Ocular Diseases in Old Dogs and Cats
World Small Animal Veterinary Association Congress Proceedings, 2019
F. Ollivier
Clinique vétérinaire d’ophtalmologie Ophtalmo Veterinaire Inc., Ophthalmology, Montreal, QC, Canada

1 Physiologic Changes Due to Aging

1-2 Eyelids

Senile ectropion

  • Signs: Eyelid margins very lax, exposure of the globes and the conjunctiva
  • Treatment: None or artificial tears or surgery (V to Y technique) if too pronounced and exposure keratitis

1-2 Lacrymal film

Quantitative or qualitative deficit

  • Decrease in tear production with age (-0.4 mm/year)
  • Signs: Discharge, ± conjunctivitis/keratitis
  • Diagnosis: Rose Bengal, Schirmer tear test, TBUT)
  • Treatment: Artificial tears, cyclosporine, …according to signs

1-3 Iris

Iris atrophy

  • Signs: Rough edge of the pupil, thin iris (even with holes) ± photophobia
  • Differential: Iris hypoplasia, coloboma, glaucoma, retina or neurologic conditions
  • Treatment: None or Doggles if photophobia

1-4 Lens

Nuclear sclerosis

  • Signs: Normal change of the lens, in dogs and cats older than 6 years, no/slight effect on vision (presbyopia in humans)
  • Differential: Cataract (disorganisation of the lens fibres=opacity) with ± effect on the vision to be differentiated by indirect ophthalmoscopy and presence of fundus reflex
  • Treatment: None

1-5 Vitreous

Vitreal degeneration

  • Asteroid hyalosis, liquefaction
  • Signs: Punctiform multifocal opacities in the vitreous, liquified vitreous, “floating bands”
  • Differential: Inflammation (vitritis)
  • Treatment: None or prophylactic retinopexy in breeds predisposed to retinal detachment

2 Physiologic Changes Due to Aging

2-1 Exophthalmia

  • Causes
    • Cellulitis/abscess
    • Myositis (eosinophilic m./extra-ocular m.)
    • Neoplasm (primary/secondary)
    • Traumatism of the orbit (hematoma/fracture)
  • Clinical signs:
    • Exophthalmia, strabism, discharge, NM protrusion, conjunctival chemosis ± hyperhemia, ± corneal lesion
  • Diagnosis approach:
    • Physical and eye exam (fluorescein test), retropulsion
    • Exam of the oral cavity
    • Imaging: radiography, ultrasound
    • Therapeutic approach
  • Temporary treatment until the cause is known:
    • Pain control
    • Globe protection (lubrification, tarsorraphy) ± treatment of the corneal lesions
  • If obvious cause → start an eatiologic treatment:
    • Abscess: Systemic AB ± drainage, syst. NSAI
    • Neoplasia

2-2 Eyelids

Eyelid tumors (meibomian gland)

  • Signs: Mass(es) at the eyelid margin ±keratitis/conjunctivitis, benign
  • Treatment: None or artificial tears or excision surgery if mass too big/ulcerated or if keratitis/conjunctivitis
  • Surgical excision:

Principle

  • a minima” incision
  • Start suturing at the edge of the eyelid’s margin
  • Figure 8 stitch
  • One suture layer, 3-0 or 4-0, nylon or silk (simple or cross pattern)

2-3 Cornea

2-3-1 Calcic Degeneration

  • Signs: White deposits on/in the cornea, rough aspect of the cornea ± oedema, ulcer, inflammation
  • Treatment:
    • Artificial tears ± AB
    • Corneal contact lens
    • (Lamellar superficial keratectomy)

2-3-2 Endothelial Decompensation

  • Endothelium ± epithelium = water pumps
  • Endothelial cell density: 2500 c/mm2 in dogs
  • Decrease of density with age: 1900–2100 in 9 y.o. dogs and decompensation at 500–800
  • Predisposed breeds: Dachshund, Boston terrier, chihuahua
  • Signs: Corneal oedema ± severe
  • Treatment:
    • Non if focal and light si monitoring)
    • Hyperosmotic ointment (Muro 128, NaCl 5%, BID to TID)
    • Thermokeratoplasty if severe

2-3-3 Indolent Ulcer (Boxer Ulcer)

