Retinal Vascular Diseases

Introduction ¹

The retina consists of 10 layers including inner and outer limiting membranes, neuronal layer, rods and cones; these layers require a continuous blood supply and nutrients in order to function optimally. The vascular system of the retina consists of arteries, capillaries and veins. Blockage of any of these blood vessels results in retinal vascular disease or retinal vascular occlusion.

A growth factor named vascular endothelial growth factor A (VEGF-A) controls angiogenesis – the growth of new blood vessels; that is thought to be implicated in retinal vascular disease. In the presence of systemic diseases such as diabetes and atherosclerosis, the retinal blood vessels can undergo a variety of changes.

Types ²

• Diabetic retinopathy
  • Diabetic retinopathy is the most common cause of retinal vessels occlusion. Both type 1 and type 2 diabetes mellitus deteriorate the retinal vessels by narrowing the lumen size, and ultimately cutting off blood supply. This can lead to the growth of new, abnormal, leaky blood vessels.
  • Its common signs and symptoms are:
    • The blurring of vision.
    •  
    • Altered colour perception.  
    • Floaters in the visual field.
    • Fluctutating vision.
  • Retinal vein occlusion
    • It is the second most common retinal vascular impairment associated with increased age, diabetes, hypertension, and smoking.
    • It leads to significant visual impairment due to ischemia of the macular area.
    • Its variants are central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO).
    • Its signs and symptoms are:
      • Painless loss of vision both in BRVO and CRVO.
      • Blurring of vision
      • Scotomas/blind spots

• Central retinal artery occlusion
  • Blockage of the central retinal artery can deprive the retina of oxygen and nutrients secondary to atherosclerosis.
  • Its signs and symptoms are:
    • Sudden visual loss or blindness
    • Sudden blurriness of the eye

• Hypertensive retinopathy
  • Constantly increased blood pressure can cause the thickness and narrowing of the retinal blood vessels
  • Its signs and symptoms may include:
    • Headache
    • Decreased vision
    • Double vision

• Wet macular degeneration
• Ocular ischemic syndrome
• Idiopathic juxtafoveal retinal telangiectasis

Causes of Retinal Vascular Disease ¹

• Thrombus/clot
• Heart disease
• Diabetes mellitus
• Hypertension
• Hypercholesterolemia
• Obesity
• Older age
• Smoking
• Blood disorders
• Inflammatory disorders of blood vessels

Diagnosis ²

Early diagnosis and management are critcal to prevent permanent damage to vision due to the potentially rapidly progressive nature of retinal vascular disease.  Depending on the presentation there are multiple tests that may be performed:

• Ophthalmoscopy
  • Retinal changes associated with diabetes and hypertension can be visualized by ophthalmoscopy
• Optical coherence tomography
  • OCT is a noninvasive imaging modality that is used to get high definition images of the retina.
  • Abnormal retinal thickness or detachment can be detected with OCT.
• Fluorescein angiography
  • Angiography is important to assess retinal blood flow. It assists in identifying specific types of vein occlusions and also in staging and treating diabetic retinopathy.
• Clinical features
  • The clinical features associated with retinal vascular disease are:
    • Hemorrhages
    • Cherry red spot
    • Cotton wool spots
    • Macular edema
  • Cardiac assessment
    • A cardiac assessment may be done to rule out cardiac causes in the case of a thrombus.
      • Echocardiogram
      • Electrocardiogram
    • Blood test
      • Blood tests may be be ordered to investigate ceratin systemic illnesses or bleeding disorders.
        • Blood sugar levels
        • HbA1c
        • Renal parameters
        • Coagulation profile

Treatment ³

Treatment of retinal vascular disease has improved in recent times due to the development and use of anti-VEGF medications. The reversibility of vision depends upon the stage and time of presentation. A patient-centered approach is critical.

• Management of risk factors
  • Regular exercise
  • Maintainance of a healthy weight
  • Smoking cessation
  • Diets low in saturated fats
  • Strict diabetes control
  • Prophylactic aspirin therapy as advised by the doctor.
• Laser coagulation
  • Laser therapy can be used to treat leaky blood vessels and control progression of the disease
• Anti-VEGF
  • Antivascular endothelial growth factors e.g ranibizumab can prevent the development of neovascurization (abnormal new vessel growth) and swelling in the retina.
• Corticosteroid injections
  • These may be injected into the eye to reduce swelling from abnormal, leaky blood vessels.

Complications

Uncontrolled systemic disease and late presentation can result in severe or permanent loss of vision. The following complications may occur in retinal vascular disease:

• Glaucoma
• Macular edema
• Neovascularization
• Retinal detachment

If you have not already, make sure to contact your eye care specialists at Eye Surgeons Associates for a complete dilated exam soon!

References

1- Retinal Vascular Disorder - an overview | ScienceDirect Topics. (n.d.). Sciencedirect.Com. Retrieved October 10, 2021, from https://www.sciencedirect.com/topics/medicine-and-dentistry/retinal-vascular-disorder

2- Gabbey, A. E. (2017, April 11). Retinal Vascular Occlusion. Healthline. https://www.healthline.com/health/retinal-artery-occlusion

3- Management of retinal vascular diseases: a patient-centric approach. (2012, April 1). PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3335302/

Author

Eye Surgeons Associates Drs. Meiraj A. Siddiqui, Zuhair H. Peracha, Manal H. Peracha-Riyaz, Eric Zuckerman and Leila Siblani are dedicated to excellence in eye care and service. We utilize the latest treatment methods and procedures, including routine eye care, cataract surgery, glaucoma treatment, retinal disease management, diabetic eye treatment, and eyelid surgery.