الفهرس 
Anatomy of the VitreousOnly 14 pages are availabe for public view
 |  | from | 108 |  |  |
| | | from | 108 | | |
Abstract
Our aim in this essay is to review the recent advances in techniques of vitreoretinal surgery and management of vitreoretinal diseases.
Intraoperative OCT can be particularly helpful in providing immediate feedback to surgeons following surgical manipulations. In complex cases, such as tractional retinal detachments and proliferative diabetic retinopathy, it can be difficult to determine whether complete membrane removal has been achieved. Following ERM surgery, intraoperative OCT can provide high-resolution visualization of any residual membranes and help to identify whether the traction has been relieved. This immediate feedback can help to minimize unnecessary surgical maneuvers if total removal has been accomplished, improving surgical feedback.
Indocyanine green and trypan blue have been extensively used to stain the ILM. However, the retinal toxicity of indocyanine green and non-uniform staining with trypan blue has necessitated development of newer vital dyes. Brilliant blue G has recently been introduced as one such dye with adequate ILM staining and no reported retinal toxicity. Brilliant blue G appears to be safe dye for ILM staining in macular hole surgery.
Prostheses can be implanted in the retina to act as a substitute for the host’s photoreceptors. Retinal prostheses are only viable if the visual pathway distal to the retina is intact and functional. Two types of prostheses are under development according to the layer of retina receiving the device: epiretinal (on the surface of the retina) and subretinal (under the retina) implants.
Some investigators believed that the ideal way to administer t-PA in CRVO would be to inject it directly into a branch of the central retinal vein, and this belief lead to the development of REVS. REVS is vitrectomy followed by insertion of a microcannula into branches of the retinal vasculature with injection of pharmacologic agents such as t-PA. Previously reported results of one surgeon suggested that REVS promotes recovery of vision in CRVO. Since that report, other surgeons began using REVS techniques to treat CRVO.
Heavy silicone oil is a transparent, homogenous solution of two substances used as a single tamponade agent with improved properties. There are currently two products licensed for use in Europe. Namely, Densiron® (F6H8 + silicone oil) and Oxane HD® (fluorinated and hydrocarbonated olefin + silicone oil). They are used mainly for treatment of RD with inferior breaks.
Sutureless vitrectomy has rapidly been accepted as an essential part of vitreoretinal surgical setup. The size and structure of the wound along with near intact conjunctival covering makes the incision self-sealing and safe. This allows the vitrectomy instruments to be used without creating an initial limited peritomy to expose sclera, and obviates the need for sutures at the end of the procedure.
Retinal transplantation with the potential to generate new retinal cells provides an alternative approach to enable the replacement of lost RPE and photoreceptors. Stem cells as well as RPE cells possess a dormant potential to abandon their phenotype and re-differentiate into a different phenotype, such as neural retina. Intraocular stem cell transplantation may be therapeutic for retinal neurodegenerative diseases such as glaucoma via neuronal replacement and/or neuroprotection.
With the continued development of more potent drugs combined with research into novel delivery methods, there is a realistic hope that optimal therapeutic drug delivery for diseases of the posterior segment will be available in the near future, such as the sustained release implants which are designed to deliver drugs with precision directly to the vitreous, retina, and choroid.
Enzymatic vitrectomy has recently been used to make the creation of a PVD easier and safer. The benefits of the use of enzymes during vitrectomy are less damage to the anterior retinal surface and the optic nerve head and the production of a clean separation between the ILM and the posterior hyaloid membrane. Therefore, the use of enzymes can reduce the surgical risk and time also can lower the cost of surgery.