
Mohajeet Balveer Bhuckory
Instructor, Ophthalmology
Academic Appointments
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Instructor, Ophthalmology
All Publications
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Enhancing prosthetic vision by upgrade of a subretinal photovoltaic implant in situ.
Nature communications
2025; 16 (1): 2820
Abstract
In patients with atrophic age-related macular degeneration, subretinal photovoltaic implant (PRIMA) provided visual acuity up to 20/440, matching its 100 µm pixels size. Next-generation implants with smaller pixels should significantly improve the acuity. This study in rats evaluates removal of a subretinal implant, replacement with a newer device, and the resulting grating acuity in-vivo. Six weeks after the initial implantation with planar and 3-dimensional devices, the retina was re-detached, and the devices were successfully removed. Histology demonstrated a preserved inner nuclear layer. Re-implantation of new devices into the same location demonstrated retinal re-attachment to a new implant. New devices with 22 µm pixels increased the grating acuity from the 100 µm capability of PRIMA implants to 28 µm, reaching the limit of natural resolution in rats. Reimplanted devices exhibited the same stimulation threshold as for the first implantation of the same implants in a control group. This study demonstrates the feasibility of safely upgrading the subretinal photovoltaic implants to improve prosthetic visual acuity.
View details for DOI 10.1038/s41467-025-58084-y
View details for PubMedID 40118873
View details for PubMedCentralID PMC11928519
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3D electronic implants in subretinal space: Long-term follow-up in rodents.
Biomaterials
2024; 311: 122674
Abstract
Clinical results with photovoltaic subretinal prosthesis (PRIMA) demonstrated restoration of sight via electrical stimulation of the interneurons in degenerated retina, with resolution matching the 100 μm pixel size. Since scaling the pixels below 75 μm in the current bipolar planar geometry will significantly limit the penetration depth of the electric field and increase stimulation threshold, we explore the possibility of using smaller pixels based on a novel 3-dimensional honeycomb-shaped design. We assessed the long-term biocompatibility and stability of these arrays in rats by investigating the anatomical integration of the retina with flat and 3D implants and response to electrical stimulation over lifetime - up to 32-36 weeks post-implantation in aged rats. With both flat and 3D implants, signals elicited in the visual cortex decreased after the day of implantation by more than 3-fold, and gradually recovered over the next 12-16 weeks. With 25 μm high honeycomb walls, the majority of bipolar cells migrate into the wells, while amacrine and ganglion cells remain above the cavities, which is essential for selective network-mediated stimulation of the retina. Retinal thickness and full-field stimulation threshold with 40 μm-wide honeycomb pixels were comparable to those with planar devices - 0.05 mW/mm2 with 10 ms pulses. However, fewer cells from the inner nuclear layer migrated into the 20 μm-wide wells, and stimulation threshold increased over 12-16 weeks, before stabilizing at about 0.08 mW/mm2. Such threshold is still significantly lower than 1.8 mW/mm2 with a previous design of flat bipolar pixels, confirming the promise of the 3D honeycomb-based approach to high resolution subretinal prosthesis.
View details for DOI 10.1016/j.biomaterials.2024.122674
View details for PubMedID 38897028
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On selectivity of neural stimulation with subretinal photovoltaic implants
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024
View details for Web of Science ID 001313316205328
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Transcriptional and Translational Profiling of Reactive Muller Glia Following Cell-type specific Retinal Injury
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024
View details for Web of Science ID 001312227704300
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Mapping the retinal resistivity with electrical impedance tomography for modeling of retinal stimulation
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024
View details for Web of Science ID 001313316205324
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Replacement of a subretinal prosthesis with a higher-resolution array improves grating acuity in the same animal
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024
View details for Web of Science ID 001313316205325
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Long-term integration of the retina with 3D implants: structure and function
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844401305225
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IFT88 Mediates Cilia-Associated Wound Repair in Retinal Pigment Epithelium
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844437004307
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Retinal absorption measurements for laser therapy through interferometric imaging of the thermal expansion
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844401303047
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3-dimensional subretinal prosthesis with single-cell resolution
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844437006274
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Retinal integration with a subretinal honeycomb-shaped prosthesis
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021
View details for Web of Science ID 000690761600452
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Dynamic Transcriptional and Translational Profiling of Reactive Muller Glia Following Retinal Injury
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021
View details for Web of Science ID 000690761100769
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Optically configurable confinement of electric field with photovoltaic retinal prosthesis
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021
View details for Web of Science ID 000690761600406
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Subretinal monopolar photovoltaic arrays provide pixel size-independent stimulation threshold and 40 mu m resolution under spatiotemporal modulation
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021
View details for Web of Science ID 000690761600405
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Titration for selective RPE therapy using a continuous line scanning laser
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2019
View details for Web of Science ID 000488800700240