Chalazion or eyelid cyst

Chalazion is the commonest of all the eyelid lumps and is also called Meibomian cyst or Tarsal Cyst. Before going into the details of the chalazion that is the definition or pathology of the chalazion, it is very important to know about the simplified anatomy or location of the meibomian glands whose inflammation result in chalazion.

Meibomian glands

These are modified sebaceous glands that secrete sebum and also their secretions form a part of the tear film formed in the eye. If we look carefully at the lid margin, we can divide it into three borders namely:

1. Anterior (in front) border: Which is rounded.

2. Intermarginal strip: Which lies between the anterior and posterior border of the lid margin, from which cilia or eyelashes arise and which has the hair follicles inside from which these eyelash come out.

3. Posterior border: Which is sharp and which is in contact with the white of the eye that is the sclera and its overlying conjunctiva and also with cornea in the centre.

Meibomian glands open in the intermarginal strip but behind the eye lashes, as the intermarginal strip in front has the hair follicles and the respective lashes and on the intermarginal strip itself behind the row of lashes there are openings of the meibomian glands.

Lid MarginLocation: Meibomian glands are located in the tarsal plate. Therefore, Meibomian glands are also called tarsal glands and that is the reason why chalazion is also called a tarsal cyst. Meibomian glands are 30-40 in the upper lid and 20-30 in the lower lid.

What is a chalazion

ChalazionIt can be defined as a chronic, non-infectious granulomatous inflammation of the meibomian glands.

That means, it is usually a long standing condition, with usually no active infection or infective organism involved and it is associated with mainly granulomatous conditions like tuberculosis etc. due to which there is inflammation of the meibomian glands.

Causes

Chalazion in upper EyeLidAs told earlier, it is a chronic or a long standing condition, so chronic irritation by organisms of low virulence causes inflammatory changes like proliferation of epithelium, infiltration of ducts of the gland with giant cells, chronic inflammatory cells like lymphocytes and epithelioid cells. This can block the glands and there is stasis of the gland secretions resulting in its enlargement. These accumulated secretions are also fatty in nature and further cause irritation of the gland and resulting in more inflammatory changes thus creating a vicious cycle.

Symptoms

1. Swelling in the eyelid which is painless.

2. Swelling increases gradually or progressively with time.

3. There are no inflammatory symptoms like redness pain etc.

4. A moderate sized chalazion may cause mild heaviness on the lid.

5. If it occurs on lower eyelid and is large in size, it would cause eversion of punctum and watering from the eye.

6. Blurred vision can result due to very large chalazion pressing the cornea and inducing astigmatism.

Signs

1. A swelling or nodule is seen. Mostly they are multiple, occurring in crops.

2. It is more common in adults than in children.

3. The swelling is slightly away from the lid margin.

4. The swelling is hard or it can be firm too.

5. The swelling is non tender.

6. Chalazia are mainly seen on upper lids than in lower lids because there are more meibomian glands on upper (30-40) than in the lower lid.

7. Usually on everting the lid, reddish purple nodule is seen on the palpebral conjunctiva where the chalazion usually points.

8. Marginal chalazion is seen or can be defined as when granulation tissue is formed in the duct of the meibomian gland from which it projects a reddish purple nodule on the intermarginal strp.

Complications

1. In rare cases, complete self resolution may occur that is the chalazia may resolve on its own.

2. Sometimes the chalazion keep on growing in size eventually with time and turn into a large size.

3. When the lesion bursts on the conjunctival side, a fungating mass of the granulation tissue can be seen.

4. Secondary infection can occur which can change it into an internal hordeolum.

5. Rarely, malignant change can be seen in the chalazion and it can turn into meibomian gland carcinoma particularly in the elderly.

Treatment

1. In cases of small chalazion, Intralesional injection of long acting steroid like triamcinolone acetonide can cause resolution in fifty percent of the cases. Some chalazion also resolve on their own with the help of conservative treatment like hot fomentation.

2. Incision and curettage

a. The conjunctival sac and the lid are well anaesthetized by a submuscular injection of 2% lignocaine deep to the orbicularis oculi muscle and a topical anaesthetic xylocaine drops.

b. The chalazion nodule is held with a clamp to keep the lid everted and to provide bloodless field for surgery.

c. The lid is everted and an incision is made with a sharp blade.

d. The incision is vertical on the conjunctival side to prevent injury to the meibomian ducts and horizontal on the skin side to avoid scar.

e. Any semi fluid contents escape and contents and walls of the cavity are thoroughly curetted out with the help of a chalazion scoop.

f. To avoid recurrence, the cavity is cauterized with carbolic acid and an antibiotic ointment is instilled.

g. Antibiotic drops, hot fomentation and oral anti-inflammatory drugs and analgesics can be given for 3-4 days, just to be on the safer side and prevent secondary infections otherwise the cyst fluid is sterile unless not infected.

3. Diathermy: Marginal chalazions are better treated with diathermy.

Prognosis

Chalazion usually follow a good prognosis that is they resolve on their own or with the help of any of the above treatments. Some chalazion tend to recur.

Reference

1. A.K Khurana, MD “Ophthalmology” (New Age International Publisher, Inc 2012) p367-368.

2. Normal lid margin image used in this page is copyright to Dr. Deans (www.robindeans.com).

3. Chalazion image used in this page is copyright to Charcoal Remedies (www.charcoalremedies.com).

4. Chalazion in upperlid image used in this page is copyright to Toronto Eye Clinic (www.torontoeyeclinic.com).