eyelid
An eyelid ( Latin palpebra , ancient Greek blepharon ) is a thin fold consisting of muscles , glands , connective tissue and skin , which forms the anterior border of the eye socket ( orbit ). There is an upper and a lower eyelid, the opening between the two is called the eyelid gap. The point on the temple and nose where both meet in both the open and closed state is called the corner of the eye or the corner of the eye, and the line between the two corners of the eye is the axis of the lid.
In general, the eyelids serve to protect and keep the eyes moist . You can cover it completely, thus keeping external influences from the eye and its sensitive front sections clean and moist with the help of tear fluid . Structure and structure can differ depending on the species , although not all species have eyelids. The "third eyelid", which is differently developed depending on the species, is called the nictitating skin .
Some of the muscles responsible for moving the eyelids belong to the group of mimic facial muscles , which underlines the important role of the eyelids in the formation of facial expressions and facial expressions .
function
The eyelids serve two main functions. On the one hand, they serve to protect the eyes from any form of contact, foreign bodies, injuries and light as well as from mechanical, chemical and other harmful and unwanted effects. The closing and opening of the eyelids is called blinking , also known as blinking . The closing movement takes place either voluntarily or involuntarily via the eyelid closing reflex . It closes the eyelids completely when the corresponding stimuli occur (in humans on average within about 300 milliseconds), whereby its stimulus threshold can be lowered by certain diseases. Closing the lid is usually faster than opening it. On the other hand, a regular blinking of the eye ensures that the sensitive cornea , which plays a major role in the refraction of light and thus in perfect vision, as well as the front part of the dermis (sclera) are adequately wetted with tear fluid at all times and thus before drying out be preserved. The frequency of blinking in humans is around 10–12 blinking per minute, with women blinking faster and more often than men.
The closing of the eyelids takes place synchronously and usually takes place via the interaction of the upper and lower eyelids. Exceptions to this are, for example, hummingbirds and parrots , in which only the upper eyelid is responsible for closing the eyelid. In the case of duck and chicken birds, on the other hand, the eyelids are closed by moving the lower eyelid upwards.
Other properties of the eyelids include the fact that, with a few exceptions, for example in rabbits , the eyelids are closed while sleeping .
In addition to their protective and supply functions, the eyelids play a not inconsiderable role in the formation of facial expressions and facial expressions. They give an impression of the current state of health and the overall personality, as they indicate, for example, a frightened or fearful look and the expression of joy, sadness or fatigue. In addition, the nictitating membrane and eyelids can take on secondary signal functions in some animals.
Anatomy and structure
The eyelids are one of the appendage organs of the eye. As a paired organ, they consist of an often somewhat larger upper eyelid (palpebra superior) and a lower eyelid (palpebra inferior) . The eyelid gap (rima palpebrarum) is located between the two . Both eyelids are connected to each other ( commissura palpebrarum ) at the corner of the eyelid ( angulus oculi or canthus ) and also with the medial and lateral edge of the eye socket via two ligaments , the ligamentum palpebrae mediale and ligamentum palpebrae laterale . In the inner corner of the eyelid there is a nodular structure, the tear caruncle .
In the case of snakes , the St. John's Lizard and some geckos , the lids have grown together and form a transparent structure on top of the cornea, which is known as glasses and is also skinned .
Cartilaginous fish do have eyelids, but with a few exceptions (e.g. nurse sharks ) they have only limited mobility.
construction
The lid consists of two leaves, one outer and one inner. The body skin, which consists of multilayered squamous epithelium , rests on the outer leaf . In addition, the ring-shaped orbicularis oculi muscle and in the upper eyelid the antagonistic eyelid lifter, the levator palpebrae superioris muscle , whose range of motion in humans is about 20 millimeters, are components of the outer leaf. Due to its special attachment to the inner and outer lid ligament ( ligamentum palpebrale mediale et laterale ), the orbicularis oculi muscle does not contract concentrically like other sphincter muscles, but only causes the eyelid to close without shortening the eyelid gap.
