Purchase this article with an account.
Katarzyna Komar, Patrycjusz Stremplewski, Maciej Szkulmowski, Marta Motoczynska, Maciej Wojtkowski; Imaging of Human Retina using Spectral Optical Coherence Tomography and high sensitive autofluorescence detection. Invest. Ophthalmol. Vis. Sci. 2013;54(15):3593.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To demonstrate the significant reduction of required intensity of AF excitation beam while using modulated excitation source and lock-in detection a device was constructed which combines two methods of imaging of the retina of the human eye in-vivo: autofluorescence (AF) and spectral optical coherence tomography (SOCT).
The instrument was designed and constructed in Optical Biomedical Imaging Group laboratory, Institute of Physics, NCU, Torun, Poland. It combines functionality of imaging fundus of human eye by registration autofluorescence signal by Scanning Laser Ophthalmoscope (FAF-SLO mode of work) with Fourier domain OCT (OCT mode of work). Native fluorescence of human fundus was excited with blue diode laser beam (λ = 473 nm) with high frequency amplitude modulation (20 MHz) directed into OCT optical path with fiber coupler. AF signal was detected with photomultiplier tube and lock-in amplifier operating at frequency of blue beam modulation. The setup allows for simultaneous acquisition of OCT and high contrast AF images using fluorescence excitation power of 50 µW without averaging consecutive images. All the test have been conducted for healthy eyes and in compliance with ANSI standards and with approval of the Ethics Committee of the Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Poland. Examinations were conducted after written informed consent was obtained.
Successful functioning of constructed device have been demonstrated for 10 objects of different age. Exemplary, wide angle, low excitation power AF images as well as high resolution OCT images of the retina are shown in Figure 1 and 2 respectively. Improved detection of AF signal allows for acquiring high contrast images using single scan without averaging and incomparable low excitation power.
Using modulated excitation source and lock-in detection in fundus autofluorescence imaging significantly improves the sensitivity of the device and allows for using much lower excitation power than used in standard devices. We expect this method to be more comfortable for the patient and safe for his eye.
This PDF is available to Subscribers Only