Viscoelastics (also called OVDs: ophthalmic visco-surgical devices) are critically important to successful cataract surgery. We can use them in many of the steps of routine cataract surgery.
Ideal viscoelastic characteristics during each step of cataract surgery:
- Keep AC maintained and pressurized during main incision creation
- cohesive is best, dispersive works well also (I use dispersive)
- Maintain anterior chamber depth and keep the anterior lens capsule flat during capsulorrhexis creation.
- cohesive is best, but dispersive works well also as long as surgeon pivots within the incision (I use dispersive)
- Protect corneal endothelial during phacoemulsification
- dispersive is best because it will coat and protect the corneal endothelium
- Lubricate the IOL injector system
- dispersive is thinner and can lightly lubricate and coat the IOL injector but it sticks to the optic more whereas cohesive is thicker but it is easier to remove from the optic
- Expand the empty capsular bag for IOL insertion cohesive
- cohesive works well to maintain space and keep the empty capsular bag open
- Removability at the end of the case
- cohesive agents are much easier to remove from the eye
In this video, the first surgeon uses a cohesive viscoelastic to help inflate the capsular bag to allow IOL repositioning. The second surgeon uses a dispersive viscoelastic to help float a displaced glaucoma stent safely out of the eye.
click below to learn these two great pearls using viscoelastics:
Can you explain me how to calculate a spherical equivalence ,and how ca i achieve an ideal IOL calculation for the second eye to be very close to the refraction of the first eye ,please.