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.