The inner leaf consists of the connective tissue septum orbitale , which is located between the periorbita and the tarsus palpebrae , and the tarsus itself. This is often incorrectly referred to as "eyelid cartilage", but is not a cartilage, but a connective tissue plate with tight collagen fibers. In humans, this has a width of around 25 millimeters, a thickness of around 1 millimeter and a height between 10 millimeters in the upper eyelid and 5 millimeters in the lower eyelid. In this structure, the tendon of the levator palpebrae superioris muscle attaches like a fan (levator aponeurosis) to the upper eyelid. Further smooth muscles for opening and regulating the involuntary eyelid gap width are embedded in the inner leaf , the tarsalis muscle . It divides in the upper eyelid as the M. tarsalis superior, in the lower eyelid as the M. tarsalis inferior. On the inside, the eyelids are covered by the conjunctiva (conjunctiva) .
From the envelope of the upper eyelid at the conjunctival fornix , an upper eyelid furrow (sulcus palpebralis superior) can arise, also known as the cover, lid or envelope fold . It is formed from the approach of the levator - aponeurosis that the orbicularis oculi muscle attaches below the skin, and is parallel to the edge of the lid. Their absence indicates an increased subcutaneous fat storage. A lower eyelid furrow (sulcus palpebralis inferior) is often only very small, inconspicuous and usually only pronounced when looking down.
In mammals , the eyelashes (cilia) are located on the edge of the eyelids , in birds the bristle feathers (setae) . They support the protective function of the eyelids by keeping dust particles and larger foreign bodies away from the eyes. There are several glands around the eyelashes:
- Moll glands (Glandulae ciliares) , named after the German ophthalmologist Jakob Antonius Moll
- Zeis glands (Glandulae sebaceae) , named after the German surgeon Eduard Zeis
- Meibomian glands or tarsal glands (Glandulae tarsales) , named after the German doctor and scholar Heinrich Meibom
Meibomian and Zeis glands form as sebaceous glands so-called " eye Butter ", a secretion, which prevents overflow of the tear fluid over the lid margin. The yellowish secretion residue in the inner corner of the eyelid, which usually dries up in the morning, is colloquially rubbed out of the eyes in humans as "sleep". The minor glands produce sweat .
Nictitating membrane
An additional fold of the conjunctiva in the nasal corner of the eye is known as the nictitating membrane ( Plica semilunaris conjunctivae , Membrana nicitans ) or third eyelid (Palpebra tertia) . In humans it is only rudimentary . In the other mammals , it is supported by cartilage and is so large that it can lie in front of the entire eye in certain diseases. In many other vertebrates, e.g. B. sharks , reptiles and many birds , it is transparent and can be folded over the eye like protective goggles. In birds, two muscles are embedded in the nictitating membrane, the quadratus membranae nicitantis muscle and the pyramidalis membranae nicitantis muscle . They enable the nictitating membrane to blink actively, which in birds plays a greater role in the distribution of tear fluid than that of the actual eyelids. In the domestic chicken, the nictitating membrane makes about 35 blink of the eye per minute. The reptiles with fused lids lack the nictitating membrane.
Musculature
The following muscles are involved in the movement of the eyelids:
| muscle | function | Innervation | Type |
|---|---|---|---|
| Levator palpebrae superioris muscle | Upper eyelid elevation | Oculomotor nerve | striated |
| Orbicularis oculi muscle | Eyelid closure | Facial nerve | striated |
| Retractor anguli oculi lateralis muscle | Retraction of the lateral corner of the eyelid in predators | Facial nerve | striated |
| Levator anguli oculi medialis muscle | Upper eyelid lifter | Facial nerve | striated |
| Malaris muscle | Cheek muscle | Facial nerve | striated |
| Frontalis muscle | facial muscles, raising the eyebrows | Facial nerve | striated |
| Tarsalis muscle | Expansion of the eyelid gap | Sympathetic | smooth |
| Bursal muscle | Movement of the nictitating membrane in lizards | Abducens nerve | striated |
|
Quadratus et pyramidalis membranae nicitantis muscle |
Movement of the nictitating membrane in birds | Abducens nerve | striated |
Innervation
The sensory innervation occurs via branches of the trigeminal nerve , the infratrochlear nerve , the supratrochlear nerve and the infraorbital nerve . In addition, the lacrimal nerve sensitively supplies the temple-side (temporal) corner of the eyelid. The tarsalis muscle is sympathetically innervated. The outer striated muscles are innervated in most cases by the facial nerve , the nictitating membrane muscles by fine branches of the abducens nerve, and the levator palpebrae superioris muscle by the oculomotor nerve.
