Treatment is dependent upon diagnosis and the stage at which the diagnosis is secured. For toxic and nutritional optic neuropathies, the most important course is to remove the offending agent if possible and to replace the missing nutritional elements, orally, intramuscularly, or intravenously. If treatment is delayed, the injury may be irreversible. The course of treatment varies with the congenital forms of these neuropathies. There are some drug treatments that have shown modest success, such as Idebenone used to treat LOHN. Often treatment is relegated to lifestyle alterations and accommodations and supportive measures.

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.

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.

Treatment of toxic and nutritional optic neuropathy is dictated by the cause of the disorder.

- Toxic optic neuropathy is treated by identification and removal of the offending agent. Depending upon the individual affected, the nature of the agent, total exposure prior to removal, and degree of vision loss at the time of diagnosis, the prognosis is variable.

- Nutritional optic neuropathy is treated with improved nutrition. A well-balanced diet with plenty of protein and green leafy vegetables, vitamin supplementation (thiamine, vitamin B, folic acid, multivitamins), and reduction of smoking and/or drinking are the mainstay of treatment. Again, prognosis is variable and dependent upon the affected individual, treatment compliance, and degree of vision loss at diagnosis.

In both toxic and nutritional neuropathy, vision generally recovers to normal over several days to weeks, though it may take months for full restoration and there is always the risk of permanent vision loss. Visual acuity usually recovers before color vision.

A range of medications that act on the central nervous system has been found to be useful in managing neuropathic pain. Commonly used treatments include tricyclic antidepressants (such as nortriptyline or amitriptyline), the serotonin-norepinephrine reuptake inhibitor (SNRI) medication duloxetine, and antiepileptic therapies such as gabapentin, pregabalin, or sodium valproate. Few studies have examined whether nonsteroidal anti-inflammatory drugs are effective in treating peripheral neuropathy.

Symptomatic relief for the pain of peripheral neuropathy may be obtained by application of topical capsaicin. Capsaicin is the factor that causes heat in chili peppers. The evidence suggesting that capsaicin applied to the skin reduces pain for peripheral neuropathy is of moderate to low quality and should be interpreted carefully before using this treatment option. Local anesthesia often is used to counteract the initial discomfort of the capsaicin. Some current research in animal models has shown that depleting neurotrophin-3 may oppose the demyelination present in some peripheral neuropathies by increasing myelin formation.

High-quality evidence supports the use of cannabis for neuropathic pain.

Transcutaneous electrical nerve stimulation therapy may be effective and safe in the treatment of diabetic peripheral neuropathy. A recent review of three trials involving 78 patients found some improvement in pain scores after 4 and 6, but not 12 weeks of treatment and an overall improvement in neuropathic symptoms at 12 weeks. Another review of four trials found significant improvement in pain and overall symptoms, with 38% of patients in one trial becoming asymptomatic. The treatment remains effective even after prolonged use, but symptoms return to baseline within a month of cessation of treatment.

Physical therapy is the predominant treatment of symptoms. Orthopedic shoes and foot surgery can be used to manage foot problems.

There is currently no known pharmacological treatment to hereditary motor and sensory neuropathies. However, the majority of people with these diseases are able to walk and be self-sufficient. Some methods of relief for the disease include physical therapy, stretching, braces, and sometimes orthopedic surgery. Since foot disorders are common with neuropathy disorders precautions must be taken to strengthen these muscles and use preventative care and physical therapy to prevent injury and deformities.

If a diagnosis of GCA is suspected, treatment with steroids should begin immediately. A sample (biopsy) of the temporal artery should be obtained to confirm the diagnosis and guide future management, but should not delay initiation of treatment. Treatment does not recover lost vision, but prevents further progression and second eye involvement. High dose corticosteroids may be tapered down to low doses over approximately one year.

Once NAION happens, it was thought that there was no accepted treatment to reverse the damage. However, a recent uncontrolled retrospective large study has shown that if patients are treated with large doses of corticosteroid therapy during the early stages of NAION, in eyes with initial visual acuity of 20/70 or worse, seen within 2 weeks of onset, there was visual acuity improvement in 70% in the treated group compared to 41% in the untreated group (odds ratio of improvement: 3.39; 95% CI:1.62, 7.11; p ¼ 0.001). That study and a natural history study on NAION (Ophthalmology 2008;115: 298–305.) showed that visual acuity can improve up to 6 months and not after that. To minimize the risk of further visual loss in the fellow eye or the same eye, it is essential to reduce the risk factors. Common sense dictates trying to control the cardiovascular risk factors for many reasons, including protection from this happening to the second eye. Sudden vision loss should lead to an ophthalmological consultation. If NAION is suspected, then ideally a neuro-ophthalmologist's consultation should be obtained.

A recent Cochrane Review sought to determine the extent of safety and efficacy of optic nerve decompression surgery for NAION, compared to other treatments, or no treatment. The one study included in the review found no improvements in visual acuity among patients who underwent surgery for NAION, and adverse events (pain, double vision) experienced by participants who underwent surgery.

There is much research currently underway looking at ways to protect the nerve (neuroprotection) or even regenerate new fibers within the optic nerve. So far there is no evidence in human studies that the so-called neuroprotectors have any beneficial effect in NAION.

