1912
The skin of the eyelid is the thinnest in the body and lacks adipose tissue.
The innermost layer of tissue of the eyelid that lies adjacent to the globe is referred to as the palpebral conjunctiva.
The eyelid is a thin fold of skin that covers and protects the human eye.
The skin of the eyelid similar to skin elsewhere, but is relatively thin.
The skin of the eyelid has more pigment cells than other area of the skin.
The eyelid contains sweat glands and hairs.
The hair becoming eyelashes as the border of the eyelid.
Eyelashes along the eyelid margin serve to heighten the protection of the eye from dust and foreign debris.
The skin of the eyelid contains the greatest concentration of sebaceous glands found anywhere in the body.
The sensory nerve supply to the upper eyelids is from the infratrochlear, supratrochlear, supraorbital and the lacrimal nerves from the ophthalmic branch (V1) of the trigeminal nerve, cranial nerve V.
The skin of the lower eyelid is supplied by branches of the infratrochlear at the medial angle, the rest is supplied by branches of the infraorbital nerve of the maxillary branch (V2) of the trigeminal nerve.
The eyelids are supplied with blood by arches are formed by anastamoses of the lateral palpebral arteries and medial palpebral arteries, branching off from the lacrimal artery and ophthalmic artery, respectively.
The levator palpebrae superioris muscle retracts the eyelid to open the eye, exposing the cornea to the outside, giving vision.
The levator palpebrae superioris muscle can be either voluntarily or involuntarily.
Ptosis is when the upper eyelid droops or sags due to weakness or paralysis of the levator muscle or due to damage to nerves controlling the muscle.
It can be a manifestation of the normal aging process, a congenital condition, or due to an injury or disease.
Risk factors related to ptosis include diabetes, stroke, Horner syndrome, Bell’s Palsy, myasthenia gravis, brain tumor or other cancers that can affect nerve or muscle function.
It has a row of eyelashes along the eyelid margin, which serve to heighten the protection of the eye from dust and foreign debris, as well as from perspiration.
The terms palpebral and blepharal mean relating to the eyelids.
The key function of the eyelid is to regularly spread the tears and other secretions on the eye surface to keep it moist, since the cornea must be continuously moist.
The eyelids keep the eyes from drying out when asleep.
Laxity is also another aging-related eyelid condition that can lead to dryness and irritation.
Surgery may be necessary to repair the eyelid to its natural position.
Excessive lower lid laxity may create a pocket between the lower eyelid and globe, which is the ideal location to administer topical ophthalmic medications.
The eyelid surgeries are called blepharoplasties
Blepharoplasty surgery is performed either for medical reasons or to alter one’s facial appearance.
Blepharoplasty is a cosmetic surgical procedure performed to correct deformities and improve or modify the appearance of the eyelids.
Blepharoplasty is the second most popular cosmetic procedure in the world behind Botulinum toxin injection.
It is the most frequently performed cosmetic surgical procedure in the world.
Most of the cosmetic eyelid surgeries are aimed to enhance the look of the face by restoring a youthful eyelid appearance.
Most of the cosmetic eyelid surgeries are intended to remove fat and excess skin that may be found on the eyelids after a certain age.
Eyelid surgeries are also performed to improve peripheral vision or to treat chalazion, eyelid tumors, ptosis, extropion, trichiasis, and other eyelid-related conditions.
The blink reflex protects the eye from foreign bodies.
It is made up of several layers; skin, subcutaneous tissue, orbicularis oculi, orbital septum and tarsal plates, and palpebral conjunctiva. .
The meibomian glands lie within the eyelid and secrete the lipid part of the tear film.
The skin is similar to areas elsewhere, but is relatively thin and has more pigment cells.
The skin of the eyelid contains sweat glands and hairs, the latter becoming eyelashes as the border of the eyelid is met.
The skin of the eyelid contains the greatest concentration of sebaceous glands found anywhere in the body.
Anterior to the palpebral conjunctiva is the tarsal plate.
The tarsal plate adds rigidity and shape to the eyelid.
Between the tarsal plate in the outermost layer of skin is muscle composed of the orbicularis oculi and levator palpebrae superioris.
The tarsal plate surrounds and protects modified sebaceous glands called meibomian glands.
Meibomian glands secrete lipid through openings along the eyelid margin that contributes to tear film stability.
The upper eyelid has 30 to 40 meibomian glands, and the lower eyelid, has 20 to 30 search glands.
Eyelashes on the margin of the eyelid or anterior to the meibomian glands.
Eyelashes are by surrounded by ciliary glands, apocrine type, called Moll, and the glands of Zeiss which are sebaceous glands.
Zeiss glands secrete sebum that coats the eyelashes and protects them from becoming brittle.
Moll glands secrete into the hair follicle and into the glands of Zeis, or onto the lid margin.
