Glaucoma

Aug 17, 2024

Glaucoma Overview

Definition

  • Glaucoma: A set of eye diseases causing increased intraocular pressure (IOP), leading to optic nerve damage and potential blindness.

Optic Nerve Function

  • Transmits visual information from the eye to the brain.
  • Damage results in vision loss and possibly permanent blindness.

Types of Glaucoma

Open Angle Glaucoma

  • Most Common Type: Known as "silent" type due to subtle symptoms.
  • Progression: Vision loss noticed late, often leading to tunnel vision.
  • Pathophysiology: Drainage angle is open, but trabecular meshwork is less effective due to age-related changes.

Angle Closure Glaucoma

  • Also Known As: Narrow-angle or closed-angle glaucoma.
  • Rarity: Less common but requires emergency treatment when it occurs.
  • Symptoms: Severe eye pain, nausea, blurred vision, red eyes, halos around lights, high IOP.
  • Pathophysiology: Drainage angle is closed, blocking aqueous humor flow.

Pathophysiology of Glaucoma

Key Components

  • Intraocular Pressure (IOP): Balance between production and drainage of aqueous humor.
  • Aqueous Humor: Produced by the ciliary body, flows through the eye, and drains via trabecular meshwork.

Flow of Aqueous Humor

  1. Produced in the ciliary body.
  2. Flows through posterior chamber between iris and lens.
  3. Enters anterior chamber between cornea and iris.
  4. Drains via trabecular meshwork and Schlemm's canal.

Diagnostic Tools

  • Tonometer: Measures IOP.
  • Gonioscope: Examines drainage angles.
  • Ophthalmoscope: Assesses optic disc cupping.

Treatment and Management

Goals

  • Reduce IOP to protect the optic nerve.

Medications

  • Types: Eye drops (primary treatment), oral medications.
  • Mechanism: Decrease aqueous humor production or increase its drainage.

Surgical Options

  • Laser Procedures (SLT): Target drainage tissue to improve flow.
  • Trabeculectomy: Removes part of trabecular meshwork to facilitate drainage.

Post-Op Care

  • Attend follow-up appointments for IOP monitoring.
  • Avoid eye rubbing, heavy lifting, and straining activities.
  • Use prescribed eye drops and wear protective eyewear.

Key Concepts for Nurses (Mnemonic: THIEF)

  • T: Treatment Goals - Reduce IOP
  • H: Helpful to remember differences between open and closed-angle glaucoma.
  • I: Immediate treatment for angle closure glaucoma (emergency).
  • E: Eye drop administration technique and importance.
  • F: Awareness of risk factors and need for early detection.

Risk Factors (Mnemonic: SAVE)

  • S: Age 60+ with family history.
  • A: Ethnic groups (African American, Hispanic, Asian).
  • V: Vascular conditions (diabetes, hypertension).
  • E: Elevated IOP.

Summary

  • Early detection and treatment are crucial in preventing vision loss due to glaucoma. Regular eye exams are important, especially for those at risk.