Contributors: Dennis E Brooks, Peter Renwick, David L Williams
Species: Feline | Classification: Diseases
- Cause: inherited (juvenile or later onset), or secondary to systemic disease or ocular abnormality (eg uveitis).
- Signs: cloudy eye, blindness.
- Diagnosis: signs, ophthalmology.
- Treatment: surgical removal of lens.
- Prognosis: good following surgical removal of lens (with or without intraocular lens implantation).
Print off the owner factsheet Cataract Cataract to give to your client.
- If removal of the lens is indicated.
- Uncommon - if occurs is usually congenital.
- Posterior polar suture line opacity (Y suture area).
- Nuclear cataract.
- Very rare (much more so than dog).
- Diabetes mellitus Diabetes mellitus (but cataract not seen at the same incidence as in diabetic dogs).
- Hyperparathyroidism Primary hyperparathyroidism.
- Secondary nutritional cataract .
- May be associated with Chediak-Higashi syndrome Chediak-Higashi syndrome.
- Diabetes mellitus → increased lens glucose → accumulation of insoluble sugars with osmotic potential → water influx → cataract but not seen in cat as frequently as dog.
- Uveitis → inflammation → cataract.
- Trauma → free radical formation (possibly) → cataract.
- Generalized progressive retinal atrophy → complex mechanisms (lipid peroxidation biproducts giving cataract (but not in cat as in dog)) → cataract.
- Cataract development varies: cortical cataracts may progress, capsular lesions are usually stable.
- Very variable: diabetic cataracts often progress rapidly; post-trauma cataracts develop at very varying rates.
- Cloudy eye.
- Grayness in the eye.
- Retina obscured on direct ophthalmoscopy Ophthalmoscopy: direct.
Set ophthalmoscope on zero.
- Nuclear sclerosis - older animals, does not compromise vision, retina visible but concentric rings in cortex due to refractive index changes.
Initial Symptomatic Treatment
- Phacoemulsification Phacoemulsification: - early operation when eye still has vision avoids secondary problems, eg lens -induced uveitis → higher success rate.
- Should only be performed by veterinary ophthalmologist.
Surgery not appropriate for inflammatory disease. May be successful for traumatic disease if performed early, eg within days of injury.
- Good following surgery if underlying disease controlled.
Expected Response to Treatment
Reasons for Treatment Failure
- Standard reasons Standard reasons for failure in a treatment.
- Recent references from PubMed and VetMedResource.
- Remillard R L, Pickett J P, Thatcher C D et al (1993) Comparison of kittens fed queen's milk with those fed milk replacers. Am J Vet Res 54 (6), 901-907 PubMed.
- Curtis R (1990) Lens luxation in the dog and cat. Vet Clin North Am Small Anim Pract 20 (3), 755-773 PubMed.
- Quam D D, Morris J G, Rogers Q R et al (1987) Histidine requirement of kittens for growth, haematopoiesis and prevention of cataracts. Br J Nutr 58 (3), 521-532 PubMed.
- Whitley R D, Moore C P (1984) Advances in feline ophthalmology. Vet Clin North Am Small Anim Pract 14 (6), 1271-1288 PubMed.
Other sources of information
- Petersen-Jones S & Crispin S (2002) BSAVA Manual of Small Animal Ophthalmology .2nd edn. British Small Animal Veterinary Association. ISBN 0 905214 54 4