Blood supply
The following branches of the ophthalmic artery supply the eyelids with blood:
- Supraorbital artery
- Lacrimal artery
- Arteria palpebralis medialis superior
- Inferior medial palpebral artery
The arc-shaped arrangement of the arterial vessels in the upper and lower eyelid is a superior Arcus palpebralis or Arcus palpebralis inferior referred. The venous outflow is via the angular vein into the facial vein and the palpebral vein into the superior ophthalmic vein .
Diseases and dysfunction
| Classification according to ICD-10 | |
|---|---|
| H00.0 | Hordeolum |
| H00.1 | Chalazion |
| H01.0 | Blepharitis |
| H01.1 | Non-infectious dermatoses of the eyelid |
| H02.0 | Entropion and trichiasis of the eyelid |
| H02.1 | Ectropion of the eyelid |
| H02.2 | Lagophthalmos |
| H02.3 | Blepharochalasis |
| H02.4 | Ptosis of the eyelid |
| H02.6 | Xanthelasma palpebrarum |
| H03.0 | Parasitic infestation of the eyelid in diseases classified elsewhere |
| ICD-10 online (WHO version 2019) | |
Eyelid position
Pathological changes in the position of the eyelids can be found as a coloboma and as an outward or inward-facing upper or lower eyelid edge, which are called ectropion and entropion . The latter can lead to trichiasis , a misalignment of the eyelashes with mechanical irritation of the cornea.
Lid skin diseases
Pathological changes in the skin of the eyelids can occur as rashes or edema . Pigment disorders and fat deposits often exist in the form of xanthelasma . An age-related change in the eyelid skin is known as blepharochalasis . In addition, the eyelids are prone to herpes simplex and herpes zoster infections and other dermatological inflammatory processes.
Eyelid glands
Acute inflammation of the Zeiss or Moll glands leads to an external hordeolum (hordeolum externum) . If the meibomian glands are affected, it is an internal hordeolum (hordeolum internum) . Both are summarized under the term stye . Chronic inflammation of the meibomian glands leads to a chalazion , commonly called hailstone .
Lid margin diseases
A typical disease of the edge of the eyelid is an inflammation called blepharitis , which can have different causes. Blepharitis often occurs in conjunction with conjunctivitis and is called blepharoconjunctivitis .
Movement disorders
Movement disorders occur in the form of partial or complete drooping of the upper eyelid ( ptosis ), combined with the inability to open the eyelid normally. The congenital or acquired causes for this can be very different and mostly represent an innervational problem of the tarsalis muscle innervated by the sympatheticus ( Horner's syndrome ) or the levator palpebrae superioris muscle innervated by the oculomotor nerve Paralysis of the facial nerve caused inability to close the eyelid completely, called lagophthalmos . This deficit also relates to the blink reflex. A spasmodic closure of the eyelids is called blepharospasm .
Another movement disorder occurs in the form of involuntary eyelid twitching ( benign fasciculation ), a type of tremor in one or both eyelids. Usually such eyelid twitches are annoying, but relatively harmless, even if they last for hours or days. It usually disappears on its own. The causes can be diverse and range from mechanical irritation, signs of fatigue, stress, to mineral deficiencies, especially magnesium deficiency , alcohol consumption or visual stress. A neurological disease is very rarely the cause.
A pathological reduction in the blinking frequency is known as the Stellwag sign and usually occurs in conjunction with endocrine orbitopathy in Graves' disease . On the other hand, increased blinking in the form of frequent blinking is usually the result of mechanical or inflammation-related impairments, such as a foreign body sensation, dry eye , and a sign of involuntary muscle contractions ( tic ) due to nervousness.
Another clinical sign of endocrine orbitopathy that manifests itself on the lid is a withdrawn upper eyelid (retraction), which gives the impression of a stare ( Kocher's sign ).
Relative hyperfunction of the eyelid lifter with noticeable upper eyelid retraction can result from paretic restriction of the elevation of the eye and the musculus rectus superior , a vertical, straight eye muscle . In this case, an increased impulse to turn upwards is only incompletely implemented by the affected muscle, but it has a full effect on the synergistic movement of the levator palpebrae superioris muscle, which leads to an abnormal pulling up of the upper eyelid.
