Snapshot Spectral Imaging for Functional Imaging of Retina

Abstract

 

Purpose:

 

Recently, functional imaging of the retina has been studied by several groups (T’so D, JJO 2009, Tsunoda K, JJO 2009). The snapshot hyper-spectral imaging system has an ability to obtain the 2-dimensional images with different spectral ranges simultaneously by a simple optical instrument. In this study, we developed a snapshot spectral fundus camera and compared the spectral intensity of the images with those obtained by conventional method of functional imaging of the retina in cats.

 

Methods:

 

We developed a snapshot fundus camera using a simple optical system which consisted of two doublet-lenses and a disperser (grating). Time series of the retinal images with 700-900nm spectral range were obtained by the snapshot system. A trial sequence of images was taken every 26 consisting of recordings for 2 sec before, 4 sec during and 20 sec after the electrical stimulation to the retina (Okawa Y, IOVS 2007). 10-nm spectral-sampling and 92x92 spatial images were reconstructed by the MART algorithm. Time series changes of the spectral intensity in an artery or a vein were calculated by these reconstructed images and compared with those obtained by the two dichroic-mirrors and three-CCD-camera system (Mihashi T, 2010 ARVO) in 2 cats.

 

Results:

 

We obtained the stimulus-evoked retinal intrinsic signals in the artery or vein for each spectrum range by the snapshot fundus camera. The spectral responses by snapshot fundus camera were similar to those obtained by three-CCD-camera system.

 

Conclusions:

 

Time series retinal spectral images of functional imaging were obtained by the snapshot fundus camera. The result suggests that spectrally high resolution functional images can be obtained by a simple optical instrument.  

 

Keywords: imaging/image analysis: non-clinical • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)