Table of Contents
Where is the macula located in relation to the optic disc?
The macula is a circular area of diameter 5.5 mm with a center located 17 degrees, or 4.0-5.0 mm, temporal, and 0.53 – 0.8mm inferior to the center of the optic disc.
What does cupping of the optic disc mean?
Glaucoma is caused by high pressure in the eye damaging the optic nerve, which results in loss of individual nerve cells. This causes a subsequent increase in the size of the cup, also called cupping.
How far is the macula from the optic disc?
The mean disc-macula distance was 4.74 ± 0.29 mm, a value almost identical with the one obtained in our study.
Is macula nasal or temporal to disc?
Thus the principal arteries, veins, and quadrants of any retina are the superior temporal, inferior temporal, inferior nasal, and superior nasal. The avascular, dusky area two disk diameters due temporal to the disk is the macula.
Where is macula located?
the retina
The macula is located near the center of the retina; its function is to process harp, clear, straight-ahead vision. 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.
How do you find the macula?
To look at the macula, ask the patient to look directly into the ophthalmoscope light. The ophthalmoscope can also be used for examining the anterior part of the eye by turning the lens dial to ∼ +10.
What disorder would cause cupping of the optic disc?
OPTIC DISC CUPPING. A hallmark of glaucoma is excavation or enlargement of the optic disc, referred to as cupping. The vast majority of pathologic cupping is caused by glaucoma. Disc cupping in the absence of elevated IOP may be caused by normal-tension glaucoma, which accounts for 20% to 30% of open-angle glaucoma.
What are the DISC signs of glaucoma?
Characteristics of a glaucomatous ONH
- generalised/focal enlargement of the cup.
- disc haemorrhage (within 1 disc diameter of ONH)
- thinning of neuroretinal rim (usually at superior & inferior poles)
- asymmetry of cupping between patient’s eyes.
- loss of nerve fibre layer.
What is disc macula?
The disc-macula: disc diameter (DM:DD) ratio is the ratio of the horizontal distance between the center of the optic disc and the macula to the mean diameter of the optic disc, as evaluated from fundus photographs.
What’s the macula?
The macula is the pigmented part of the retina located in the very center of the retina. 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.
What is optic nerve cupping?
Optic nerve cupping progresses as the cup becomes larger in comparison to the optic disc. Both people with and without optic nerve damage have optic nerve cupping, although those with glaucoma tend to have a greater cup-to-disc ratio.
Where is the macula located on the retina?
A fundus photograph showing the macula as a spot to the left. The optic disc is the area on the right where blood vessels converge. The grey, more diffuse spot in the centre is a shadow artifact. Time-Domain OCT of the macular area of a retina at 800 nm, axial resolution 3 µm.
Why is my eye cup larger than my optic disc?
In people with glaucoma damage, because of increased pressure in the eye and/or loss of blood flow to the optic nerve, these nerve fibers begin to die. This causes the cup to become larger in comparison to the optic disc, since the support structure is not there.
What is macular sparing with visual field testing?
Visual input from the macula occupies a substantial portion of the brain’s visual capacity. As a result, some forms of visual field loss that occur without involving the macula are termed macular sparing. (For example, visual field testing might demonstrate homonymous hemianopsia with macular sparing .)