This video describes the basic principles of cannulas insertion in vitreoretinal surgery.
Video created by Dr. Anfisa Ayalon
Surgical technique: Dr. Alexander Rubowitz, Israel
Trocar-cannula system insertion
Before making the first incision check that all the instruments are available and the infusion system works.
Making the right incisions allows:
- Easy insertion of instruments through the cannula during the surgery
- Prevents postoperative leak of fluid, gas, silicone oil
Multiple techniques exist. One of the techniques you can see in the video.
Important tips:
- Stabilize the eye with forceps or a cotton tip applicator
- Stay radial to the limbus
- Stay flat with your trocar and create a scleral tunnel (allows better self-sealing of the wound)
- In phakic patients be careful not to punch the lens
The video describes important tips for infusion placement.
Video created by Dr. Anfisa Ayalon
Surgical technique: Dr. Alexander Rubowitz, Israel
Evaluation of the infusion placement
The infusion system allows passage of irrigating solution or air during the surgery.
- Before insertion, check that the infusion system works properly
- After insertion, make sure that the infusion tip was placed into the vitreous cavity and not under the retina
Important tips:
-Press on the globe till you observe the appearance of the infusion tip
- Look from the side in a case when infusion tip is not detected under the direct view
-Use a light pipe in cases with opaque media
This video describes the principles of core vitrectomy & peripheral shave.
Video created by Anfisa Ayalon
Surgical technique: Dr. Alexander Rubowitz, Israel
Core vs Shave
The idea of core vitrectomy is to remove a central part of the vitreous.
Debulking of the central vitreous allows:
- To perform manipulations during the surgery without traction on vitreous strands
- To approach a preretinal space (eg for injection of triamcinolone or dyes for membrane stain)
Important tips for core vitrectomy:
- Illuminate well the area of work
- Move with a vitrector to cut a vitreous and not just aspirate a BSS solution
The idea of peripheral shaving is to release peripheral traction over the detached retina.
Lower vacuum and higher cut-rate during shaving reduce pulling the retina toward the vitrector.
Tips for better visualization of the peripheral part of the vitreous:
-Use a scleral depression
-Close illumination
-Stain the vitreous fibers with a triamcinolone
-Use a perflurocarbone liquid to shift the subretinal fluid anteriorly and to elevate the peripheral part of the retina
This video describes the principles of fluid-air exchange: indications of FAX, how to drain the fluid, and how to avoid intraoperative venous air embolism.
Video created by Dr. Anfisa Ayalon
Surgical technique: Dr. Alexander Rubowitz, Israel
Fluid-air exchange (FAX)
Fluid air exchange is done by simultaneous injection of the air into the vitreous cavity and removal of the fluid.
FAX allows:
- Retinal reattachment and removal of subretinal fluid during retinal detachment surgery
- Replacement of fluid for further air-gas or air-oil exchange
Air by itself can be used as a short term tamponade
Important tips to improve visualization during FAX:
- Refocus
- Keep the light pipe at the fluid level to reduce reflections
-Don’t try to remove the air bubble once they got into the anterior chamber,
instead of this merge them or use a viscoelastic material to displace them
Be aware of venous air embolism syndrome!
Reconfirm that the infusion cannula didn’t slip. This simple precaution can help to prevent rare but fatal complication.
This video highlights the principles of vitreous visualization, chromovitrectomy, and dyes helping to identify the vitreous.
Video created by Anfisa Ayalon
Surgical technique: Dr. Alexander Rubowitz & Dr. Itzhak Hemo, Israel
How to “see” the vitreous?
Vitreous is a transparent substance that should be properly removed during vitrectomy.
Few ways to identify the vitreous strands:
- No stain ( by using the light pipe illumination and watching the reflections from the vitreous fibers)
-Choromovitrectomy (implies the use of dyes identifying the vitreous strands e.g. triamcinolone acetonide, membrane blue dual dye)
This video describes the principles of PVD induction: why and how to perform PVD, what instruments to use and how to create a retinal pick by yourselves.
Video created by Dr. Anfisa Ayalon
Surgical technique: Dr. Alexander Rubowitz & Dr. Itzhak Hemo, Israel
Posterior vitreous detachment induction
Complete removal of the posterior hyaloid is an important step in vitrectomy for different vitreoretinal disorders
PVD allows:
- To reduce tractional forces acting upon the retina
- To prevent peripheral retinal tears as well as vitreomacular tractions
-To eliminate the scaffold for new membrane formation in eyes with proliferative diabetic retinopathy
Few ways to perform PVD:
- The vitrector active aspiration (the most common)
- Forceps
- Retinal (vitreous) pick or angled needle
Important tips:
- Stay with the vitrector above the peripapillary retina and aspirate with a cutter off till the port of the vitrector is occluded by the vitreous
- Once the port is occluded, gently and slowly pull forward and radially the posterior hyaloid in an attempt to lift the Weiss ring
- Switch between cutter on and cutter off to reduces excessive dragging of the vitreous