram or visual evoked potentials. Neuron-specific enolase and axonal heavy chain neurofilament blood markers may predict conversion to affected status.
Cyanocobalamin (a form of B12) may also be used.
Avoiding optic nerve toxins is generally advised, especially tobacco and alcohol. Certain prescription drugs are known to be a potential risk, so all drugs should be treated with suspicion and checked before use by those at risk. Ethambutol, in particular, has been implicated as triggering visual loss in carriers of LHON. In fact, toxic and nutritional optic neuropathies may have overlaps with LHON in symptoms, mitochondrial mechanisms of disease and management. Of note, when a patient carrying or suffering from LHON or toxic/nutritional optic neuropathy suffers a hypertensive crisis as a possible complication of the disease process, nitroprusside (trade name: Nipride) should not be used due to increased risk of optic nerve ischemia in response to this anti-hypertensive in particular.
Idebenone has been shown in a small placebo controlled trial to have modest benefit in about half of patients. People most likely to respond best were those treated early in onset.
α-Tocotrienol-quinone, a vitamin E metabolite, has had some success in small open label trials in reversing early onset vision loss.
There are various treatment approaches which have had early trials or are proposed, none yet with convincing evidence of usefulness or safety for treatment or prevention including brimonidine, minocycline, curcumin,
glutathione, near infrared light treatment, and viral vector techniques.
"Three person in vitro fertilization" is a proof of concept research technique for preventing mitochondrial disease in developing human fetuses. So far, viable macaque monkeys have been produced. But ethical and knowledge hurdles remain before use of the technique in humans is established.
Naegeli–Franceschetti–Jadassohn syndrome (NFJS), also known as chromatophore nevus of Naegeli and Naegeli syndrome, is a rare autosomal dominant form of ectodermal dysplasia, characterized by reticular skin pigmentation, diminished function of the sweat glands, the absence of teeth and hyperkeratosis of the palms and soles. One of the most striking features is the absence of fingerprint lines on the fingers.
Naegeli syndrome is similar to dermatopathia pigmentosa reticularis, both of which are caused by a specific defect in the keratin 14 protein.
Tullio phenomenon, sound-induced vertigo, dizziness, nausea or eye movement (nystagmus) was first described in 1929 by the Italian biologist Prof. Pietro Tullio. (1881–1941) During his experiments on pigeons, Tullio discovered that by drilling tiny holes in the semicircular canals of his subjects, he could subsequently cause them balance problems when exposed to sound.
The cause is usually a fistula in the middle or inner ear, allowing abnormal sound-synchronized pressure changes in the balance organs. Such an opening may be caused by a barotrauma (e.g. incurred when diving or flying), or may be a side effect of fenestration surgery, syphilis or Lyme disease.
Patients with this disorder may also experience vertigo, imbalance and eye movement set off by changes in pressure, e.g. when nose-blowing, swallowing or when lifting heavy objects.
Tullio phenomenon is also one of the common symptoms of superior canal dehiscence syndrome (SCDS), first diagnosed in 1998 by Dr. Lloyd B. Minor, The Johns Hopkins University, Baltimore, United States.
There is little research on treatment for phantom vibrations. Carrying the cell phone in a different position reduces phantom vibrations for some people. Other methods include turning off the vibrate mode or using a different device.
Howel–Evans syndrome is an extremely rare condition involving thickening of the skin in the palms of the hands and the soles of the feet (hyperkeratosis). This familial disease is associated with a high lifetime risk of esophageal cancer. For this reason, it is sometimes known as tylosis with oesophageal cancer (TOC).
The condition is inherited in an autosomal dominant manner, and it has been linked to a mutation in the "RHBDF2" gene. It was first described in 1958.
Mees' lines appear after an episode of poisoning with arsenic, thallium or other heavy metals, and can also appear if the subject is suffering from renal failure. They have been observed in chemotherapy patients.
Leber's congenital amaurosis is an inherited disease resulting in optic atrophy and secondary severe vision loss or blindness. It was first described by Theodore Leber in the 19th century.
Amaurosis fugax (Latin: "fugax" meaning "fleeting") is a temporary loss of vision in one eye caused by decreased blood flow (ischemia) to the retina. It may also be caused by embolization from atherosclerotic plaques in the ipsilateral (same side) internal carotid artery. It is a type of transient ischaemic attack (TIA). Those experiencing amaurosis usually experience complete symptom resolution within a few minutes. In a small minority of those who experience amaurosis, stroke or permanent vision loss results. Diabetes, hypertension and smoking are factors known to increase the risks of suffering this condition. It also can be the result of surgical repair to the mitral valve, when very small emboli may break away from the site of the repair, while the patient's tissue grows to cover the plastic annuloplasty band.
Quinidine toxicity can lead to cinchonism and also to quinine amaurosis.