Anatomy

• Layers of eyelid: conjunctiva, mullers muscle, levator muscle, orbital fat, septum, ROOF, orbicularis occuli, skin
• Mullers lies below levator insertion to  the superior border of the tarsus and is visualized during repair, Whitnalls ligament superior to levator
• There is an anterior and posterior lamella
• Anterior lamella consists of skin and orbicularis oculi muscle
• Posterior lamella includes the tarsoligamentous sling consisting of the tarsal plate, medial/lateral canthal tendons and the capsulopalpebral fascia and conjunctiva
• The orbital septum or middle lamella separates the anterior and posterior lamella
• There are 7 bones of the orbit
• Medial orbital wall formed mainly by ethmoid bone; enophthalmos and diplopia occurs if >5% volume post-operatively. Lacrimal bone, palatine bone, lesser wing of sphenoid also contributes to medial orbital wall
• Orbital floor (maxilla-medially and zygoma-anterior)
• Distance from the orbital rim to the apex is 45mm
• Fat compartments: 
• Fat pads are posterior to the septum and anterior to the levator
• Two fat pads in upper lid- central and nasal
• Three fat pads of the lower lid (medial, central, and lateral)
• Inferior oblique is found between medial and central fat compartment of lower eyelid. Receives innervation from oculomotor nerve, and moves eye in external rotation and elevation
• Inferior oblique can be entrapped in orbital floor fractures (test up and outward gaze)
• Voluntary eyelid animation from the zygomatic branch of the facial nerve (innervates extracanthal orbicularis), involuntary eyelid movement/closure (like blinking) from buccal branch of the facial nerve (innervates inner canthal orbicularus)
• Common canaliculus enters lacrimal sac posterior to medial canthal tendon
• Medial canthal tendons formed by pretarsal muscles and orginates anterior/superior to lacrimal crest
• Deep head pretarsal extends posterior to lacrimal sac
• Levator lies superior to medial canthal tendon 
• Nasolacrimal duct drains beneath the inferior turbinate
• During eye closure- lacrimal puncta CLOSES due to forced positioning, tears are milked medial to lateral –> shorten canniculi, open sac
• Sensation to eye: infraorbital nerve lower eyelid, lateral palpebral branch (from infraorbital nerve superior lateral portion of upper eyelid), infratrochlear – medial portions of upper and lower eyelid, lacrimal nerve V1 upper eyelid
• Zygomaticofacial branch provides sensation to the lateral fat pad of the lower eyelid
• Orbital malar ligament- Anatomic basis of tear trough: osteocutaneous ligament arising from medial portion of maxilla-between palpebral/orbital portions of the muscle, inferolateral to medial canthus. 
• released to access midface for suborbicular fat redraping through transconj approach; attaches to the orbicular muscle of eye at orbital rim; separates lower eye from mid face
• Fillers should be placed inferior to tear trough ligament, placing superiorly serves to emphasize lower eyelid fat
• Lockwood ligament supports globe; orbital septum contains orbital contents
• Tears: a trilaminar fluid
• Mucin secreting goblet cells form precorneal layer (promotes dispersion of the overlying aqueous layer)
• Aqueous middle layer secreted by the lacrimal gland and is composed of water and proteins (promotes osmotic regulation and control of infectious agents)
• Meibomian glands  prevent evaporation of tears, outer lipid layer (dysfunction can lead to dry eye)

Physical Exam

• MRD (marginal reflex distance-1) is the distance in millimeters from the light reflex to the patients cornea to the level of the upper eyelid margin with the patient in primary gaze (normal is >2.5)
• <2.5mm is evidence of ptosis
• Measuring exophthalmos: anterior border of globe and most anterior portion of lateral rim- enophthalmos <14mm; exop >18mm
• Eyelid snap back >6mm is considered lax. May do wedge resection if positive canthal tilt or canthopexy. For negative canthal tilt must to canthopexy
• Orbicularis positioning for minimal laxity 1-2mm
• Intercanthal distance best approximated by orbital fissure width
• Schirmer test: evaluates tear production and tear breakup time
• Hering’s Law: equal and simultaneous innervation of both levator palpebrae muscles –> when one eye has ptosis the brain signals both eyelids to raise (can hide ptosis)
• Phenylephrine drops into the more ptotic eye stimulate Muller muscle to raise the eyelid –> in turn afferent signals to raise the eyelids decrease –> if c/l eyelid falls  over the next 10-15 minutes then likely need bilateral ptosis repair
• Can also use patch
• Bell’s phenomenon: upward and outer movement of eye on eye closing is protective mechanism. Absence can predelict to corneal ulcers after bleph
• Horner’s syndrome: blepharoptosis, pupil miosis, facial anhidrosis
• Apex of the brow should be at the lateral limbus of the eye in forward gaze
• Thyroid disease: proptosis, diplopia, puffy, swollen, injected, eyelid lag

