Lipogranulomatous Conjunctivitis – Feline

Published by Rachel Davis, DVM, MS, DACVO July 2017
Publication: Veterinary Information Network (VIN)

Disease Description
Lipogranulomatous conjunctivitis is an uncommonly described palpebral intradermal and subconjunctival inflammatory disease seen in cats.¹  Lipogranulomatous conjunctivitis is characterized by lobulated areas of lipid deposition and granulomatous inflammation along the eyelid margin at the level of the Meibomian glands and ducts.^1-3  It may occur bilaterally or unilaterally and is seen more commonly in the dorsal eyelids, although the ventral eyelids may also be affected.²

Etiology
The underlying etiology remains unknown, although there is a higher incidence in color-dilute and white cats.³  This suggests that there may be an actinic (UV mediated) etiology.  Damage to the Meibomian glands with leakage of the sebaceous material leading to severe granulomatous inflammation is the most likely cause of lipogranulomatous conjunctivitis.²  Trauma may be the inciting cause of Meibomian gland damage, although this has not been elucidated fully.

Diagnosis
Ophthalmic Examination Findings
Cats with lipogranulomatous conjunctivitis typically present with variably-sized, lobulated whitish to tan eyelid masses emerging from the conjunctival side of the eyelids at the level of the Meibomian glands and ducts.²  The lesions are smooth and non-ulcerated.  Affected cats typically have significant ocular discomfort with blepharospasm and epiphora being the most common presenting complaints.  Other concurrent ocular conditions may also be present causing discomfort, thus it may be difficult to determine how much the lipogranulomatous conjunctivitis is contributing to this versus other ocular disease.² Lipogranulomatous conjunctivitis may be present bilaterally or unilaterally and may affect just the dorsal eyelid or both the ventral and dorsal eyelids.  Lesions limited to the ventral eyelids alone have not been reported.

Physical Examination Findings: No systemic conditions have been associated with lipogranulomatous conjunctivitis.  This condition has evidence of free subcutaneous lipid, thought to be a result of leakage of the Meibomian glands.²  However, the possibility of systemic lipid metabolic disorders cannot be completely ruled out based on current data.

Disease Description in this Species
Signalment
Lipogranulomatous conjunctivitis is typically seen in middle-aged to older cats with a reported mean age of 11.2yr.²  No breed predilection has been reported, but white and color dilute cats are overrepresented.

Clinical Signs
Lesions range widely in severity.  Some mildly affected cats may have solitary to 2-3 enlarged, smooth, whitish to pale pink 1-2mm nodules on the conjunctival surface of the eyelids at the level of the Meibomian glands.  More severe lesions may appear as overlapping, severely engorged pale pink to cream subconjunctival lobules up to 5mm in size at the level of the Meibomain glands running the length of the eyelids.³  Most cats have signs of ocular discomfort, although many of these cats have other concurrent ocular disease that may be contributing to the discomfort (e.g. ventral entropion).

Etiology
Inflammatory
UV light mediated
Autoimmune

Breed Predilection
None
Seen more commonly in white and color-dilute cats (decreased pigment on eyelids)

Sex Predilection
None

Age Predilection
Middle aged to older cats

Diagnostic Procedures
These lesions may be diagnosed based on typical appearance and location, in most cases.  Histopathology is confirmatory for the disease and shows large clear spaces within the lamina propria presumed to be lipid surrounded by mild to severe granulomatous inflammation.²  Some mild to moderate subepithelial lymphoplasmacytic and neutrophilc inflammation was observed in most cases, but was not the predominate type of inflammation.  Periglandular fibrosis was also a prominent histologic feature.

Treatment/Management/Prognosis
Specific Therapy
Medical therapy with topical antibiotics and anti-inflammatories (e.g. neopolydex, prednisolone acetate, diclofenac) may be effective for mildly affected cats.³  For severe cases and in cats that have ongoing discomfort despite medical therapy, surgical resection of the lobules at the level of the Meibomian glands as has been described for distichia therapy⁴ is warranted.  Because this surgery also excises Meibomian glands, loss of some or all of the lipid component of the tear film is likely (depending on the extent of the excision), which may result in qualitative tear deficiencies and resultant corneal disease.^5,6

Supportive Therapy
Because lipogranulomatous conjunctivitis often occurs with other concurrent ocular disease, treatment of other irritating conditions should be pursued.  In addition, lipogranulomatous conjunctivitis has been more commonly reported in white and color-dilute cats in areas of higher UV radiation year-round.  Interestingly, lipogranulomatous conjunctivitis has also been reported with ocular squamous cell carcinoma, lending further credence to the idea of actinic damage being a contributing fator.⁷ Preventing sun exposure in affected cats should be considered.

Monitoring and Prognosis
In severely affected cats, the prognosis with surgical excision is good in the short term (4-21months); however, studies with a long-term follow up period are lacking.  Removal of large sections of the palpebral tissue has been shown to result in cicatricial entropion,⁴ although this was not reported in affected cats treated surgically.  In addition, if large areas of the eyelid tissue containing Meibomian glands are excised, periodic monitoring (q4-6 months) of the tear film may be warranted as removal of or damage to the Meibomian glands has been show to cause qualitative tear disorders.⁸

Differential Diagnosis
Chalazion
Blepharitis
Eyelid inflammatory mass
Eyelid neoplastic mass

References

1. Kerlin RL, Dubielzig RR. Lipogranulomatous conjunctivitis in cats. Veterinary and Comparative Ophthalmology 1997; 7: 177–179.
2. Read RA and Julia Lucas. Lipogranulomatous conjunctivitis: clinical findings from 21 eyes in 13 cats. Veterinary Ophthalmology (2001) 4, 2, 93–98.
3. Stiles J and Townsend WM. Feline Ophthalmology. In Gelatt KN (ed): Veterinary Ophthalmology 4^th pp 1106-7.
4. Long RD.  Treatment of distichiasis by conjunctival resection. Journal of Small Animal Practice 1991; 32: 146–148.
5. Bron AJ, Tiffany JM. The meibomian glands and tear film lipids. Structure, function, and control. Adv Exp Med Biol.1998;438:281-95.
6. Bron AJ, Tiffany JM, Gouveia SM, Yokoi N, Voon LW. Functional aspects of the tear film lipid layer. Exp Eye Res.2004 Mar;78(3):347-60.
7. Teifke JP, Löhr CV. Immunohistochemical detection of P53 overexpression in paraffin wax-embedded squamous cell carcinomas of cattle, horses, cats and dogs. J Comp Pathol.1996 Feb;114(2):205-10.
8. Pucker AD, Haworth KM. The presence and significance of polar meibum and tear lipids. Ocul Surf. 2015 Jan;13(1):26-42.