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What is a normal macula?
It measures approximately 5.5 mm in diameter and is centered approximately 4 mm temporal to and 0.8 mm inferior to the center of the optic disc ( Figure 1.01 ). On the basis of microscopic anatomy, the macular area can be further subdivided into several zones.
What should the macula look like?
The macula is yellow in color. The yellow color is derived from lutein and zeaxanthin in the diet, both yellow xanthophyllcarotenoids contained within the macula. Because of its yellow color, the macula absorbs excess blue and ultraviolet light that enters the eye, acting as a sunblock to protect the retinal area.
How would you describe macula?
The macula is the part of your eye that processes what you see directly in front of you (your central vision). It's part of your retina and is key to your vision. The macula is the round area at the center of your retina, at the back of your eyeball.
Should the macula be flat?
This small part of the retina is called the macula. The macula normally lies flat against the inside back surface of the eye.
What is normal macula thickness?
Mean macular thickness for all subjects was 262.8±13.34 µm.
What does it look like with macular degeneration?
The first sign you may notice is a gradual or sudden change in the quality of your vision or that straight lines appear distorted to you. This may gradually turn into a dramatic loss of your central vision. Other symptoms include: Dark, blurry areas or whiteout that appears in the center of your vision.
Why is the macula darker?
The pigment epithelial cells are taller and contain more pigment than cells elsewhere in the retina, contributing to the darkness of this area. However, the density of the pigment varies greatly from person to person. The choroidal capillary bed also is thicker in the macula lutea than elsewhere.
What is the difference between macular and macula?
The macula is a place. It is the functional center of the retina. The term macular is an adjective. “Macular” is not a disease.
What gives the macula its color?
The existence of the macula lutea of the human retina has been known for more than 200 years. It is established that the xanthophylls lutein and zeaxanthin are responsible for the yellow color. The effect of macular photopigments on blue-light filtration and color perception is well established.
Can cataract surgery make macular pucker worse?
Performing cataract surgery can exacerbate macular edema related to diabetic retinopathy, so any edema should be treated prior to performing cataract surgery.
Does cataract surgery cause macular pucker?
A macular pucker may develop in response to injury or swelling in the eye after a retinal tear or detachment, after cataract surgery, or in association with diseases such as uveitis or diabetes. However, in most cases there is no identifiable cause.
Can glasses correct macular pucker?
The membrane can contract and lead to wrinkling or puckering of the underlying macula. This may result in painless distortion and blurring of vision. A change in eye glasses cannot overcome this physical change. Visual change from a macular pucker may not be noticeable to the patient.
What does a spot on the macula mean?
07, 2022. Macular hole is when a circular opening forms in your macula. As the hole forms, things in your central vision will look blurry, wavy or distorted. As the hole grows, a dark or blind spot appears in your central vision. A macular hole does not affect your peripheral (side) vision.
What happens if macula is damaged?
In the centre is the macula – the part responsible for central and fine-detail vision needed for tasks such as reading. In the early stages, a macular hole can cause blurred and distorted vision. Straight lines may look wavy or bowed, and you may have trouble reading small print.
Why is the macula darker?
The pigment epithelial cells are taller and contain more pigment than cells elsewhere in the retina, contributing to the darkness of this area. However, the density of the pigment varies greatly from person to person. The choroidal capillary bed also is thicker in the macula lutea than elsewhere.
What is the difference between macula and macular?
The macula is a place. It is the functional center of the retina. The term macular is an adjective. “Macular” is not a disease.
Which nerve cells are present in the macula and concentrated in the fovea?
Cones: The photoreceptor nerve cells present in the macula and concentrated in the fovea (the very center of the macula); enable people to see fine detail and color. Fovea: The pit or depression at the center of the macula that provides greatest visual acuity.
Which tissue is responsible for the visual acuity of the eye?
The retina is the paper-thin tissue that lines the back of the eye and contains the photoreceptor (light sensing) cells (rods and cones) that send visual signals to the brain. The pit or depression within the macula, called the fovea, provides the greatest visual acuity.
What is the name of the cell that protects and nourishes the retina?
Retina: The light sensitive layer of tissue that lines the back of the eye. Retinal Pigmented Epithelium (RPE): A layer of cells that protects and nourishes the retina, removes waste products, prevents new blood vessel growth into the retinal layer ...
Which layer of the retina contains blood vessels that nourish the retina?
