III. DEFORMITIES OF THE LID
This group of diseases includes:
Maldirected lashes that rub against cornea and conjunctiva.
1. Congenital trichiasis (Dystrichiasis):
There is a complete extra row of lashes at site of Meibomian glands.
It is characterized by:
- Affects the 4 lids.
- Lashes arise behind the grey line.
- Damage of cornea occurs in the age of 3- 6 years when lashes become strong.
2. Acquired trichiasis:
It may be single or multiple. It occurs due to fibrosis near to the hair follicle as in cases of:
- Trachoma (the commonest cause of multiple trichiasis).
- Stye (the commonest cause of single lash trichiasis).
- Ulcerative blepharitis.
- Membranous conjunctivitis.
- Chemical injuries.
- F.B. sensation, pain, headache and reflex lacrimation.
If the cornea is affected there will be photophobia and blepharospasm.
- The maldirected lashes are seen.
- Signs of the etiology are seen as PTDs or bleeding ulcers at the lid margin.
1. Corneal complications:
- Corneal ulcers and opacities that may require keratoplasty.
- Superficial vascularization.
2. Conjunctival complications:
- Chronic conjunctivitis with discharge.
- Conjunctival ulcers.
I. Congenital trichiasis: The follicles of lashes are killed by either:
A. Multiple electrolysis sessions.
B. Cryo therapy by freezing the root of lash into - 20 degrees.
II. Acquired trichiasis: The mode of treatment differ according to site and number of rubbing lashes as following:
A. If 1 - 4 rubbing lashes are present; the follicles of lashes are destroyed by either electrolysis, electrocautery or cryotherapy.
NB. Apilation may be used as a temporary measure.
B. If a large number of rubbing lashes are present adjacent to each other, they can not be destroyed because the cosmetic appearance of the patient will be disfigured. So that the position of these lashes should be corrected surgically.
i. For more than 4 rubbing lashes in the lateral canthus area of upper or lower eyelids we do Z‑plasty.
ii. For more than 4 rubbing lashes aggregated in the middle of upper lid without entropion we do Van Millengen's operation.
iii. For more than 4 rubbing lashes aggregated in the middle of lower lid with or without entropion we do Webester's operation.
C. Snellen's operation done to correct cicatricial entropion trichiasis of upper lid.
* The idea is to destroy the lash follicle by chemical cautery.
* Technique: - Local or general anaesthesia.
- The negative electrode is inserted in the lash follicle.
- The positive electrode touches the skin.
- Current is adjusted at 3 mA for 30 sec.
* Mechanism: H2O is dissociated into H+ (gas bubbles) & OH-. The negative electrode will attract the sodium ions that will combine with OH- to form Na OH leading to chemical cauterization of the lash follicle.
* The main advantages of electrolysis are the sure action and minimal fibrosis.
* Idea: Thermal destruction of the root of maldirected lash.
* Technique: The current is adjusted at 30 mA for 3 seconds. Any electrode is inserted inside the lash follicle while the other touches skin of the patient.
* Mechanism: This current heats the electrode leading to coagulative necrosis of the lash follicle.
* Its complication is the production of marked fibrosis that leads to lid notching (coloboma) and maldirection of the neighbouring lashes.
Van Millengen's operation:
* Idea: Insertion of a mucus membrane graft in the grey line to push the rubbing lashes away from the cornea and conjunctiva. The graft is taken from the buccal mucosa or mucosa of the inner side of lips.
* Indications: Large number of rubbing lashes aggregated in the middle the upper eyelid.
- Trichiasis of lower lid because the graft is cosmetically bad.
- Cicatricial entropion of upper lid (in this case we do Snellen's operation).
* Idea: Insertion of a mucus membrane graft in sulcus subtarsalis.
- Large number of rubbing lashes in the middle of the lower lid.
- Lower lid cicatricial entropion.
- Cicatricial entropion of upper lid with short tarsus.
* Disadvantages: When done in the upper lid the graft will rub the cornea because the upper lid has a wide range of movement.
It is inward rolling of the lid margin.
Surgical anatomy of the eyelid:-
1. The eyelid is considered to be formed of two lamellae:
a. The anterior lamella which consists of the skin and orbicularis oculi.
b. The posterior lamella which consists of tarsus and conjunctiva.
NB. Scarring of the anterior lamella leads to ectropion. It can be replaced by skin grafts taken from skin covering the mastoid bone or medial side of arm.
NB. Scarring of the posterior lamella causes entropion. It can replaced by grafts taken from the tarsus of upper lid, nasal cartilage or ear cartilage.
NB. Scarring of both lamellae cause coloboma. Both lamellae should be reconstructed.
