Abstract
Purpose :
Late-onset retinal degeneration (L-ORD) is a rare monogenic disorder that has important parallels with age-related macular degeneration (AMD). We describe the novel finding of asymptomatic choroidal neovascular membranes (CNV), which has implications for our understanding of the development of neovascular AMD.
Methods :
Four individuals with the C1QTNF5_S163R point mutation (heterozygous) underwent multimodal imaging with color fundus photography, fundus autofluorescence, near-infrared reflectance, spectral domain OCT (SD-OCT) and SD-OCT angiography (OCT-A). High-speed indocyanine green angiography (ICGA) and fluorescein angiography (FA) were performed and included wide-field imaging. Imaging was performed every 6 months over 3 years in 2 participants and over 2 years in the other participants.
Results :
All four individuals had classic clinical features of L-ORD, including elongated anterior lens zonules, delayed dark adaptation and retinal drusenoid deposits. All four individuals demonstrated evidence of peripheral CNV in several peripheral areas in both eyes with the superotemporal and inferior retina as apparent sites of preference . FA demonstrated branching vascular networks outside the vascular arcades, with some lesions in one individual exceeding an area of 20 disc diameters with minimal late leakage. Wide-field ICGA revealed large hypercyanescent lesions with a striking hypocyanescent border with irregular, well-demarcated edges. SD-OCT of the less peripheral lesions demonstrated irregular elevation of the RPE (consistent with a shallow, broad fibrovascular PED), while OCT-A demonstrated sub-RPE CNV.
Longitudinal follow-up revealed that the posterior borders of the CNVs show progressive centripetal advancement, with nascent lesions of hypercyanesence appearing over time.
Conclusions :
Multiple large areas of CNV with characteristics of occult/subclinical type 1 neovascularization exist in eyes with L-ORD. These appear to arise from the mid-peripheral retina. Progressive enlargement of these lesions is led by a hypocyanescent border, suggesting that nascent CNVs may arise from nidi of choroidal hypoperfusion. Identification of these progressive changes is helpful in elucidating cellular mechanisms underlying CNV and may give insights into neovascular AMD.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.