Author: ISABEL SENDINO-TENORIO (Spain)
Co-authors: Carlos Plaza-Laguardia, Amancia Mateos-Hernández, Laura Monje-Fernández, Felipe Costales-Mier, Esteban Pertejo-Fernandez, Borja Errazquin-Aguirre
Purpose
To describe the pathological findings in the optical coherence tomography (OCT) images using high segmentation technology such as the En Face mode or the OCT – Angiography (OCT – A).
Setting/Venue
Complejo Asistencial Universitario de León.
Methods
Case report.
Results
A 47-year-old caucasian woman presented with acute central scotoma in her left eye (OS) of 7 hours of evolution without other symptoms. Her best corrected visual acuity (BCVA) was 20/20 in the right eye (OD) and 20/70 in the OS. The OCT showed an hyper-reflective lesion in the inner nuclear layer (INL) and the outer plexiform layer (OPL). An identical shaped area was found in the OCT En Face analysis: an hyper-reflective zone in the middle retinal layers and hypo-reflective in the ellipsoid segmentation. In the OCT – A we found the hypo-reflective perifoveal area at the DCP level. Two and a half months later her BVCA was 20/20 with complete subjective resolution of the clinical process. The improvement was remarkable in the complementary tests with resolution of the ischemic area in the funduscopy, the disappearance of the hyperreflective area in the structural OCT (although a slight thinning of the internal layers was observed), and the resolution of the abnormalities in the En Face segmentation. A visual field test was performed to detect possible residual scotoma, however apparently the recovery was complete.
Conlusions
The En Face OCT technology, although it was initially described in 2006, has experienced a growth in its clinical use in recent times. Instead of employing high-resolution cross-sectional scans, En Face analysis allows the physician to enjoy c-scan images in the coronal plane thanks to the cubic image obtained by a dense raster scan. The advantages of this technology include the ability to locate lesions with great precision in the different layers of the retina using the axial distribution of cross sections and tracking systems that use retinal vessels and other reference points. The role that En face OCT has played in the study of PAMM has made it possible to differentiate 3 types of lesions based on the pathogenetic mechanism of microvascular ischemia of the retina. Our patient presented a fern-like pattern in the context of a PAMM with associated venous occlusion, so it is assumed that an increase of the intraluminal hydrostatic pressure was transmitted from the obstruction to the venous drainage area, which clinically translated into a wide zone of parafoveal retinal whitening and an acute onset paracentral scotoma. The visual prognosis of PAMM is usually good. To date, the majority of bibliographic publications report patients with partial recovery of the scotoma in the visual field, as well as stable retinal changes during the months following the acute phase. These changes are atrophy with attenuation of INL and OPL. On the other hand, although complete campimetric recovery is very infrequent, significant visual sequelae are extremely rare. Masaki Nakamura et al described a case that presented a serous retinal detachment in the fourth year of the follow-up of an hypertensive patient without associated ophthalmological pathology. Our patient presented a surprising visual recovery, in the absence of microperimetry in our center, which was observed by visual field analysis two and a half months after the clinical onset. The rise of new tomographic imaging techniques of the retina has dramatically increased the number of cases described in the literature of patients with PAMM. The physiopathogenesis, deduced thanks to the patterns obtained in the En Face OCT, suggests that within all the possible mechanisms and given the good evolution of the case, the transitory occlusion of the venous drainage of the ischemic area may be the reason for the fast and complete improvement, and therefore maybe this mechanism represents the one that offers the best prognosis as long as the venous flow remains altered for a short period of time.
Financial Disclosure
No
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