Retinal haemorrhage
Encyclopedia
Retinal haemorrhage is a disorder of the eye
in which bleeding occurs into the retina
.
The retina is a thin disc-shaped layer of light-sensitive tissue on the back wall of the eye. Its job is to translate what we see into neural impulses and send them to the brain via the optic nerve
. A retinal haemorrhage can be caused by hypertension
, retinal vein occlusion (a blockage of a retinal vein), or diabetes mellitus
(which causes small fragile blood vessels to form, which are easily damaged). Retinal haemorrhages can also occur due to shaking, particularly in young infant
s (shaken baby syndrome
) or from severe blows to the head.
Retinal haemorrhages that take place outside of the macula
can go undetected for many years, and may sometimes only be picked up when the eye is examined in detail with an ophthalmoscope. However, some retinal haemorrhages can cause severe impairment of vision.
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
in which bleeding occurs into the retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
.
The retina is a thin disc-shaped layer of light-sensitive tissue on the back wall of the eye. Its job is to translate what we see into neural impulses and send them to the brain via the optic nerve
Optic nerve
The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...
. A retinal haemorrhage can be caused by hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, retinal vein occlusion (a blockage of a retinal vein), or diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
(which causes small fragile blood vessels to form, which are easily damaged). Retinal haemorrhages can also occur due to shaking, particularly in young infant
Infant
A newborn or baby is the very young offspring of a human or other mammal. A newborn is an infant who is within hours, days, or up to a few weeks from birth. In medical contexts, newborn or neonate refers to an infant in the first 28 days after birth...
s (shaken baby syndrome
Shaken baby syndrome
Shaken baby syndrome is a triad of medical symptoms: subdural hematoma, retinal hemorrhage, and brain swelling from which doctors, consistent with current medical understanding, infer child abuse caused by intentional shaking...
) or from severe blows to the head.
Retinal haemorrhages that take place outside of the macula
Macula
The macula or macula lutea is an oval-shaped highly pigmented yellow spot near the center of the retina of the human eye. It has a diameter of around 5 mm and is often histologically defined as having two or more layers of ganglion cells...
can go undetected for many years, and may sometimes only be picked up when the eye is examined in detail with an ophthalmoscope. However, some retinal haemorrhages can cause severe impairment of vision.