Duration 5min, Q&A 3min
Fluorescence Lifetime Imaging in Eyes After Successful Macula-Off Retinal Detachment Repair and in Unaffected Partner Eyes
The fluorescence of organic molecules is not only characterized by the emission spectrum, it has also a specific decay rate or lifetime. Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a novel imaging method that allows measurements of fluorescence lifetimes in vivo in the retina. The instrument used for FLIO imaging is based on a Heidelberg Engineering Spectralis® system. In this study, we assessed fluorescence lifetimes in eyes after successful macula-off retinal detachment surgery. Values were compared to the unaffected partner eyes.
Twenty eyes of 10 patients after successful macula-off retinal detachment repair have been included 6-8 weeks after surgery. Unaffected partner eyes were used as controls.
Fluorescence decay times were measured in a short wavelength channel (498 - 560 nm) and in a long wavelength channel (560 - 720 nm). Short fluorescent lifetimes (tau1), long fluorescence lifetimes (tau2), as well as corresponding amplitudes were calculated for each acquired pixel within the retina by time-correlated single photon counting. For comparison purposes an ETDRS grid was used to average all values for 3 zones (center, inner ring, outer ring). Values of affected eyes were compared with corresponding healthy retina of partner eyes using a student's t test.
Results and Conclusion
Mean tau1 lifetimes (in picoseconds) in the short wavelength channel were significantly longer in all ETDRS zones of affected eyes (center: 231.7 ± 17.64; inner ring: 288.0 ± 19.67; outer ring: 301.4 ± 15.88) compared to controls (center: 182.6 ± 13.63, p<0.041; inner ring: 240.4 ± 10.51, p<0.047; outer ring: 262.3 ± 9.420, p<0.049). In the long wavelength channel, tau1 differences were also significant for the ETDRS center. (affected eyes: 278.2 ± 17.44; controls: 223.3 ± 14.49, p<0.026). Mean amplitudes have been found to be significantly higher in affected eyes compared to controls. Mean amplitudes in the center were 0.002485 ± 0.0003058 in affected eyes and 0.001614 ± 0.0002483 in controls (p<0.041). In the inner ETDRS ring mean amplitudes were 0.002496 ± 0.0002823 in affected eyes and 0.001606 ± 0.0002334 in controls (p<0.025). In the outer ETDRS ring mean amplitudes were 0.002740 ± 0.000284 in affected eyes and 0.001791 ± 0.0002641 in controls (p<0.025). All other values showed no statistically significant difference.
In conclusion, we were able to show that macula-off retinal detachment leads to specific and quantifiable changes in fluorescence lifetimes in the macula, in particular in short fluorescence lifetimes (tau 1) and amplitudes.
[ Keyword ]
Fluorescence lifetime imaging / Macula / retinal detachment
[ Conflict of Interest ]