Glaucoma

Continuing his excellent series of ophthalmology videos Jameel Mushtaq looks at glaucoma.

 

Lecture by

Video Duration: 12 minutes

  • Glaucoma
    Created by Helen Bartlett
    General
    Epidemiology

    A progressive optic neuropathy with characteristic changes in the optic nerve head and visual field which is strongly associated with increased intraocular pressure. It is, however, possible to have glaucoma with normal intraocular pressure.


    More common in the elderly and Afro caribbean

    Pathology

    In open angle glaucoma - canal of schelemm is not obstructed by the iris

    Closed angle glaucoma - there is an acute angle between the iris and the cornea, resulting in the iris impeding the drainage of the aqueous humour. The iris may be pushed shut by posterior chamber pathology or pulled shut by anterior pathology.

    The consequences of this is corneal oedema and optic neuropathy and optic head changes

    Top three causes

    Closed angle glaucoma

    • Pupil block
    • Plateau iris - peripheral iris is pushed forward closing the angle
    • Anterior neurovascular disease

    Open angle glaucoma

    • Primary
    • Pseudoexfoliation syndrome
    • Pigment dispersion syndrome
    Clinical Features
    Symptoms

    Closed angle glaucoma

    • Pain
    • Blurred vision
    • Haloes

    Open angle glaucoma

    • Asymptomatic
    • Rarely has featurs of closed angle glaucoma
    Signs

    Glaucoma triad

    • Raised intraocular pressure (>21mmHg)
    • Abnormal disc
      • Cup to disc ratio asymmetry
      • Large cup to disc ratio
      • Neuro Retinal Rim notch/thinning
      • Disc haemorrhages
      • Nasal displacement of vessels
    • Visual field defect
      • Nasal step
      • Paracentral scotoma
      • Arcuate scotoma
      • Central sparing (in chronic forms)

    Closed angle

    • Unilateral red eye, fixed dilate pupil, corneal oedema, shallow anterior chamber
    Investigations
    Cultures

    None

    Bloods

    None

    Imaging

    None

    Scopic/Biopsy

    None

    Functional

    Tonometry

    Photographs of the optic nerve head

    Pachymetry

    Treatment
    Conservative

    None

    Medical

    Closed angle glaucoma

    • Systemic acetazolamide
    • Topical: Beta blocker, steeroid, Pilocarpine

    Open angle glaucoma

    • Prostaglandin
    • Beta blocker
    • alpha2 agonist
    • Carbonic anhydrase
    Surgical

    Closed angle glaucoma

    • Laser or surgical peripheral iridectomy (bilateral)

    Open angle glaucoma

    • Laser trabeculectomy
    • Surgical trabeculectomy
    • Shunt procedures