Evaluation of Glaucoma

Pachymetry

  • NORMAL CENTRAL CORNEAL THICKNESS

    IS VARIABLE 500-550 MICRONS

    • Thinner cornea (cct < 500 µm) can give falsely low pressure readings
    • A thick cornea (>600 µm) can give falsely high pressure readings

Evaluating Optic Disc

Introduction

Glaucoma: Optic Nerve Head Changes

  • Increased size of the cup
  • Thinning of disc rim
  • Progressive loss of neural rim tissue
  • Disc hemorrhages
  • Loss of nerve fibers

Glaucomatous Cupping

Healthy neuroretinal rim

Healthy, symmetric optic nerves

C:D ratio = 0.3

Thinning neuroretinal rim, elongated cup

  • C:D ratio = 0.9
  • C:D ratio = 0.7

Extensive glaucomatous damage

Flame-shaped disc hemorrhage

Retinal nerve fibers

Pattern of retinal nerve fibers

Optical nerve imaging: examples of new technologies

  • Confocal scanning laser ophthalmoscopy

  • Optical coherence tomography

  • Scanning laser polarimetry

Visual Field Assessment

Normal visual field

Nasal visual field and midperipheral vision loss

Automated perimetry

Visual Fields in Glaucoma

Electroretinogram ERG

Pattern electroretinogram