title: Development of a surgical procedure for implantation of a prototype suprachoroidal retinal prosthesis.
abstract: BACKGROUND
  Current surgical techniques for retinal prosthetic implantation require long and complicated surgery, which can increase the risk of complications and adverse outcomes.
  
  
  METHODS
  The suprachoroidal position is known to be an easier location to access surgically, and so this study aimed to develop a surgical procedure for implanting a prototype suprachoroidal retinal prosthesis. The array implantation procedure was developed in 14 enucleated eyes. A full-thickness scleral incision was made parallel to the intermuscular septum and superotemporal to the lateral rectus muscle. A pocket was created in the suprachoroidal space, and the moulded electrode array was inserted. The scleral incision was closed and scleral anchor point sutured. In 9 of the 14 eyes examined, the device insertion was obstructed by the posterior ciliary neurovascular bundle. Subsequently, the position of this neurovascular bundle in 10 eyes was characterized. Implantation and lead routing procedure was then developed in six human cadavers. The array was tunnelled forward from behind the pinna to the orbit. Next, a lateral canthotomy was made. Lead fixation was established by creating an orbitotomy drilled in the frontal process of the zygomatic bone. The lateral rectus muscle was detached, and implantation was carried out. Finally, pinna to lateral canthus measurements were taken on 61 patients in order to determine optimal lead length.
  
  
  RESULTS
  These results identified potential anatomical obstructions and informed the anatomical fitting of the suprachoroidal retinal prosthesis.
  
  
  CONCLUSIONS
  As a result of this work, a straightforward surgical approach for accurate anatomical suprachoroidal array and lead placement was developed for clinical application.
authors: Bionics Institute, Melbourne, Victoria, Australia.
authors: Alexia L
authors: AL
authors: Saunders
authors: Chris E
authors: CE
authors: Williams
authors: Wilson
authors: W
authors: Heriot
authors: Robert
authors: R
authors: Briggs
authors: Jonthan
authors: J
authors: Yeoh
authors: David A X
authors: DA
authors: Nayagam
authors: Mark
authors: M
authors: McCombe
authors: Joel
authors: J
authors: Villalobos
authors: Owen
authors: O
authors: Burns
authors: Chi D
authors: CD
authors: Luu
authors: Lauren N
authors: LN
authors: Ayton
authors: Michelle
authors: M
authors: McPhedran
authors: Nicholas L
authors: NL
authors: Opie
authors: Ceara
authors: C
authors: McGowan
authors: Robert K
authors: RK
authors: Shepherd
authors: Robyn
authors: R
authors: Guymer
authors: Penelope J
authors: PJ
authors: Allen
mesh_terms: D002102:Cadaver; D002829:Choroid / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008422:Materials Testing; D013508:Ophthalmologic Surgical Procedures; D019919:Prosthesis Implantation / Q000379:methods*; D013524:Surgical Flaps; D013536:Suture Techniques; D014019:Tissue Donors; D057488:Visual Prosthesis
keywords: blindness; cadaver; retinal prosthesis; retinitis pigmentosa