Dense fibrous tissue that imparts structural integrity to the eyelids. Medially and laterally they taper to 2mm in height as they pass into the canthal tendons. Contain meibomian glands (25 upper, 20 lower) that as not associated with lash follicles..produce lipid layer of the precornal tear film
Striated muscles divided into 3 parts. Orbital overlies the bony orbital rim. Arise from insertions on the frontal process of maxillary bone, orbital process of frontal, medial canthal tendon. Palpebral overlies the mobile eyelid from the orbital rim to the eyelid margins. Fixed medially and laterally to canthal tendons. Preseptal over septum, arise from upper and lower borders of medial canthal tendon and insert along the lateral horizontal raphe. Pretarsal overlies tarsal plates from MCT via superficial and deep heads arc around the lids and insert into LCT..contraction aids lacrimal pump
Tarsal plates pass in to fibrous bands and form the crura of the MCT lies between orb oculi (ant) and conjuctiva (post).. The superior and inferior crura fuse to form stout common tendon that inserts via 3 limbs. Anterior onto orbital process of the maxillary bone infront of and above anteror lacrimal crest. Posterior limb passes between the canaliculi and inserts onto the posterior lacrimal crest. Superior limb arises from both ant and post limbs, inserts onto orbital process of frontal bone..posterior head of preseptal orb oculi inserts onto this limb….forms roof of lacrimal sac fossa
Laterally the tarsal pates pass into not very well developed fibrous strands that becomes crura of LCT..distinct entity separate from orb oculi. Inserts posteriorly along the lateral orbital wall…where t blends with strands of the lateral check ligament from the sheath of the lateral rectuc mm
Thin fibrous multilayered membrane begins at arcus marginalis along the orboital rim and represents a coninuation of the orbital fascial system.
Ectropion may be defined as eversion of the eyelid or when the lid rolls out away from the globe. It ranges in severity from mild punctal malposition (such as this case - note the puncta has moved out away from the globe - in this case due to medial canthal tendon laxity) to involvement of the whole lid (referred to as a tarsal ectropion.
Individuals will seek medical assistance for ectropion because it is unsightly, because they get epiphora, keratinization of conj may occur with chronic exposure, they may develop punctate keratopathy and at its extreme loss of vision
It is important to work out the cause of the ectropion as this will help direct your management. Causes of ectropion may classified as involutional, mechanical, cicatrical, paralytic or congenital
Involutional ectropion results from age related degenerative changes to the eyelid. Either medial or lateral canthal tendons become weak as does pre-tarsal orbicularis. This gentleman also has other evidence of tissue weakness (orbital fat pad herniation).
Mechanical ectropion occurs when a tractional force is applied to the lid by a discrete lesion. In this case, a BCC is pulling the lower lid down and out.
Cicatrical ectropion occurs when there is deficiency of anterior lamella tissue (including skin) on the eyelid. It may result from trauma or burns, skin conditions or may be iatrogenic (eg. Blephroplasty). In this case, the patient suffers from eczma affecting the face - you can appreciate how tight the eyelid tissue is.
Paralytic ectropion occurs from a facial nerve palsy. Loss of muscle tone and weakening contraction of orb oculi
This is a modified algorithm from Richard Collin’s book on eyelid surgery to assist in sorting out the cause of ectropion. Essentially you need only ask 3 questions to get the answer. 1. Is there shortage of skin? - if yes then they have cicatrical. If not, then 2. Do they have abnormal eyelid closure? - if yes then they have paralytic. If no, then 3. Is there a lump on the lid? - if yes then it is mechanical and if not then it must be involutional.
As with everything, history is an important part of the assessment.
MCT laxitywatch the displacement of the punctum on lateral excursion…shouldn’t be displaced greater than 1-2mm. Pulling lid>10mm from globe suggests horizontal laxity and if slow to return to position then positive snap test. Punctum usually just lateral to caruncle and below superior punctum. Also shouldn’t be visible as usually faces posteriorly towards the globe
Definitive management of ectropion is with surgery but there are some temporizing measures that may be of use: lubricants if cornea exposed, taping lateral canthus, massaging scar or steroid injection, taping wieghts to upper lid in paralytic ectropion may improve lagophthalmos, wiping tears in an up and in inward direction may reduce exacerbation of ectropion.
