Canis ISSN: 2398-2942
Contributor(s): Paul Gerding, David L Williams
- See also cataract Cataract for details of diagnosis and management.
- Cause: multiple etiologies all resulting in similar clinical picture.
- Signs: of underlying disease and lens opacity.
- Diagnosis: recognition of cataract and identification of underlying cause.
- Treatment: manage cause, cataract surgery may be indicated.
- Prognosis: depends on cause.
Progressive retinal atrophy
- If injury penetrates lens capsule → cataract .
- Cataract may be focal (at point of capsular penetration) or may over days/weeks radiate (from point of capsular penetration) to involve whole lens.
- Also occur following radiation damage, eg radiotherapy for nasal neoplasia.
- May be associated with posterior synechiae.
- Uveitis Uveitis may occur secondary to lens damage (in this case may be aqueous flare in acute phase and possible posterior synechiae as a later change).
- All luxated lens Lens: luxation eventually → cataracts.
- May → glaucoma → cataract.
- Cataract may be associated with retinal detachment or other concurrent ocular anomalies that result in uveitis.
- May be transient .
- Increased levels of free radicals in lens, eg substituted hydrocarbons → transient hyperglycemia → cataract.
- Uncommon cause of cataract occasionally due to intra-ocular tumor abutting lens.
- Neoplasia may also cause glaucoma/lens subluxation/uveitis → cataract.
- Hyperglycemia, ie diabetes mellitus results in altered osmotic gradient and water is drawn into the lens .
- Hypocalcemia is very rare cause.
- Occurs in puppies fed milk replacements.
- Cause may be amino acid imbalance.
- Often do not progress to total vision loss.
- May be acute (diabetes mellitus) Diabetes mellitus (over days) or develop over months.
- Recent references from PubMed and VetMedResource.
- 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.
- Davidson M, Nasisse M, Jamieson V et al (1991) Traumatic anterior lens disruption. JAAHA 27 (4), 410-414 VetMedResource.