The eyelids are highly specialized structures which are in charge of protecting the eyeball, distributing tears on the ocular surface by blinking and improving vision.
They are a physic barrier against external elements and avoid lesions as they immediately close when an object gets too close to the eye.
There are two types of ophthalmological interventions involving the eyelids; those related to ocular pathologies or disorders and those which have esthetical purposes (blepharoplasty).
- Pathologies or disorders
- Lachrymal system disorders
- Trichiasis and distichiasis
- Entropion and ectropion
- Hordeolum or stye
- Palpebral tumours
Pathologies or disorders
Tears are a saline fluid on the outer surface of the eye in charge of keeping it moist. They have antibodies which protect the eye from infections. They are produced by the lachrymal glands and are removed from the eye surface through two small drain openings (punctums) in the lower eyelids into the lachrymal ducts and palatine fossa.
If the tear film on the eye surface is not enough to keep it moist, it is at risk of partially drying out and being damaged.
Nasolachrymal duct obstruction
Nasolachrymal duct obstruction (dacryostenosis) can be caused by recurrent or chronic ocular infections, inadequate development of the nasolachrymal system at birth, or by nasal or facial fractures. The obstruction can be partial or complete.
Lachrymal sac infection
Lachrymal sac infection (dacryocystitis) is generally caused by nasolachrymal duct obstruction. The infection causes pain, reddening and swelling of the area surrounding the lachrymal sac. The eye may redden and ooze fluids.
The treatment is based on antibiotics and anti-inflammatory drugs. In case of chronic infection, probing of the duct may be done.
Trichiasis is the misdirected growth of eyelashes, not following a uniform pattern.
Distichiasis is a disorder in which eyelashes grow from an abnormal position, generally from the orifices of the Meibomian glands.
In both cases, eyelashes generally grow back towards the eyeball rubbing against the cornea and conjunctiva.
The treatment consists in eliminating the eyelashes which have an abnormal growth by using laser treatment which eliminates the eyelash follicle to avoid it from growing back again.
Ptosis refers to drooping upper eyelids. It may be congenital (present at birth) or acquired.
Congenital ptosis generally appears due to improper development of the levator muscle. In case it alters vision by totally or partially stopping light from passing through the pupil, it may cause amblyopia or lazy eye due to insufficient light stimulation.
When ptosis alters children’s vision, they tend to lean their head back or arch their eyebrows in order to compensate droopy upper eyelids.
Acquired ptosis (much more frequent) appears as a consequence of poor levator muscle function due to aging, muscular degenerative disorders (eg. Steinert’s disease), or nervous system dysfunction.
A rigorous examination is necessary to decide the correct treatment as, although in most cases it involves eyelid surgery, other factors must be taken into account.
Ptosis surgical treatment requires deep understanding of the functional anatomy of the eyelid as it is formed by complex dynamic structures. It is a minimally invasive procedure and it involves no visible incisions.
Entropion is a condition in which the eyelid folds inwards (towards the eyeball), causing the eyelashes and skin to rub against the cornea, which can lead to ulcer formation.
On the other hand, ectropion is a condition in which the eyelid turns outwards. This does not allow the eyelid to close appropriately so eye lubrication becomes insufficient, giving place to eye discomfort.
Both medical conditions usually occur in older people due to weakening of the orbicularis muscles and, therefore, the surgical treatment involves tightening the eyelids so that they can go back to their normal position.
A hordeolum is a localized infection involving the hair follicles of the eyelashes and their associated Zeiss or Moll glands. This results in painful inflammation of the margin of the eyelid. Overflow tearing, increased light sensitivity and foreign body sensation may appear.
Hordeolums are frequently a stress-related medical condition.
A chalazion is an inflammation of Meibomian glands in the eyelid, caused by the blockage of the ducts through which sebaceous fluids are secreted.
Initially it looks like a hordeolum: a painful inflammation of the margin of the eyelid. However, after a few days, these symptoms disappear and a non-painful lump appears.
Sometimes, chalazia go away with medical treatment, and in case they do not, they can be surgically eliminated.
Any type of tumour which can appear in the skin can do so too in the eyelids.
The main benign tumours are papilloma, xanthelasma and nevus in adults, and hemangioma in children.
The treatment of the first three (papilloma, xanthelasma and nevus) involves surgery, whilst hemangiomas only need to be addressed if they interfere with vision in order to prevent amblyopia or lazy eye from developing.
The main malignant tumours are basal cell carcinoma (more frequent) and squamous cell carcinoma. They are both ulcerative lesions. Basal cell carcinoma does not generally metastasize even though it is considered a malignant tumour.