At first glance, maybe this photo looks very normal. But if you look more carefully at the superior edge of the optic nerve, you will see a circular red area that is a retinal hemorrhage. A hemorrhage is blood inside of the eye, in this case trapped in a layer of the retina underneath the overlying retinal arterioles and venules (you can see the vessel clearly passing over top of it). Blood in the retina is never good (especially not near the nerve where it could be a harbinger of serious ocular conditions like glaucoma), and when I see blood there is a lengthy discussion to be had. The good news: this type of small hemorrhage in and of itself does not cause vision damage, and will be reabsorbed by the ocular tissue and gone in around 3 months, like nothing was ever there. Bleeding inside the eye isn't painful, and unless your doctor finds it during your exam, likely you would never even know it was there. So why do we worry so much about blood in the eye? Because it means a number of things could be going wrong in your body (not just your eye!). Here's a differential overview of what I need to investigate when I see blood inside a patient's eye:
- Hypetension, Diabetes, or other systemic vascular condition
If a medical condition causes issues with blood flow, then it can cause bleeding inside the eye. Diabetic retinopathy tends to cause multiple pinpoint dot hemorrhages, whereas hypertensive retinopathy tends to be associated with larger flame shaped hemorrhages. In any case, a full work up for blood pressure, blood sugar, cholesterol levels, and hypercoagulable states may be needed when blood is found inside the eye.
- Glaucoma
The position of this hemorrhage near the optic nerve is especially suspicious for glaucoma. A drance hemorrhage (it is so special it has it's own name!) tends to be flame shaped, and near the area of the optic nerve that is suffering active thinning and damage. When I see a hemorrhage at or next to the nerve, glaucoma is always on the top of my list so ordering a full glaucoma work-up (visual field, OCT, pressure checks) is a next step. Normal Tension Glaucoma (also called Low Tension Glaucoma) appears to be more closely associated with drance hemes, and this type of glaucoma often goes untreated longer because the patient will appear to have normal eye pressure at their yearly examinations. The appearance of a drance heme is often a first signal to a doctor that something must be wrong if pressures run low in a patient's eye.
- Valsalva Event
Have you ever popped a blood vessel on the white of your eye due to coughing, sneezing, or straining too hard? Well any strain of this nature can cause a vessel inside the eye to bust also. Basically if you are putting undue strain on your vessels, they can break open and blood will leak temporarily into the surrounding tissue. Ocular vessels are some of the smallest in the body, so they are very at risk to break. Coughing, sneezing, lifting heavy weights, and vomiting are common culprits.
- New Floater
Have you ever had a floater appear all of a sudden, like a fly or black speck in your vision that just won't go away. Floaters really are inside the eye, a clump of the vitreous jelly that fills the eye that has pulled together and broken loose. Sometimes when a large area of the vitreous pulls away from the retinal tissue, the tractional force of the floater breaking off can cause a blood vessel to bust open. This is common in conditions like Posterior Vitreal Detachment which is a normal aging change that occurs when the vitreous separates from the back of the eye permanently. Of course, a new sudden floater and blood in the eye can also be a sign of a retinal tear, so please see your doctor immediately if you see a new floater or flashing lights in your vision.
- High Risk Medications
Hard to believe, but sometimes the medications that you are taking to keep your body healthy can cause damage to your blood vessels as a side effect. Very common medications that cause hemorrhages inside the eye are blood thinners such as Warfarin, Coumadin, and even Aspirin. If you are taking a blood thinner, you should be having yearly eye exams to make sure that the dosage prescribed isn't causing the blood vessels to leak. If there is bleeding inside the eye as a side effect of these medications, usually lowering the dosage can solve the issue.
This is not an exhaustive list, but look at all the potential culprits for a spot of blood in the eye! Your eye doctor is not only trained to find these broken blood vessels, but also to determine the cause of your bleed before any permanent harm from systemic or ocular diseases can cause actual vision loss or major health issues. Many people have had high blood pressure and diabetes diagnosed due to problems being caught at their routine eye exam! The eye is truly the window into the body, and your eye doctor will work closely with your primary care doctor, cardiologist, endocrinologist, neurologist, or any other specialist that is treating you medically to help use the information found on your eye exam to keep your eyes and your entire body healthy for years to come.