Selected Diseases of the Cornea Dick Dubielzig July 20 th, 2009

Transcription

1 Selected Diseases of the Cornea Dick Dubielzig July 20 th, 2009

2 Canine Collagenolytic Keratitis

3 Canine Collagenolytic Keratitis 270 cases (1.5%) Usually associated with suppurative keratitis Collagenolytic enzymes from neutrophils, bacteria or native cells Rapid lysis of the entire stroma Breeds Shih-tzu: 63 cases Boston Terrier: 29 cases Pug: 18 cases Lab & Golden Combined: 14 cases

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5 Canine Collagenolytic Keratitis

6 Canine Collagenolytic Keratitis Peracute Lesion Gram negative bacteria

7 Corneal Hydrops (Feline) Associated with a break in Descemet s membrane and extreme but transient edema

8 Equine Mycotic Keratitis 82 cases (10% of Equine Cases) Superficial vs. Deep presentation Suppurative inflammation Lesions poorly vascularized In deep keratitis, look first in Descemet s membrane for fungi

9 Equine Mycotic Keratitis

10 Equine Mycotic Keratitis

11 Equine Mycotic Keratitis

12 Superficial Stromal Mycotic Keratitis

13 Mycotic Keratitis other than Equine Canine Mycotic Keratitis

14 Feline Corneal Sequestrum 119 Cases = 1.9% of Feline Cases Associated with superficial ulcer The superficial stroma becomes acellular Desiccation might play a role in sequestrum formation Absorbs pigment of unknown chemical make-up 25% of cases are in Persian cats

15 Feline Corneal Sequestrum

16 Feline Corneal Sequestrum

17 Feline Corneal Sequestrum

18 Feline Corneal Sequestrum

19 Feline Corneal Sequestrum

20 Feline Corneal Sequestrum

21 Feline Corneal Sequestrum Conjunctival Opportunistic Bacteria

22 Canine Indolent Ulcer or Recurrent Erosion Syndrome (72 cases) 19% of case series in Boxer dogs Poor epithelial attachment with superficial stromal acellular zone Basement membrane is lost but laminin is overexpressed on the surface Very commonly seen in enucleated globes as a secondary phenomenon Possibly bullous edema

23 Indolent Ulcer/Recurrent Erosion

24 Canine Indolent Ulcer

25 Laminin Immunohistochemistry

26 Indolent Ulcer Sequestrum

27 Canine Indolent Ulcer

28 The Doubling Phenomenon of Descemet s Membrane from Blunt Trauma or Surgical Trauma Kafarnik C, Murphy CJ, Dubielzig RR (2009) Canine Duplication of Descemet's Membrane. Vet Pathol. 46:464-73

29 200x, Alcian blue PAS eye hit with a bottle rocket 2 years ago 25x, H&E

30 Electron microscopic findings

31 Descemetization Cytokeratin 600x, Cytokeratin

32 Mechanical Damage to Endothelium

33 Corneal Squamous Cell Carcinoma in Dogs with a history of Superficial Chronic Keratitis that were treated with Cyclosporin or Tacrolimus 117 cases of canine SCC in the COPLOW collection out of 6984 ocular tumors in dogs 29 cases of corneal SCC in the COPLOW Collection 9 Pugs and 4 Bulldogs Only 8 from non-brachyocephalic breeds All have pre-existing chronic keratitis All have been treated with cyclosporin and/or tacrolimus Dubielzig RR, Schobert CS, Dreyfus J. (2008) Corneal squamous cell carcinoma in dogs with a history of chronic keratitis. ACVO, Boston

34 Corneal Squamous Cell Carcinomas diagnosed at COPLOW 1.00% 0.90% 0.80% 0.70% 0.60% 0.50% 0.40% 0.30% 0.20% 0.10% 0.00% *

35 Clinical Appearance of Corneal SCC

36 Risk Factors 21 of 21 had superficial chronic corneal inflammatory disease most often diagnosed as keratoconjunctivitis sicca Treatment information Cyclosporin alone 10 cases Tacrolimus alone 4 cases Combination of both drugs 6 cases Other drugs or unknown 5 cases

37 Morphology Superficial central corneal malignant transformation

38 Morphology Superficial keratectomy is adequate treatment in most cases

39 Morphology

40 Follow-up (n = 23) Follow-up interval 5 days to 31 months Only one dog had recurrent disease because of dirty deep margins

41 Conclusions Canine Corneal Squamous Cell Carcinoma The number of submissions is increasing Previous superficial inflammation is a strong risk factor The Pug and Bulldog are over-represented Relationship to cyclosporin &/or tacrolimus The disease remains superficial and is treatable with keratectomy

42 Corneal Protozoal Keratoconjunctivitis in Dogs Treated with Cyclosporin or Tacrolimus

43 Corneal Protozoal Keratoconjunctivitis in Dogs Treated with Cyclosporin or Tacrolimus