Others
A number of tissue changes or tumors are known that can affect the lid, including lid abscesses , cysts , tumors (for example hemangiomas , carcinomas , basaliomas or melanomas ). Treacher Collins syndrome (also: Franceschetti syndrome ), a hereditary disease with facial deformities, can lead to sometimes massive abnormalities of the eyelids . Further diseases of the eyelids can result from parasite infestation . Lid edema, thickening of the upper eyelid or eyelid hematoma can lead to pseudoptosis .
A particular sign of Down syndrome and other hereditary diseases is the nasal crease in the eyelid ( epicanthus ), which, however, also occurs physiologically, especially in Asia, and is therefore sometimes called the Mongolian crease or double crease .
Ablepharia is the absence of an eyelid.
A slackening of the connective tissue that occurs with increasing age is referred to as a drooping eyelid and in some cases is viewed as cosmetically disadvantageous and therefore in need of correction. In Austria, the operative correction of a drooping eyelid is paid for by the social security system if this causes a restriction of the field of vision that leads to relevant disabilities in the practice of the profession - for example with a cameraman.
The nictitating membrane can also be affected by special diseases ( see: Diseases of the nictitating membrane ).
examination
The eyelids are generally inspected with the naked eye, with the aid of magnifying glasses or a slit lamp . To examine the conjunctiva and the edges of the eyelid, it is often sufficient to pull the upper and lower eyelids apart. To assess the conjunctiva on the underside , the upper eyelid can also be folded back to the tarsus or further to the upper crease . This is done either with the help of a simple cotton swab or glass stick, or with a Desmarres eyelid holder (after the French ophthalmologist Louis-Auguste Desmarres ). The procedure is called single and double ectropionation . In order to keep the eyelids open during examinations or surgical interventions and to prevent unwanted eyelid closure, an eyelid lock is used that keeps the upper and lower eyelids open without restricting the access to and the top view of the examination or treatment area. In some cases, and often in combination with retrobulbar anesthesia, an artificial paralysis of the orbicularis oculi muscle, a facial block , is brought about as a support.
Meaning of the lid axis
A special course of the lid axis can be helpful in the diagnosis of disabilities .
A laterally increasing course of the lid axis (inclination of the lid axis outwards upwards) is often found in people with Down syndrome (trisomy 21), trisomy 3 and Zellweger's syndrome .
A laterally sloping course of the lid axis (inclination of the lid axis outwards downwards), as favored by hypoplasia (underdevelopment) or the absence of cheekbones, is common in people with Rubinstein-Taybi syndrome , Pierre Robin syndrome , Noonan syndrome , Marfan syndrome , DiGeorge syndrome , fetal alcohol syndrome , Haller-Streiff syndrome , Oto-palato-digital syndrome , cri du chat , Cohen syndrome and cat eye syndrome to be found.
Lid fissure diagnostics
The assessment of the eyelid gap (rima palpebrarum) is particularly useful in the clinical picture of endocrine orbitopathy to assess the status and course. These are the following symptoms:
- by an exophthalmos excessively dilated palpebral fissure due, ( Dalrymple-mark )
- Retention of the upper eyelid when looking down ( from Graefe sign )
All of these findings can be quantified for a more precise assessment: Dalrymple and von Graefe signs in millimeters, Stellwag signs in blinking eyes per minute.
A clinical sign of myasthenia gravis is fatigue of the eyelid. The Simpson test is carried out, in which the patient is required to look up for a longer period of time, which results in an increasing lowering of the upper eyelid if the result is positive. After the administration of Tensilon , these symptoms disappear again temporarily.
Operations on the eyelid
Ophthalmology offers a range of conservative and surgical procedures for the medically indicated local treatment of eyelid diseases, removal of chalazion and tumors, positional anomalies and movement disorders. Surgical procedures are, for example, interventions on the levator palpebrae superioris muscle in the event of ptosis, different techniques of displacement plastic , free skin transplants, as well as upper and lower eyelid lengthening and lateral eyelid gap reduction. Another technique for narrowing the eyelid gap using a special suture is known as tarsoraphy . Operations in the area of the lid edges are particularly demanding because of the functional and anatomical conditions.