2. Stretching mechanisms of the eyelids:
a. The upper and lower lid retractor are responsible for vertical stability of lid. LPS and superior Muller’s muscles are the retractors of upper lid. Senile dis-insertion of upper lid retractors cause senile ptosis. The inferior Muller’s muscle and the fibrous expansion of inferior rectus are the retractors of lower lid. Senile dis-insertion of lower lid retractors cause senile entropion.
b. The medial and lateral canthal tendons attach the eyelids to the medial and lateral orbital margins. They stretch the lids horizontally.
3. The orbital contents:
The eyeball and orbital fat support the eyelids posteriorly to counter entropion.
Clinical picture of entropion:-
- If the condition is mild there will be no symptoms.
- If the condition is severe enough that lashes rub against the globe, the patient will complain of the same symptoms of trichiasis (mention).
- The posterior lid margin could not be seen because it is rolled inwards (the most important sign).
- Lashes may be rubbing the cornea and conjunctiva.
- Specific signs of each type (see later).
Types of entropion:-
A. Cicatricial entropion:
Occurs due to fibrosis of the palpebral conjunctiva as in case of:
- Trachoma (the commonest cause).
- Chemical injuries.
It can occur in both lids, but most common in the upper lid. (other types of entropion occur only in the lower eyelid).
Clinical picture and complications:- as before plus scarring of palpebral conjunctiva.
Treatment of cicatricial entropion:
A. In the upper lid we do:
1. If tarsus is large we do Snellen’s operation:
- Idea: Correction of the tarsal deformity by removing an anterior wedge from its substance.
- Local anaesthesia (xylocaine) injected in the submuscular layer plus benoxinate eye drops.
- Lid spatula is placed to support of the lid and protect of the globe.
- Horizontal skin incision 4 mm above the lid margin.
- Excise a bundle of orbicularis oculi.
- Excise a base anterior wedge from the tarsus.
- Close the incision.
- Pure trichiasis of upper lid (do Van Millengen’s operation).
- Cicatricial entropion with small tarsus as in cases of lower lid cicatricial entropion or upper lid affection with small tarsus (do Webester's operation).
2. In recurrent cases with small tarsus we do:
a. Tarsus graft.
b. Webester's operation.
c. Lid splitting then repositioning of the anterior lamella upwards to make the posterior lamella act as a barrier between the maldirected lashes and cornea.
B. In lower lid we do :
1. Tarsus fracture and lid margin evertion: A horizontal incision is done through the conjunctiva and tarsus, then 3 double armed lid everting sutures are placed.
2. Tarsus grafting using nasal septum or ear cartilage.
3. Webester's operation (mention).
B. Spastic entropion:
It occurs only in the lower eyelid. It occurs due to 2 factors:-
1. Spasm of orbicularis oculi as in cases of corneal ulcer, corneal foreign body, trichiasis, uncorrected errors of refraction, ... etc.
2. Lack of support of the lid by the globe as in cases of enophthalmos, after enucleation or in cases of atrophia bulbi.
It affects the lower lid mainly.
Clinical picture and complications:- as before.
Treatment of spastic entropion:
1. Treatment of the cause of irritation.
2. Fitting an artificial eye in cases of enucleation.
3. T-shaped plaster for temporary fixation of the lid.
C. Senile (involutional) entropion:
Entropion may occur commonly in old age due to:
a. Weakness of collagenous bundles that fix fibers of orbicularis oculi in site. So that, the preseptal fibers will override the pretarsal fibers of the muscle leading to inward rolling of the margin of the lower lid.
b. Lack of lid support by the eyeball because of senile enophthalmos that occurs due to senile atrophy of retrobulbar fat.
Clinical picture and complications:- as before.
Treatment of senile entropion:
a. Temporary bedside measures:-
1. Plaster application to stretch the eyelid out.
2. Lid everting sutures: Three double armed sutures running obliquely from the lower conjunctival fornix to the skin just below the eyelashes. When these sutures are tightened, the eyelid will be everted. The sutures are removed after 2 weeks. Recurrence occur 6-12 months later.
b. Permanent measures:
1. Weis operation (total blepharotomy with marginal rotation): A full thickness horizontal eyelid incision is done. Then 3 eyelid everting sutures are done to transfer the pull of lower lid retractors to the lid margin. Finally skin is closed. The scar resulting form healing of the full thickness eyelid incision will be a barrier between preseptal and pretarsal fibers of orbicularis oculi.
2. Wheeler's operation: We do a horizontal skin incision then:
- Cut the continuity of an orbicularis oculi bundle to relieve its spasm.
