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Glaucoma
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Glaucoma
An optic neuropathy characterized by:
–Elevated intraocular pressure–Optic disk cupping –Visual field loss
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Normal visual field
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Shrinking vision
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Advanced field loss
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Tunnel vision
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Raised intraocular pressure
Impaired outflow of aqueous resulting from:
abnormalities within the drainage system of the anterior chamber angle (i.e. open-angle glaucoma) Impaired access of aqueous to the drainage system
(i.e. closed angle glaucoma)
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Physiology of the Aqueous Humor
Clear liquid that fills anterior and posterior chambers of the eyeUltrafiltrate of plasma produced in the stroma of the ciliary processVolume: 250 uL, 2.5 uL/minOsmotic pressure: slightly higher than plasmaComposition : like plasma but higher concentration of ascorbate, pyruvate and lactate & lower concentration of protein, urea, and glucose
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Aqueous formation and flow• Ciliary body
• Posterior chamber
• Pupil
• Anterior chamber
• Trabecular meshwork
• Schlemm’s canal
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Pathophysiology
• Ganglion cell atrophy - Major mechanism of visual loss in glaucoma - Leads to thinning of the inner nuclear and nerve layers of the retina and axonal loss in
the optic nerve
• Optic disk becomes atrophic, with enlargement of the optic cup• Iris and ciliary body also become atrophic and the ciliary processes show hyaline degeneration
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Risk Factors for developing Glaucoma
• Age (>40 years old)• Females > Males• Hyperope• (+) Family history of glaucoma• GIC1a (myocillin gene) in open angle gl• Systemic disease: HPN, DM• Trauma• Underlying ocular conditions: ex. CRAO,
phacolytic, uveitis• Drugs, ex. steroids
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Clinical Assessment
1. Fundoscopy / Optic Disc Assessment
2. Tonometry3. Gonioscopy4. Visual Field Evaluation
Optic Disk Assessment
• Physiologic Cup– Normal central
depression– Size depends on the
bulk of the fibers that form the optic nerve relative to the size of the scleral opening
– Hyperopic eyes – scleral opening is small -> small optic cup
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Optic Disk Assessment
• Glaucomatous optic atrophy– Loss of disc substance; enlargement of optic
disc cup– Disc pallor in the area of cupping– Concentric enlargement of the optic cup or
preferential superior and inferior cupping with focal notching of the rim of the optic disc
– Retinal vessels on disc are displaced nasally– “bean pot cup” – Cup-disc ratio: ratio of cup size to disc
diameter (>0.5 or significant asymmetry between the two eyes)
– Atrophy of nerve fiber layer (Hoyt’s sign)
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Optic Disc Cupping:
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Tonometry
• Measurement of intraocular pressure (IOP) • Normal pressure = 10-24 mmHg
• Types of Tonometry– Goldmann Applanation Tonometer – measures
the force required to flatten a fixed area of the cornea, gold standard
– Perkins Tono Pen – portable– Pneumomatotonometer – irregular surface
cornea– Schiotz – portable, measure corneal
indentation produced by known weight
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Applanation Tonometry
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Gonioscopy
• Clinical technique used to examine structures in the anterior chamber
• 4 structures:– Schwalbe’s line– Trabecular
meshwork– Schlemm’s canal– Ciliary body
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Visual Field Exam:
Confrontation Test - Simplest - Used for screening purposes only
Goldmann Perimeter - Kinetic form of visual field testing
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
Intro. Aqueous Production & Flow. Pathophysiology. Assessment. Types. Medical Treatment. Surgical Treatment
THANK YOU!
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