The choroid layer contains blood vessels that nourish the retina. Bruch's membrane provides support to the retina. The retinal pigmented epithelium (RPE) protects and nourishes the retina, removes waste products and prevents new blood vessels from growing into the retina.
Where is Bruch's membrane located?
Bruch's membrane: Located in the retina between the choroid and the retinal pigmented epithelium (RPE) layer; provides support to the retina and functions as the 'basement' membrane of the RPE layer.
What is the macula?
The macula is recognized as the specialized region of the retina in charge of high-resolution visual acuity. Anatomically, it can be defined as the central part of the posterior retina that contains xanthophyll pigment and two or more layers of ganglion cells. In this chapter, we focus primarily on the aspects of the normal anatomy of the macula as an introduction to the understanding and management of age-related macular degeneration.
What are the anatomic subdivisions of the macula?
The anatomic subdivisions of the macula are ill-defined ophthalmoscopically. The margins of either the 0.35-mm diameter foveola or the 1.5-mm diameter fovea are difficult to define. A poorly defined zone of greater pigmentation (one-fourth to one disk diameter in size) corresponds to the center of the macula, which is maximum in the foveolar area. The foveal reflex is present in most normal eyes, and it lies just in front of the center of the foveola ( Fig. 1.3 ). We can see the foveal depression with the narrow slit lamp beam.
What is the macula fovea?
Anatomically, the macula (macula lutea or central retina) is defined as the portion of the posterior retina that contains xanthophyll and two or more layers of ganglion cells. This region is about 5.5 mm in diameter and is centered approximately 4 mm temporal and 0.8 mm inferior to the center of the optic disk ( 15 ). It corresponds clinically to the posterior pole and is approximately bounded by the superior and inferior temporal vascular arcades. On the basis of microscopic anatomy, the macular area can be further subdivided into several zones ( Fig. 1.2 ).
How long does it take for a fovea to develop?
Human fovea at birth. B. Human fovea at 45 months. C. Human fovea at 72 years of age. Black lines mark the width of the rod-free foveola; at birth, the foveola is wider (A) than at 45 months (B). Full foveal development is not complete until sometime between 15 and 45 months of age.
How does the macula vascularize?
Some have proposed that the capillary-free zone (CFZ) develops by regression of previously formed capillaries, because the retina is thin enough in this area that sufficient oxygen can diffuse inward from the choroidal circulation ( 12 ). Others believe that the CFZ forms primarily, with the embryonic vessels gradually encircling the center of the fovea and with no evidence of regression ( 13 ).
What are the two zones of the macula?
Figure 1.2 ▪ Topographic anatomy of the normal macula. On the basis of microscopic anatomy, the macular area can be further subdivided into several zones. I. Fovea containing the foveola ( 1 ). II. Parafovea. III. Perifovea.
When do the retinae differentiate?
The central and peripheral retinae start to differentiate between the first and third months. The ganglion cell layer becomes thicker, as do the inner plexiform layer and the amacrine cell layer. The cones appear in the 5th month. They are a protoplasmic extension of the outer neuroblastic layer ( 4, 5, 6 ). The rods appear in the 6th month ( 5 ). The macula becomes thinner in the 7th month because the cells of the different layers move laterally, and the foveal pit appears more evident ( Fig. 1.1) ( 7, 8 ).
What is the color of the macula?
Color. The macula is yellow in color. The yellow color is derived from lutein and zeaxanthin in the diet, both yellow xanthophyllcarotenoids contained within the macula. Because of its yellow color, the macula absorbs excess blue and ultraviolet light that enter into the eye, acting as sunblock to protect the retinal area.
What is the macula in the eye?
Symptoms of Macular Damage. The macula is part of the eye's retina. Located in the center of the retina, the macula is responsible for giving us clear vision and the ability to see fine detail. Although it is small, it enables us to see " 20/20 " and to see our world in color. Learn more about the important role the macula plays inside the eye.
How does the macula work?
Much like film in a camera, images come through the eye's lens and are focused on the retina. The retina then converts these images to electric signals and sends them to the brain. The macula has a diameter of about 5 mm. 1 The macula can be seen with the use of an ophthalmoscope or a retinal camera.
What is the name of the hole in the eye?
Macular Hole. A macular hole occurs when the nerve cells of the macula become separated from each other and pull away from the back surface of the eye, forming a hole. As the hole forms, central vision can become blurry, wavy, or distorted.
What happens if you damage your macula?