Definitions:

• Blepharochalasis: thin upper eyelid tissue, painless edema of eyelids, baggy appearance and usually levator dehiscence
• Dermatochalasis: loosening of the eyelid skin with fat protrusion
• Blepharophimosis: a form of congenital ptosis. Presents with ptosis, telecanthus, phimosis, and large epicanthal folds with epicanthus inversus 
• Correction involves Z plasty, transnasal wiring of medial canthal tendon, ptosis correction with frontalis suspension
• Epiblepharon: vertical eyelashes as a result of excess pretarsal muscle and skin overriding the margin of the eyelid (often affects lower lids)
• Should observe for several years –> if does not correct can shorten anterior lamella
• Entropion: inward rotation of the eyelid margin

Ptosis: defined by how much of the upper limbus is covered by the lid margin at rest and at forward gaze (1-2mm normally)

• Senile (involutional) Ptosis: common in the elderly progressive attenuation of levator aponeurosis (otherwise known as levator dehiscence)
• Signs: elevated tarsal crease >7mm, thinned upper eyelid, lid droop with downward gaze
• Treatment: levator advancement or plication (to the tarsal plate)
• Evaluate also for skin excision (blepharoplasty)
• Most important consideration in ptosis is levator function
• Good levator function >10mm with mild to moderate ptosis = repositioning of levator aponeurosis to the tarsal plate . Every 3mm of levator advancement results in 1mm of elevation
• To achieve proper contour for levator advancement, should place primary lifting suture at the vertical plane of the mid pupil
• Good levator function <2mm ptosis= Fasanella-Servant
• FS uses posterior conjuctival approach to correct mild ptosis without levator disinsertion, plication only works if not dehisced 
• does not remove excess skin of eyelid fold but levator aponeurosis reinsertion can include skin resection
• Good levator function and response with phenylephrine= mullerectomy
• Levator response 5-10mm= levator resection/advancement 
• Levator resection for  ptosis >3mm 
• Levator advancement for mild/moderate ptosis (3mm advancement for 1mm ptosis)
• Levator response <5mm= frontalis suspension (and severe ptosis)
• Autologous fascia lata has the lowest long term recurrence rates and complication rates
• Congenital ptosis:  most commonly a result of localized myogenic dysgenesis. Most causes are idiopathic
• Should obtain an MRI initially to rule out nerve compression from external forces (like a tumor) particularly when it presents acutely or subacutely in a child >1 year of age
• Good levator function (minimal ptosis) use fasenella but this may alter lid contour
• Muller resection also for minimal ptosis but cannot achieve symmetry and cannot make intraop corrections
• Resection and advancement of levator aponeurosis allows for symmetry (need function of levator >5mm)

Blepharoplasty:

• Asian lid management: epiphoria- due to excess pretarsal skin and orbic muscle at lower eyelid margin
• 50% of population has general lack of insertion of levator aponeurosis into the dermis causing lack of supratarsal fold, more and lower epicanthal folds, more fat
• Transconjunctival approach versus transcutaneous approach in lower eyelids:
• Transconj bleph preserves the middle lamella (IE septum) and has less incidence of scleral show and more difficult access to the lateral fat compartment
• used for pat pad reduction and will not violate septum, deep to septum, incision should be placed 4-5mm below tarsal border or 8mm for lid margin
• Transcutaneous: easier and more effective for blending the lid-cheek junction and transposing fat
• Lower eyelid laxity treated with: lower bleph and canthopexy –> decreases risk for ectropion
• If snapback test is slow on lower eyelid, may perform horizontal shortening of lower eyelid and canthopexy
• Repositioning of  inferior limb lateral retinaculum on orbital rim, suturing lateral orbic to orbital rim, (all support lateral canthus)- variety of structures to lower orbital rim
• Lateral canthoplasty: treats lower eyelid laxity, protects against malposition
• Greater >6mm use lateral cantholysis with canthoplasty ESPECIALLY if negative tilt; can also use horizontal excision
• Mild eyelid laxity 1-2mm orbic repositioing

