Abstract
Purpose: :
Infrared imaging of the fundus has theoretical advantages for the study of the subretinal structures and it has been proposed in the past by means of experimental devices. We present results from the use of infrared imaging in the clinical practice, by means of a new generation confocal scanning laser ophthalmoscope.
Methods: :
622 eyes of 311 patients with a variety of chorioretinal pathologies were studied. For infrared imaging the HRA2 (Heidelberg Engineering, Heidelberg, Germany) confocal scanning laser ophthalmoscope was used.
Results: :
The acquisition of the images is fast and images of adequate quality may be obtained even without mydriasis or in cloudy media. Presentation is in grayscale. There are significant disparities from color and red–free fundus photography. Hemorrhagic lesions appear less dense and the underlying structures may be visualized. Hard exudates are whitish and highly reflective. Pigmentary lesions have similar appearance. Soft drusen have low reflectivity while hard drusen are highly reflective. In some patients with age–related maculopathy (ARM) and confluent drusen, gray dots, not corresponding to any ophthalmoscopic lesions, may be seen. Retinal pigment epithelium (RPE) alterations are clearly recorded even when these are not visible by other means. In central serous chorioretinopathy (CSCR) the localized detachment of the neurosensory retina appears dense gray with very clear delineation. Naevi are whitish and clearly delineated, while melanomas show white and gray areas.
Conclusions: :
We present results from the recording of infrared imaging in a large series of patients with a variety of chorioretinal disorders. Infrared imaging has significant differences from color and red–free fundus photography, which should be taken into consideration for the appropriate interpretation of the results. This technique appears promising for the recording and follow–up of RPE changes, choroidal naevi, and CSCR. Further study is required for the evaluation of the significance of its findings in ARM, which are recorded only in infrared imaging and not by other techniques.
Keywords: imaging/image analysis: clinical • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)