Damage to the macula results in the loss of the ability to see objects clearly in the center of vision. Since peripheral vision is not affected, a person with damage to the macula can adapt to life and continue some normal daily activities, such as walking, without assistance. Several problems can affect the macula. The most common is macular degeneration. Other common conditions that affect the macula are macular edema and macular hole, discussed below.
What is the macula responsible for?
It is responsible for all of our central vision and most of our color vision. The fine detail we see is made possible by the macula. Because it is responsible for our central vision, diseases involving the macula, such as macular degeneration, cause loss of central vision.
Which part of the eye is the most important?
In the center of the macula is the fovea, perhaps the most important part of the eye. The fovea is the area of best visual acuity. It contains a large amount of cones—nerve cells that are photoreceptors with high acuity.
How big is the macula?
The macula in humans has a diameter of around 5.5 mm (0.22 in) and is subdivided into the umbo, foveola, foveal avascular zone, fovea, parafovea, and perifovea areas. The anatomical macula at 5.5 mm (0.22 in) is much larger than the clinical macula which, at 1.5 mm (0.059 in), corresponds to the anatomical fovea.
What is the clinical macula?
The clinical macula is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography. The anatomical macula is defined histologically in terms of having two or more layers of ganglion cells. The umbo is the center of the foveola which in turn is located at the center of the fovea.
Why is the macula yellow?
Because the macula is yellow in colour it absorbs excess blue and ultraviolet light that enter the eye and acts as a natural sunblock (analogous to sunglasses) for this area of the retina. The yellow color comes from its content of lutein and zeaxanthin, which are yellow xanthophyll carotenoids, derived from the diet.
What is the role of the macula in vision?
The macula is responsible for the central, high-resolution, color vision that is possible in good light; and this kind of vision is impaired if the macula is damaged, for example in macular degeneration. The clinical macula is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography.
How many types of cones are there in the human eye?
In detail, the normal human eye contains three different types of cones, with different ranges of spectral sensitivity. The brain combines the signals from neighboring cones to distinguish different colors. There is only one type of rod, but the rods are more sensitive than the cones, so in dim light, they are the dominant photoreceptors active, and without information provided by the separate spectral sensitivity of the cones it is impossible to discriminate colors. In the fovea centralis, cones predominate and are present at high density. The macula is thus responsible for the central, high-resolution, color vision that is possible in good light; and this kind of vision is impaired if the macula is damaged, for example in macular degeneration.
What is the right eye in a fundus?
Fundus photographs of the right eye (left image) and left eye (right image), seen from front so that left in each image is to the person's right. The gaze is into the camera, so in each picture the macula is in the center of the image, and the optic disk is located towards the nose.
What color is the macula after death?
After death or enucleation (removal of the eye), the macula appears yellow, a color that is not visible in the living eye except when viewed with light from which red has been filtered.
What are the exclusion criteria for healthy eyes?
Exclusion criteria for healthy eyes included any history or evidence of pathological features of the retina, diabetes mellitus or other systemic disease that could affect the eye, glaucoma or first-degree relative with glaucoma, intraocular pressure higher than 21 mm Hg, abnormal visual fields, intraocular surgery or laser therapy (although refractive surgery >1 year before enrollment was acceptable), best-corrected visual acuity worse than 20/32, and refractive error greater than 6.00 or less than −6.0 diopters.
How thick is the foveal?
Foveal thickness (mean thickness in the central 1000-μm diameter area) and central foveal thickness (mean thickness at the point of intersection of 6 radial scans) on the OCT3 were 212 ± 20 and 182 ± 23 μm, respectively. Macular thickness measurements were thinnest at the center of the fovea, thickest within 3-mm diameter of the center, and diminished toward the periphery of the macula. The temporal quadrant was thinner than the nasal quadrant. Central foveal thickness was also manually determined as 170 ± 18 μm, approximately 12 μm less than the value automatically obtained from the OCT3 software. There was no correlation between age and foveal thickness (P= .80).
What is the difference between central and foveal thickness?
In B, central foveal thickness is defined as the mean thickness measured at the point of intersection of the 6 radial scans on optical coherence tomography. The mean foveal thickness is approximately 30 μm greater than the mean central foveal thickness.
How many healthy eyes are there with the OCT3?
Macular Thickness Measurements in 37 Healthy Eyes Using the OCT3
Does age affect foveal thickness?
By using linear regression analysis, we found no relationship between age and foveal thickness within the central 1000-μm diameter (P= .80) (Figure 3).