However, there is a new current clinical trial for the treatment of NAION in the United States with plans to include sites in India, Israel, Germany and Australia (see NORDICclinicaltrials.com and https://clinicaltrials.gov/). This trial will test the use of a synthetic siRNA that blocks caspase 2, an important enzyme in the apoptosis cycle.

In addition to such research, patents have been applied for by Pfizer, The University of Southern California, Otsuka Pharmaceutical and other individual inventors for innovations related to the treatment of anterior ischemic optic neuropathy.

There is no cure for retinitis pigmentosa, but the efficacy and safety of various prospective treatments are currently being evaluated. The efficiency of various supplements, such as Vitamin A, DHA, and Lutein, in delaying disease progression remains an unresolved, yet prospective treatment option. Clinical trials investigating optic prosthetic devices, gene therapy mechanisms, and retinal sheet transplantations are active areas of study in the partial restoration of vision in retinitis pigmentosa patients.

Studies have demonstrated the delay of rod photoreceptor degeneration by the daily intake of 15000 IU (equivalent to 4.5 mg) of vitamin A palmitate; thus, stalling disease progression in some patients. Recent investigations have shown that proper vitamin A supplementation can postpone blindness by up to 10 years (by reducing the 10% loss pa to 8.3% pa) in some patients in certain stages of the disease.

The Argus retinal prosthesis became the first approved treatment for the disease in February 2011, and is currently available in Germany, France, Italy, and the UK. Interim results on 30 patients long term trials were published in 2012. The Argus II retinal implant has also received market approval in the US. The device may help adults with RP who have lost the ability to perceive shapes and movement to be more mobile and to perform day-to-day activities. In June 2013, twelve hospitals in the US announced they would soon accept consultation for patients with RP in preparation for the launch of Argus II later that year. The Alpha-IMS is a subretinal implant involving the surgical implantation of a small image-recording chip beneath the optic fovea. Measures of visual improvements from Alpha-IMS studies require the demonstration of the device's safety before proceeding with clinical trials and granting market approval.

The goal of gene therapy studies is to virally supplement retinal cells expressing mutant genes associated with the retinitis pigmentosa phenotype with healthy forms of the gene; thus, allowing the repair and proper functioning of retinal photoreceptor cells in response to the instructions associated with the inserted healthy gene. Clinical trials investigating the insertion of the healthy RPE65 gene in retinas expressing the LCA2 retinitis pigmentosa phenotype measured modest improvements in vision; however, the degradation of retinal photoreceptors continued at the disease-related rate. Likely, gene therapy may preserve remaining healthy retinal cells while failing to repair the earlier accumulation of damage in already diseased photoreceptor cells. Response to gene therapy would theoretically benefit young patients exhibiting the shortest progression of photoreceptor decline; thus, correlating to a higher possibility of cell rescue via the healthy inserted gene.

In the treatment of polyneuropathies one must ascertain and manage the cause, among management activities are: weight decrease, use of a walking aid, and occupational therapist assistance. Additionally BP control in those with diabetes is helpful, while intravenous immunoglobulin is used for multifocal motor neuropathy.

According to Lopate, et al., methylprednisolone is a viable treatment for chronic inflammatory demyelinative polyneuropathy (which can also be treated with intravenous immunoglobulin) The author(s) also indicate that prednisone has greater adverse effects in such treatment, as opposed to intermittent (high-doses) of the aforementioned medication.

According to Wu, et al., in critical illness polyneuropathy supportive and preventive therapy are important for the affected individual, as well as, avoiding (or limiting) corticosteroids.

Rapid blood transfusions, to correct anemia and raise blood pressure, may improve PION outcomes. In one report of a related disease, hypotension-induced AION, 3 out of 3 patients who received rapid transfusions reported partial recovery of vision. While rapid transfusions offer some hope, the prognosis for perioperative PION remains poor. Prevention remains the best way to reduce PION.

One retrospective report proposes that incidence of PION could be reduced in high-risk cases by altering surgical management. For example, for patients undergoing spine surgery, measures could be taken to minimize intraoperative hypotension, to accelerate the process of blood replacement, and to aggressively treat facial swelling.

The progressive nature of and lack of a definitive cure for retinitis pigmentosa contribute to the inevitably discouraging outlook for patients with this disease. While complete blindness is rare, the patient's visual acuity and visual field will continue to decline as initial rod photoreceptor and later cone photoreceptor degradation proceeds. Possible treatments remain in the research and clinical trial stages; however, treatment studies concerning visual restoration in retinitis pigmentosa prove promising for the future.

Studies indicate that children carrying the disease genotype benefit from presymptomatic counseling in order to prepare for the physical and social implications associated with progressive vision loss. While the psychological prognosis can be slightly alleviated with active counseling the physical implications and progression of the disease depend largely on the age of initial symptom manifestation and the rate of photoreceptor degradation, rather than access to prospective treatments. Corrective visual aids and personalized vision therapy provided by Low Vision Specialists may help patients correct slight disturbances in visual acuity and optimize their remaining visual field. Support groups, vision insurance, and lifestyle therapy are additional useful tools for those managing progressive visual decline.

