The diagnosis usually starts with a dilated examination of the retina, followed with confirmation by optical coherence tomography and fluorescein angiography. The angiography test will usually show one or more fluorescent spots with fluid leakage. In 10%-15% of the cases these will appear in a "classic" smoke stack shape. Differential diagnosis should be immediately performed to rule out retinal detachment, which is a medical emergency.

A clinical record should be taken to keep a timeline of the detachment. An Amsler grid can be useful in documenting the precise area of the visual field involved. The affected eye will sometimes exhibit a refractive spectacle prescription that is more far-sighted than the fellow eye due to the decreased focal length caused by the raising of the retina.

Indocyanine green angiography can be used to assess the health of the retina in the affected area which can be useful in making a treatment decision.

Retinal detachment can be examined by fundus photography or ophthalmoscopy. Fundus photography generally needs a considerably larger instrument than the ophthalmoscope, but has the advantage of availing the image to be examined by a specialist at another location and/or time, as well as providing photo documentation for future reference. Modern fundus photographs generally recreate considerably larger areas of the fundus than what can be seen at any one time with handheld ophthalmoscopes.

Ultrasound has diagnostic accuracy similar to that of examination by an ophthalmologist. The recent meta-analysis shows the diagnostic accuracy of emergency department (ED) ocular ultrasonography is high. The sensitivity and specificity ranged from 97% to 100% and 83% to 100%. The typical feature of retinal detachment when viewed on ultrasound is "flying angel sign". It shows the detached retina moving with a fixed point under the B mode, linear probe 10 MHz.

Usually being asymptomatic, drusen are typically found during routine eye exams where the pupils have been dilated.

A minority of retinal detachments result from trauma, including blunt blows to the orbit, penetrating trauma, and concussions to the head. A retrospective Indian study of more than 500 cases of rhegmatogenous detachments found that 11% were due to trauma, and that gradual onset was the norm, with over 50% presenting more than one month after the inciting injury.

Fluorescein angiography is usually performed for diagnosis and follow-up of patients with POHS.

Patients and their primary care physicians must be made fully aware of the ophthalmic risks and the need for regular screening examinations to detect retinal toxicity at an early stage.

Baseline evaluation for patients beginning treatment with a chloroquine derivative should include a complete eye examination by an eye care professional, retinal photography for follow-up comparisons, and Visual field testing with a white pattern. Central visual field assessment should test the central 10° of vision with a white test target (such as Humphrey 10-2 program).

In patients at risk or those with unclear presentation, optical coherence tomography (loss of IS/OS junctions), fundus autofluorescence (focal hyper or hypoautofluorescence), and multifocal electroretinography (paracentral depressions) may be obtained.

Profound abnormalities detected with visual field and multifocal electroretinography testing can be observed in the presence of a normal retinal appearance. Retinal examinations are advised for documentation, but visible bull's-eye maculopathy is a late change, and the goal of screening is to recognize toxicity at an earlier stage. Annual screening should begin after 5 years (or sooner if there are unusual risk factors).

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.

Cessation of the drug at the first sign of toxicity is recommended. No treatment exists as yet for this disorder, so it is imperative that patients and their ophthalmologists be aware of the best practices for minimizing toxic damage.

Imaging studies such as ultrasonography (US), Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) can aid diagnosis. On ultrasound, Coats' disease appears as a hyperechoic mass in the posterior vitreous without posterior acoustic shadowing; vitreous and subretinal hemorrhage may often be observed.

On CT, the globe appears hyperdense compared to normal vitreous due to the proteinaceous exudate, which may obliterate the vitreous space in advanced disease. The anterior margin of the subretinal exudate enhances with contrast. Since the retina is fixed posteriorly at the optic disc, this enhancement has a V-shaped configuration.

On MRI, the subretinal exudate shows high signal intensity on both T1- and T2-weighted images. The exudate may appear heterogeneous if hemorrhage or fibrosis is present. The subretinal space does not enhance with gadolinium contrast. Mild to moderate linear enhancement may be seen between the exudate and the remaining vitreous. The exudate shows a large peak at 1-1.6 ppm on proton MR spectroscopy.

