Visualisation of active subretinal implants with external connections by high-resolution CT

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Subretinal implants offer a promising approach for vision restoration.
• Assessing the position and integrity of these implants is crucial for patient outcomes.
• External components of retinal implants are not directly visible during clinical examination.

Purpose of the Study:

• To evaluate the utility of high-resolution computed tomography (CT) for assessing subretinal implants.
• To visualize the three-dimensional path and mobility of subretinal implants within the orbital cavity.
• To determine if CT can assess the technical integrity, biocompatibility, and biostability of retinal implants.

Main Methods:

• High-resolution CT scans were performed on two patients with active subretinal implants.
• Cranial scans were acquired in multiple gaze directions with eyes open and closed.
• Three-dimensional image reconstruction was used to visualize implant pathways and components.

Main Results:

• High-quality CT images and 3D models were obtained, detailing the entire implant path.
• The subretinal implant demonstrated mobility following eye movements in all directions.
• Minimal restriction of eye movements was observed, consistent with previous findings.

Conclusions:

• High-resolution CT is a valuable tool for assessing the position and integrity of subretinal implants.
• CT imaging can visualize extraocular and subretinal portions of the implant, including the micro-photodiode array.
• This imaging modality aids in evaluating the biocompatibility and biostability of retinal implant technology.