Abstract
Purpose :
To characterize the microscopic structure of photoreceptors surrounding cuticular drusen in patients with age-related macular degeneration (AMD) using multimodal imaging, including adaptive optics scanning laser ophthalmoscopy (AOSLO).
Methods :
Study patients (n = 8, aged 70.1 ± 6.6 years) with early to intermediate AMD (grade 2-8 on the AREDS 9-step severity scale) and predominantly cuticular drusen in both eyes underwent color fundus photography, blue and infrared reflectance, autofluorescence (AF), and optical coherence tomography (OCT). AOSLO was performed to image macular cone photoreceptors. Cuticular drusen were characterized into 3 phenotypes: type 1 had shallow retinal pigment epithelium (RPE) elevations, type 2 appeared as saw-tooth mounds, and type 3 formed broad mounds causing significant elevations of the RPE band. Type 1 lesions had indiscernible druse internal contents, whereas type 2&3 manifested hyporeflective internals. Cone photoreceptor structure was evaluated by cone reflectivity on AOSLO.
Results :
AOSLO revealed distinctive cone reflectivity alterations over different phenotypes of cuticular drusen (Figure). While most cones maintained normal orientation on type 1 lesions, the area impacted by the cuticular druse became hyporeflective. Cones lost reflectivity on type 2 lesions. Most cones became invisible on type 3 lesions. We measured 1501 cuticular drusen affected areas showing quasicircular hyporeflectivity in 16 eyes. The diameter was 49.12 ± 16.42 μm, ranging from 15.81 to 99.22 μm.
Conclusions :
The characterized photoreceptor reflectivity perturbation associated with cuticular drusen indicates that the optical properties of the photoreceptors have been impacted at the beginning of the lesion development, suggesting displacement or dysfunction of the supporting RPE cells, as evidenced by characteristic hypertransmission underneath in the choroid.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.