Pathology of the Eyelids, Conjunctiva and Orbit · Pathology of the Eyelids, Conjunctiva and Orbit Philippe Labelle, DVM, DACVP Antech Diagnostics. 12 th Biannual William MagraneBasic

Pathology of the Eyelids, Conjunctiva and OrbitPhilippe Labelle, DVM, DACVP

Antech Diagnostics12th Biannual William Magrane Basic

Science Course in Veterinary and Comparative Ophthalmology

Overview

• Non-neoplastic diseases of the eyelid skin

• Non-neoplastic diseases of the eyelid margin

• Non-neoplastic diseases of the conjunctiva

Eyelid/periocular skin

General Considerations

• Any skin disease can affect the eyelid skin (allergic/hypersensitivity disease, zinc-responsive dermatosis, pemphigus foliaceus, demodicosis, dermatophytosis, habronemiasis, etc)

• Eyelid skin reacts similarly to skin elsewhere• Eyelids may be the first or the most severely

affected site• Veterinary Ocular Pathology (Dubielzig et al.),

Veterinary Dermatopathology (Gross, Ihrke, Walder)

Demodicosis

• Demodex sp.• Juvenile and adult forms• Localized and generalized• Perivascular inflammation, periadnexal

inflammation, folliculitis and furunculosis

Demodicosis

Demodicosis

Dermatophytosis

• Microsporum sp., Trichophyton sp.• Fungal hyphae and spores colonize hairs• Folliculitis and furunculosis• Lesions may be more subtle in cats and

pustular disease may predominate

Dermatophytosis

Courtesy of Dr. Marlan Fender

Dermatophytosis

Courtesy of Dr. Marlan Fender

Dermatophytosis

Fungal hyphae invade the hair shaft. Spores surround the hair. Hamster

Habronemiasis

• Draschia megastoma, Habronemamicrostoma/majus, Habronema muscae

• Eosinophilic and granulomatous inflammation• Larvae may be few in numbers• May be diagnosed as “Equine eosinophilic

granuloma” if no larvae are present

Habronemiasis

Courtesy of Dr. Chris Reilly

Habronemiasis


Eyelid Margin

Eyelid Margin

Chalazion

• Meibomian adenitis• Lipogranulomatous inflammation• Secondary to leakage of meibomian

secretions, most often from neoplasia• Macrophages and multinucleated giant cells• Acicular cytoplasmic clefts on HE,

refractile/birefringent material

Chalazion

Chalazion

Chalazion


Chalazion


Idiopathic Marginal Blepharitis

• Dogs• Sterile granuloma syndrome• Granulomatous to pyogranulomatous

inflammation• Typically forms a mass effect, but can be poorly

circumscribed or diffuse• Can be bilateral. • Unknown etiology• No microorganisms (HE or special stains)



Conjunctiva

General Considerations

• The conjunctiva has limited ways in which it responds to injury

• Conjunctival biopsies rarely identify a specific cause for the conjunctivitis

• Only a few specific entities• Biopsies are taken late in the disease process,

often after treatment

Conjunctival Overgrowth• Rabbits• Pseudopterigium• Unknown cause• Hyperplastic conjunctival tissue• Normal tissue organization• Extends to cover the cornea• Does not invade and is not adhered to the cornea

• Note: true pterygium should have solar/actinic changes (ie solar elastosis +/- actinic keratosis) and will invade the cornea following dissolution of Bowman’s membrane

Conjunctival Overgrowth

Conjunctival Overgrowth

Courtesy of COPLOW

Ligneous Conjunctivitis• Doberman Pinscher, Yorkshire terrier, Golden Retriever,

Scottish terrier• Conjunctivitis, hard consistency, pseudomembranous

exudate• Subepithelial deposition of mostly acellular hyalinized

eosinophilic matrix• PTAH positive, Congo red negative• Fibrin deposition in the conjunctiva, oral cavity,

esophagus and +/- glomeruli and other sites• Plasminogen deficiency in humans and some dogs

– Plasmin is fibrinolytic– PTAH positive (compatible with fibrin)

• Mason et al, JSAP, 2016; Mason et al, JSAP, 2012; Torres et al, VO 2009; McLean et al JAVMA, 2008; Ramsey et al, JAAHA , 1996

Vet Ophthalmol. 2009 12(4):248-5

Ligneous Conjunctivitis

Ligneous Conjunctivitis


Solar Elastosis, Fibrosis and Vasculopathy

• Conjunctiva, not cornea• “Solar conjunctivitis”• Overlaps with solar induced neoplasia• Solar elastosis

– Altered fibers within the superficial substantia propria– New production +/- degradation of collagen and

elastin• Can form plaques in horses• Often seen with conjunctival squamous cell

carcinoma, hemangioma or hemangiosarcoma


• Solar “fibrosis”– Altered collagen, pale, hypocellular (sclerotic)– Forms a band underlying the epithelium– Not true fibrosis

• Solar vasculopathy– Rare, more common in skin– Thickened hyalin vessel walls– May be endothelial swelling