Plastic surgery is increasingly finding ways to change the cosmetic and aesthetic appearance, for example blepharoplasty to tighten the eyelids. The superior palpebral sulcus plays a special role here, as it forms, among other things, the access point for all internal structures of the upper eyelid. The use of the neurotoxin botulinum toxin is also widespread, for example to remove irritating wrinkles or to treat blepharospasm. In addition come laser procedures for use, for example in the removal of Xanthelasmen.
In the field of cosmetic surgery in particular, there is therefore a high need for education with regard to the expectations of patients in relation to risks and chances of success.
Etymology and Cultural
The term lid comes from Old or Middle High German ( hlit or lit ) and means "lid" or "closure".
The Japanese character茶 ( pinyin transcription chá ) means both "eyelid" and "tea". According to a popular legend , a tea bush grew out of the thrown eyelids of the Buddhist monk Bodhidharma .
In many cultures, one of the last human services is to close the eyelids of the deceased.
For cosmetic purposes, the upper eyelid, in particular, is highlighted with eyeliner and / or eyeshadow .
See also
literature
- Theodor Axenfeld (founder), Hans Pau (ed.): Textbook and atlas of ophthalmology. With the collaboration of Rudolf Sachsenweger and others 12th, completely revised edition. Gustav Fischer, Stuttgart et al. 1980, ISBN 3-437-00255-4 .
- Albert J. Augustin: Ophthalmology. 3rd, completely revised and expanded edition. Springer, Berlin et al. 2007, ISBN 978-3-540-30454-8 .
Web links
- Injuries to the eye and its appendages (PDF; 81 kB) Guideline No. 8 of the Professional Association of Ophthalmologists in Germany (BVA)
- Misalignment of the eyelids / tear problems (a), tumors of the eyelids (b) (PDF; 77 kB) Guideline No. 9 of the Professional Association of Ophthalmologists in Germany (BVA)
- Hordeolum / Chalazion (PDF; 72 kB) Guideline No. 10 of the Professional Association of Ophthalmologists in Germany (BVA)
Individual evidence
- ^ A b Albert J. Augustin: Ophthalmology. 3rd, completely revised and expanded edition. Springer, Berlin et al. 2007, ISBN 978-3-540-30454-8 , p. 168.
- ↑ Robert A. Moses (Ed.): Adler's Physiology of the eye. Clinical application. 7th edition. Mosby, St. Louis MO et al. 1981, ISBN 0-8016-3541-1 , Chapter 1, pp. 1-15.
- ↑ Chiarella Sforza, Mario Rango, Domenico Galante, Nereo Bresolin, Virgilio F. Ferrario: Spontaneous blinking in healthy persons: an optoelectronic study of eyelid motion. In: Ophthalmic and Physiological Optics. Vol. 28, No. 4, July 2008, ISSN 0275-5408 , pp. 345-353, PMID 18565090 , doi: 10.1111 / j.1475-1313.2008.00577.x .
- ↑ a b Wilfried Westheide , Reinhard Rieger (Ed.): Special Zoology. Part 2: vertebrates or skulls. Spektrum, Akademischer Verlag, Heidelberg et al. 2004, ISBN 3-8274-0307-3 , p. 416.
- ↑ a b Axenfeld, Pau: Textbook and Atlas of Ophthalmology. 1980, p. 145.
- ↑ a b Winnie Achilles, Franz-Viktor Salomon: Anatomie der Reptilien . In: Franz-Viktor Salomon, Hans Geyer, Uwe Gille (Ed.): Anatomy for veterinary medicine. 2nd, revised and expanded edition. Enke, Stuttgart et al. 2008, ISBN 978-3-8304-1075-1 , p. 836.
- ↑ Wilfried Westheide, Reinhard Rieger (Ed.): Special Zoology. Part 2: vertebrates or skulls. Spektrum, Akademischer Verlag, Heidelberg et al. 2004, ISBN 3-8274-0307-3 , p. 210.
- ↑ a b c d e f Herbert Kaufmann: Strabismus . 3rd fundamentally revised and expanded edition, with the collaboration of W. de Decker u. a., Georg Thieme Verlag, Stuttgart, New York 2003, ISBN 3-13-129723-9
- ^ Karl Zilles, Bernhard Tillmann : Anatomie. Springer Medicine, Heidelberg 2010, ISBN 978-3-540-69481-6 , p. 676.
