Outer Retinal Microstructure in a Case of Acute Idiopathic Blind Spot Enlargement Syndrome

Abstract

Purpose: To present a patient with acute idiopathic blind spot enlargement syndrome who had abnormal changes in the outer retinal microstructure limited to areas with reduced responses on multifocal electroretinograms as well as to the area involving a scotoma. Methods and Results: We report the case of a 44-year-old man who developed an arcuate scotoma which was associated with a physiological blind spot in the left eye. The ophthalmoscopic, fluorescein angiographic, and full-field electroretinogram findings were normal. The amplitudes of the multifocal electroretinograms were reduced in the area of the scotoma. Optical coherence tomography showed that both the external limiting membrane and the inner and outer segment (IS/OS) line were intact, but that the middle cone outer segment tip line between the IS/OS line and the retinal pigment epithelium was absent in the nasal macular area of the left eye. Conclusions: These findings indicate that the integrity of not only the external limiting membrane and IS/OS line but also the cone outer segment tip line is important for the function of the retina.

Recovery of photoreceptor inner and outer segment layer thickness after reattachment of rhegmatogenous retinal detachment

“…Several investigators have examined the correlation between the integrity of the microstructures and the BCVA in eyes with a macular hole, occult macular dystrophy and the acute zonal occult outer retinopathy complex 4 8 14 15 18 19. Recently, a significant correlation was found between foveal function, for example, the VA, and the quantitative parameters of the photoreceptor microstructures 10 13 14.…”

High-definition Optical Coherence Tomography Findings in Acute Idiopathic Blind Spot Enlargement (AIBSE) Syndrome

“…5 Our observation of transient loss of ELM in the absence of cone outer segment tip line may represent a transient damage that occurs early in the course of the diseases. The integrity of external FIGURE 1.…”

Objective Assessment of Local Retinal Function by Focal Macular and Multifocal Electroretinograms

“…Optical coherence tomographic image showing that the IS/OS line, the middle cone outer segment tip (COST) line between the IS/OS line and the retinal pigment epithelium (RPE) are discernible in the control subject, but the IS/OS line is relative obscure and the COST line is absent in the patient. Modified and reproduced from (Hanazono et al, 2011) with permission from Dove Medical Press Ltd.…”

“…(Fletcher et al, 1988;Gass 2003) The pathological site for the visual field abnormalities is not the optic nerve but the retina, and the diagnosis is made from the mfERG findings ( Figure 8). (Sugahara et al, 2011) The spectral domain OCT (SD-OCT) images showed abnormalities in the microstructures of the outer retina, e.g., disruption or loss of the external limiting membrane (ELM), the IS/OS line, and/or an absence of the COST line in the areas of the visual field defects ( Figure 9). (Spaide et al, 2008;Sugahara et al, 2011;Tsunoda et al, 2011) It is still under discussion whether fmERGs are better than OCT in detecting the early abnormalities in OMD and in monitoring the changes in the severity or stage of OMD and AZOOR-complex.…”

“…(Bottom) Mean retinal thickness was within normal limits in each of the 9 ETDRS areas in the right macula (bottom left) whereas it was significantly thinner in the corresponding area for thevisual field defect in the left macula (bottom right). Modified and reproduced from (Sugahara et al, 2011) with permission from S. Karger AG, Basel.…”