Sclera
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View Verlyn Yang's current disclosuresAt the time the article was last revised Raymond Chieng had no financial relationships to ineligible companies to disclose.
View Raymond Chieng's current disclosures- Sclerae
- Scleras
- Scleral
The sclera (plural: scleras or sclerae) is the fibrous, opaque white, coat of the eye. It functions to protect the intraocular contents.
On this page:
Summary
location: posterior fifth-sixths of the eyeball
blood supply: ciliary arteries
innervation: ciliary nerves
relations: anteriorly continuous with the cornea
Gross anatomy
Outermost coat of the trilaminar globe. Anteriorly continuous with the cornea. Posteriorly perforated by the optic nerve at the lamina cribrosa.
Sclera is continuous with dura, pia, and arachnoid sheaths of the optic nerve 2.
Arterial supply
anteriorly, the anterior ciliary arteries form a dense episcleral plexus
posteriorly, supplied by branches of the short and long posterior ciliary arteries
Lymphatic drainage
The sclera is an alymphatic organ.
Innervation
Anteriorly supplied by the long ciliary nerves. Posteriorly supplied by the short ciliary nerves.
Histology
The sclera may be divided into three histological layers:
-
episclera
outermost, loose connective tissue layer, connected to the Tenon capsule
rich vascular supply from anterior ciliary arteries
-
scleral stroma
dense fibrous tissue intermingled with fine elastic fibers
irregular arrangement of type I and III collagen responsible for its opacity
-
lamina fusca
innermost layer with melanocytes
weakly related to the choroid
Radiographic features
Ultrasound and CT are not useful modalities.
Anterior segment ocular coherence tomography (AS-OCT)
readily used in clinical practice to measure scleral thickness, monitor therapeutic response in scleritis treatment
quantitative measurements obtained
MRI
useful in the diagnosis of posterior scleritis and episcleritis
T1-weighted sequences, sclera appears as the hypointense rim of the globe
History and etymology
The word derives from medical Latin, itself from the Greek sklera "the hard (membrane)," feminine form of skleros "hard".
Related pathology
episcleritis/scleritis: inflammation of the sclera
staphyloma: full or partial thickness scleral defect lined by the uvea
References
- 1. Richard S. Snell, Michael A. Lemp. Clinical Anatomy of the Eye. (2013) ISBN: 9781118691007
- 2. Barral J & Croibier A. Optic Nerve. Manual Therapy for the Cranial Nerves. 2009;:73-89. doi:10.1016/b978-0-7020-3100-7.50014-8
Incoming Links
- Small communicating branch
- Senile calcific scleral plaques
- Scleritis
- Optic nerve
- Jaundice
- Osteogenesis imperfecta classification
- Orbital pathology
- Short posterior ciliary arteries
- Osteogenesis imperfecta
- Choroidal detachment
- Short ciliary nerves
- Normal intracranial calcifications
- Uvea
- Lateral rectus muscle
- Optic perineuritis
- Long posterior ciliary arteries
- Superior oblique muscle
- Cribriform plate
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- Ocular foreign body (nail)
- Hypoxic ischaemic encephalopathy
- Ruptured globe
- Idiopathic intracranial hypertension
- Vogt-Koyanagi-Harada disease
- Sturge-Weber syndrome
- Frontoethmoidal sinus osteoma
- Multifocal orbital and calvarial fractures
- Meningioma of the optic nerve sheath
- Ocular choroidal detachment
- Ocular foreign body
- Ocular choroidal detachment
- Ocular foreign body
- Traumatic ocular choroidal detachment, vitreous and retrobulbar haemorrhage
- Traumatic ocular choroidal detachment
- Ocular foreign body
- Ocular globe rupture
- Ocular foreign body and rupture
- Ocular globe rupture
- Ocular rupture
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