terminology and guidelines for glaucoma ii - Kwaliteitskoepel

2.3 - SECONDARY OPEN-ANGLE GLAUCOMAS
Elevated IOP causing progressive typical glaucomatous optic neuropathy and visual field loss, caused by ophthalmological
or extraocular disease(s), drugs and treatments. Assessment of the glaucomatous damage to visual function, including visual
field staging, may be difficult because of the underlying ophthalmological diseases or complex clinical picture.
The following classification is primarily based on pathophysiologic mechanisms. Distinct clinical glaucoma types are discussed
at the corresponding point of the mechanistic classification.
When no etiology and pathomechanism are evident, a primary glaucoma should be considered.
In secondary Open-angle Glaucomas the anterior chamber-angle is open for over 270°.
In several forms of secondary glaucoma pathomechanisms leading to both secondary open-angle and angle-closure glaucoma
are combined. Since the number of the combinations is very high, in each case individual evaluation is necessary.
2.3.1 - SECONDARY OPEN-ANGLE GLAUCOMAS CAUSED BY OPHTHALMOLOGICAL CONDITIONS
2.3.1.1 - Pseudoexfoliation Glaucoma (PEX) 4,5
Etiology: Pseudoexfoliative material, an abnormal fibrillo-granular protein, and pigment accumulate in the trabecular
meshwork, where TM function decreases. Similar material has been identified in the conjuntiva and body parts outside the
eye. Why many eyes with pseudoexfoliation do not have glaucoma is not known.
Pathomechanism: Reduction of the trabecular outflow owing to the pseudoexfoliative material.
Features:
Onset: usually older than 60 years
Frequency: large racial variations
Asymptomatic until visual field loss advanced
One or both eyes affected, often bilateral and asymmetrical
Sign and symptoms:
IOP: > 21 mm Hg, frequently higher than in average POAG cases
Visual field loss as in POAG; frequently severe at least in one eye
Slit lamp examination: dandruff-like exfoliation material on the pupil border and on the surface of the anterior lens
capsule except the central zone, better visualized after pupillary dilation. The pupillary collarette is irregular and typically
has a moth-eaten appearance.
Frequently associated with nuclear cataract, pigmentary loss from the central or mid-iris, pigment granules in the
angle. When pigment accumulates along an ondulating line on or anterior to Schwalbe’s line, it is called Sampaolesi’s line.
Loose zonules are frequent with occasional phacodonesis and lens subluxation.
Narrow or closed-angle is relatively common.
2.3.1.2 - Pigmentary Glaucoma 5,6
Etiology: Melanin granules accumulate in the trabecular meshwork, where TM function decreases.
Pathomechanism: Reduction of the trabecular outflow owing to melanin granules. According to the theory of ‘reverse pupillary
block’ the iris works as a valve resulting in IOP higher in the anterior chamber than in the posterior chamber, causing
peripheral posterior bowing of the iris. Melanin granules are released from the iris as a result of rubbing between the zonules
and the posterior surface of the iris.
Ch. 2 - 9 EGS