Meibomian cyst or the growth of a white
nodule on the rabbit eyelid
Esther van Praag, Ph.D.
Warning: this file contains pictures that may be distressing for
people.
The meibomian glands, located in the
tarsal plate of the eyelid, are sebaceous (oil-secreting) glands. Its
secretions help lubricate the eyelids. Sometimes the glands become impacted
or blocked and a meibomian cyst (chalazion) will develop. It is a slowly
growing, firm nodule, located on the upper or lower eyelid. The accumulation
of secretions within the glands is caused either by an impaction of the gland
opening, a thickening of the oil or the presence of a tumor next to the
glands that hinder proper drainage by compressing the opening. The distended
gland may rupture and the freed material will irritate the surrounding
tissue, which becomes granulomatous. The accumulation of secretion on the
edge of the lids can lead to the development of bacteria normally found on
the skin, or pathogen bacteria such as Staphylococcus sp. or Streptococcus
sp. If the nodule is infected, it becomes painful and swollen.
Diagnosis
While clinical
signs are evident, the meibomian cyst must be differentiated from
conjunctivitis, a hordeolum (sty, a localized
infection or an inflammation of the eyelid margin involving hair follicles of
the eyelashes), blepharitis, meibomianitis,
or meibomian cell carcinoma.
Treatment
A meibomian cyst may disappear by
itself, without need of treatment. The swelling can be brought down by the
application of warm compresses on the eye, 4 to 5 times a day. If a bacterial
infection is present, administration of antibiotics is necessary.
Usually, the cyst is lanced with a
needle or a small incision, and the oozing gelatinous pus is removed.
Curettage of the cavity follows. This step is repeated till the cavity is
devoid of remaining material. The lose material is removed by flushing the
cavity with a saline solution. If bleeding appears, application of pressure
on the wound with a sterile gauze pad during a few minutes will stop it. An
antibiotic ointment is given immediately after the procedure.
The eyelid usually looks bruised and
swollen after the procedure, due to the injection of anesthetic agents in the
eyelid, and the use of clamping tools and forceps. This is normal and should
disappear over the next days.
If the cyst is large, persistent or
infected, surgical excision of the inflammatory granuloma is advisable. If
the removed cyst presents tumor-like characteristics, it should be sent for
analysis to a laboratory for histopathological analysis.
Post-surgical care includes the use of
an antibiotic ointment during a few days and the gentle application of cold
compresses, in order to reduce the swelling.
Usually, no pain medication is
necessary. When the rabbit shows signs of pain or discomfort, meloxicam or ibuprofen can be given.
Acknowledgement
Thanks are due to Akira Yamanouchi (Veterinary
Exotic Information Network, http://vein.ne.jp/), for the permission to use
their pictures.
Further information
Greiner JV, Glonek T,
Korb DR, Whalen AC, Hebert E, Hearn SL,
Esway JE, Leahy CD. Volume of the
human and rabbit meibomian gland system. Adv Exp Med
Biol. 1998; 438:339-43.
Millar TJ, Pearson ML. The effects of dietary and
pharmacological manipulation on lipid production in the meibomian and harderian glands of the rabbit. Adv Exp Med Biol.
2002; 506(Pt A):431-40.
Steagall RJ, Yamagami H,
Wickham LA, Sullivan DA. Androgen control of gene
expression in the rabbit meibomian gland. Adv Exp Med Biol. 2002;
506(Pt A):465-76.
Tiffany
JM, Marsden RG. The meibomian lipids of the rabbit.
II. Detailed
composition of the principal esters. Exp
Eye Res. 1982; 34:601-8.
Tiffany JM. The meibomian
lipids of the rabbit. I. Overall composition. Exp Eye Res. 1979 ;29:195-202.
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