Abstract
Purpose :
Macular telangiectasia type 2 (MacTel) is an inherited retinal disease affecting the foveal and parafoveal area, subsequently leading to vision loss. Fluorescence lifetime imaging ophthalmoscopy (FLIO), a novel imaging modality, has proven to be extremely helpful in diagnosing patients with this disease. Particularly, FLIO shows distinct and early changes in MacTel patients. This study investigates FLIO changes over time with the aim to better understand disease etiology and progression.
Methods :
29 patients with MacTel (age 59 ± 15 years) were investigated and followed at the Moran Eye Center with a prototype Heidelberg FLIO. The mean follow-up time was 17 ± 7 months (range 6 - 32 months). 8 patients received two follow-up images, one at 12 and the second at 24 months. Fundus autofluorescence was excited with a 473 nm laser with subsequent fluorescence lifetimes recorded in short (498-560 nm) and long (560-720 nm) spectral channels. All subjects also underwent OCT, macular pigment, autofluorescence intensity and infrared reflectance images.
Results :
All patients with MacTel showed the previously described MacTel FLIO pattern. The baseline FLIO lifetimes from within the MacTel area were 279 ± 38 ps (SSC) and 301 ± 28 ps (LSC). Over time, these values prolonged to 307 ± 50 ps (SSC) and 310 ± 34 ps (LSC), p<0.001 for both. The average 12-months prolongation of FLIO lifetimes is 19 ps (SSC) and 7 ps (LSC).
Conclusions :
Using FLIO imaging, it is possible to detect characteristic changes in fluorescence lifetimes in patients with MacTel. It has been shown that these changes are visible at early disease stages, indicating that FLIO has a high sensitivity to detect MacTel. To further understand the signals measured with FLIO, follow-up investigations of great importance. The prolongation of FLIO lifetimes over time could indicate an accumulation of toxic products, potentially deoxy-sphingolipids, within the eye. FLIO may be of help to understand disease processes and to diagnose MacTel even before patients experience visual disturbances.
This is a 2020 ARVO Annual Meeting abstract.