CNV can be detected by using a type of perimetry called preferential hyperacuity perimetry. On the basis of fluorescein angiography, CNV may be described as classic or occult. Two other tests that help identify the condition include indocyanine green angiography and optical coherence tomography.

Generally speaking, people diagnosed with photic retinopathy recover visual acuity completely within two months, though more severe cases may take longer, or not see complete recovery at all.

Grossly, retinal detachment and yellowish subretinal exudate containing cholesterol crystals are commonly seen.

Microscopically, the wall of retinal vessels may be thickened in some cases, while in other cases the wall may be thinned with irregular dilatation of the lumen. The subretinal exudate consists of cholesterol crystals, macrophages laden with cholesterol and pigment, erythrocytes, and hemosiderin. A granulomatous reaction, induced by the exudate, may be seen with the retina. Portions of the retina may develop gliosis as a response to injury.

Macular telangiectasia type 1 must be differentiated from secondary telangiectasis caused by retinal vascular diseases such as retinal venous occlusions, diabetic retinopathy, radiation retinopathy, sickle cell maculopathy, inflammatory retinopathy/Irvine–Gass syndrome, ocular ischemic syndrome/carotid artery obstruction, hypertensive retinopathy, polycythemia vera retinopathy, and localized retinal capillary hemangioma. In addition, Macular telangiectasia type 1 should be clearly differentiated from dilated perifoveal capillaries with evidence of vitreous cellular infiltration secondary to acquired inflammatory disease or tapetoretinal dystrophy. Less commonly, macular telangiectasis has been described in association with fascioscapulohumeral muscular dystrophy, incontinentia pigmenti, and familial exudative vitreoretinopathy with posterior pole involvement.

Macular telangiectasia type 2 is commonly under-diagnosed. The findings may appear very similar to diabetic retinopathy, and many cases ave been incorrectly ascribed to diabetic retinopathy or age-related macular degeneration. Recognition of this condition can save an affected patient from unnecessarily undergoing extensive medical testing and/or treatment. MacTel should be considered in cases of mild paramacular dot and blot hemorrhages and in cases of macular and paramacular RPE hyperplasia where no other cause can be identified.

Predisposing factors for Postoperative PVR are preoperative PVR, aphakia, high levels of vitreous proteins, duration of retinal detachment before corrective surgery, the size of the retinal hole or tear, intra-ocular inflammation, vitreous hemorrhage, and trauma to the eye. An equation to calculate the patient's risk for acquiring PVR is:

1 is added if the risk factor is present and 0 if the risk factor is absent. A patient is at a high risk for developing PVR is the PVR score is >6.33.

Although MacTel is uncommon, its prevalence is probably higher than most physicians believe. The early findings are subtle, so the diagnosis is likely often missed by optometrists and general ophthalmologists. MacTel was detected in 0.1% of subjects in the Beaver Dam study population over age 45 years, but this is probably an underestimate because identification was made based only on color photographs.

No major new biomicroscopic features of MacTel have been identified since the early work of Gass and colleagues.

The advent of optical coherence tomography (OCT) has allowed better characterization of the nature of the inner and outer lamellar cavities. Loss of central masking seen on autofluorescence studies, apparently due to loss of luteal pigment, is now recognized as probably the earliest and most sensitive and specific MacTel abnormality.

The key fundus findings in macular telangiectasia type 2 involve retinal crystalline—fine, refractile deposits in the superficial retinal layers—may be seen within the affected area.a focal area of diminished retinal transparency (i.e. "greying") and/or small retinal hemorrhages just temporal to the fovea. Dilated capillaries may also be noted within this area, and while this is often difficult to visualize ophthalmoscopically, the abnormal capillary pattern is readily identifiable with fluorescein angiography.

Areas of focal RPE hyperplasia, i.e.pigment plaques, often develop in the paramacular region as a response to these abnormal vessels. Other signs of macular telangiectasia type 2 include right angle venules, representing an unusual alteration of the vasculature in the paramacular area, with vessels taking an abrupt turn toward the macula as if being dragged.

