terminology and guidelines for glaucoma ii - Kwaliteitskoepel

1.3.4.3 - OCT
The Optical Coherence Tomograph is a laser scanning interpherometer which can quantify the retinal structure by
measuring the retardation of the reflected light 30-32 .
1.3.4.4 - RTA
The Retinal Thckness Analyzer measures the distance between the vitreoretinal interface and the pigment epithelium
using a 543 nm laser source 33-34 .
1.3.5 - ONH APPEARANCES AND CLINICAL TYPES OF GLAUCOMA
Optic disc appearance has been used to divide POAG (HPG and NPG) into different groups. Each ophthalmologist
may or may not elect to use this further sub-division.
ONH features have been used to identify a variety of POAG subtypes. However, a clear separation between these
types of glaucoma is usually lacking.
Features that in some studies are more common in normal pressure glaucoma (NPG) include 35-41 :
Optic disc:
localized rim damage (notch) early in the course
flat disc excavation (no laminar excavation)
splinter hemorrhage (often)
peripapillary chorioretinal atrophy
narrowing of retinal arteries
Retinal Nerve Fiber Layer:
localized loss
It is unlikely for ONH findings alone to be pathognonomic of a specific type of glaucoma 37,41 .
1.3.6 - PROGRESSION OF DAMAGE
Imaging is likely to play a role in the future for longitudinal follow-up 42,43 . Ophthalmoscopy techniques have also
proved to be clinically useful for disease staging and for semiquantitative longitudinal evaluation of the disc 44-48 .
Confirmed worsening of ONH or RNFL parameters is a strong sign of glaucoma progression.
Ch. 1 - 21 EGS