Short-term assessment of subfoveal injection of AAV2-hCHM gene augmentation in choroideremia using adaptive optics ophthalmoscopy

Subretinal injection for gene augmentation in retinal degenerations forcefully detaches the neural retina from the retinal pigment epithelium (RPE), potentially damaging photoreceptors and/or RPE cells. Here, we use adaptive optics scanning light ophthalmoscopy (AOSLO) to assess the short-term integrity of the cone mosaic following subretinal injections of AAV2-hCHM gene augmentation in subjects with choroideremia (CHM). Nine adult CHM patients received uniocular subfoveal injections of low dose (5x10^10 vector genome (vg) per eye, n=5) or high dose (1x10^11 vg per eye, n=4) AAV2-hCHM. The macular regions of both eyes were imaged pre- and one-month post-injection using a custom-built, multimodal AOSLO. Post-injection cone inner segment mosaics were compared to pre-injection mosaics at multiple regions of interest (ROIs). Post-injection AOSLO images showed preservation of the cone mosaic in all 9 AAV2-hCHM injected eyes. Mosaics appeared intact and contiguous one-month post-injection, with the exception of foveal disruption in one patient. Co-localized optical coherence tomography showed foveal cone outer segment (COS) shortening post-injection (significant, n=4; non-significant, n=4; unchanged, n=1). Integrity of the cone mosaic is maintained following subretinal delivery of AAV2-hCHM, providing strong evidence in support of the safety of the injections. Minor foveal thinning observed following surgery corresponds with short-term COS shortening rather than cone cell loss.

Download Full-text

Multimodal imaging of torpedo maculopathy including adaptive optics

European Journal of Ophthalmology ◽

10.1177/1120672119827772 ◽

2019 ◽

Vol 30 (2) ◽

pp. NP27-NP31 ◽

Cited By ~ 1

Author(s):

Juliette Hugo ◽

Marie Beylerian ◽

Eric Denion ◽

Aurore Aziz ◽

Pierre Gascon ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Retinal Pigment Epithelium ◽

Fluorescein Angiography ◽

Adaptive Optics ◽

Multimodal Imaging ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Optical Coherence ◽

Cone Mosaic ◽

Torpedo Maculopathy

Purpose: The etiology of torpedo maculopathy remains unknown, but it has been recently suggested that it could represent a persistent defect in the development of the retinal pigment epithelium. As retinal pigment epithelium and photoreceptors form a functional unit, an alteration of photoreceptor distribution or function is predictable. The aim of this study is to describe multimodal imaging, including adaptive optics, in three cases of torpedo maculopathy, and discuss its pathogenesis. Methods: Multimodal imaging is presented, including fundus photographs, optical coherence tomography, adaptive optics, autofluorescence, fluorescein angiography, and ultra-widefield retinal imaging in three cases of torpedo maculopathy. Results: An oval-shaped well-delimited chorioretinal lesion both hypopigmented centrally and with a hyperpigmented border in the temporal macula, consistent with torpedo maculopathy, was observed in three patients. Optical coherence tomography showed a preservation of the inner retina, a mild atrophy of the outer retina, an alteration of the ellipsoid zone and of the retinal pigment epithelium layer, and a neurosensory detachment. These lesions were hypoautofluorescent with a hyperautofluorescent border. Fluorescein angiography showed a hyperfluorescence by window effect. Adaptive optics imaging showed an alteration of the cone mosaic within the lesions, with a lower cone density and a higher spacing between cones. Conclusion: The alteration of the cone mosaic suggested by adaptive optics in torpedo maculopathy has never been described and could be explained by the alteration of the retinal pigment epithelium. Our results support the existing hypothesis on the pathogenesis of torpedo maculopathy that a persistent defect in the development of the retinal pigment epithelium may be responsible for this clinical entity.

Download Full-text

Assessment of fundus autofluorescence and adaptive optics high-resolution images in macular disorders

10.21203/rs.3.rs-176004/v1 ◽

2021 ◽

Author(s):

Radu Ochinciuc ◽

Uliana Ochinciuc ◽

George Balta ◽

Adrian Teodoru ◽

Leila Al Barri ◽

...

