En-face OCT and OCT angiography analysis of macular choroidal macrovessel.

PURPOSE: To analyze en-face optical coherence tomography (OCT) and decorrelation signals on OCT angiography (OCTA) in two cases of macular choroidal macrovessel (MCM). OBSERVATIONS: Case report. Both the 64-year-old and 71-year-old females presented for a routine evaluation, and multimodal imaging analysis, including color fundus photography, indocyanine green angiography (ICG), spectral-domain optical coherence tomography (SD-OCT) and OCTA, was performed to diagnose a MCM. En-face OCT, en-face OCTA and decorrelation signals were analyzed through the MCM. In both reported cases, color fundus photograph revealed a serpiginoid lesion in the temporal macula. Red-free imaging enhanced the appearance of this lesion resembling a dilated choroidal vessel. Cross-sectional OCT showed an enlarged choroidal vessel causing elevation of the retinal pigment epithelium (RPE) within the fovea. En-face OCTA with segmentation below the choriocapillaris enhanced the MCM delineation. En-face OCT with segmentation below the choriocapillaris showed MCM with a greater distinctness than the en-face OCTA imaging. Decorrelation signals were not observed within MCM on cross-sectional OCTA. CONCLUSION AND IMPORTANCE: En-face OCT and decorrelation signals on OCTA may have diagnostic value in distinguishing macular choroidal macrovessel from other choroidal vascular diseases.

Optimizing optical coherence tomography and histopathology correlation in retinal imaging.

OBJECTIVE: To develop a methodology to correlate optical coherence tomography (OCT) images and histopathological sections from the same eye. Part 1: To determine the best fixative for optimal OCT and histopathological analysis in post-mortem eyes. Part 2: A protocol is proposed to correlate histopathological features and OCT scans from the same post-mortem eyes. DESIGN: Experimental study. PARTICIPANTS: Part 1: Twenty-three rabbit eyes and 14 post-mortem human eyes. Part 2: Nineteen post-mortem human eyes. METHODS: Part 1: Six different fixatives were tested, and specimens were evaluated on 4 criteria: globe shape, structure opacification, retinal detachment, and nuclear details. Part 2: Based on the findings from Part 1, fixed human eyes were imaged using OCT. Orientation-controlled histopathological processing was performed to obtain serial tissue sections from paraffin embedded tissue, which were matched to corresponding OCT images. RESULTS: Part 1: Of the 6 fixatives, 2% glutaraldehyde and Davidson's solution met the proposed criteria in rabbit eyes. Of these, glutaraldehyde showed similar results in human eyes and was selected for Part 2. Part 2: Using anatomical landmarks, cross-sectional histopathological sections in the same orientation as the OCT images were correlated to their corresponding OCT images. Retinal lesions such as a macular hole, an epiretinal membrane, and the presence of drusen were easily correlated, proving the reliability of our methodology. Moreover, the photoreceptor's inner/outer junction was correlated to a hyperreflective band on OCT. CONCLUSIONS: A standardized protocol was developed to correlate OCT images and histopathological findings by generating serial cross-sections of the retina, which can be used to better understand otherwise ambiguous OCT findings.

Choriocapillaris Loss in Advanced Age-Related Macular Degeneration.

The purpose of this review is to summarize the current knowledge on choriocapillaris loss in advanced age macular degeneration (AMD). Several histopathological studies in animal models and human eyes had showed that the choriocapillaris density decreases with age. However, the role of choriocapillaris loss is still unclear in AMD and its advanced forms, either choroidal neovascularization (CNV) or geographic atrophy (GA). Some authors have hypothesized that choriocapillaris loss might precede overt retinal pigment epithelium atrophy. Others have hypothesized that deposition of complement complexes on and around the choriocapillaris could be related to the tissue loss observed in early AMD. The development of imaging modalities, such as optical coherence tomography angiography (OCTA), have led to a better understanding of underlying physiopathological mechanisms in AMD. OCTA showed atrophy of choriocapillaris underneath and beyond the region of photoreceptors and RPE loss, in agreement with previous histopathologic studies. The evolution of OCTA technology suggests that CNV seems to originate from regions of severe choriocapillaris alteration. Significant progress has been made in the understanding of development and progression of GA and CNV. In vivo investigation of the choriocapillaris using OCTA may lead to new insights related to underlying disease mechanisms in AMD.

Ten-Year Follow-Up after Bilateral Submacular Neovascular Membrane Removal in a Case of Autosomal Recessive Bestrophinopathy.

Herein, we report the case of an 8-year-old girl who presented in December 2000 with a submacular neovascular membrane in the right eye, with a clinical diagnosis of Best disease. At that time, she underwent pars plana vitrectomy (PPV) with removal of the subretinal choroidal neovascularization (CNV). Her vision improved from 20/200 to 20/25. Four years later, a new CNV developed in the other eye. Initially, she underwent unsuccessful photodynamic therapy. As her vision worsened, she underwent a second, this time successful, PPV with membrane removal in the left eye, with vision improving to 20/30. Ten years later, she returned complaining of vision loss over the last year. Her vision was 20/200 OU, and optical coherence tomography demonstrated very large intraretinal cystoid spaces resembling bilateral macular schisis. Four ranibizumab injections as well as dorzolamide eye drops were tried, both without success. Finally, she underwent PPV with internal limiting membrane peeling and gas-fluid exchange in the left eye. One month later, the macula appeared flat and vision had improved to 20/60. The same procedure was performed 1 year later for the right eye, with vision improving to 20/80. One year later, mild cystic spaces developed again in both eyes, although much smaller than previously observed. Her vision remained stable.