Primary%20open-angle%20glaucoma Diagnosis

• Review of history of family, ocular and systemic diseases (eg DM, hypertension, asthma, vascular disorders) are obtained during initial evaluation
• Current medications (ocular and systemic) being taken and history of adverse reactions to these drugs
• History of eye surgery
  
  • Cataract surgery, photorefractive keratectomy may result in a falsely low intraocular pressure (IOP)

• Ocular trauma (eg contusion)

Visual Acuity

• Measure and determine best corrected near and distance visual acuity

Examination of Pupils

• Examine for reactivity and presence of afferent pupillary defect

Examination of the Fundus

• Look for cupping, macular degeneration, disc edema, retinovascular occlusion, optic nerve pallor and pits
  
  • Cupping is the hallowing out of the optic nerve or “disc” and a diameter of >50% of the vertical disc signifies glaucoma

Biomicroscopy

• Assess the anterior chamber depth and angle, look for corneal defects, iris pathology or inflammation using slit-lamp biomicroscope to help determine if there is presence of a secondary cause of intraocular pressure (IOP) elevation

Tonometry

• Bilateral measurement of IOP using Goldmann applanation tonometry done at varying times of the day or on different days to detect fluctuations
• It is recommended to measure untreated IOP more than once prior to starting treatment

Gonioscopy

• Important to exclude secondary causes of IOP (eg peripheral anterior synechiae, angle neovascularization, angle recession, etc) or exclude diagnosis of angle-closure glaucoma

Examination of Optic Nerve Head and Retinal Nerve Fiber Layer

• Changes in these structures often precede visual field loss in glaucoma patients
  
  • Look for changes such as optic disc hemorrhages, peripapillary choroidal atrophy

• Performed using magnified stereoscopic visualization, digital photography and stereophotographic techniques with red-free illumination

Other Tests

• Central corneal thickness (CCT) measurement (pachymetry) helps to determine level of risk for ocular damage
• Visual field test (eg automated static threshold perimetry, short-wavelength automated perimetry or SWAP, frequency doubling technology or FDT)
• Computer-based quantitative imaging of the optic nerve head and retinal nerve fiber layer using one of the following modalities: Optical Coherence Tomography (OCT), confocal scanning laser ophthalmoscopy (CLSO: Heidelberg Retinal Tomogram, HRT) and scanning laser polarimetry
  • For early detection of nerve fiber layer thinning, facilitating earlier diagnosis and detection of optic nerve damage
  • Serves as an adjunct to the clinical examination of the optic nerve head