A chalazion (plural: chalazia) is a lump in the eyelid caused by obstruction of the drainage duct of an oil gland within the upper or lower eyelid. It is also known as a meibomian cyst or tarsal cyst.
A chalazion may sometimes be mistaken as a stye which also has the appearance of a lump in the eyelid. Unlike a chalazion, a stye is an acute infection of a lash follicle and forms a red sore lump near the edge of the eyelid. A chalazion, on the other hand, is usually a reaction to trapped oily secretions within an oil gland called a meibomian gland. It is not primarily caused by bacterial infection although it can become infected by bacteria. A chalazion tends to occur further from the edge of the eyelid than a stye. It also tends to “point” towards the inside of the eyelid.
The gland involved in the formation of a chalazion is a modified oil gland that lies within the eyelid. There are about 30 to 40 of these glands within each of the upper and lower eyelids. Each of these meibomian glands secretes oil to form the most superficial layer of the tear film on the eye surface. This thin oily layer reduces evaporation of the tears. The oil exits from each gland through a tiny circular opening just behind the eyelashes in the upper and lower eyelids.
When the oily secretions harden and block the drainage duct, it leads to retention of the secretions within the gland and a visible lump in the eyelid. Sometimes, breakage of the gland wall releases oil into the surrounding tissues of the eyelid, causing inflammation and swelling.
Chalazia are more common in people with certain eyelid and skin conditions such as blepharitis, seborrhoeic dermatitis, eczema and rosacea.
A small lump which can usually be felt in the eyelid
- Gradual or sudden swelling of the eyelid
- Eyelid tenderness
- Heaviness of the eyelid
- Increased tearing
- Sensitivity to light
In some cases, a chalazion may persist for more than several weeks and enlarge to become cosmetically unappealing.
A large chalazion may press on and distort the cornea, causing astigmatism and blurring of vision.
A chalazion may be self-limiting and resolve without any treatment. However, most chalazia require treatment. Depending on the severity of the symptoms, management of chalazion may vary from conservative treatment to more invasive options.
Medical treatment usually entails applying warm compress to the eyelids for 5 to 10 minutes, followed by scrubbing of the eyelid margins using commercially prepared sterile lid wipes (e.g., Lid-care sterile wipes), cleansing gel (e.g., Sterilid) or baby shampoo at least twice daily. The heat softens the hardened oils blocking the gland and promotes drainage and healing.
A chalazion that is large and unsightly or is infected can be removed through an outpatient minor surgical procedure under local anaesthesia. The operation may also be carried out under general anaesthesia for uncooperative patients. An incision is made on the inside of the affected eyelid to drain out the contents or pus, leaving no visible scar on the outside afterwards. Antibiotic eye drops (e.g., Zymar, Vigamox) and ointment (e.g., Terramycin) are prescribed after the procedure to prevent or fight infection. Some patients may have mild pain after the procedure and this can be relieved by using pain-killers (e.g., Panadeine, Arcoxia).
An oral antibiotic called Doxycap (doxycycline) taken once a day can inhibit the production of free fatty acid from the breakdown of eyelid oil. Free fatty acid can destabilise the tear film (causing dry eye) and can promote inflammation. By reducing the formation of free fatty acid, Doxycap makes the tear film more stable and reduces eyelid inflammation. The preferred treatment duration is typically at least 3 months.
Chalazion usually responds well to treatment. However, for some people who are prone to recurrences, maintaining good eyelid hygiene with periodic warm compress and eyelid scrub can reduce its recurrence.