The symptoms of AMD vary and depend on the form and progression of the disease. Visual deterioration can develop gradually over many years, then suddenly deteriorate significantly due to fluid leakage. Since symptoms occur in the central field of vision, the changes are generally noticeable when reading, watching television, driving, or recognizing faces. Although AMD generally develops in both eyes, a sudden deterioration tends to occur in one eye only and may only be noticed when the better eye is covered. 

The first changes are known as metamorphopsia—straight lines appear distorted, wavy, or crooked. Sensitivity to bright light also increases, and colors appear less bright and faded.

If the photoreceptor cells are permanently damaged, this leads to visual field defects in central vision: fine details in the near and distant fields can no longer be recognized. Peripheral vision remains intact.

The image illustrates changes in AMD that are noticeable when looking at the Amsler grid with one eye.

After assessing the family history, visual acuity is tested. Near vision correction and the Amsler grid are used to identify distortion that may signal the sudden onset of fluid leakage in wet AMD, or missing spots, related to damaged retinal cells.

The eye care clinician then examines the fundus with a slit lamp under pupil dilation and may request further imaging, including optical coherence tomography (OCT), fluorescein angiography, OCT angiography, or fundus autofluorescence.

OCT in dry AMD (1), Image source: Prof. Frank Holz, University Eye Hospital, Bonn
OCT in wet AMD (2), Image source: Prof. Frank Holz, University Eye Hospital, Bonn

For wet AMD, anti-VEGF treatment is considered the standard therapy worldwide: a drug is injected into the jelly at the back of the eye (vitreous body) that inhibits the growth factor VEGF and prevent the formation of new abnormal blood vessels. Because the effect of these drugs is relatively short-lived, injections usually have to be repeated several times, and the retina has to be checked every few months.

For dry AMD, two drugs have been approved for use in some countries, to slow down the progression of geographic atrophy. 

General preventive measures include avoiding smoking, taking regular exercise, and eating a balanced diet. Dietary supplements such as vitamins C and E, lutein/zeaxanthin, omega-3 fatty acids, and zinc may have a positive effect on the disease's progression.

The image illustrates the injection of anti-VEGF inhibitors into the vitreous body.

Early visible symptoms may include patches of reduced contrast perception and color vision. When a diabetic macular edema develops, central vision is perceived as blurred, distorted, or unclear, which is particularly noticeable when reading.

Hemorrhages in the vitreous or retina can appear as dark spots or a veil in the visual field and may cause a sudden, severe loss of vision.

In cases of retinal detachment, patients may also experience flashes of light, a “shower of black dots” and/or a “curtain” being drawn over their vision.

The image illustrates typical changes in the visual field in diabetic macular edema.  

After a comprehensive medical history, including information on the duration of diabetes, blood sugar control, symptoms, and family history, an assessment of visual acuity and contrast sensitivity is performed.
The whole of the eye including the fundus are then examined using a slit lamp examination with dilated pupils.
In addition to fundus photography of the central and peripheral retina, the following imaging diagnostic procedures may be performed in patients with DR:

• Optical coherence tomography (OCT) for visualizing and localizing retinal edema, assessing the integrity of photoreceptors, detecting microvascular changes. 

• Fluorescein angiography for detecting ischemic areas, neovascularization, and vascular leakage.

• OCT angiography for identifying areas of the retina with no blood flow, neovascularization, and other microvascular changes.

The image illustrates an OCT scan with a diabetic macular edema.
Image source: Rosa Dolz-Marco, MD, Oftalvist Clinic, Valencia

Prevention and early treatment of diabetic retinopathy primarily depend on optimal control of diabetes mellitus, including strict regulation of blood glucose and blood pressure, regular ophthalmic examinations, and a healthy lifestyle.

In macular edema, the more advanced stages of non-proliferative DR with visual impairment, or proliferative diabetic retinopathy, intravitreal anti-VEGF therapy is used to suppress pathological vessel growth and limit further retinal damage; repeated treatments and follow-up are required. If a macular edema is present, intravitreal corticosteroids may also be administered to reduce edema and inflammation.

Panretinal photocoagulation (PRP) is the standard treatment for proliferative diabetic retinopathy, aiming to reducing VEGF production and inhibiting neovascularization by applying multiple laser burns to the peripheral retina while sparing the macula. 

In advanced cases with vitreous hemorrhage or tractional retinal detachment, pars plana vitrectomy is indicated.

The image illustrates three therapy options—anti-VEGF injection, panretinal laser photocoagulation and intravitreal corticosteroid implant.

In retinal artery occlusions the interruption of blood flow leads to a sudden and painless loss of vision in one eye. Depending on whether it is a branch retinal artery occlusion (BRAO) or a central retinal artery occlusion (CRAO), the vision loss affects only part or the entire visual field. There are usually no warning signs before the event occurs.

Any sudden loss of vision should be treated as a medical emergency and requires immediate ophthalmologic evaluation.

In retinal vein occlusions, impaired blood drainage from the retina leads to increased pressure, bleeding, and fluid leakage, resulting in painless vision changes in one eye such as blurred or distorted vision, dark spots, or a general reduction in visual clarity. Depending on whether it is a branch retinal vein occlusion (BRVO) or a central retinal vein occlusion (CRVO), the visual impairment may affect only part of the visual field or the entire vision of the affected eye. Symptoms can develop suddenly or gradually.

The image illustrates typical changes in the visual field in a branch retinal vein occlusions.  

After taking a detailed medical history, including cardiovascular risk factors such as hypertension, diabetes, or vascular disease, visual acuity is assessed. The pupil is then dilated to allow a thorough examination of the retina and optic nerve.

Optical coherence tomography (OCT) is used to detect retinal swelling and assess structural damage, particularly in the macular region. Fluorescein angiography helps visualize blood flow within the retinal vessels and identify areas of impaired perfusion, leakage, or ischemia. OCT angiography can be used to evaluate microvascular changes without the need for dye injection.

Because retinal occlusions are often associated with systemic vascular conditions, additional medical evaluation may be recommended to identify underlying risk factors and prevent further vascular events.

The image shows an OCT scan revealing swelling of the retina due to a branch retinal vein occlusion.
Image source: PD Dr. Christoph R. Clemens, University Hospital Münster

In retinal artery occlusions, immediate medical attention is critical, as the condition represents an ocular emergency. Although there is no proven therapy to reliably restore blood flow, urgent evaluation aims to rule out life-threatening causes, reduce the risk of further vascular events, and manage underlying systemic conditions such as high blood pressure or cardiovascular disease.

In retinal vein occlusions, treatment focuses on managing complications rather than reopening the blocked vessel. Retinal swelling, particularly macular edema, is commonly treated with intravitreal injections of anti-VEGF medications, which help reduce fluid accumulation and improve or stabilize vision. In some cases, corticosteroid injections may be used. Laser treatment can be applied to prevent or treat abnormal blood vessel growth and reduce the risk of further complications.

The image illustrates three therapy options—anti-VEGF injection, laser treatment and intravitreal corticosteroid implant.