Biological Considerations for an Intraocular Retinal Prosthesis - Artificial Sight: Basic Research, Biomedical Engineering, and Clinical Advances - page 13

Figure 1.14. Schematic diagram of intraocular instruments in vitreoretinal surgery; note
that the instruments pass through the pars plana, an area located between the ciliary body
and the beginning of the retina (arrow).
remove it with simple aspiration; conversely, vigorous aspiration may also result
in retinal tears and subsequent retinal detachment. To overcome these problems,
the vitrectomy probe simultaneously cuts the vitreous in a guillotine-like manner
and aspirates the small chunks of vitreous, hence reducing traction on the retina.
For an epiretinal implant to be placed close to the retina, the vitreous should be
completely removed at the site of implantation. At the end of the vitrectomy,
the scleral incisions are closed using absorbable sutures, and the conjunctiva is
reattached to the limbus to cover the scleral incisions.
Retinal Disease
Common retinal diseases fall into one of two main categories: retinal vascular
disease and degenerative retinal disease. In general, vascular disease principally
damages the inner retinal layers, while degenerative disease primarily affects
outer retinal layers.
Inner Retinal Disease
Diseases of the inner retina are often associated with systemic diseases such as
diabetes mellitus and hypertension. In fact, diabetic retinopathy is the leading