LONGITUDINAL FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY ANALYSIS IN PATIENTS WITH MACULAR TELANGIECTASIA TYPE 2 (MacTel)

Abstract

Purpose: Fluorescence lifetime imaging ophthalmoscopy (FLIO) shows characteristic patterns in macular telangiectasia Type 2 (MacTel). This study investigates FLIO changes over time to better understand disease progression.Methods: Thirty-three patients with MacTel (age 60 ± 15 years) were followed at the Moran Eye Center with a prototype Heidelberg Engineering FLIO. The mean follow-up time was 19 ± 8 months (range 6-34 months). Fundus autofluorescence was excited at 473 nm, and FLIO lifetimes were recorded in in short (498-560 nm) and long (560-720 nm) spectral wavelengths channelsResults: Autofluorescence lifetimes imaging ophthalmoscopy lifetimes from the MacTel area prolonged significantly over time (subfield T1, baseline: short spectral channel 210 ± 54 ps, long spectral channel 269 ± 58 ps; follow-up: short spectral channel 225 ± 59 ps, P , 0.001, long spectral channel 282 ± 64 ps, P , 0.01). The average 12-months prolongation of FLIO lifetimes was 9 ps (short spectral channel) and 8 ps (long spectral channel). Autofluorescence lifetimes changes correlated positively with ellipsoid zone loss and negatively with changes in retinal thickness.Conclusion: Autofluorescence lifetimes in MacTel slowly prolong over time, and temporal patterns progress to full rings. Detailed knowledge about FLIO changes will aid in understanding disease development and progression.

Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) in Macular Telangiectasia Type 2 (MacTel) Patients with and without Diabetes

“…Figure 2 shows boxplots from ROIs. Similarly, comparing MacTelandDM with (7) and without (79) DR did not show any significant differences in ROIs (P values 0.589-1.0). Details are summarized in Table 3, summarizing Bonferroni-corrected P values (P values were not significant prior to correction).…”

“…This prolongation occurs independently of changes in macular pigment. 7,14,15 As FLIO gives an en face image of retinal FLTs, it is difficult to attribute individual signals to specific structures at the posterior pole. A previous study focusing on retinal anatomy showed that the prolongation of FLTs in MacTel is influenced by ellipsoid zone loss.…”

“…There was also a significant negative correlation with FLTs and thickness changes of the ganglion cell layer in the temporal fovea. 7,14 Multiple studies emphasized that FLIO may be a sensitive method to detect early DR and changes related to diabetes. 8,9 In these studies, FLTs were significantly prolonged in diabetic eyes.…”

“…In MacTel, FLTs are prolonged in a temporal crescent or ring within the MacTel zone, 4 which further prolong by 9 ps annually. 7 Other studies investigated diabetic patients with FLIO and found a prolongation of FLTs in patients with nonproliferative DR compared with healthy controls. 8 Changes in FLTs were also reported for patients with diabetes early in the disease.…”

Macular Telangiectasia Type 2

“…conducted a longitudinal study of FLIO in persons with MacTel and found that autofluorescence lifetimes slowly prolonged over time with very specific patterns. 34 Although such data on this condition may be informative in future developments of the MacTel classification, it will depend on how FLIO will be incorporated into clinical care. Currently, it is highly experimental and is limited by the small number of instruments available for testing.…”