Optical coherence tomography angiography suggests choriocapillaris perfusion deficit as etiology of acute macular neuroretinopathy.

Acute macular neuroretinopathy (AMN) can cause sudden-onset and permanent scotoma in healthy young patients. Analysis of optical coherence tomography (OCT) and OCT angiography (OCTA) of AMN patients may provide insights into disease mechanism. We conducted a retrospective study of consecutive SARS-Cov-2-related AMN patients that presented in our clinic between Jan 1st, 2022, and April 30th, 2023, within 30 days of symptom onset. Retinal vessel area density (VAD) of AMN lesions in OCTA was quantified and compared to an adjacent tissue control (ATC). This quantification was performed for the superficial vascular plexus (SVP), the intermediate capillary plexus (ICP), the deep capillary plexus (DCP), the choriocapillaris (CC), and choroid. Furthermore, en face OCT images were analyzed. Nine AMN patients were identified, 6 of these (4 female, 2 male, average age 25 years) fulfilled the inclusion criteria and were included into this study. Average time from symptom onset to OCTA was 14.3 days. No VAD differences between AMN and adjacent tissue were found in either retinal layer (SVP, ICP, DCP). In contrast, VAD in CC was reduced by 27% against the ATC (p = 0.007) and choroidal VAD was reduced by 41% (p = 0.017). Further analysis of en face OCT could show that the pathognomonic infrared hyporeflectivity in AMN is caused by photoreceptor alterations rather than changes in the inner retinal layers. Our data suggests that a perfusion deficit in the choroidal layers is responsible for AMN rather than in the DCP, which is the predominant hypothesis in current literature.

von der Burchard C ，Gruben A ，Roider J 《-》

Acute macular neuroretinopathy: pathogenetic insights from optical coherence tomography angiography.

To describe the optical coherence tomography angiography (OCT-A) features of patients affected by acute macular neuroretinopathy (AMN). This is a prospective, observational, cross-sectional study. Multimodal imaging, including spectral domain OCT (Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany) and 6×6 mm swept source OCT-A (ZEISS PLEX Elite 9000; ZEISS, Dublin, California), was performed on all patients. The primary outcome measure was assessment of the vascular alterations of the superficial (SCP) and deep (DCP) capillary plexuses and choriocapillaris (CC). A segmentation of the AMN lesions using enface OCT images of photoreceptors-retinal pigment epithelium complex was used to discriminate intralesional and extralesional regions on the OCT-A enface slabs of the DCP and CC reconstructions. Each OCT-A slab was imported into ImageJ V.1.50 and digitally binarised for quantitative analyses. Overall, seven patients (mean age 19.4±3.2 years, six women) affected by AMN were included. The mean best-corrected visual acuity was 0.00±0.00 logarithm of the minimum angle of resolution. Twelve healthy age-matched subjects (mean age 22±3.4 years, 10 women) represented the control group. The quantitative analysis of global vessel densities showed that the CC vessel density was significantly lower in patients with AMN (0.495±0.03) compared with the age-matched controls (0.545±0.02) (corrected p=0.0003). The intralesional vessel density of the DCP was 0.349±0.04 in AMN and vs 0.497±0.02 in the controls (corrected p=0.0002). Our study confirmed inner choroidal vascular flow void as a possible pathogenetic mechanism of AMN. We also found a focal impairment of the DCP within the AMN lesions. Future studies are needed to clarify which is the primary location of the vascular insult in this condition.

Casalino G ，Arrigo A ，Romano F ，Munk MR ，Bandello F ，Parodi MB ... -  《-》

Association of Acute Macular Neuroretinopathy or Paracentral Acute Middle Maculopathy with Sickle Cell Disease.

To investigate the structural and microvascular changes in the retina and choriocapillaris in patients with sickle cell disease (SCD) demonstrating acute vision loss and acute macular neuroretinopathy (AMN) or paracentral acute middle maculopathy (PAMM) using multimodal imaging including OCT and OCT angiography (OCTA). Retrospective case series. Four hemoglobin SS (HbSS) or hemoglobin SC (HbSC) patients who demonstrated vision loss attributed to AMN (n = 2) or PAMM (n = 2). Clinical characteristics including best-corrected visual acuity and multimodal imaging features from fundus photography, fluorescein angiography, OCT, and OCTA were analyzed. Longitudinal changes in the structure and microvasculature of the retina and choriocapillaris were examined. In 2 patients with AMN, characteristic hyperreflective changes were observed in the outer nuclear layer with involvement of the ellipsoid and interdigitation zones. In 1 patient, the lesion was located in the foveal avascular zone, and only flow deficits in the choriocapillaris were noted. In the second patient, no flow loss was observed in the superficial capillary plexus (SCP) corresponding to the lesion, but flow loss was seen in the deep capillary plexus (DCP) and choriocapillaris. At the respective 1-year and 4-month follow-up examinations, the hyperreflectivities improved with no ensuing retinal atrophy. Deep capillary plexus and choriocapillaris flow also improved. Of the 2 patients with PAMM, 1 had PAMM in association with branch retinal arteriolar occlusions. In both patients, a hyperreflective band involving the inner plexiform, inner nuclear, and outer plexiform layers was seen in or adjacent to areas of prior macular thinning. These areas corresponded to flow deficits in both the SCP and DCP. At the respective 1-month and 1-year follow-up examinations, the hyperreflective band improved with ensuing atrophy of the middle retinal layers. OCT angiography demonstrated worsening of flow deficits in the corresponding SCP and DCP. To the best of our knowledge, this is the first report of AMN and the largest case series of AMN or PAMM in SCD to date. Paracentral acute middle maculopathy may precede macular thinning commonly observed in SCD. OCT angiography is a useful tool to demonstrate associated microvascular changes in AMN and PAMM in SCD.

Ong SS ，Ahmed I ，Scott AW 《-》

Choroidal Features of Acute Macular Neuroretinopathy via Optical Coherence Tomography Angiography and Correlation With Serial Multimodal Imaging.

Lee SY ，Cheng JL ，Gehrs KM ，Folk JC ，Sohn EH ，Russell SR ，Guo Z ，Abràmoff MD ，Han IC ... -  《-》

Projection-Resolved OCT Angiography of Microvascular Changes in Paracentral Acute Middle Maculopathy and Acute Macular Neuroretinopathy.

Chu S ，Nesper PL ，Soetikno BT ，Bakri SJ ，Fawzi AA ... -  《-》