Optic pits themselves do not need to be treated. However, patients should follow up with their eye care professional annually or even sooner if the patient notices any visual loss whatsoever. Treatment of PVD or serous retinal detachment will be necessary if either develops in a patient with an optic pit.

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.

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.

Optic pits occur equally between men and women. They are seen in roughly 1 in 10,000 eyes, and approximately 85% of optic pits are found to be unilateral (i.e. in only one eye of any affected individual). About 70% are found on the temporal side (or lateral one-half) of the optic disc. Another 20% are found centrally, while the remaining pits are located either superiorly (in the upper one-half), inferiorly (in the lower one-half), or nasally (in the medial one-half towards the nose).

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.

Studies in the 1970s reported that the use of cannabis may lower intraocular pressure. In an effort to determine whether marijuana, or drugs derived from it, might be effective as a glaucoma treatment, the US National Eye Institute supported research studies from 1978 to 1984. These studies demonstrated some derivatives of marijuana lowered intraocular pressure when administered orally, intravenously, or by smoking, but not when topically applied to the eye.

In 2003, the American Academy of Ophthalmology released a position statement stating that cannabis was not more effective than prescription medications. Furthermore, no scientific evidence has been found that demonstrates increased benefits and/or diminished risks of cannabis use to treat glaucoma compared with the wide variety of pharmaceutical agents now available.

In 2012 the American Glaucoma Society published a position paper discrediting the use of cannabis as a legitimate treatment for elevated intraocular pressure, for reasons including short duration of action and side effects that limit many activities of daily living.

There is no cure for ONH; however, many therapeutic interventions exist for the care of its symptoms. These may include hormone replacement therapy for hypopituitarism, occupational, physical, and/or speech therapy for other issues, and services of a teacher of students with blindness/visually impairment. Special attention should be paid to early development of oral motor skills and acclimation to textured foods for children with texture aversion, or who are otherwise resistant to eating.

Sleep dysfunction can be ameliorated using melatonin in the evening in order to adjust a child's circadian clock.

Treatment for strabismus may include patching of the better eye, which may result in improved vision in the worse eye; however, this should be reserved for cases in which the potential for vision improvement in both eyes is felt to be good. Surgery to align the eyes can be performed once children with strabismus develop equal visual acuity in both eyes, most often after the age of three. Generally surgery results in improved appearance only and not in improved visual function.

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.

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.

Coloboma of optic nerve, is a rare defect of the optic nerve that causes moderate to severe visual field defects.

Coloboma of the optic nerve is a congenital anomaly of the optic disc in which there is a defect of the inferior aspect of the optic nerve. The issue stems from incomplete closure of the embryonic fissure while in utero. A varying amount of glial tissue typically fills the defect, manifests as a white mass.

Optic disc drusen are found clinically in about 1% of the population but this increases to 3.4% in individuals with a family history of ODD. About two thirds to three quarters of clinical cases are bilateral. A necropsy study of 737 cases showed a 2.4% incidence with 2 out of 15 (13%) bilateral, perhaps indicating the insidious nature of many cases. An autosomal dominant inheritance pattern with incomplete penetrance and associated inherited dysplasia of the optic disc and its blood supply is suspected. Males and females are affected at equal rates. Caucasians are the most susceptible ethnic group. Certain conditions have been associated with disc drusen such as retinitis pigmentosa, angioid streaks, Usher syndrome, Noonan syndrome and Alagille syndrome. Optic disc drusen are not related to Bruch membrane drusen of the retina which have been associated with age-related macular degeneration.

It is known to occur in Scotch Collies (smooth and rough collies), Shetland Sheepdogs, Australian Shepherds, Border Collies, Lancashire Heelers, and Nova Scotia Duck Tolling Retrievers. Frequency is high in Collies and Shetland Sheepdogs, and low in Border Collies and NSDTRs. In the United States, incidence in the genotype of collies has been estimated to be as high as 95 percent, with a phenotypic incidence of 80 to 85 percent.

Laser treatment of drusen has been studied. While it is possible to eliminate drusen with this treatment strategy, it has been shown that this fails to reduce the risk of developing the choroidal neovascularisation which causes the blindness associated with age-related macular degeneration.

Retinoschisis involving the central part of the retina secondary to an optic disc pit was erroneously considered to be a serous retinal detachment until correctly described by Lincoff as retinoschisis. Significant visual loss may occur and following a period of observation for spontaneous resolution, treatment with temporal peripapillary laser photocoagulation followed by vitrectomy and gas injection followed by face-down positioning is very effective in treating this condition.

In the early stages, there are a few treatment options. Laser surgery or cryotherapy (freezing) can be used to destroy the abnormal blood vessels, thus halting progression of the disease. However, if the leaking blood vessels are clustered around the optic nerve, this treatment is not recommended as accidental damage to the nerve itself can result in permanent blindness. Although Coats' disease tends to progress to visual loss, it may stop progressing on its own, either temporarily or permanently. Cases have been documented in which the condition even reverses itself. However, once total retinal detachment occurs, sight loss is permanent in most cases. Removal of the eye (enucleation) is an option if pain or further complications arise.

