Abstract
Purpose :
To evaluate long-term efficacy and safety of adjunct stereotactic radiotherapy (SRT) to anti-VEGF injections in a treat-and-extend regimen (TER) in neovascular age-related macular degeneration (nAMD).
Methods :
Clinical routine setting of 50 consecutive patients treated with a single session of SRT under continued TER with 3 year efficacy follow-up and reading center (Vienna Reading Center) based safety evaluation including standardized 7-field color fundus photography (CF), 7-field fluoresceine angiography plus peripheral imaging (FA) and Spectral-domain Optical coherence tomography (SD-OCT).
Results :
After significant increase from baseline (4.24±0.66 weeks) to 12 months (7.52±3.05 weeks, p<0.001), mean maximum recurrence free treatment interval (RFTI) remained stable at 24 (7.40±3.17 weeks, p=0.746) and 36 months (6.89±3.00, p=0.175). 50% of eyes did not reach anymore their individual maximum RFTI at 36 months. Best corrected visual acuity (BCVA) remained stable during the first 12 months after SRT (p= 0.744), but decreased afterwards by -5.8±15.9 and -11.0±20.1 letters at 24 and 36 months, respectively. At the safety visit after 24±4 months 36% of SRT eyes showed microvascular abnormalities (MVA) on CF and/or FA most frequently located in the parafoveal inferior and nasal regions; in the inferior subfields accompanied by significant decreases of layer thicknesses at SD-OCT. The retinal nerve fiber layer was significantly decreased in the outer nasal subfield of central ETDRS grid representing parts of the papillomacular bundle (p= 0.0245). Peripheral fluoresceine angiography did not reveal any MVAs outside the standard ETDRS fields 1-7. However, there was no significant difference in mean BCVA change between eyes without and with MVAs at 24 and 36 months (-5.4 ±18.2 vs -6.4±11.4 letters, p=0.831; -9.7±19.2 vs -13.4±21.9 letters, p=0.545).
Conclusions :
Due to MVAs in more than one third of patients, a significant decrease in retinal nerve fiber layer thickness in the papillomacular bundle and possibly weakening of the interval lengthening effect in parts of patients within year 3 after SRT a further close follow-up of all SRT patients is recommended.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.