SITE-App algorithm variant 2007 was first reported at ARVO Meeting, Fort Lauderdale, 2008, as an audio-visual poster. Results of measurements on fluorescein angiography and red free images realized by using SITE-App software were presented as posters at ARVO Meeting, Fort Lauderdale, 2009 and 2010, SITE-App variant 2021 was published on the website https://www.eyestorywithnarcisa.com, SITE-App variant 2022 is finished and soon to be released to publication.
PurposeTo design an algorithm for quantitative assessment of retinal lesions size in fluorescein angiography (FA).Methods: Black-white fundus photos were recorded during FA from patients with age related macular degeneration, before and after Bevacizumab intravitreal injections. Area of "white lesions" was quantified in white pixels inside standardized retinal areas of interest, by using SITE-App algorithm. Method reproducibility was assessed by comparing two independent readers measurements. Method sensitivity was evaluated by comparing SITE-App results with the ones of other published quantitative methods: greatest linear dimension in millimeters -GLD [mm]
or pixels -GLD[pix], mouse-delimited lesions area in MPS units -A[MPS], mm2 -A[mm2], total pixels -A[tpix] or white pixels A[wpix]. Correlation between methods was analyzed by calculation of correlation factor.Results: SITE-App is reproducible because differences between two independent readers measurements were not statistically significant (p>0.05). The reproducibility was found very good for SITE-App (p=0.49) and A[wpix] (p=0.22). The reproducibility was lower, but still good for A[MPS] and A[mm2] (p=0.13). A[tpix] (p=0.01), GLD[pix] (p=0.0003) and GLD[mm] (p=0.0005) were found not reproducible. The highest sensitivity was observed for SITE-App (p1=0.002, p2=0.021) and A[wpix] (p1=0.007, p2=0.02), that also showed high correlation (r1=0,96, r2=0,94). A[MPS] and A[mm2] offered very dispersed and unsure results (R1=1.54±26.1, R2=3.51±17.3). No statistical significance of data correction for incidence angle variations of images capture was found.
Conclusion:Quantification of retinal lesions in white (or black) pixels inside of interest standardized areas (SITE-App algorithm) is reproducible, sensitive, easy, fast and low cost, very useful for longitudinal clinical studies.