Keyword(s):

High Resolution ◽

Adaptive Optics ◽

Pigment Epithelium ◽

Fundus Autofluorescence ◽

Retinal Pigment ◽

Subretinal Fluid ◽

Cellular Level ◽

Cone Mosaic ◽

High Resolution Images ◽

Cone Density

Abstract Purpose This study analyzed and compared the results of adaptive optics (AO) and fundus autofluorescence (FAF) in various maculopathies. Methods The study included four different types of maculopathy: central serous chorioretinopathy (CSC), retinitis pigmentosa (RP), Stargardt disease (STGD) and phototoxic retinopathy. In all four cases cone mosaic and cone density were obtained using AO fundus camera. Further the high resolution images were compared with the FAF and optical coherence tomography (OCT) results. Results In CSC, FAF and AO were able to show changes in the macula even two years after the subretinal fluid resorption, as opposed to a normal OCT. The improvement of FAF and cone mosaic appearance was concomitant with the visual acuity growth. Several cone mosaic phenotypes were observed in RP and STGD. In RP the cone density was 24.240cones/mm2 in the center, and decreased to 8.163cones/mm2 in the parafoveolar area. In STGD the cone density was lower in the center, 9.219cones/mm2, and higher at the periphery, 12.594cones/mm2. In the case of phototoxic retinopathy, AO and OCT were more effective than FAF in highlighting the photoreceptor and retinal pigment epithelium lesions. Conclusions FAF and AO are very useful tools in macular pathologies examination. FAF can give us a true picture about metabolic changes in the macula while AO allows us to view changes up to the cellular level.

Download Full-text

A human model of Batten disease shows role of CLN3 in phagocytosis at the photoreceptor–RPE interface

Communications Biology ◽

10.1038/s42003-021-01682-5 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Cynthia Tang ◽

Jimin Han ◽

Sonal Dalvi ◽

Kannan Manian ◽

Lauren Winschel ◽

...

Keyword(s):

Photoreceptor Cell ◽

Vision Loss ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Cell Loss ◽

Human Model ◽

Lysosomal Storage ◽

Rpe Cells ◽

Cln3 Disease

AbstractMutations in CLN3 lead to photoreceptor cell loss in CLN3 disease, a lysosomal storage disorder characterized by childhood-onset vision loss, neurological impairment, and premature death. However, how CLN3 mutations cause photoreceptor cell death is not known. Here, we show that CLN3 is required for phagocytosis of photoreceptor outer segment (POS) by retinal pigment epithelium (RPE) cells, a cellular process essential for photoreceptor survival. Specifically, a proportion of CLN3 in human, mouse, and iPSC-RPE cells localized to RPE microvilli, the site of POS phagocytosis. Furthermore, patient-derived CLN3 disease iPSC-RPE cells showed decreased RPE microvilli density and reduced POS binding and ingestion. Notably, POS phagocytosis defect in CLN3 disease iPSC-RPE cells could be rescued by wild-type CLN3 gene supplementation. Altogether, these results illustrate a novel role of CLN3 in regulating POS phagocytosis and suggest a contribution of primary RPE dysfunction for photoreceptor cell loss in CLN3 disease that can be targeted by gene therapy.

Download Full-text

Multimodal Imaging of Torpedo Maculopathy With Fluorescence Adaptive Optics Imaging of Individual Retinal Pigmented Epithelial Cells

Frontiers in Medicine ◽

10.3389/fmed.2021.769308 ◽

2021 ◽

Vol 8 ◽

Author(s):

Kari V. Vienola ◽

Kunal K. Dansingani ◽

Andrew W. Eller ◽

Joseph N. Martel ◽

Valerie C. Snyder ◽

...

Keyword(s):

