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Argus II retinal prosthesis malrotation and repositioning with intraoperative optical coherence tomography in a posterior staphyloma.

Seider MI, Hahn P - Clin Ophthalmol (2015)

Bottom Line: During tacking of the electronics array a clockwise rotation occurred resulting in malposition.The patient experienced an improvement in vision as a result of the surgery.It is important to differentiate malrotation from tack misplacement - the former may be addressed with array unrotation or partial tack withdrawal and the latter may require tack removal and reinsertion.

View Article: PubMed Central - PubMed

Affiliation: Duke University Eye Center, Durham, NC, USA.

ABSTRACT

Introduction: The Argus II retinal prosthesis may improve visual function in patients with severe vision loss from retinitis pigmentosa. Optimal centration of the electrode array over the macula is important to achieve optimal visual results. Argus tack malrotation is a novel entity that may be encountered during placement, especially in patients with posterior staphyloma.

Methods: Retrospective case review.

Results: During tacking of the electronics array a clockwise rotation occurred resulting in malposition. We hypothesize this was secondary to undue rotation or posterior pressure applied during tack insertion in conjunction with placement over a previously unrecognized posterior staphyloma. Intraoperative optical coherence tomography, because of the cross-sectional images provided, was helpful in visualizing the distance between the electronics array and the retina, which was difficult to assess using the surgical microscope alone. Repositioning was achieved by adjusting the tack without removal. The patient experienced an improvement in vision as a result of the surgery.

Conclusion: Malrotation may occur when tacking the Argus II prosthesis, and the presence of a posterior staphyloma may increase this risk. It is important to differentiate malrotation from tack misplacement - the former may be addressed with array unrotation or partial tack withdrawal and the latter may require tack removal and reinsertion. Also, intraoperative optical coherence tomography may be helpful in characterizing electronics array position during surgery.

No MeSH data available.


Related in: MedlinePlus

Argus II prosthesis repositioning.Notes: (A) Preoperative color fundus photo of the left eye of a 66-year-old man with end-stage retinitis pigmentosa. (B) Preoperative spectral-domain optical coherence tomography (OCT) image showing sloping of the eye wall consistent with a posterior staphyloma. The elevated edge of the staphyloma (yellow arrow) and sub-retinal hyper-reflective material (red asterisk) are also in subsequent OCT images (D, F, and H) as landmarks showing similar scan locations. Note that all OCT images are shown in the standard format with elongated axial dimensions that exaggerate the distance between the prosthesis and the retinal surface. (C) Intrasurgical video-still image showing array malrotation over the optic nerve. (D) Intraoperative hand-held spectral-domain OCT image captured just after the moment in surgery imaged in (C), showing the array propped-up by the edge of the staphyloma. (E) Intrasurgical video-still image after array unrotation showing optimal positioning in the macula. (F) Intraoperative hand-held spectral-domain OCT captured just after the moment in surgery imaged in (E), showing the array free from the staphyloma edge. (G) Color scanning laser ophthalmoscopy image captured 3 months after surgery showing sustained optimal array positioning. The green line represents the OCT scan location shown in (H). (H) Spectral-domain OCT image 3 months after surgery confirming the array remains free from the staphyloma edge. The array does not fully contact the retina, and maximal distance between the array and retinal surface measures 500 µm (yellow calipers).
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f1-opth-9-2213: Argus II prosthesis repositioning.Notes: (A) Preoperative color fundus photo of the left eye of a 66-year-old man with end-stage retinitis pigmentosa. (B) Preoperative spectral-domain optical coherence tomography (OCT) image showing sloping of the eye wall consistent with a posterior staphyloma. The elevated edge of the staphyloma (yellow arrow) and sub-retinal hyper-reflective material (red asterisk) are also in subsequent OCT images (D, F, and H) as landmarks showing similar scan locations. Note that all OCT images are shown in the standard format with elongated axial dimensions that exaggerate the distance between the prosthesis and the retinal surface. (C) Intrasurgical video-still image showing array malrotation over the optic nerve. (D) Intraoperative hand-held spectral-domain OCT image captured just after the moment in surgery imaged in (C), showing the array propped-up by the edge of the staphyloma. (E) Intrasurgical video-still image after array unrotation showing optimal positioning in the macula. (F) Intraoperative hand-held spectral-domain OCT captured just after the moment in surgery imaged in (E), showing the array free from the staphyloma edge. (G) Color scanning laser ophthalmoscopy image captured 3 months after surgery showing sustained optimal array positioning. The green line represents the OCT scan location shown in (H). (H) Spectral-domain OCT image 3 months after surgery confirming the array remains free from the staphyloma edge. The array does not fully contact the retina, and maximal distance between the array and retinal surface measures 500 µm (yellow calipers).

Mentions: The Argus II epiretinal prosthesis was placed in the left eye of a 66-year-old man with bare light-perception vision in each eye from retinitis pigmentosa (Figure 1A). Preoperatively, spectral-domain OCT (Heidelberg Engineering, Heidelberg, Germany) demonstrated a posterior staphyloma (Figure 1B). During surgery, at the final moment of tack insertion, unintentional rotation of the array occurred (Figure 1C), resulting in the array partially overlying the optic nerve instead of being centered in the macula. The reason for this malrotation is unclear. We hypothesize this occurred because of an unintentional manual clockwise rotation of the forceps during insertion. It is also possible that excessive posterior pressure during tack placement resulted in tack rotation from over-compression of the tack spring. The position of the electronics array is determined by the orientation of the electronics cable as it enters the sclera, and it is also possible that array rotation occurred because of uneven tension on this cable due to an oblique sclerotomy.