There is no current treatment, however management of hereditary neuropathy with liability to pressure palsy can be done via:

- Occupational therapist

- Ankle/foot orthosis

- Wrist splint (medicine)

- Avoid repetitive movements

There is no pharmacological treatment for Roussy–Lévy syndrome.

Treatment options focus on palliative care and corrective therapy. Patients tend to benefit greatly from physical therapy (especially water therapy as it does not place excessive pressure on the muscles), while moderate activity is often recommended to maintain movement, flexibility, muscle strength and endurance.

Patients with foot deformities may benefit from corrective surgery, which, however, is usually a last resort. Most such surgeries include straightening and pinning the toes, lowering the arch, and sometimes, fusing the ankle joint to provide stability. Recovering from these surgeries is oftentimes long and difficult. Proper foot care including custom-made shoes and leg braces may minimize discomfort and increase function.

While no medicines are reported to treat the disorder, patients are advised to avoid certain medications as they may aggravate the symptoms.

There is currently no defined treatment to ameliorate the muscle weakness of CPEO. Treatments used to treat other pathologies causing ophthalmoplegia has not been shown to be effective.

Experimental treatment with tetracycline has been used to improve ocular motility in one patient. Coenzyme Q has also been used to treat this condition. However, most neuro-ophthalmologists do not ascribe to any treatment.

Ptosis associated with CPEO may be corrected with surgery to raise the lids, however due to weakness of the orbicularis oculi muscles, care must be taken not to raise the lids in excess causing an inability to close the lids. This results in an exposure keratopathy. Therefore, rarely should lid surgery be performed and only by a neuro-ophthalmologist familiar with the disease.

The most common strabismus finding is large angle exotropia which can be treated by maximal bilateral eye surgery, but due to the progressive nature of the disease, strabismus may recur. Those that have diplopia as a result of asymmetric ophthalmoplegia may be corrected with prisms or with surgery to create a better alignment of the eyes.

AON is a rare disease and the natural history of the disease process is not well defined. Unlike typical optic neuritis, there is no association with multiple sclerosis, but the visual prognosis for AON is worse than typical optic neuritis. Thus AON patients have different treatment, and often receive chronic immunosuppression. No formal recommendation can be made regarding the best therapeutic approach. However, the available evidence to date supports treatment with corticosteroids and other immunosuppressive agents.

Early diagnosis and prompt treatment with systemic corticosteroids may restore some visual function but the patient may remain steroid dependent; vision often worsens when corticosteroids are tapered. As such, long-term steroid-sparing immunosuppressive agents may be required to limit the side-effects of steroids and minimize the risk of worsening vision.

Currently there is no cure for myotubular or centronuclear myopathies. Treatment often focuses on trying to maximize functional abilities and minimize medical complications, and involvement by physicians specializing in Physical Medicine and Rehabilitation, and by physical therapists and occupational therapists.

Medical management generally involves efforts to prevent pulmonary complications, since lung infections can be fatal in patients lacking the muscle strength necessary to clear secretions via coughing. Medical devices to assist with coughing help patients maintain clear airways, avoiding mucous plugs and avoiding the need for tracheostomy tubes.

Monitoring for scoliosis is also important, since weakness of the trunk muscles can lead to deviations in spinal alignment, with resultant compromise of respiratory function. Many patients with congenital myopathies may eventually require surgical treatment of scoliosis.

As of 2010, there was no cure for MMND. People with MMND are given supportive care to help them cope, which can include physical therapy, occupational therapy, counselling, and hearing aids.

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.

Gene-based therapies for patients with HSAN I are not available to date, hence supportive care is the only treatment available for the patients. Ulcero-mutilating complications are the most serious, prominent, and leading diagnostic features in HSAN I. Since the complications mimic foot ulcers caused by diabetic neuropathy, the treatment for foot ulcers and infections can follow the guidelines given for diabetic foot care which starts with early and accurate counseling of patients about risk factors for developing foot ulcerations. Orthopedic care and the use of well fitting shoes without pressure points should also be included. Recently, the treatment of the foot complications has reached an efficient level allowing treatment on an outpatient basis. Early treatment of the foot complications often avoids hospitalization and, in particular, amputations. In sum, the principles of the treatment are removal of pressure to the ulcers, eradication of infection, and specific protective footwear afterwards.

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.

Those diseases understood as congenital in origin could either be specific to the ocular organ system (LHON, DOA) or syndromic (MELAS, Multiple Sclerosis). It is estimated that these inherited optic neuropathies in the aggregate affect 1 in 10,000

Of the acquired category, disease falls into further etiological distinction as arising from toxic (drugs or chemicals) or nutritional/metabolic (vitamin deficiency/diabetes) insult. It is worth mentioning that under-nutrition and toxic insult can occur simultaneously, so a third category may be understood as having a combined or mixed etiology. We will refer to this as Toxic/Nutritional Optic Neuropathy, whereby nutritional deficiencies and toxic/metabolic insults are the simultaneous culprits of visual loss associated with damage and disruption of the RGC and optic nerve mitochondria.

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.