How Certain Types of Anemia Affect Your Eyes
Anemia causes a variety of symptoms, including dizziness, shortness of breath, fatigue, and headaches. If you've noticed changes in your vision, you're not imagining things. Anemia can also cause problems with the eyes.
What Is Anemia?
Anemia occurs when you don't have enough red blood cells in your blood. Red blood cells carry oxygen to every part of your body. Your body uses oxygen to make energy and remove carbon dioxide from your blood, a waste product produced by energy production. Red blood cells return the carbon dioxide to the lungs, where it is removed by breathing.
Anemia has several causes and may happen if:
- Your Body Doesn't Make Enough Red Blood Cells
- Your Body Destroys Too Many Red Blood Cells
- You Have Experienced Blood Loss
- Your Body Doesn't Have Enough Iron to Make Red Blood Cells
- Your Red Blood Cells Are Abnormally Shaped
- Your Body Has Trouble Absorbing Iron or Vitamin B12
You may be more likely to develop anemia if you have ulcers, problems with nutrient absorption, pregnancy, poor nutrition, or immune system diseases and conditions. Some diseases, like cancer, leukemia, lymphoma, kidney disease, ulcerative colitis, or rheumatoid arthritis, may increase your risk for anemia. Women are at increased risk of anemia if they have heavy menstrual periods.
Certain medications can cause anemia, including nitrofurantoin, levodopa, dapsone, and diclofenac, as can some antibiotics and non-steroidal anti-inflammatory drugs.
How Iron Deficiency Anemia Affects the Eyes
Iron deficiency anemia, the most common form of anemia, occurs when your iron level is too low. Your body uses iron when it makes new red blood cells.
This type of anemia can cause blockages in the central retinal vein or retinal artery. These blockages prevent blood and oxygen from reaching your retina. The retina captures light rays, turns them into signals, and passes them on to the brain for processing. The signals travel from the eyes to the brain via the optic nerve. If your retinas are deprived of oxygen for too long, damage can occur.
In addition to blockages, iron deficiency anemia can cause white cotton wool spots and swelling of the optic disk, the part of the retina that sends signals to the optic nerve. Optic nerve damage or bleeding due to hemorrhages in the eye may occur in some cases.
Iron deficiency anemia can cause several vision signs and symptoms, including:
- Inner Eyelids That Look White Instead of Pink
- Blue Appearance to the Sclera (Whites of the Eyes)
- Blurry Vision
- Blind Spots
- Eye Pain
- Flashes and Floaters
- Temporary Darkening of Vision
- Dark Circles Under the Eyes
Loss of vision can occur in some cases if anemia is severe and not treated promptly.
Sickle Cell Anemia Vision Changes
Red blood cells are normally round. If you have sickle cell anemia, your blood cells look like sickles or half moons. The abnormal shape causes the red blood cells to stick together in the blood vessels, preventing oxygen from reaching your cells. Red blood cells usually live about 120 days before they're destroyed and replaced with new cells, according to Frontiers in Physiology. Sickle cells may only live about 10 days before they're destroyed.
Sickle cell anemia may cause retinal thinning and blood vessel blockages in the retina or choroid, a layer of tissue and blood vessels between the white part of your eye and the retina. New abnormal vessels may grow in the retina and leak fluid or blood. If you have anemia caused by sickle cell anemia, you may experience these vision issues:
- Floaters
- Blurred Vision
- Blind Spots
- Flashes of Light
- Loss of Side Vision
- Retinal Detachment
Vitamin B12 Anemia
Your body needs vitamin B12 to make red blood cells. Anemia can occur if you don't have enough of this important vitamin. The condition can be caused by a lack of a stomach protein needed for B12 absorption, an autoimmune disorder that makes it hard for your intestines to absorb vitamin B12, intestinal conditions, or removal of the small intestine or stomach.
Vitamin B12 can cause optic nerve damage or retinal hemorrhages. Signs and symptoms of vitamin B12 include:
- Vision Loss
- Dull Colors
- Blurry Vision
- Eye Pain
- Flashes and Floaters
- Blind Spots
Worried that you may have vision problems due to anemia? Contact our office to schedule an appointment with the ophthalmologist.
Sources:
Frontiers in Physiology: How Do Red Blood Cells Die?, 3/15/2021
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006275
American Society of Retina Specialists: Sickle Cell Retinopathy
https://www.asrs.org/patients/retinal-diseases/41/sickle-cell-retinopathy
Optometry Today: Women Suffers Vision Loss After Developing Severe Iron Deficiency During Lockdown, 8/3/2021
National Heart, Lung and Blood Institute: Vitamin B12-Deficiency Anemia
https://www.nhlbi.nih.gov/health/anemia/vitamin-b12-deficiency-anemia
Cleveland Clinic Journal of Medicine: Blue Sclera: An Overlooked Finding of Iron Deficiency, 10/2022