Cataract

From Cat
Congenital cataract in a 6-month-old Persian female
Dislocated cataract and microphakia in a 17-week-old DSH cat
Lens coloboma with mainly nuclear cataract in a 7-month-old DSH cat

Cataracts are a rare lens disease in cats, compared to dogs where there is a high genetic predisposition to the disease.. In addition, cataract secondary to generalised form of progressive retinal atrophy does not occur in the cat[1].

Cases of advanced hereditary retinal degeneration in the Abyssinian cat have been examined over several years and the lens has always remained free of opacity. To date there are no proven reports of primary, hereditary, noncongenital cataract in the cat, apart from chylomicronaemia. However, Rubin[2] reported three cases in related Himalayan cats in which the condition was bilateral and present as early as 12 weeks and with variable expression from posterior polar through posterior subcapsular to total; progression was recorded in one case. The relationship of the cats indicated simple autosomal recessive inheritance.

The Chediak-Higashi syndrome has been recorded in blue smoke Persian cats as an autosomal recessive condition and includes catract in addition to thin pale irises and fundic hypopigmentation [3].

Feline cataract is, therefore, almost always secondary in form;

  • age-related (senile cataracts)
  • post-inflammatory uveitis
  • traumatic (particularly penetrating corneal injuries)
  • metabolic (e.g. diabetes mellitus; more rare in cats than dogs or humans)
  • secondary to glaucoma
  • malnutrition (e.g. arginine deficiency) in kittens[4]

Treatment is identical to canine cataracts, usually requiring surgical removal of the affected len(s).

References

  1. Barnett, KC & Crispin, SM (2002) Feline Ophthalmology: An atlas & text. Saunders, USA
  2. Rubin, LF (1986) Hereditary cataract in Himalayan cats. Feline Practice. 16(1):14-15
  3. Collier, LD, Vryan, GM, & Prieur DJ (1979) Ocular manifestations of the Chediak-Higashi Syndrome in four species of animals. Journal of the American Veterinary Medical Association 175:587-595
  4. Frankel DJ (2001) Malnutrition-induced cataracts in an orphaned kitten. Can Vet J 42(8):653-654