Argus II retinal prosthesis malrotation and repositioning with intraoperative optical coherence tomography in a posterior staphyloma.

Seider MI, Hahn P - Clin Ophthalmol (2015)

Argus II prosthesis repositioning.Notes: (A) Preoperative color fundus photo of the left eye of a 66-year-old man with end-stage retinitis pigmentosa. (B) Preoperative spectral-domain optical coherence tomography (OCT) image showing sloping of the eye wall consistent with a posterior staphyloma. The elevated edge of the staphyloma (yellow arrow) and sub-retinal hyper-reflective material (red asterisk) are also in subsequent OCT images (D, F, and H) as landmarks showing similar scan locations. Note that all OCT images are shown in the standard format with elongated axial dimensions that exaggerate the distance between the prosthesis and the retinal surface. (C) Intrasurgical video-still image showing array malrotation over the optic nerve. (D) Intraoperative hand-held spectral-domain OCT image captured just after the moment in surgery imaged in (C), showing the array propped-up by the edge of the staphyloma. (E) Intrasurgical video-still image after array unrotation showing optimal positioning in the macula. (F) Intraoperative hand-held spectral-domain OCT captured just after the moment in surgery imaged in (E), showing the array free from the staphyloma edge. (G) Color scanning laser ophthalmoscopy image captured 3 months after surgery showing sustained optimal array positioning. The green line represents the OCT scan location shown in (H). (H) Spectral-domain OCT image 3 months after surgery confirming the array remains free from the staphyloma edge. The array does not fully contact the retina, and maximal distance between the array and retinal surface measures 500 µm (yellow calipers).
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Related In: Results  -  Collection

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f1-opth-9-2213: Argus II prosthesis repositioning.Notes: (A) Preoperative color fundus photo of the left eye of a 66-year-old man with end-stage retinitis pigmentosa. (B) Preoperative spectral-domain optical coherence tomography (OCT) image showing sloping of the eye wall consistent with a posterior staphyloma. The elevated edge of the staphyloma (yellow arrow) and sub-retinal hyper-reflective material (red asterisk) are also in subsequent OCT images (D, F, and H) as landmarks showing similar scan locations. Note that all OCT images are shown in the standard format with elongated axial dimensions that exaggerate the distance between the prosthesis and the retinal surface. (C) Intrasurgical video-still image showing array malrotation over the optic nerve. (D) Intraoperative hand-held spectral-domain OCT image captured just after the moment in surgery imaged in (C), showing the array propped-up by the edge of the staphyloma. (E) Intrasurgical video-still image after array unrotation showing optimal positioning in the macula. (F) Intraoperative hand-held spectral-domain OCT captured just after the moment in surgery imaged in (E), showing the array free from the staphyloma edge. (G) Color scanning laser ophthalmoscopy image captured 3 months after surgery showing sustained optimal array positioning. The green line represents the OCT scan location shown in (H). (H) Spectral-domain OCT image 3 months after surgery confirming the array remains free from the staphyloma edge. The array does not fully contact the retina, and maximal distance between the array and retinal surface measures 500 µm (yellow calipers).
Mentions: The Argus II epiretinal prosthesis was placed in the left eye of a 66-year-old man with bare light-perception vision in each eye from retinitis pigmentosa (Figure 1A). Preoperatively, spectral-domain OCT (Heidelberg Engineering, Heidelberg, Germany) demonstrated a posterior staphyloma (Figure 1B). During surgery, at the final moment of tack insertion, unintentional rotation of the array occurred (Figure 1C), resulting in the array partially overlying the optic nerve instead of being centered in the macula. The reason for this malrotation is unclear. We hypothesize this occurred because of an unintentional manual clockwise rotation of the forceps during insertion. It is also possible that excessive posterior pressure during tack placement resulted in tack rotation from over-compression of the tack spring. The position of the electronics array is determined by the orientation of the electronics cable as it enters the sclera, and it is also possible that array rotation occurred because of uneven tension on this cable due to an oblique sclerotomy.

Bottom Line: During tacking of the electronics array a clockwise rotation occurred resulting in malposition.The patient experienced an improvement in vision as a result of the surgery.It is important to differentiate malrotation from tack misplacement - the former may be addressed with array unrotation or partial tack withdrawal and the latter may require tack removal and reinsertion.

View Article: PubMed Central - PubMed

Affiliation: Duke University Eye Center, Durham, NC, USA.

ABSTRACT

Introduction: The Argus II retinal prosthesis may improve visual function in patients with severe vision loss from retinitis pigmentosa. Optimal centration of the electrode array over the macula is important to achieve optimal visual results. Argus tack malrotation is a novel entity that may be encountered during placement, especially in patients with posterior staphyloma.

Methods: Retrospective case review.

Results: During tacking of the electronics array a clockwise rotation occurred resulting in malposition. We hypothesize this was secondary to undue rotation or posterior pressure applied during tack insertion in conjunction with placement over a previously unrecognized posterior staphyloma. Intraoperative optical coherence tomography, because of the cross-sectional images provided, was helpful in visualizing the distance between the electronics array and the retina, which was difficult to assess using the surgical microscope alone. Repositioning was achieved by adjusting the tack without removal. The patient experienced an improvement in vision as a result of the surgery.

Conclusion: Malrotation may occur when tacking the Argus II prosthesis, and the presence of a posterior staphyloma may increase this risk. It is important to differentiate malrotation from tack misplacement - the former may be addressed with array unrotation or partial tack withdrawal and the latter may require tack removal and reinsertion. Also, intraoperative optical coherence tomography may be helpful in characterizing electronics array position during surgery.

No MeSH data available.


Related in: MedlinePlus