Sequential spectral domain OCT documentation of retinal changes after branch retinal artery occlusion

Evaluation of retinal sensitivity and microstructure in areas of capillary nonperfusion of eyes with branch retinal vein occlusion

Background

To evaluate macular microstructure alterations in the parafoveal nonperfusion areas of eyes with branch retinal vein occlusions (BRVO), and to investigate their impact on retinal sensitivity.

Methods

This was a cross-sectional study including thirteen BRVO patients with parafoveal capillary nonperfusion areas (NPA). Multiple modalities including microperimetry, optical coherence tomography angiography, and optical coherence tomography were performed to measure retinal sensitivity and thickness, and to identify the microstructure changes and perfusion status.

Results

The retinal sensitivity and thickness in the NPA were significantly lower than those in the perfusion areas (PA) (P = 0.001, P = 0.003). Microstructure changes, including disorganization of the retinal inner layers (DRIL), disruption of the outer retinal layers, and cysts were more frequently observed in NPA (P = 0.002, P = 0.018, P = 0.068). Within NPA, the retinal sensitivity of areas with DRIL, and outer retinal layers disruption was significantly lower than that of the areas without DRIL (P = 0.016), and with intact outer retinal layers (P < 0.001), respectively. 1dB increase in retinal sensitivity was correlated with 2.2 μm (95 % confidence interval, 1.71–2.7) increase of the thickness (P < 0.001). The retinal sensitivity was significantly lower at points with both DRIL and outer retinal layers disruption than at the points with DRIL or outer retina layers disruption alone (P = 0.001, P = 0.001).

Conclusions

Alterations in the macular microstructure are associated with ischemia, especially DRIL. DRIL and outer retinal layers disruption are imaging features that have important implications for local retinal sensitivity in the ischemic areas, and where the microstructure of both inner and outer retinal layers is disrupted the function is further destructed.

Multimodal imaging in acute retinal ischemia: spectral domain OCT, OCT-angiography and fundus autofluorescence

AIM

To describe retinal findings of various imaging modalities in acute retinal ischemia.

METHODS

Fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), OCT-angiography (OCT-A) and fundus autofluorescence (FAF) images of 13 patients (mean age 64y, range 28-86y) with acute retinal ischemia were evaluated. Six suffered from branch arterial occlusion, 2 had a central retinal artery occlusion, 2 had a combined arteriovenous occlusions, 1 patient had a retrobulbar arterial compression by an orbital haemangioma and 2 patients showed an ocular ischemic syndrome.

RESULTS

All patients showed increased reflectivity and thickening of the ischemic retinal tissue. In 10 out of 13 patients SD-OCT revealed an additional highly reflective band located within or above the outer plexiform layer. Morphological characteristics were a decreasing intensity with distance from the fovea, partially segmental occurrence and manifestation limited in time. OCT-A showed a loss of flow signal in the superficial and deep capillary plexus at the affected areas. Reduced flow signal was detected underneath the regions with retinal edema. FAF showed areas of altered signal intensity at the posterior pole. The regions of decreased FAF signal corresponded to peri-venous regions.

CONCLUSION

Multimodal imaging modalities in retinal ischemia yield characteristic findings and valuable diagnostic information. Conventional OCT identifies hyperreflectivity and thickening and a mid-retinal hyperreflective band is frequently observed. OCT-A examination reveals demarcation of the ischemic retinal area on the vascular level. FAF shows decreased fluorescence signal in areas of retinal edema often corresponding to peri-venous regions.

Detection of underdiagnosed concurrent branch retinal artery occlusion in a patient with central retinal vein occlusion using spectral domain optical coherence tomography

Background

Combined branch retinal artery and central retinal vein occlusion is a rare condition that has been infrequently reported. This case report, aside from reporting the above-mentioned condition, highlights the importance of performing spectral domain optical coherence tomography in establishing a complete diagnosis, especially in uncertain and complicated cases. We also present spectral domain optical coherence tomography findings of a case of combined unilateral simultaneous central retinal vein and branch retinal artery occlusion.

Case presentation

We present a single case of an initially missed, unilateral branch retinal artery occlusion combined with central retinal vein occlusion in a 51-year-old female Chinese patient without a significant past medical history, who experienced sudden, painless vision diminution in her right eye eleven days prior to presentation. She eventually recovered visual acuity to 0.60, despite having presented with poor vision.

Conclusion

Combined unilateral central retinal vein and branch retinal artery occlusion may occur in patients with no medical history of arterial hypertension and diabetes mellitus and can achieve a relatively good visual outcome. This case reaffirms the significance of performing a spectral domain optical coherence tomography examination in patients suffering from central retinal vein occlusion with suspicion of unilateral simultaneous branch retinal artery occlusion to identify the affected pathological areas.

In vivo identification of alteration of inner neurosensory layers in branch retinal artery occlusion

Background/aims

To characterise the extension and progression of alteration of neurosensory layers following acute and chronic branch retinal artery occlusion (BRAO) in vivo using spectral-domain optical coherence tomography.

Methods

In this observational case series, eight eyes with acute BRAO and nine eyes with chronic BRAO were analysed using a Spectralis Heidelberg Retina Angiograph (HRA)+optical coherence tomography system including eye tracking. Patients with acute BRAO were examined within 36±5 h after primary event and at weekly/monthly intervals thereafter. Segmentation measurements of all individual neurosensory layers were performed on single A-scans at six locations in affected and corresponding non-affected areas. The thickness values of the retinal nerve fibre layer together with the ganglion cell layer (NFL/GCL), inner plexiform layer (IPL), inner nuclear layer together with outer plexiform layer (INL/OPL), outer nuclear layer (ONL), and photoreceptor layers together with the retinal pigment epithelium (PR/RPE) were measured and analysed.

Results

Segmentation evaluation revealed a distinct increase in thickness of inner neurosensory layers including the NFL/GCL (35%), IPL (80%), INL/OPL (48%) and mildly the ONL by 21% in acute ischaemia compared with corresponding layers in non-ischaemic areas. Regression of intraretinal oedema was followed by persistent retinal atrophy with loss of differentiation between IPL and INL/OPL at month 2. In contrast, the ONL and subjacent PR/RPE retained their physiological thickness in patients with chronic BRAO.

Conclusion

In vivo assessment of retinal layer morphology allows a precise identification of the pathophysiology in retinal ischaemia.