What is the Blood in the Eye
The symptom commonly described as "blood in the eye" is caused by the rupture of the small superficial capillaries, located between the sclera and the conjunctiva; this results in an appreciable blood spill as a red patch located in the "white part" of the eye (ocular sclera).
In most cases, blood loss in the eye is harmless and does not cause vision problems or significant discomfort, despite its visible appearance. Subconjunctival hemorrhage can be caused by sudden increases in pressure, such as violent sneezing or coughing. Capillary ruptures can also occur in people suffering from hypertension or taking anticoagulants.
In most cases, treatment is not necessary. Usually, the blood spill in the eye resolves spontaneously within 1-3 weeks.
Symptoms
In addition to bleeding, evident in the space between the conjunctiva and the sclera (the white part of the eye), many patients describe a scratchy sensation.
The blood initially appears bright red, below the transparent conjunctival surface. Later, the bleeding can spread and become green or yellow, similar to a bruise. Pain is generally non-existent or minimal and there is no change in vision.
Causes and risk factors
Subconjunctival hemorrhage occurs when a small blood vessel ruptures and spills blood into the bulbar conjunctiva. The conjunctival epithelium, in fact, contains numerous blood vessels (generally they are visible when the eye is inflamed). These vases are quite fragile and their walls can easily break.
Blood loss in the eye can occasionally be caused by a sneeze or a severe cough. In other cases, it may be due to suffocation, heavy lifting, vigorous rubbing of the eye and vomiting. However, the blood in the eye can also be determined by more serious conditions: blunt trauma, cranial fracture, increased intracranial or intraocular pressure, hypertension or coagulation disorders. Occasionally, blood loss in the eye can also be a sign of other types of potentially serious eye conditions, especially when associated with eye discharge (eye infection). Furthermore, subconjunctival hemorrhage may appear as a minor post-operative complication in refractive surgery (example: LASIK).
Several factors can increase the risk of breaking a blood vessel in the eye. For example, this may represent a side effect of anticoagulant drugs, such as aspirin (acetylsalicylic acid) and warfarin. Although rare, St. John's wort, ginkgo biloba, ginger and cayenne pepper can increase the risk of bleeding if taken in high doses.
Diagnosis
In most cases, a simple eye exam is sufficient to correctly diagnose an under-conjunctival hemorrhage. If the cause is unknown, however, the ophthalmologist can carry out a series of investigations to rule out eye diseases that can cause the manifestation.
If the loss of blood in the eye is induced by a trauma, a more thorough examination will be carried out to ascertain that the damage has not involved other structures. If other areas of bruising or bleeding are present in the body, more specific diagnostic tests may be required.
Treatment
In the absence of infection or significant trauma, subconjunctival hemorrhage is a condition that does not require treatment. If associated with pain or discomfort, analgesic drugs may be recommended. Even artificial tears can help reduce irritation.
Patients on aspirin or anticoagulants should consult their doctor to determine if it is safe to continue taking these medications. If subconjunctival bleeding is due to trauma, additional medical measures may be needed to promote recovery. If an infection is present, eye drops or antibiotic ointments may be prescribed.
Generally, blood loss in the eye is self-limiting and resolves in two or three weeks, with no long-term complications.
Prevention
The loss of blood in the eye can sometimes be prevented. To avoid eye injuries, it is useful to wear protective glasses whenever exposure to environments where volatile particles (such as dust) and intense sunlight are expected. If recurrent bleeding in the eye occurs, it is advisable to seek medical attention to rule out a bleeding disorder.