Diagnosis of MacTel type 2 may be aided by the use of advanced imaging techniques such as fluorescein angiography, fundus autofluorescence, and OCT. These can help to identify the abnormal vessels, pigment plaques, retinal crystals, foveal atrophy and intraretinal cavities associated with this disorder.

Fluorescein angiography (FA) is helpful in identifying the anomalous vasculature, particularly in the early stages of Type 2 disease. Formerly, FA was essential in making a definitive diagnosis. However, the diagnosis can be established with less invasive imaging techniques such as OCT and fundus autofluorescence. Some clinicians argue that FA testing may be unnecessary when a diagnosis is apparent via less invasive means.

The natural history of macular telangiectasia suggests a slowly progressive disorder. A retrospective series of 20 patients over 10 to 21 years showed deterioration of vision in more than 84% of eyes, either due to intra-retinal edema and serous retinal detachment (Type 1) or pigmented RPE scar formation or neovascularisation (Type 2).

Photic retinopathy generally goes away on its own over time, but there is no specific treatment known to be reliable for speeding recovery. One path sometimes attempted, which has unclear results, is to treat the initial macular edema with corticosteroids.

The fundus exam via ophthalmoscopy is essentially normal early on in cone dystrophy, and definite macular changes usually occur well after visual loss. Fluorescein angiography (FA) is a useful adjunct in the workup of someone suspected to have cone dystrophy, as it may detect early changes in the retina that are too subtle to be seen by ophthalmoscope. For example, FA may reveal areas of hyperfluorescence, indicating that the RPE has lost some of its integrity, allowing the underlying fluorescence from the choroid to be more visible. These early changes are usually not detected during the ophthalmoscopic exam.

The most common type of macular lesion seen during ophthalmoscopic examination has a bull’s-eye appearance and consists of a doughnut-like zone of atrophic pigment epithelium surrounding a central darker area. In another, less frequent form of cone dystrophy there is rather diffuse atrophy of the posterior pole with spotty pigment clumping in the macular area. Rarely, atrophy of the choriocapillaris and larger choroidal vessels is seen in patients at an early stage. The inclusion of fluorescein angiography in the workup of these patients is important since it can help detect many of these characteristic ophthalmoscopic features. In addition to the retinal findings, temporal pallor of the optic disc is commonly observed.

As expected, visual field testing in cone dystrophy usually reveals a central scotoma. In cases with the typical bull’s-eye appearance, there is often relative central sparing.

Because of the wide spectrum of fundus changes and the difficulty in making the diagnosis in the early stages, electroretinography (ERG) remains the best test for making the diagnosis. Abnormal cone function on the ERG is indicated by a reduced single-flash and flicker response when the test is carried out in a well-lit room (photopic ERG). The relative sparing of rod function in cone dystrophy is evidenced by a normal scotopic ERG, i.e. when the test is carried out in the dark. In more severe or longer standing cases, the dystrophy involves a greater proportion of rods with resultant subnormal scotopic records. Since cone dystrophy is hereditary and can be asymptomatic early on in the disease process, ERG is an invaluable tool in the early diagnosis of patients with positive family histories.

Cone dystrophy in general usually occurs sporadically. Hereditary forms are usually autosomal dominant, and instances of autosomal recessive and X-linked inheritance also occur.

In the differential diagnosis, other macular dystrophies as well as the hereditary optic atrophies must be considered. Fluorescent angiography, ERG, and color vision tests are important tools to help facilitate diagnosis in early stages.

Diagnosis of age-related macular degeneration rests on signs in the macula, irrespective of visual acuity. Diagnosis of AMD may include the following procedures and tests:

- The transition from dry to wet AMD can happen rapidly, and if it is left untreated can lead to legal blindness in as little as six months. To prevent this from occurring and to initiate preventative strategies earlier in the disease process, dark adaptation testing may be performed. A dark adaptometer can detect subclinical AMD at least three years earlier than it is clinically evident.