An infection in meobomian gland is referred to as a internal hordeolum.
A hordeolum is a stye.
Hordeolum (stye) is an infection of the sebaceous glands of Zeis usually caused by Staphylococcus aureus bacteria.
Stye is characterized by an acute onset of symptoms and it looks like a red bump placed underneath the eyelid.
Stye symptoms include pain, redness of the eyelid and sometimes swollen eyelids.
Styes usually disappear within a week without treatment.
Styes are normally harmless and do not cause long lasting damage.
Patients with a hordeolum present with tender, and red bump as the eyelid bcomes infected my painful erythematous and swollen.
The acute infection in a hordeolum is most commonly caused by Staphylococcal aureus and may coincide with blepharitis.
Eyelid edema is a condition in which the eyelids are swollen and tissues contain excess fluid.
The main symptoms are swollen red eyelids, pain, and itching.
Eyelid dermatitis is the inflammation of the eyelid skin.
It is mostly a result of allergies or contact dermatitis of the eyelid.
Symptoms include dry and flaky skin on the eyelids and swollen eyelids.
The affected eyelid may itch.
Treatment consists in proper eye hygiene and avoiding the allergens that trigger the condition. In rare cases, topical creams may be used.
Eyelid edema may affect eye function when it increases the intraocular pressure.
Eyelid edema is caused by allergy, trichiasis or infections.
The main symptoms of eyelid edema are swollen red eyelids, pain, and itching.
Chronic eyelid edema can lead to blepharochalasis.
Blepharitis is the irritation of the lid margin, where eyelashes join the eyelid.
Blepharospasm or eyelid twitching, is an involuntary spasm of the eyelid muscle.
The most common factors that make the muscle in the eyelid twitch are fatigue, stress, and caffeine.
Eyelid twitching is not considered a harmful condition and therefore there is no treatment available.
Patients are however advised to get more sleep and drink less caffeine.
Internal hordeolum may also be associated with rosacea, inward turned eyelashes (trichiasis) or ectropion.
The abscess of the internal hordeolum can be visible only when the eyelid is everted, and without eversion only a generalized swelling will be apparent, since the muscle tissue anterior to the myoglobin glands and the tarsal plate block visualization of the lesion.
In advanced hordeolum cases a yellow lesion can be seen on the palpebral conjunctiva.
Internal hordeolum may spontaneously resolve.
Conservative therapy includes: using warm compresses applied for 5-10 minutes two-four times a day.
Heat therapy softens the granuloma and lipids, and this allows the material to drain with more facility.
Eyelid scrubs and wipes with gentle shampoo are beneficial to promote drainage and using a diluted solution of baby shampoo and water is nonirritating to the eyes and clean the lids.
Topical antibiotics are not effective in treating internal hordeolum, since infection occurs deep within the tarsal plate.
If the lesion does not resolve or appears to be spreading oral antibiotics should be affective against a S. aureus the species that is usually the primary cause of the process.
If the process remains unresolved, surgical incision and drainage of the infection may be necessary.
After drainage topically applied ophthalmology antibiotic ointment can prevent secondary infection.
External hordeolum reflects the infection of Moll and Zeis glands.
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It occurs with infection of the lumen of either gland , causing tender, erythematous swelling near the lid margin.
As the glands are anterior to the tarsal muscle, the abscess is seen without the eyelid being exerted.
Pointed lesions develop in a few days after initial swelling, at the lid margin.
Following the formation of the point very spontaneous drainage occurs in 3 to 4 days.
External hordeolum commonly caused by S aureus infection, and in advanced cases can lead to cellulitis.
It is commonly associated with blepharitis ,fatigue and can be recurrent.
An external hordeolum usually resolves spontaneously.
Generally external hordeolum are shorter lasting and less painful than an internal hordeolum.
Treatment is conservative with the reservation of surgery for persistent, non-resolving lesions.
First-line therapy for external hordeolum is warm compresses to facilitate the pointing and drainage of the lesion.
Topical antibiotics are effective in promoting the resolution of external hordeolum, unlike with internal hordeolum.
Styes are normally harmless and do not cause long lasting damage.
Chalazion is caused by the obstruction of the oil glands and can occur in both upper and lower eyelids.
Chalazia may be mistaken for styes due to the similar symptoms.
This condition is however less painful and it tends to be chronic.
Chalazia heal within a few months if treatment is administered and otherwise they can resorb within two years.
Chalazion may be mistaken for styes, but it is less less painful and it tends to be chronic.
Chalazia that do not respond to topical medication are usually treated with surgery as a last resort.
Demodex mites are a genus of tiny mites that live as commensals in and around the hair follicles of humans, cats and dogs.
Human demodex mites typically live in the follicles of the eyebrows and eyelashes.
While normally harmless, human demodex mites can sometimes cause irritation of the skin (demodicosis) in persons with weakened immune systems.