Surgical management differs depending on the cause. In involutional ectropion, the aim is to correct horizontal lid laxity. This may be achieved by lateral canthoplasty or sling. Horizontal lid shortening, by removing an full thickness wedge, is sometimes used. There is also either medial tarsoconjunctival (diamond shaped segment of tarsus and conjuctiva is resected directly below the punctum) or medial canthal tendon plication…plication of anterior limb or resection for medial ectropion. In resection you resect the MCT structres combined with horizontal lid shortening, then the posterior limb is recontructed with a permanent suture and the cut inferior canaliculus is marsupialised into the conjuctival sac of the lower fornix
Mechanical ectropion is usually corrected by removing the offending lesion using a vertical excision.
The aim of surgery for cicatricial ectropion is to increase the vertical height of the lid. This may be achieved with either a Z-plasty that both shorthens the lid horizontally and lengthens vertically, or skin replacement usually with lower lid retractor reinsertion.
Surgical management of paralytic ectropion may be thought of in terms of passive and dynamic procedures. Passive procedurs include medial canthoplasty with lateral canthal sling, medial canthal tendon resection or if paralysis is severe mid face lift may be of benefit. dynamic procedures, include such things as temporalis transfer and or nerve grafting and are aimed at improving lid function.
9. ECTROPIO N• Definition – Abnormal eversion of the eyelid away from the globe• Key Features: – Eyelid margin and lash drive are turned away from the cornea – Conjuctival surface is exposed, which can lead to keratinisation of the epithelium – Corneal exposure results in foreign body sensation, corneal dryness and ulceration
10. ECTROPION DefinitionInvolutional cosmeticMechanical Epiphora Cicatricial Keratinization of conjunctiva Paralytic Punctate KeratopathyAssessment Loss of visionManagement
12. ECTROPION DefinitionInvolutionalMechanical Cicatricial Age-related changes cause horizontal Paralytic laxity of lidAssessment Weakness of canthal tendons and pre-tarsal orbicularisManagement
13. ECTROPION DefinitionInvolutionalMechanical Cicatricial BCC Paralytic Lesions near lid margin cause tractionAssessment leading to ectropion eg tumours, conjuctival Cysts, oedemaManagement
14. ECTROPION DefinitionInvolutionalMechanical Cicatricial Lid pulled from globe by vertical shortening Paralytic of the anterior lamella of the lower eyelid, caused by:Assessment trauma burnsManagement skin conditions (dermatitis, eczema) iatrogenic (post-op bleph, laser)
18. ECTROPION Definition Full Ocular HistoryInvolutional Onset and duration of signs/symptomsMechanical Trauma/burns/surgery Cicatricial Patient’s concerns ParalyticAssessmentManagement
19. ECTROPION Definition Examination Location of ectropion: horizontal vs vertical, punctal, medial, lateral, tarsal (complete)Involutional VA, Slit lamp exam or cornea and conj InvolutionalMechanical Snap back test Lateral distraction Cicatricial Cicatricial Skin conditions or scars Push skin over lid margin Paralytic Mechanical Lump/lesion on eyelid ParalyticAssessment Presence of Bell’s phenomenon Corneal sensation Degree of lagophthalmosManagement Facial movements (LMN vs UMN) Palpate parotid, check hearing, slit-lamp for uveitis
20. ECTROPION DefinitionInvolutional Non-operative Management Lumbricants for corneal exposure/Mechanical conjunctival keratinization Taping lateral canthal skin superotemporally Cicatricial Scar (cicatricial) massage, ? Steroid injection Paralytic Taped lid weights for Facial nerve palsy Advice on wiping tears (up and in towardAssessment nose)Management