Complications

• General Bleph complications:
• Most common complication after asian eyelid surgery is asymmetry
• Most common complication of lower bleph is lower eyelid malposition
• Carrying incision past punctum in bleph can cause webbing of nasal skin
• Dry Eye: 
• Pre-operative risks of dry eye syndrome after blepharoplasty: minimal exopthalmos, moderate scleral show, proptosis, hypotonia, maxillary hypoplasia, four eyelid surgery
• LASIK creates corneal flap that interrupts long ciliary nerves of trigeminal nerve and results in decreased sensation of corneal reflex arc (lose compensatory blink)
• Ectropion
• If lower or upper eyelid malposition and epiphoria is diagnosed early in the post-operative period massages are recommended
• Transconj approach decreases risk of lower eyelid malposition (0% risk for ectropion in some studies) post-operatively (subciliary is as high as 25%)
• Ectropion a) involutional (horizontal laxity)  b) cicatricial (veritcal shortening of anterior lamella or posterior lamella and septum) c) neurogenic (paralysis of orbic)
• Risks: negative vector (when the orbital rim is retropositioned relative to the vertical plane of the cornea), excessive skin resection, horizontal laxity of tarsoligamentous sling, aggressive imbrication of the orbital septum, Graves disease with exophthalmos, persistent edema, and hematoma
• Scarring between the capsulopalpebral fascia and septum cause cictracial ectropion in the lower lid
• Involutional entropion and ectropion distinguished by animation of orbicularis oculij
• Caused by orbicularis dysfunction of the preseptal portion, disinsertion, loss of eyelid support
• Lower eyelid ectropion after burn: FTSG and release of tissues even after early burn!!!; involutional ectropion (lax skin) treated with canthoplasty and wedge excision, neurogenic treated with gold weights
• Lateral compartment fullness after upper blehparoplasty = descending lacrimal glands (lateral fat compartments in LOWER eyelids)
• Hyphema: traumatic hemorrhage into anterior chamber, can result in increased ocular pressure –> treatment includes acetazolamide and corticosteroid drops
• Lagophthalmos is complication of upper eyelid blepharoplasty
• If the patient received epinpehrine or phenylephrine drops (alpha adrenergic agonist), lagophthalmos may be a result of activation of Muller’s muscle (also known as the superior tarsal muscle)
• Von graefe is lagophthalmos on down gaze (related to graves)
• Central facial numbness after bleph likely from supratrochlear nerve: courses through corrugator and innervates central forehead skin, deep supraorbital supplies forehead periosteum
• Ptosis common after bleph: common causes include postoperative edema of the eyelids and hemoorhage into Muller’s muscle
• Complications typically resolve over time, reassurance and observaiton with frequent follow up examinations are the most appropriate
• Traumatic aponeurotic injuries after blepharoplasty: ptosis, iris shadow, elevated tarsal crease, good levator function –> treat with early re-attachment of levator
• Increased intraocular pressure from retrobulbar hematoma: can lead to blindness (can be diagnosed after orbital fracture repair, blepharoplasty etc)
• Steady, severe pain in globe and orbit, which can have sparkles/flashes, appear as a window shade being pulled over the lower half of the visual field
• Physical exam in an affected patient will show visual loss associated with a pupillary defect (loss of pupillary reaction to light)
• Can measure increased pressure with a tonometer
• Treatment includes lateral canthotomy (relieves pressure)

Nasolacrimal Duct

• Jones test: 
• I: evaluates lacrimal outflow under normal physiologic conditions –> flourescien diye is instilled in conjunctival cornice –> dye recovered 5 minutes by asking pateint to blow their nose –> if no dye perform jones 2
• II: residual flourescein flushed out from conjunctival sac–> asks patient to expel drainage from pharynx –> no dye means complete obstruction
• Congenital tearing: likely nasolacrimal duct, treated with massage and abx drops until 13 months –> probe nasolacrimal duct –> silastic intubation –> dacryocystorhinostomy
• Post-operative obstruction of naso-lacrimal duct: dacryocysorhinostomy (for negative jones 1 and 2 which signifies distal obstruction past the lacrimal sac) and those not involving the proximal cannalicular system 
• Obstruction at canalicular level or proximal obstruction= conjunctivodacryocysotostomy
• Obliteration of sac= conjunctivorhinostomy; intubation of tear sac= dacryocystostomy
• Conjunctivorhinostomy is used in patients who have obliteration or absence of the tear sac 

Miscellaneous:

• Blepharospasm: frequent blinking and squeezing of eyelids –> administration of botox
• Botox induced ptosis (ptosis of levator muscle), treat with alpha adrenergic drops (apraclonidine) to elevate muller’s muscle
• Botox prevents release of acetycholine into the presynaptic membrane
• Medial canthal degloving injuries can result in telecanthus, ptosis, and epiphoria (from canalicular injuries)
• Should initially repair the telecanthus and canalicular repair, followed by ptosis repair at 3-6 months