Entropion usually results from aging, but sometimes can be due ongenital defect, a spastic eyelid muscle, or a scar on the inside of the lid that could be from surgery, injury, or disease.
Entropion is an asymptomatic condition that can, rarely, lead to trichiasis, which requires surgery. It mostly affects the lower lid, and is characterized by the turning inward of the lid, toward the globe.
Ectropion is another aging-related eyelid condition that may lead to chronic eye irritation and scarring.
It may also be the result of allergies and its main symptoms are pain, excessive tearing and hardening of the eyelid conjunctiva.
Eyelid tumors may also occur.
Basal cell carcinomas are the most frequently encountered kind of cancer affecting the eyelid, making up 85% to 95% of all malignant eyelid tumors.
Eyelid tumors may also occur, and basal cell carcinomas are the most frequently encountered cancer affecting the eyelid.
Blepharospasm, or eyelid twitching, refers to an involuntary spasm of the eyelid muscle.
Blepharospasm factors are fatigue, stress, and caffeine.
No treatment is usually needed, as the process is not thought to be harmful.
Dermatitis of the eyelid refers to the inflammation of the eyelid skin, and is mostly a result of allergies or contact dermatitis of the eyelid.
Dermatitis of the eyelid symptoms include itching, dry and flaky skin on the eyelids and swollen eyelids.
Treatment of eyelid dermatitis includes eye hygiene and avoiding the allergens that trigger the condition.
Ptosis occurs when the eyelid droops or sags due to weakness or paralysis of the levator muscle or due to damage to nerves controlling the muscle.
Ptosis can be a manifestation of aging, congenital or due to an injury or disease.
Risk factors related to ptosis include diabetes, stroke, Horner syndrome, Bell’s Palsy, myasthenia gravis, brain tumor or other cancers that can affect nerve or muscle function.
Blepharoplasties are eyelid surgeries: performed either for medical reasons or to alter one’s facial appearance.
Most eyelid surgeries are designed to enhance the look of the face by restoring a youthful eyelid appearance.
Blepharoplasties are intended to remove fat and excess skin that may be found on the eyelids.
Other indications for blepharoplasty: to improve peripheral vision or to treat chalazion, eyelid tumors, ptosis, extropion, trichiasis, and other eyelid-related conditions.
Blepharoplasty is reported to be the most common aesthetic procedure in Taiwan and South Korea.
The eyelids protect the anterior surface of the globe from local injury, aid in regulation of light reaching the eye; in tear film maintenance, distributing the protective and optically important tear film over the cornea during blinking; and in tear flow, by their pumping action on the conjunctival sac and lacrimal sac.
Structures of lid anatomy include the skin and subcutaneous tissue; the orbicularis oculi muscle, the submuscular areolar tissue; the fibrous layer, consisting of the tarsi and the orbital septum; the lid retractors of the upper and lower eyelids; the retroseptal fat pads; and the conjunctiva.
The upper and lower lids are analogous structures, with differences mainly in the lid retractor arrangement.
The anterior lamella consists of skin and orbicularis, and the posterior lamella consists of the tarsus and conjunctiva.
The upper eyelid skin crease, known as the superior palpebral sulcus, is approximately 8-11 mm superior to the eyelid margin and is formed by the attachment of the superficial insertion of levator aponeurotic fibers.
The inferior eyelid fold, known as the inferior palpebral sulcus, is seen more frequently in children, runs from 3 mm inferior to the medial lower lid margin to 5 mm inferior to the lateral lid margin.
The nasojugal fold runs inferiolaterally from the inner canthal region along the depression of separation of the orbicularis oculi and the levator labii superioris, forming the tear trough.
The malar fold runs inferiorly and medially from the outer canthus toward the inferior aspect of the nasojugal fold.
The open eye presents the palpebral fissure.
The palpebral fissure is a space between the lid margins that is 28-30 mm in length and about 9 mm in maximal height.
The curvature of the upper lid reflex the static shape of the tarsus combined with adaptation of the lid to the curvature of the globe.
In the normal adult palpebral fissure, the highest point of the upper lid is just nasal to the center of the pupil, while the lowest point of the lower lid is just temporal to the center of the pupil.
In young people, the upper lid margin rests at the upper limbus, while in adults, it rests 1.5 mm below the limbus.
The lower eyelid margin rests at the level of the lower limbus.
The lateral canthal angle is 2 mm higher than the medial canthal angle in Europeans.
The lateral canthal angle is is 3 mm higher in Asians.
The distance from the medial canthus to the midline of the nose is approximately 15 mm.
The skin of the eyelids is the thinnest of the body (< 1 mm).
The nasal portion of the eyelid skin has finer hairs and more sebaceous glands than the temporal aspect, making this skin smoother and oilier.