- ^ Anton Waldeyer: Human anatomy. 17th, completely revised edition. de Gruyter, Berlin et al. 2003, ISBN 3-11-016561-9 .
- ↑ Raveewan Choontanom: The Fasanella-Servat method for the surgical treatment of ptosis. Münster 2006 (Münster, University, dissertation, 2006), (PDF; 2.7 MB).
- ↑ ENT, ophthalmology, dermatology and urology for nursing professions; Elmar Oestreicher; Page 101 Fig. 6.5 in the Google book search
- ^ Albert J. Augustin: Ophthalmology. 3rd, completely revised and expanded edition. Springer, Berlin et al. 2007, ISBN 978-3-540-30454-8 , p. 169.
- ^ Franz-Viktor Salomon, Maria-Elisabeth Krautwald-Junghanns: Anatomy of the birds. In: Franz-Viktor Salomon, Hans Geyer, Uwe Gille (Ed.): Anatomy for veterinary medicine. 2nd, revised and expanded edition. Enke, Stuttgart et al. 2008, ISBN 978-3-8304-1075-1 , p. 806.
- ^ Franz-Viktor Salomon: Textbook of poultry anatomy. Fischer, Jena et al. 1993, ISBN 3-334-60403-9 , p. 358.
- ^ Frank H. Netter : Atlas of Anatomy. 4th edition. Urban & Fischer in Elsevier, Munich 2008, ISBN 978-3-437-41602-6 .
- ^ Albert J. Augustin: Ophthalmology. 3rd, completely revised and expanded edition. Springer, Berlin et al. 2007, ISBN 978-3-540-30454-8 , p. 186.
- ↑ Axenfeld, Pau: Textbook and Atlas of Ophthalmology. 1980, p. 588.
- ↑ a b Fritz Hollwich, Baerbel Verbeck: Ophthalmology for nursing professions . 2nd, revised and expanded edition. Georg Thieme, Stuttgart 1980, ISBN 3-13-500402-3 .
- ↑ Volker Hessemer: Peribulbar anesthesia versus retrobulbar anesthesia with facial block - techniques, local anesthetics and additives, akinesia and sensitive blocks, complications. In: Clinical monthly sheets for ophthalmology. Vol. 204, No. 2, 1994, ISSN 0023-2165 , pp. 75-89, doi: 10.1055 / s-2008-1035503 .
- ↑ Carlos Thomas: Special Pathology. Schattauer, Stuttgart et al. 1996, ISBN 3-7945-1713-X , p. 47, online here .
- ↑ Axenfeld, Pau: Textbook and Atlas of Ophthalmology. 1980.
- ↑ Information on endocrine orbitopathy, Center for Ophthalmology at the Essen University Hospital
- ↑ Titus von Lanz , W. Wachsmuth (founder), Johannes Lang, Werner Wachsmuth (ed.): Practical anatomy. A textbook and auxiliary book on the anatomical principles of medical practice. Volume 1, part 1: head. B: Johannes Lang, Werner Wachsmuth: brain and eye skull. Special edition of the 1st edition published in 1979. Springer, Berlin et al. 2004, ISBN 3-540-40569-0 .
- ↑ Ernst R. Kastenbauer, M. Eugene Tardy (ed.): Aesthetic and plastic surgery on the nose, face and auricle. 3rd, unchanged edition. Thieme, Stuttgart et al. 2005, ISBN 3-13-112343-5 , p. 572.
- ↑ Peter Roggenkämper, Bettina Wabbels, Zita Nüssgens: Botulinum toxin in ophthalmology. In: Deutsches Ärzteblatt . Vol. 102, No. 41, 2005, A-2782, B-2347, C-2215, online .
- ↑ Duden Online
- ↑ Helwi Braunmiller: Black or Green - The Truth About Tea. Focus online, November 8, 2007.
- ↑ Jan Koolman, Hans Moeller, Klaus-Heinrich Röhm (Eds.): Coffee, cheese, caries ... Biochemistry in everyday life. Wiley-VCH, Weinheim 2009, ISBN 978-3-527-32622-8 , p. 83.
- ↑ Planet Wissen , WDR, SWR, BRalpha .
