sclera (redirected from sclerae)

sclera /scle·ra/ (sklēr´ah) pl. scle´rae   [L.] the tough white outer coat of the eyeball, covering approximately the posterior five-sixths of its surface, continuous anteriorly with the cornea and posteriorly with the external sheath of the optic nerve.scler´al

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scle·ra (sklîr)

n. pl. scle·ras or scle·rae (sklîr)

The tough fibrous tunic forming the outer envelope of the eye and covering all of the eyeball except the cornea; the white of the eye. Also called sclerotic.

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scleral adj.

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Sclera

The tough, fibrous, white outer protective covering that surrounds the eye.

Mentioned in: Eye Examination, Eye Muscle Surgery, Glaucoma, Osteogenesis Imperfecta, Trabeculectomy

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sclera

[sklir′ə]

Etymology: Gk, skleros, hard

the tough, inelastic white opaque membrane covering the posterior five sixths of the eyebulb. It maintains the size and form of the bulb and attaches to muscles that move the bulb. Posteriorly it is pierced by the optic nerve and, with the transparent cornea, makes up the outermost of three tunics covering the eyebulb.

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sclera (skler´),

n the opaque, fibrous, protective layer of the eye containing collagen and elastic fibers. It is commonly known as the white of the eye. Because the sclera is thinner in children, some of the underlying eye pigment is visible, making the eye appear slightly bluish. In older adults, fatty deposits on the sclera make it appear slightly yellowish.

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sclera

pl. sclerae [L.] the tough, usually white, outer coat of the eyeball, covering all the posterior surface and continuous anteriorly with the cornea. The stroma is banded by loose connective tissue, the lamina fusca internally and episclera externally.

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sclera inflammation

see scleritis.

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sclera 

The tough, white, opaque, fibrous outer tunic of the eyeball covering most of its surface (the cornea contributes 7% of, and completes, the outer tunic). Its anterior portion is visible and constitutes the 'white' of the eye. In childhood (or in pathological conditions) when the sclera is thin, it appears bluish, while in old age it may become yellowish, due to a deposition of fat. The sclera is thickest posteriorly (about 1 mm) and gradually becomes thinner towards the front of the eyeball. It is a sieve-like membrane at the lamina cribrosa. The sclera is pierced by three sets of apertures: (1) the posterior apertures round the optic nerve and through which pass the long and short posterior ciliary vessels and nerves; (2) the middle apertures, 4 mm behind the equator which give exit to the vortex veins; and (3) the anterior apertures through which pass the anterior ciliary vessels. The tendons of insertion of the extraocular muscles run into the sclera as parallel fibres and then spread out in a fan-shaped manner. The sclera is commonly considered to be divided into three layers from without inward: (1) the episclera, (2) the scleral stroma and (3) the suprachoroid (lamina fusca) which is interposed between choroid and sclera. Syn. sclerotic. Note: some authors consider the suprachoroid as belonging to the choroid. However, when choroid and sclera are separated part of the suprachoroid adheres to the choroid and part to the sclera. See cribriform plate; evisceration.
blue sclera A hereditary defect in which the sclera has a bluish appearance. The sclera is thinner than normal and is susceptible to rupture if the person engages in contact sports. It is often associated with fragility of the bones and deafness as part of a condition called osteogenesis imperfecta (fragilitas ossium, van der Hoeve's syndrome), with keratoconus or with acquired scleral thinning (e. g. necrotizing scleritis). Syn. blue sclerotic (Fig. S3). See Ehlers-Danlos syndrome; Marfan's syndrome.

Fig. S3 Blue sclera

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Patient discussion about sclerae.

Q. My 11 y/o son eyes appear to have a slight yellow in the whites toward the corners. I am assuming he will need blood work, but does anyone have any idea what may be the cause?

A. If it's not a spot, but rather a diffuse color, it may be jaundice - high levels in the blood of a substance called bilirubin (http://en.wikipedia.org/wiki/Jaundice).

If your child is generally healthy, and this change appeared without any overt problem (e.g. liver disease or blood problem), or your child had fever or fasted recently, this jaundice may represents Gilbert syndrome. It's a syndrome of slightly elevated levels of bilirubin, and considered not dangerous.

You may read more here:http://www.nlm.nih.gov/medlineplus/ency/article/000301.htm