- We overlap the cut muscle bundle to press the attached border of the tarsus posteriorly leading to correction of the position of its free border.
D. Congenital entropion:
It occurs in the lower lid due to congenital hypertrophy of skin and a bundle of orbicularis at the medial side causing a fold called “epiblepharon”. If not resolved spontaneously, it is treated surgically by lid everting sutures of excision of an ellipse of skin and muscle at the medial side.
It is outward rolling of the lid margin, so that the posterior lid margin will not be in contact with the surface of the eyeball. This malposition will disturb tear spreading over the surface of cornea and conjunctiva. Also the lacrimal punctum will not be in contact with tears, so that epiphora will occur.
1. Watering of the eye (epiphora).
2. Burning sensation due to incomplete lid closure (lagophthalmos) in severe cases.
3. Cosmetic disfigurement in severe cases.
1. The posterior lid margin is seen to be rolled outward away from the globe, so that the punctum can be seen.
2. Assessment of the degree of ectropion:
- In mild ectropion the punctum can be seen.
- In moderate ectropion the palpebral conjunctiva can be seen.
- In severe ectropion the lower fornix can be seen.
1. Epiphora ---> eczema ---> dermatitis ---> cicatricial ectropion
---> more epiphora.
2. Complications of exposure as:
- Conjunctival ulceration and keratinization.
- Corneal ulceration (ulcer with lagophthalmos; in the lower 1/3 of cornea with straight upper level due to Bell's phenomenon)
- Corneal keratinization.
A. Senile ectropion:
It is the commonest type. It occurs only in the lower lid and it occurs bilaterally. It is gradual and progressive. It occurs due to laxity of orbicularis oculi as well as lid ligaments. So that, the lower lid drops down by its weight.
Symptoms, signs & complications:- See before.
1. In mild cases confined to medial part of the eyelid we do diathermy about 5 mm below the lacrimal punctum. This cautery induces fibrosis of palpebral conjunctiva to correct ectropion.
2. In more advanced cases confined to medial part we do "medial conjunctivoplasty". In this operation we excise a trapezoid from conjunctiva below the lower canaliculus. Suturing the conjunctiva will lead to correction of the medial part of the lower eyelid.
3. In severe cases are treated by "modified Kuhnt - Szymanowski operation". In this operation we do:
i. Incision of skin below the lashes.
ii. Excision of a base up triangle from the tarsus and the conjunctiva to correct their laxity.
iii. Excision of a triangle from the skin at the lateral canthus to correct its redundancy.
B. Paralytic ectropion:
It occurs due to paralysis of orbicularis oculi due to LMNL of the facial nerve.
Causes of facial paralysis: - The commonest cause is Bell's palsy.
- Fracture base of the skull.
- Otitis media.
- Parotid malignancy.
Ectropion is characterized by:-
- It occurs only in the lower lid due to the effect of gravity.
- It is unilateral and acute. It is regressive in cases of Bell's palsy.
- Other signs of facial palsy can be seen as:
* Inability to elevate the brow.
* Loss of nasolabial fold.
* Mouth shift and drippling of saliva.
Symptoms, signs & complications:-
I. We wait for 6 months aiming for spontaneous improvement. During this period we have to do:
1. Protect the eye from dryness by artificial tears in the day and ointment by night.
2. Protect orbicularis oculi muscle from disuse atrophy by physiotherapy (galvanic current stimulation and massage).
3. In Bell's palsy we give systemic steroids, vasodilators and consult a neurologist.
II. Surgical correction after 6 months:
- In mild cases we do lateral tarsorrhaphy.
- In moderate cases we do fascia lata sling operation where a strip of fascia lata is passed under the lid margin from the medial canthus to lateral orbital margin .
- Lateral canthus sling operation: The lateral end of lower tarsus is sutured to the lateral orbital margin to act as a sling to support the redundant eyelid.
C. Cicatricial ectropion:-
It occurs due to scarring of the skin of the lid. It is the only type that can occur in upper lid. Also it can occur in lower lid.
Symptoms, signs & complications:- See before.
- If small scar we do Z-plasty.
- If large scar we fit a skin graft. The graft is taken from a thin non hairy skin (as skin behind the ear). Then median tarsorrhaphy is done for 1 month to allow healing.
D. Mechanical ectropion:
It occurs only in the lower lid due to lower lid masses as tumours (the same lesions in the upper lid will cause mechanical ptosis not ectropion). It is treated by excision of the mass.
E. Congenital ectropion:-
It is a bilateral ectropion occurring due to short skin of the lower lid. It may be an isolated anomaly especially with Down's syndrome or associated with blepharophemosis syndrome. It is treated by full thickness skin graft.