  • Predisposed breeds: Boxer, Pekingese, Corgi, Lhasa Apso and others...
  • Middle and old age, female
  • Hemidesmosomes deficit, basal membrane defect, presence of an hyaline membrane.
  • Signs: Epithelial loss of substance with « lips » avec des “lèvres”, local corneal oedema, conjunctivitis, blepharospasm, discharge, photophobia, usually unilateral
  • Improvement, then relapse
  • Diagnosis: From history but mainly by exclusion of other causes of non-healing
  • Confirmation: Fluorescein stain (that will pass underneath the epithelial lips)
  • Initial treatment:
    • Antibiotics: Drops (tobramycin 0.3%) TID–QID
    • Cycloplegic: Atropine 1% (not too frequent SID)
    • Hyperosmotic ointment (Muro 128, NaCl 5%, BID)
    • Serum (frequent)
    • E-collar 24h/24 7d/7
  • If no progress, following treatment:
    • Contact corneal lens, collagen auto-dissolving lens (72hrs)
    • Debridement with Q-tip
    • Same medication
    • Nictitating flap (tarsorrhaphy): No
    • Partial eyelid suture (blepharorrhaphy) possible
  •  If no progress, then:
    • Topical anesthesia
    • ± Sedation
    • Debridement with Q-tip: scrapping of the non-attached epithelium
  • If no progress, then:
    • Superficial linear scarification (superficial linear keratotomy)

2-3-4 “Indolent” Ulcer in Cats

  • Do not exist in cats
  • Often associated with feline herpes virus type 1
  • Avoid debridments
  • Keratotomy not indicated

Important risk of corneal sequestrum

  • Treat as a superficial ulcer

2-4 Glaucoma

  • Main disease causing blindness in humans in the world
  • Frequent condition in dogs (as in humans); prevalence of 1.7 to 2%
  • Disease often diagnosed too late in our pets
  • Age = important risk factor
  • At any age, but onset around 6–7 years old
  • Clinical suspicion: Decrease in vision
  • Pain
  • Mydriasis
  • Scleral redness
  • Increase of globe’s size
  • Opacity of the cornea

Differential diagnosis:

  • Red eye syndrome: conjunctivitis, keratitis, uveitis, episcleritis
  • Exophthalmia
  • Oedema of cornea: keratitis with or without ulcer uveitis, endothelial dystrophy
  • Mydriasis: retinal atrophy, iris sphincter atrophy, optic nerve disease
  • Tonometry: Confirmation of the clinical diagnosis
  • Follow-up of treatment installed
  • “Screening” for predisposed breeds
  • This test should be part of a geriatric exam

Treatment objectives

As of today, there is no curative treatment for glaucoma.

Objectives of the therapy:

  • Maintain vision and control the pain by reducing the IOP:
    • Increase of the drainage of the AH
    • Decrease the production of the AH
    • Prevent and delay the onset of glaucoma in the contro-lateral eye

2-5 Lens

Cataract

  • Disorganisation of the lens fibers = opacity
  • With ± effect on vision
  • At any age (congenital, juvenile...) by increase in frequency with age
    • C50 at 9.4±3.3 years old
    • C100 at 13.5 years old
  • Differential: Nuclear sclerosis, vitreous degeneration differentiated by indirect ophthalmoscopy and positive fundus reflex

Refer as soon as possible in order to:

  • Follow the progression of the cataract
  • Avoid complications from cataract
  • Choose the right time to perform

2-6 Retina

Hereditary diseases of the retina

  • Various types: Progressive atrophy, rod/cones dysplasia
  • Many breeds affected
  • Often early signs but not diagnosed
  • Diagnosis made in terminal phase, when animal is older
  • Fundic exam ± electroretinogram for earlier diagnosis
  • Treatment: Anti-oxidants: Ocu-glo

Degenerative diseases of the retina

  • Sudden acquired retinal degeneration syndrome (SARDs)
  • Female, 6 y.o. and older, Cushing
  • Fundic exam: Normal
  • Electroretinogram: Flat
  • Treatment: None

Hypertensive retinopathy of cats

  • Aged cats
  • Ocular signs:
    • Sudden blindness
    • Dilated pupils barely or no reactive to light
    • Tortuous retinal vessels
    • Serous retinal detachment
    • Vitreal and retinal hemorrhages
  • Systemic signs:
    • Systolic arterial blood pressure >160 mm Hg
    • Cardiomegaly
    • Chronic renal failure
    • Hyperthyroidism
    • Hyperglycemia
  • Treatment
    • Treat underlying cause
    • Calcium channel blocker agents: Amlodipine 0.625 mg/animal/day

Conclusions

  • Ocular diseases are frequent in aged dogs and cats.
  • Importance of a complete eye exam to detect as soon as possible an ocular disease in order to put a prophylactic or a therapeutic treatment.
  • Importance to take into consideration age, breed and health status of the animal in order to propose the adequate treatment for the diagnosed eye disease.

 

Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

F. Ollivier
Ophthalmology
Clinique vétérinaire d’ophtalmologie
Ophtalmo Vétérinaire Inc.
Montreal, QC, Canada


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