6 Diagnostic Capability of Optical Coherence Tomography …
133
It has been shown that there is a loss of the GCC in both type 1 and 2 diabetes
before clinically detectable retinopathy would occur that is most possibly attributable
to retinal diabetic neurodegeneration [20–22]. We could also show that in the case
of cataract surgery the photoreceptors seem to be mostly involved in the subtle
thickening of the retina, an effect that can be potentially avoided using femtosecondlaser assisted surgical procedures [23].
There are multiple, promising results with OCT segmentation in multiple sclerosis
(MS), Alzheimer’s disease, Parkinson’s, vascular dementia, etc. where the thickness
of the RNFL (cpRNFL) and the macular GCL may provide a surrogate marker for
pathological processes in the central nervous system [16, 24–32]. Recently, it has
been shown that circumpapillary RNFL measurements may even predict the risk of
disability worsening in MS [33].
OCT image segmentation has also been shown to be useful in heredodegenerative
diseases, for example in retinitis pigmentosa, Stargardt’s disease, and other macular
dystrophies. In the case of retinitis pigmentosa we could show that inner retinal layers
can still be preserved when there is already observable damage in the outer layers of
the macula.
In this chapter, the diagnostic capability of OCT based quantitative analysis for
various eye diseases and additional factors affecting morphological measurements
are outlined based on a review of the literature and specific related studies published
to date from our group. We have organized the chapter as follows. The quantitative
measurements of retinal pathology based on the OCT image along with image quality,
artifacts and error issues is presented in Sect. 6.2. Section 6.3 provides the necessary
clinical background about the specific retinal diseases that will be outlined in this
chapter to show the diagnostic capabilities of OCT technology as well as additional
factors affecting OCT measurements. Section 6.4 offers some concluding remarks.
6.2 OCT-Based Retinal Morphological Measurements
6.2.1 Quantitative Measurements of Retinal Morphology
OCT can aid in identifying, monitoring and quantitatively assessing various posterior segment conditions including macular edema, age-related macular degeneration, full and partial-thickness macular hole, epiretinal membrane, intaretinal exudate, idiopathic central serous chorioretinopathy, RPE detachment, detachment of
the neurosensory retina, macular lesions associated with ONH pits or glaucoma and
numerous other conditions.
As a matter of fact, OCT can demonstrate the presence of edema where it is
not seen on biomicroscopy or angiographically. A very important feature of the
OCT system is that it provides information on the retinal structures. For example,
the location of fluid accumulation in relation to the different retinal layers may
be determined and the response to treatment without the need to perform invasive
133
It has been shown that there is a loss of the GCC in both type 1 and 2 diabetes
before clinically detectable retinopathy would occur that is most possibly attributable
to retinal diabetic neurodegeneration [20–22]. We could also show that in the case
of cataract surgery the photoreceptors seem to be mostly involved in the subtle
thickening of the retina, an effect that can be potentially avoided using femtosecondlaser assisted surgical procedures [23].
There are multiple, promising results with OCT segmentation in multiple sclerosis
(MS), Alzheimer’s disease, Parkinson’s, vascular dementia, etc. where the thickness
of the RNFL (cpRNFL) and the macular GCL may provide a surrogate marker for
pathological processes in the central nervous system [16, 24–32]. Recently, it has
been shown that circumpapillary RNFL measurements may even predict the risk of
disability worsening in MS [33].
OCT image segmentation has also been shown to be useful in heredodegenerative
diseases, for example in retinitis pigmentosa, Stargardt’s disease, and other macular
dystrophies. In the case of retinitis pigmentosa we could show that inner retinal layers
can still be preserved when there is already observable damage in the outer layers of
the macula.
In this chapter, the diagnostic capability of OCT based quantitative analysis for
various eye diseases and additional factors affecting morphological measurements
are outlined based on a review of the literature and specific related studies published
to date from our group. We have organized the chapter as follows. The quantitative
measurements of retinal pathology based on the OCT image along with image quality,
artifacts and error issues is presented in Sect. 6.2. Section 6.3 provides the necessary
clinical background about the specific retinal diseases that will be outlined in this
chapter to show the diagnostic capabilities of OCT technology as well as additional
factors affecting OCT measurements. Section 6.4 offers some concluding remarks.
6.2 OCT-Based Retinal Morphological Measurements
6.2.1 Quantitative Measurements of Retinal Morphology
OCT can aid in identifying, monitoring and quantitatively assessing various posterior segment conditions including macular edema, age-related macular degeneration, full and partial-thickness macular hole, epiretinal membrane, intaretinal exudate, idiopathic central serous chorioretinopathy, RPE detachment, detachment of
the neurosensory retina, macular lesions associated with ONH pits or glaucoma and
numerous other conditions.
As a matter of fact, OCT can demonstrate the presence of edema where it is
not seen on biomicroscopy or angiographically. A very important feature of the
OCT system is that it provides information on the retinal structures. For example,
the location of fluid accumulation in relation to the different retinal layers may
be determined and the response to treatment without the need to perform invasive