A successful journey requires all equipment working in concert; the same applies to conducting a clinical trial. A successful multi-center trial requires intrinsic understanding of various imaging techniques, developing meaningful outcome correlations, and formulating computational methodologies that yield high sensitivity and specificity.
Optical Coherence Tomography
Optical coherence tomography (OCT) is a non-invasive imaging technique that provides three-dimensional and cross sectional views of ocular structures including retinal layers, vitreous, and portions of the choroid and optic nerve.
OCT is used widely to provide quantitative thickness and volumetric values for the central retina. It is particularly useful in the clinical diagnosis and longitudinal monitoring of macular edema, macular hole, glaucoma and age-related macular degeneration.
Stereo Color Fundus Photography
High resolution digital and film-based stereo color fundus photography is used to document the appearance of basic ocular structures such as the external eye, anterior segment and retina and to assess pathology of the eyes, lids, and ocular adnexa throughout the life of the study.
Fluorescein angiography is used to assess the integrity of the retinal and choroidal vasculature. In clinical studies, this technique can be used to detect diabetic retinopathy, occlusions, edema, and tumors.
Indocyanine Green Angiography
Indocyanine green angiography is a technique used in basic ophthalmic medical diagnostics to image the ocular fundus when deep patterns of circulation are needed to reveal particular forms of retinal damage, AMD, CNV, or other ocular diseases.
Fundus autofluorescence imaging has been shown to be a useful tool to document metabolic changes at the level of the retinal pigment epithelium (RPE), suggesting areas of high risk for visual function loss.
Dark Adaptation with AdaptDx
The AdaptDx® is the first instrument to provide a practical and objective measurement of dark adaptation function, which is severely impaired in AMD, RP, and other macular degenerations. It is a valuable complement to existing imaging devices used in routine eye exams for retinal disease assessment. This additional information is particularly valuable for early assessment, as biological function is often affected earlier than structural changes can be identified.
Corneal Specular Microscopy
A specular microscope is used to magnify the density and distribution of endothelial cells in the cornea.
Images can be photographed and then analyzed using corneal endothelial analysis software. Cell densities (cell counts), coefficient of variation of cell size (CV) and % hexagonal cells are typically the most important measures determined. These measures or readings can then be compared with prior readings (usually cell density is most important).
Slit Lamp Imaging
A standard slit lamp imaging and lens grading protocol is used to identify principal characteristics including the optical density of the nucleus and the clarity of its normal landmarks, record the degree of nuclear sclerosis, assess nuclear color, and estimate the presence and extent of any cortical, posterior, or other opacity.
Electrodiagnostic examination includes any of the following assessments, which are applied by trained investigators following ISCEV standards to assure optimal clinical trials:
- Full-field electroretinogram
- Pattern electroretinogram
- Multi-focal electroretinogram
- Visual evoked potentials