Abstract
Purpose: :
To present a new high resolution imaging technique combining the modalities of scanning laser ophthalmoscope (SLO), optical coherence tomography (OCT) and micro–multifocal ERG (micro–mfERG) to allow simultaneous structural and functional assessment of the macula without compromising the recording quality of the individual components.
Methods: :
A combined SLO/OCT scanner was modified to include an organic light emitting diode (OLED) display within the optics of the system to provide the capacity for simultaneous micro–multifocal ERG recording and SLO/OCT imaging of the central 15 degrees. The OLED display has a maximum luminance of 820 cd/m2 and allows high frequency micro–mfERG recording of up to 85Hz with a rapid 1ms rise time. The micro–mfERG stimulus array consists of 19 empirically scaled hexagons.
Results: :
Micro–mfERG recordings allow functional assessment of the central macula at almost 3 times the spatial resolution of conventional mfERG. The quality of the recovered signal is however currently lower than with conventional mfERG. The image recording quality of the SLO and OCT is unaffected by the integration of micro–mfERG into the system.
Conclusions: :
While this multimodal imaging technique is at an early stage of development, it appears to be a viable technology providing improved resolution of macular assessment than previously possible. However, stimulating smaller focal areas of the retina results a reduction of the signal to noise ratio. Signal enhancement methods need to be employed to recover robust signals for clinical assessment. SLO/OCT/micro mfERG provides a single tool for the simultaneous assessment of macular structure and function.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • electroretinography: clinical