The subcutaneous tissue consists of loose connective tissue.
Fat is very sparse or absent.
Subcutaneous tissue is absent over the medial and lateral palpebral ligaments, so that skin adheres to the underlying fibrous tissue.
The orbicularis oculi muscle is one of the superficial muscles of facial expression.
Muscle contracture is translated into movement of the overlying tissues by the fibrous septa extending from the superficial musculoaponeurotic system into the dermis.
The superficial musculoaponeurotic system is divided into the orbital and palpebral parts, with the latter being divided further into the preseptal and pretarsal portions.
The palpebral portion is used in blinking and voluntary winking.
The orbital portion is used in forced closure of the eyelid.
Facial nerve innervation is from the temporal branches and from zygomatic branches of the facial nerve.
The nerves innervate the muscle from the undersurface.
The orbital portion manifests in a circular fashion around the orbit, interdigitating with other muscles of facial expression.
The fibers from the upper and lower lid join laterally to form the lateral palpebral raphe, which is attached to the overlying skin.
Submuscular areolar tissue consists of variable, loose connective tissue below the orbicularis oculi muscle.
The upper lid, is traversed by fibers of the levator aponeurosis, some of which pass through the orbicularis to attach to the skin to form the lid crease.
The lower eyelid is traversed by fibers of the orbitomalar ligament.
The tarsal plates are composed of dense fibrous tissue and are responsible for the structural integrity of the lids.
Each tarsus is approximately 29 mm long and 1 mm thick.
The superior tarsus is 10 mm in vertical height centrally, narrowing medially and laterally.
The lower border of the superior tarsus forms the posterior lid margin.
The posterior surfaces of the tarsi adhere to conjunctivae.
Each tarsus encloses about 25 sebaceous meibomian glands.
The medial palpebral ligament is a fibrous band stabilizing the medial tarsi and is intricately related with the orbicularis oculi muscle and the lacrimal system.
The orbicularis retaining ligament attaches the orbicularis oculi to the inferior orbital rim.
The orbicularis retaining ligament is an important surgical landmark.
The orbicularis retaining ligament and the orbital septum fuse to from the arcus marginalis.
The levator palpebra superioris arises at the orbital apex from the undersurface of the lesser wing of the sphenoid bone, and ends in an aponeurosis approximately 10 mm behind the orbital septum.
The levator palpebra superioris is a smooth muscle innervated by the sympathetic nervous system.
With age, fatty infiltration of the levator palpebra superioris may occur, giving the muscle a yellowish color.
The levator palpebra superioris may also be involved in thyroid eye disease, by fibrosis and mast cell infiltration, may function as a large, serial muscle spindle.
With the Horner syndrome about 2mm of ptosis is observed.
The orbital fat of the upper eyelid is divided into two components: the preaponeurotic fat pad and the medial fat pad.
The central fat pad is yellow due to a higher level of carotenoids.
The conjunctiva is a smooth, translucent mucous membrane.
Palpebral conjunctiva lines the posterior surface of the lids as tarsal conjunctiva and continues as orbital palpebral conjunctiva into the fornix.
The infratrochlear nerve, a terminal branch of the nasociliary nerve (CN V1), supplies the skin and conjunctiva of the medial canthus, the most medial aspect of the eyelids, and the nasolacrimal sac.
The sensory supply of the remaining lower eyelid is provided by the infraorbital nerve (CN V2) and the zygomaticofacial nerve (CN V2).
The zygomaticofacial nerve supplies skin to the lateral lower eyelid, while the palpebral branch of the infraorbital nerve supplies the central lower eyelid skin and conjunctiva.
Branches of the facial nerve innervate the muscles of facial expression.
The frontal and zygomatic branches of CN VII innervate the orbicularis oculi muscle; the frontal branch of CN VII innervates the forehead muscles.
The orbicularis oculi is innervated by multiple motor branches from the branches of CN VII.
The levator palpebra superioris is innervated by the superior branch of the oculomotor nerve.
The Müller muscle requires sympathetic innervation.
Postganglionic sympathetic fibers from the superior cervical ganglion travel superiorly in the neck as a plexus with the internal carotid artery, traveling intracranially to the superior orbital fissure into the orbit via CN branches.
The pathways for sympathetic innervation of the superior and inferior tarsal muscles is unknown.
The internal and external carotid arteries contribute to lid arterial supply.
The internal carotid arterial supply is from the terminal branches of the ophthalmic artery medially giving supraorbital, supratrochlear, and dorsal nasal branches and the lacrimal artery laterally.
The eyelids and conjunctiva have an extensive lymphatic drainage, with most of the upper lid and the lateral half of the lower lid to the preauricular lymph nodes.
While the medial portion of the upper lid and the medial half of the lower lid drain into the submandibular nodes by way of vessels that follow the angular and facial vessels.