Eye: lens luxation

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Sections available in full article Introduction, Presenting signs, Age predisposition, Breed predisposition, Cost considerations, Pathogenesis, Etiology, Predisposing factors, Pathophysiology, Diagnosis, Presenting problems, Client history, Clinical signs, Diagnostic investigation, Histopathology findings, Differential diagnosis, Treatment, Initial symptomatic treatment, Standard treatment, Sequelae, Prognosis, Expected response to treatment, Reasons for treatment failure, Sources, Publications, Vetstream contributor(s),
Contributors Dr Dennis E Brooks DVM PhD DipACVO

Introduction

  • Lens becomes detached from suspensory ligament (zonule).
  • May come forwards through pupil (anterior luxation) or drop down into vitreous (posterior luxation).
  • Cause :
    • Primary luxation (in absence of any other ocular pathology) rare in cat.
    • Secondary luxation follows trauma, uveitis, glaucoma.
  • Signs : lens visible in anterior chamber, aphakic crescent and iridodonesis (subluxation), sub-central corneal opacity, deep anterior chamber (posterior luxation).
  • Diagnosis : gross ocular and ophthalmoscopic examination should reveal above signs.
  • Treatment : surgical lens extraction.
  • Prognosis : good provided secondary changes not too advanced.

Diagnosis

Clinical signs

  • Lens visible in anterior chamber anterior luxation  Lens: anterior luxation 01   Lens: anterior luxation 02  .
  • Iridodenesis.
  • Subcentral corneal opacity.
  • Aphakic crescent noted on distant direct ophthalmoscopy  Ophthalmoscopy: direct  .
  • Deep anterior chamber (posterior luxation).

Diagnosis

Differential diagnosis

  • Uveitis .
  • Glaucoma  Glaucoma  .
  • Ulcer  Eye: corneal ulcer  .
  • Endothelial dystrophy.
  • Microphakia/lens coloboma  Eye: congenital disease  may mimic aphakic crescent.
  • Usually associated with other ocular abnormalities.

Sequelae

Prognosis

  • Poor prognosis for saving sight in cats with secondary lens luxation.
  • Fair chance glaucoma will develop before or following lensectomy.

Expected response to treatment

  • Retention or regaining of vision within short time following surgery.
  • Monitor IOP, pain, condition of other eye.

Reasons for treatment failure

  • Advanced secondary changes, eg retinal degeneration  Retina: degeneration  , hydrophthalmos.
  • Glaucoma.

Sources

Publications

Refereed papers

  • Sansom J (2000)Diseases involving the anterior chamber of the dog and cat.In Practice22, 58-70.
  • Olivero D K, Riis R C, Dutton A G, Murphy C J, Nasisse M P & Davidson M G (1991)Feline lens displacement - a retrospective analysis of 345 cases.Prog Vet Comp Ophthalmol1, 239-244.

Other sources of information

  • Gelatt K N (1999)Veterinary Ophthalmology.3rd edn. Lippincott, Williams & Wilkins.
  • Petersen-Jones S & Crispin S (2002)BSAVA Manual of Small Animal Ophthalmology. 2nd edn. British Small Animal Veterinary Association. ISBN 0 905214 54 4

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