Contributors: Paul Gerding
Species: Canine | Classification: Diseases
Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading
Introduction
- Important cause of visual disability.
- Cause: inherited (juvenile or later onset), or secondary to systemic disease, eg diabetes, or ocular abnormality, eg uveitis or progressive retinal atrophy.
- Signs: ocular opacity.
- Treatment: surgery.
- Prognosis: good following surgical removal of lens (with or without intra-ocular lens implantation).
Print off the owner factsheet on Cataract to give to your client.
Presenting Signs
- Cloudy eye.
- Deteriorating vision.
Breed Predisposition
- Afghan Hound Afghan Hound.
- American Cocker Spaniel American Cocker Spaniel.
- Boston Terrier Boston Terrier.
- Cavalier King Charles Spaniel Cavalier King Charles Spaniel.
- German Shepherd dog German Shepherd Dog.
- Golden Retriever Retriever: Golden.
- Labrador Retriever Retriever: Labrador.
- Norwegian Buhund Norwegian Buhund.
- Staffordshire Bull Terrier Staffordshire Bull Terrier.
- Standard Poodle Poodle: Standard.
- Welsh Springer Spaniel Spaniel: Welsh Springer.
Pathogenesis
Etiology
Inherited
- Posterior subcapsular (triangular), eg Labrador, Golden Retriever.
- Nuclear cataract, eg Miniature Schnauzer
. - Equatorial/posterior cortex, eg Afghan Hound.
- Posterior/anterior cortex, eg American Cocker Spaniel.
- Posterior sutures/nuclear, eg Boston Terrier.
- Nuclear cortex, eg Chesapeake Bay Retriever.
- Equatorial cortex, eg Standard Poodle.
- Nuclear/posterior cortex, eg Welsh Springer Spaniel.
- Posterior sutures, eg West Highland White Terrier.
- Diabetes mellitus Diabetes mellitus.
- Galactosemia.
- Hypocalcemia Primary maternal dystocia.
- Uveitis Uveitis.
- Generalized progressive retinal atrophy Retina: generalized progressive retinal atrophy.
- Toxic.
- Injury.
- Radiation.
Pathophysiology
- Diabetes mellitus → increased lens glucose → accumulation of insoluble sugars with osmotic potential →water influx→ cataract.
- Uveitis →inflammation→ cataract.
- Trauma → free radical formation (possibly) → cataract.
- Generalized progressive retinal atrophy → complex mechanisms (not fully understood) → cataract.
- Lens luxation.
- Cataract development varies: cortical cataracts generally progress more quickly than capsular lesions.
Timecourse
- Very variable: diabetic cataracts progress rapidly; post-trauma cataracts develop at very varying rates.
Diagnosis
Presenting Problems
- Cloudy eye.
Client History
- Grayness in the eye. Care to differentiate cataract from nuclear sclerosis also giving "grayness".
- Reduced vision.
- Signs related to underlying etiology.
Diagnostic Investigation
Other
- Ophthalmoscopy: retina obscured on ophthalmoscopy
.
Differential Diagnosis
- Corneal opacity:
- Edema.
- Lipid.
- Scar.
- Nuclear sclerosis - older animals, does not compromise vision, retina visible but concentric rings of cortex.
Treatment
Initial Symptomatic Treatment
- Phacoemulsification: - early operation when eye still has vision avoids secondary problems, eg lens induced uveitis → higher success rate.
- Discission/aspiration: - removal of lens cortex material by irrigation and aspiration.
- Extracapsular lens extraction.
Outcomes
Further Reading
Publications
Refereed papers
- Recent references from PubMed and VetMedResource.
- Adkins E A & Hendrix D V H (2005) Outcomes of dogs presented for cataract evaluation: a retrospective study. JAAHA 41, 235-240 PubMed.
- Denis H M, Brooks D E, Alleman A R, Andrew S E & Plummer C (2003) Detection of anti-lens crystallin antibody in dogs with and without cataracts. Vet Ophthalmol 6 (4), 321-327 PubMed.
- Williams D L, Boydell I P & Long R D (1996) Current concepts in the management of canine cataract: a survey of techniques used by surgeons in Britain, Europe and the USA and a review of recent literature. Vet Rec 138 (15), 347-353 PubMed.
Other sources of information
- Nasisse M P & Davidson M B (1999)Surgery of the lens.In:Veterinary Ophthalmology.3rd edn. Lippincott, Williams & Wilkins. pp 827-856.