Adaptive Optics ◽

Imaging Techniques ◽

Pigment Epithelium ◽

Fundus Autofluorescence ◽

Retinal Pigment ◽

Tissue Level ◽

Cellular Level ◽

Clinical Imaging ◽

Rpe Cells ◽

Torpedo Maculopathy

Torpedo maculopathy (TM) is a rare congenital defect of the retinal pigment epithelium (RPE). The RPE is often evaluated clinically using fundus autofluorescence (AF), a technique that visualizes RPE structure at the tissue level from the intrinsic AF of RPE fluorophores. TM lesions typically emit little or no AF, but this macroscopic assessment is unable to resolve the RPE cells, leaving the organization of the RPE cell mosaic in TM unknown. We used fluorescence adaptive optics scanning laser ophthalmoscopy (AOSLO) to show here for the first time the microscopic cellular-level structural alterations to the RPE cell mosaic in TM that underlie the tissue-level changes seen in conventional clinical imaging. We evaluated two patients with TM using conventional clinical imaging techniques and adaptive optics (AO) infrared autofluorescence (IRAF) in AOSLO. Confocal AOSLO revealed relatively normal cones outside the TM lesion but altered cone appearance within it and along its margins in both patients. We quantified cone topography and RPE cell morphometry from the fovea to the margin of the lesion in case 1 and found cone density to be within the normal range across the locations imaged. However, RPE morphometric analysis revealed disrupted RPE cells outside the margin of the lesion; the mean RPE cell area was greater than two standard deviations above the normative range up to approximately 1.5 mm from the lesion margin. Similar morphometric changes were seen to individual RPE cells in case 2. Multi-modal imaging with AOSLO reveals that RPE cells are abnormal in TM well beyond the margins of the characteristic TM lesion boundary defined with conventional clinical imaging. Since the TM fovea appears to be fully formed, with normal cone packing, it is possible that the congenital RPE defect in TM occurs relatively late in retinal development. This work demonstrates how cellular level imaging of the RPE can provide new insight into RPE pathologies, particularly for rare conditions such as TM.

Download Full-text

Polypoidal Choroidal Vasculopathy – A Type I Polypoidal Subretinal Neovasculopathy

The Open Ophthalmology Journal ◽

10.2174/1874364101307010082 ◽

2013 ◽

Vol 7 (1) ◽

pp. 82-84 ◽

Cited By ~ 12

Author(s):

Gregg T Kokame

Keyword(s):

Polypoidal Choroidal Vasculopathy ◽

Pigment Epithelium ◽

Retinal Pigment ◽

High Dose ◽

Type I ◽

Vascular Abnormality ◽

Icg Angiography ◽

New Development ◽

The Right ◽

Choroidal Vasculopathy

This 47 year old female developed the new onset of a polypoidal subretinal neovascular membrane in the left eye 13 years after having polypoidal choroidal vasculopathy (PCV) treated in the right eye. The indocyanine green (ICG) angiography of the left eye at initial presentation showed a normal choroidal vascular pattern without PCV. The new development of a PCV complex on ICG angiography demonstrates that PCV is truly a type of subretinal neovascularization, and not a choroidal vascular abnormality. The optical coherence tomography shows that the polypoidal vascular complex lies above Bruch’s membrane and beneath the retinal pigment epithelium, and not within the choroid. Treatment with high dose ranibizumab (2.0 mg) resulted in excellent polyp closure and regression of the branching vascular network. The documented new development of polypoidal subretinal vessels on ICG angiography and the response to ranibizumab supports that PCV is a polypoidal neovasculopathy (PNV).

Download Full-text

Monocarboxylate Transporter 1 (MCT1) mediates succinate export in the retina

10.1101/2021.11.19.469314 ◽

2021 ◽

Author(s):

Celia M Bisbach ◽

Daniel T Hass ◽

James B Hurley

Keyword(s):

Plasma Membranes ◽

Ex Vivo ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Monocarboxylate Transporter ◽

Gas Chromatography Mass Spectrometry ◽

Short Term ◽

Monocarboxylate Transporter 1 ◽

Retinal Tissue ◽

Ex Vivo Culture

Purpose: Succinate is exported by the retina and imported by eyecup tissue. The transporter(s) mediating this process have not yet been identified. Recent studies showed that Monocarboxylate Transporter 1 (MCT1) can transport succinate across plasma membranes in cardiac and skeletal muscle. Retina and retinal pigment epithelium (RPE) both express multiple MCT isoforms including MCT1. We tested the hypothesis that MCTs facilitate retinal succinate export and RPE succinate import. Methods: We assessed retinal succinate export and eyecup succinate import in short term ex vivo culture using gas chromatography-mass spectrometry. We test the dependence of succinate export and import on pH, proton ionophores, conventional MCT substrates, and the MCT inhibitors AZD3965, AR-C155858, and diclofenac. Results: Succinate exits retinal tissue through MCT1 but does not enter RPE through MCT1 or any other MCT. Intracellular succinate levels are a contributing factor that determines if an MCT1-expressing tissue will export succinate. Conclusions: MCT1 facilitates export of succinate from retinas. An unidentified, non-MCT transporter facilitates import of succinate into RPE.

Download Full-text