- There is a loss of contrast sensitivity, so that contours, shadows, and color vision are less vivid. The loss in contrast sensitivity can be quickly and easily measured by a contrast sensitivity test like Pelli Robson performed either at home or by an eye specialist.

- When viewing an Amsler grid, some straight lines appear wavy and some patches appear blank

- When viewing a Snellen chart, at least 2 lines decline

- Preferential hyperacuity perimetry changes (for wet AMD)

- In dry macular degeneration, which occurs in 85–90 percent of AMD cases, drusen spots can be seen in Fundus photography

- In wet macular degeneration, angiography can visualize the leakage of bloodstream behind the macula. Fluorescein angiography allows for the identification and localization of abnormal vascular processes.

- Using an electroretinogram, points in the macula with a weak or absent response compared to a normal eye may be found

- Farnsworth-Munsell 100 hue test and Maximum Color Contrast Sensitivity test (MCCS) for assessing color acuity and color contrast sensitivity

- Optical coherence tomography is now used by most ophthalmologists in the diagnosis and the follow-up evaluation of the response to treatment with antiangiogenic drugs.

The prognosis for CSR is generally excellent. Whilst immediate vision loss may be as poor as 20/200 in the affected eye, clinically over 90% of patients regain 20/30 vision or better within 6 months.

Once the fluid has resolved, by itself or through treatment, visual acuity should continue to improve and distortion should reduce as the eye heals. However, some visual abnormalities can remain even if visual acuity is measured at 20/20, and lasting problems include decreased night vision, reduced color discrimination, and localized distortion caused by scarring of the sub-retinal layers.

Complications include subretinal neovascularization and pigment epithelial detachment.

The disease can re-occur causing progressive vision loss. There is also a chronic form, titled as type II central serous retinopathy, which occurs in approximately 5% of cases. This exhibits diffuse rather than focalized abnormality of the pigment epithelium, producing a persistent subretinal fluid. The serous fluid in these cases tends to be shallow rather than dome shaped. Prognosis for this condition is less favorable and continued clinical consultation is advised.

The long-term prognosis for patients with Stargardt disease is widely variable although the majority of people will progress to legal blindness.

Stargardt disease has no impact on general health and life expectancy is normal. Some patients, usually those with the late onset form, can maintain excellent visual acuities for extended periods, and are therefore able to perform tasks such as reading or driving.

A practical application of AMD-associated genetic markers is in the prediction of progression of AMD from early stages of the disease to neovascularization.

Norrie disease and other NDP related diseases are diagnosed with the combination of clinical findings and molecular genetic testing. Molecular genetic testing identifies the mutations that cause the disease in about 85% of affected males. Clinical diagnoses rely on ocular findings. Norrie disease is diagnosed when grayish-yellow fibrovascular masses are found behind the eye from birth through three months. Doctors also look for progression of the disease from three months through 8–10 years of age. Some of these progressions include cataracts, iris atrophy, shallowing of anterior chamber, and shrinking of the globe. By this point, people with the condition either have only light perception or no vision at all.

Molecular genetic testing is used for more than an initial diagnosis. It is used to confirm diagnostic testing, for carrier testing females, prenatal diagnosis, and preimplantation genetic diagnosis. There are three types of clinical molecular genetic testing. In approximately 85% of males, mis-sense and splice mutations of the NDP gene and partial or whole gene deletions are detected using sequence analysis. Deletion/duplication analysis can be used to detect the 15% of mutations that are submicroscopic deletions. This is also used when testing for carrier females. The last testing used is linkage analysis, which is used when the first two are unavailable. Linkage analysis is also recommended for those families who have more than one member affected by the disease.

On MRI the retinal dysplasia that occurs with the syndrome can be indistinguishable from persistent hyperplastic primary vitreous, or the dysplasia of trisomy 13 and Walker–Warburg syndrome.

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.

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.

Diagnosis is made by an ophthalmologist during eye examination. Further tests such as fluorescein angiography or lumbar puncture are usually performed to confirm the diagnosis.

Neurosarcoidosis is a similar autoimmune disorder that can be confused with APMPPE.