Noninvasive monitoring of blood flow in retinal circulation will reveal the progression and treatment of ocular disorders,
such as diabetic retinopathy, age-related macular degeneration and glaucoma. A non-invasive and direct BF
measurement technique with high spatial-temporal resolution is needed for retinal imaging. Laser speckle imaging (LSI)
is such a method. Currently, there are two analysis methods for LSI: spatial statistics LSI (SS-LSI) and temporal
statistical LSI (TS-LSI). Comparing these two analysis methods, SS-LSI has higher signal to noise ratio (SNR) and TSLSI
is less susceptible to artifacts from stationary speckle. We proposed a hybrid temporal and spatial analysis method
(HTS-LSI) to measure the retinal blood flow. Gas challenge experiment was performed and images were analyzed by
HTS-LSI. Results showed that HTS-LSI can not only remove the stationary speckle but also increase the SNR. Under
100% O2, retinal BF decreased by 20-30%. This was consistent with the results observed with laser Doppler technique.
As retinal blood flow is a critical physiological parameter and its perturbation has been implicated in the early stages of
many retinal diseases, HTS-LSI will be an efficient method in early detection of retina diseases.