ISSN 2398-2969      

Glaucoma: due to lens luxation

icanis

Introduction

  • Cause: anterior dislocation of lens from patellar fossa impairs flow and drainage of aqueous humor within and from the eye. Results in pathologically elevated intraocular pressure.
  • Signs: abnormal lens position, ocular pain, corneal edema, episcleral congestions, vision loss.
  • Diagnosis: ophthalmic examination and tonometry.
  • Treatment: removal of lens from anterior chamber, antiglaucoma medications.
  • Prognosis: guarded.

Pathogenesis

Etiology

Predisposing factors

General
  • Breed.
  • Trauma.
  • Intraocular inflammation.

Specific

  • Homozygosity for known mutation.

Pathophysiology

  • In primary lens luxation there is progressive weakening and breakdown of the zonular fibers which hold the lens in place.
  • Zonular breakdown may also result from chronic inflammation Eye: anterior lens luxation - German Shepherd dog , chronic cataract Eye: anterior lens luxation - Miniature Poodle , trauma Eye: anterior lens luxation - Labrador Retriever or neoplastic expansion within the globe.
  • Anterior displacement of the lens results in 'pupillary block'. The lens and vitreous which follows it impedes the circulation of aqueous humor from the posterior to anterior chamber.
  • Build-up of aqueous behind the iris displaces it anteriorly leading to collapse of the iridocorneal angle and eventual development of anterior synechiae

Timecourse

  • Weakening and breakdown of lens zonules occurs over years.
  • Early lens luxation may be detected by presence of aphakic crescent, lens or iris trembling (phacodonesis or iridodonesis) or presence of vitreous within anterior chamber.

Epidemiology

  • Breed predisposition.

Diagnosis

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Gould D et al (2011) ADAMTS17 mutation associated with primary lens luxation is widespread among breeds. Vet Ophthalmol 14 (6), 378-384 PubMed.
  • Farias F H et al (2010) An ADAMTS17 splice donor site mutation in dogs with primary lens luxation. Invest Ophthalmol Vis Sci 51 (9), 4716-4721 PubMed.

Other sources of information

Related Images

OWNER FACTSHEETS

Glaucoma

Want more related items, why not
contact us

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code