Lymphoplasmacytic conjunctivitis

• Most common inflammatory response• Does not suggest a specific etiology• Infectious and non-infectious causes• Perivascular to diffuse• Non-ulcerative• Can be severe enough to warrant concern for

neoplasia

Lymphoplasmacytic Conjunctivitis

Lymphoplasmacytic Conjunctivitis

Lipogranulomatous Conjunctivitis

• Cats• Nodular inflammation• Macrophages with lipid lakes, multinucleated

giant cells may be present• Can be associated with neoplasia






Triamcinolone Granuloma

• Macrophages and multinucleated giant cells• Rounded rectangular vacuoles• Rarely biopsied





Nodular Granulomatous Episcleritis

• Episclerokeratitis, episcleritis, NGE• Smooth nodules to diffuse thickening• Most often in the limbal conjunctiva• Also occurs in other conjunctival sites, orbit• Unknown cause• Epithelioid and spindle macrophages admixed

with lymphocytes and plasma cells• Some spindle cells are myofibroblasts

Nodular Granulomatous Episcleritis• The relative proportion of inflammatory cell types is highly

variable• The macrophages do not form distinct granulomas• Some cases may include multinucleated giant cells or

eosinophils• Cases with a predominance of spindle cells have been

called nodular fasciitis• Special stains for infectious organisms are always negative

(and must be) • The proportion of T-cells and B-cells has been said to be

predictive of response to treatment (B-cell predominant were more refractory).

• Breaux et al. VO, 2007 (T vs B); Barnes et al, VO 2010 (orbit)







Eosinophilic conjunctivitis

• Eosinophils are a component of the inflammation

• Eosinophils may not be the predominant cell type (lymphoplasmacytic)

• Perivascular to diffuse• Allergic/ hypersensitivity disease• Cannot exclude (or confirm) Herpesvirus

infection in cats

Eosinophilic Conjunctivitis



Herpes Keratoconjunctivitis

• Cats, primarily kittens• Unlikely to be biopsied• Window for inclusions is narrow• May include eosinophils

• Role of Herpervirus in adult cats is controversial• Clinical lesions suspected to be, diagnosed as, and treated for

herpesviral infection lack any histologic evidence to specifically support a viral cause

• The presence of eosinophils is not a helpful feature as many hypersensitivity disease has eosinophils as a hallmark of the lesion

Feline Herpes Keratoconjunctivitis

Courtesy of Dr. Chris ReillyTongue from a shelter cat

Inclusions

Syncytial cell

Feline Herpes Keratoconjunctivitis

Skin from the face of a cat

Inclusions

Conjunctival Histoplasmosis

• Histoplasma capsulatum• Cats• Subconjunctival nodules• Pyogranulomatous inflammation• Special stains (GMS) often needed to best

visualize the organisms





ORBIT

Conjunctival/Orbital Onchocerciasis

• Onchocerca lupi• Dogs and cats• 205 canine, 2 feline and 18 human infections in

Europe, Tunisia, Turkey, Iran and the USA (2015).• Subconjunctival or periscleral/orbital nodules• Granulomatous inflammation• Eosinophils may be present in large numbers,

there may be fibrosis• Parasites may not elicit severe inflammation


• Must be differentiated from other nematodes with microfilariae

• Annular/circumferential ridges distinguish from Dirofilaria immitis

• Association with onchocerciasis and glaucoma in humans, unclear in dogs and cats

• Endosymbiotic bacteria Wolbachia• Larval development in blackflies


• Canine• Tudor et et al Parasitol Res 2016• Otranto D et al. Emerg Infect Dis

2015• Otranto D et al Parasit Vectors

2015• Otranto D et al. Emerg Infect Dis

2013• Labelle AL et al. Vet Parasitol, 2013• Fascia P et al VO 2010• Zarfoss et al. Vet Pathol 2007• Komnenou A et al. VO 2002• Egyed Z et al. Vet Parasitol, 2001

• Intraocular k9• Komnenou AT et al. VO 2016

• Feline• Labelle AL et al. VO 2011

• Review• Gracio AJ et al. Parasitol Res 2015


Modified from : Am J Trop Med Hyg. 2013 Mar;88(3):601-5


Modified from : Parasit Vectors 2015

Feline cases


Vet Ophthalmol.

2002 5(4):119-26

Vet Ophthalmol. 2016 May;19(3):245-249Emerg Infect Dis. 2015 21(5):868-871


Courtesy of COPLOW




Courtesy of COPLOW


Feline


Feline

Annular ridges

Striae

Orbital extraocular polymyositis• Affects all the extraocular muscles except the retractor

bulbi muscle• Rare disease, typically young dogs• Bilateral and variably symmetric exophthalmos,

retraction of the upper eyelid, and mild chemosis• Chronic: enophthalmos and strabismus• CD3+ predominant lymphocytic myositis with

myonecrosis• Attempts at regeneration with muscle atrophy and

fibrosis• Immune-mediated attack directed specifically against

the extraocular muscles is suspected• Unlikely to be biopsied

Orbital extraocular polymyositis

Courtesy of COPLOW

Documents

Pathology of the Eyelids, Conjunctiva and Orbit · Pathology of the Eyelids, Conjunctiva and Orbit Philippe Labelle, DVM, DACVP Antech Diagnostics. 12 th Biannual William MagraneBasic