Although both optic nerve colobomas and morning glory disc anomaly (MGDA) involve mutations of the PAX6 gene, these two separate diseases represent two distinct causes. An optic nerve coloboma is easily differentiated from morning glory anomaly. Colobomas affect only the inferior aspect of the nerve as it represents an incomplete closure of the embryonic fissure, whereas MGDA encompasses all aspects of the nerve and represents more generally a dysgenesis of the mesoderm.

Treatment requires careful consideration of angiographic findings when a choroidal neovascular membrane is suspected which is a condition that responds to treatment. A vitreo-retinal specialist (an ophthalmologist specialized in treatment of retinal diseases) should be consulted for proper management of the case.

Presumed ocular histoplasmosis syndrome and age-related macular degeneration (AMD) have been successfully treated with laser, anti-vascular endothelial growth factors and photodynamic therapy. Ophthalmologists are using anti-vascular endothelial growth factors to treat AMD and similar conditions since research indicates that vascular endothelial growth factor (VEGF) is one of the causes for the growth of the abnormal vessels that cause these conditions.

A 2013 Cochrane Systematic Review compared the effect of brimonidine and timolol in slowing the progression of open angle glaucoma in adult participants. The results showed that participants assigned to brimonidine showed less visual field progression that those assigned to timolol, though the results were not significant, given the heavy loss-to-followup and limited evidence. The mean intraocular pressures for both groups were similar. Participants in the brimonidine group had a higher occurrence of side effects caused by medication than participants in the timolol group.

Colobomas of the iris may be treated in a number of ways. A simple cosmetic solution is a specialized cosmetic contact lens with an artificial pupil aperture. Surgical repair of the iris defect is also possible. Surgeons can close the defect by stitching in some cases. More recently artificial iris prosthetic devices such as the Human Optics artificial iris have been used successfully by specialist surgeons. This device cannot be used if the natural lens is in place and is not suitable for children. Suture repair is a better option where the lens is still present.

Vision can be improved with glasses, contact lenses or even laser eye surgery but may be limited if the retina is affected or there is amblyopia.

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.

The most recognized cause of a toxic optic neuropathy is methanol intoxication. This can be a life-threatening event that normally accidentally occurs when the victim mistook, or substituted, methanol for ethyl alcohol. Blindness can occur with drinking as little as an ounce of methanol, but this can be counteracted by concurrent drinking of ethyl alcohol. The patient initially has nausea and vomiting, followed by respiratory distress, headache, and visual loss 18–48 hours after consumption. Without treatment, patients can go blind, and their pupils will dilate and stop reacting to light.

- Ethylene glycol, a component of automobile antifreeze, is a poison that is toxic to the whole body including the optic nerve. Consumption can be fatal, or recovery can occur with permanent neurologic and ophthalmologic deficits. While visual loss is not very common, increased intracranial pressure can cause bilateral optic disc swelling from cerebral edema. A clue to the cause of intoxication is the presence of oxalate crystals in the urine. Like methanol intoxication, treatment is ethanol consumption.

- Ethambutol, a drug commonly used to treat tuberculosis, is notorious for causing toxic optic neuropathy. Patients with vision loss from ethambutol toxicity lose vision in both eyes equally. This initially presents with problems with colors (dyschromatopsia) and can leave central visual deficits. If vision loss occurs while using ethambutol, it would be best to discontinue this medication under a doctor’s supervision. Vision can improve slowly after discontinuing ethambutol but rarely returns to baseline.

- Amiodarone is an antiarrhythmic medication commonly used for abnormal heart rhythms (atrial or ventricular tachyarrythmias). Most patients on this medication get corneal epithelial deposits, but this medication has also been controversially associated with NAION. Patients on amiodarone with new visual symptoms should be evaluated by an ophthalmologist.

- Tobacco exposure, most commonly through pipe and cigar smoking, can cause an optic neuropathy. Middle-aged or elderly men are often affected and present with painless, slowly progressive, color distortion and visual loss in both eyes. The mechanism is unclear, but this has been reported to be more common in individuals who are already suffering from malnutrition.

ONSM does not improve without treatment. In many cases, there is gradual progression until vision is lost in the affected eye. However, this takes at least several months to occur, and a minority of patients remain stable for a number of years.

Although many perinatal and prenatal risk factors for ONH have been suggested, the predominant, enduring, most frequent risk factors are young maternal age and primiparity (the affected child being the first child born to the mother). Increased frequency of delivery by caesarean section and fetal/neonatal complications, preterm labor, gestational vaginal bleeding, low maternal weight gain, and weight loss during pregnancy are also associated with ONH.

Untreated glaucoma leads to total blindness. Surgical treatment is required. Presently-utilized surgical procedures include goniotomy, trabeculotomy, or trabeculectomy.

This may be present in conditions causing traction on the retina especially at the macula. This may occur in:

a) The vitreomacular traction syndrome; b) Proliferative diabetic retinopathy with vitreoretinal traction; c) Atypical cases of impending macular hole.