Abstract
Purpose :
To evaluate HRF characteristics and dynamics in eyes with AMD during disease progression from early to advanced stages.
Methods :
26 eyes of 20 patients with early AMD were included in this ongoing prospective study. All eyes had HRF. We randomly selected a maximum of 10 HRF in the central and inner ETDRS subfields for imaging with the Spectralis HRA-OCT2 and confocal laser ophthalmoscope HRA II (Heidelberg Engineering) and evaluated the following characteristics on horizontal B-scans: retinal localization; arrangement (single, conglomerate); appearance (round, irregular); volume (μm3); presence of shadowing; integrity of outer retinal layers (ORL) and association with drusen within a 250-μm horizontal distance from HRF. We also evaluated the autofluorescence (AF) properties of HRF obtained on en face AF images with excitation wavelengths of 488nm (fundus AF [FAF]) and 787nm (near infrared fundus reflectance [NIR]). Data were analyzed manually using custom-made validated software (OCTAVO, Vienna Reading Center).
Results :
Mean patient age was 73.5±7.9 (SD) years. 15 were women. 8/8 eyes of 6/8 patients converted to geographic atrophy/choroidal neovascularization (CNV/GA) (type 1) within a mean of 26.3±13.5 / 43.5±15.4 months after baseline. A mean of 5.0±2.1 HRF were analyzed and followed every 6 months. At baseline 65% of HRF were arranged in a conglomerate and 52% were round. HRF volume ranged from 20000 to 250000μm3. 74% of eyes had drusen below HRF. 96% had HRF between the inner nuclear layer and external limiting membrane. The ellipsoid and interdigitation zones were disrupted in 75% and RPE in all eyes, while the external limiting membrane was intact in 70%. 85% showed no HRF shadowing effects. Individual HRF volume varied greatly during disease progression, while retinal localization, shadowing status and ORL integrity remained unchanged (all p<0.05). 7/5 eyes developed CNV/GA in the exact area of baseline HRF. At the conversion visit all HRF above the lesion area were arranged in an irregular conglomerate, not observed in nonconverted eyes. 97% of HRF showed no hyper-AF in FAF/NIR at baseline with no change during progression.
Conclusions :
Our ongoing prospective study revealed that HRF arranged in irregular conglomerates are characteristic at the time of disease conversion from early to advanced AMD.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.