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OPHTHALMIC 
VISCOSURGICAL DEVICES 
SIVATEJA CHALLA
INTRODUCTION 
Substances having dual properties 
1.Viscocity of fluid 
2.Elasticity of gel or solid
HISTORY 
• Viscosurgery was a term coined by Balazs 
• Sodium Hyaluronate was 1st used in 
ophthalmic surgery as viscoelastic in 1972 as a 
replacement for vitreous & aqueous humor
IDEAL VISCOELASTIC 
• Ease of infusion 
• Retention under +ve pressure in eye 
• Retention during phaco 
• Easy removal/no removal needed 
• Doesnt interfere with instruments/IOL placement 
• Protects endothelium 
• Nontoxic 
• Does not obstruct aq.outflow
PROPERTIES 
RHEOLOGICAL PROPERTIES 
viscoelasticity 
viscosity 
Pseudo plasticity 
surface tension
VISCOELASTICITY 
• Elasticity refers to the ability of a solution to 
return to its original shape after being stressed 
• Elasticity allows the anterior chamber to 
reform after deformation by depression on the 
cornea when external forces are released.
VISCOSITY 
• Viscosity reflects a solution's resistance to flow, 
• A function of the molecular weight of the 
substance. 
• Viscosity of OVDs is measured in centipoise 
(cPs) or centistokes (cSt), which are measures 
of the resistance to flow relative to a given 
shear force. 
• The higher the solution's molecular weight, 
the more it resists flow
PSEUDOPLASTICITY 
• Pseudoplasticity refers to a solution's ability to 
transform when under pressure, from a gel-like 
substance to a more liquid substance 
• More pseudoplastic a material is, the more 
rapidly it changes from being highly viscous at 
rest to a thin, watery solution at high shear 
rates.
SURFACE TENSION 
- The coating ability of an OVD is determined not 
only by the surface tension of material itself but 
also by the surface tension of the contact tissue, 
surgical instrument or IOL. 
- By measuring the angle formed by a drop of 
OVD on a flat surface (contact angle),the 
coating ability is estimated. 
- At lower surface tension & lower contact 
angle, better ability to coat.
COMPOSITION
SODIUM HYALURONATE 
• Biopolymer, disaccharide 
• occurring in many connective tissues throughout 
the body, including both the aqueous and vitreous 
humors 
• Hyaluronate has a half-life of approximately 1 day 
in aqueous and 3 days in vitreous. 
• Mainly present in visco cohesives
CHONDROITIN SULFATE 
• Chondroitin sulfate (CDS) is another 
viscoelastic biopolymer that is found as one of 
the three major mucopolysaccharides in the 
cornea. 
• Obtained from shark fin cartilage 
• Eliminated from the anterior chamber in 
approximately 24 to 30 hours 
• Coats tissues but poor space maintainer
HYDROXYPROPYL METHYL CELLULOSE 
• Does not occur naturally in animals but is 
distributed widely in plant fibers 
• Easy availability 
• Ease of preparation 
• Storage at room temperature 
• Ability to with stand autoclaving 
• Main component in dispersives
HYALURONATE PRODUCTS 
Healon, Healon5, Healon GV, Healon D 
Amvisc, Amvisc plus, Provisc 
HA+CS PRODUCTS 
Viscoat, Discovisc 
HPMC PRODUCTS 
Occucoat, Cellugel
CLASSIFICATION OF OVDS 
High viscosity-cohesive OVDs 
Lower viscosity-dispersive OVDs 
Viscoadaptive OVDs 
1 
2 
3
COHESIVES VS DISPERSIVES 
COHESIVES DISPERSIVES 
High viscocity Low viscocity 
Low mol wt High mol wt 
Long chain molecules Short chain molecules 
Adhere to themselves through 
intramolecular bonds, resists 
breaking apart. 
They adhere well to external 
surfaces, e.g., tissues and 
instruments.These materials 
tend to break apart easily 
High degree of pseudoplasticity 
and high surface tension 
Lower surface tension and 
lower pseudoplasticity
COHESIVE DISPERSIVE
Ocular viscoelastic devices(OVD)
HIGH VISCOSITY--COHESIVES 
SUPER VISCOUS VISCOUS 
1.Healon GV(1.4%) 
2.Ivisc plus 1.Ivisc 
2.Provisc 
3.Healon(1%) 
4.Amvisc
• All products contain Na.hyaluronate 
• Indications of highviscous cohesive OVD- 
-To deepen the AC 
-To enlarge small pupils 
-to dissect adhesions 
-during IOL implantation
ADVANTAGES 
1.Maintain space at low shear rates 
2.Easily displaced at high shear rates 
3.Sticks together,aspirated out easily 
4.Low risk of post op IOP rise even if retained 
DISADVANTAGES 
1.Minimal coating,so less endothelial protection
LOWER VISCOSITY-- DISPERSIVES 
MEDIUM VISCOCITY VERY LOW VISCOCITY 
1.Viscoat 
2.Vitrax 
3.Cellugel 
4.Biovisc 
1.Occucoat 
2.Ocuvis 
3.I-cell 
4.Hymecel 
5.Viscilon 
Most of them are Hydroxypropyl methyl cellulose
ADVANTAGES 
1.Excellent coating and gives superior endothelial 
protecton 
DISADVANTAGES 
1. Complete removal of dispersive OVDs is 
difficult because the molecules do not tend to 
join together and do not aspirate as a unit, 
2. Do not maintain or stabilise spaces 
3. Can form microbubbles and obscure view 
4. High risk of post op IOP rise
VISCOADAPTIVES 
• Behaviour changes at different flow rates 
• Acts as a viscous cohesive agent at lower flow 
rate & as a pseudo-dispersive agent at higher 
flow rates 
• Adapts its behaviour to surgeon’s needs during 
surgery 
• Highly purified non inflammatory high mol.wt. 
Na Hyaluronate at a 2.3% conc. dissolved in a 
physiological buffer 
• Example  HEALON 5
Ocular viscoelastic devices(OVD)
ADVANTAGES 
• 1. Crystal clear & has higher refractive index than 
aq.humor, so increases clarity within surgical field. 
• Ability to bind to & to protect delicate corneal endoth. 
cells from debris & turbulence during phaco 
• Helpful in small pupil as it causes viscomydriasis 
• Neutralises the +ve vitreous pressure & prevents the 
capsulorrhexis extension 
DISADVANTAGES 
1.Risk of post op IOP rise if retained
Ocular viscoelastic devices(OVD)
Ocular viscoelastic devices(OVD)
CLINICAL USES 
 Cataract surgery 
• Protection of endothelium 
• Maintaining of AC 
• CAPSULAR RHEXXIS 
• Cleavage of lens structure 
• Visco ecpression of lens 
• Phacoemulsification of nucleus 
• IOL implantation 
• dilate the pupil & maintain a good intraoperative 
mydriasis
SOFT SHELL TECHNIQUE 
• Developed by Arshinoff 
• Use of both lower viscosity dispersive & high 
viscosity cohesive OVDs together to minimise 
their drawbacks & to get best properties of both
SOFT SHELL TECHNIQUE
Ocular viscoelastic devices(OVD)
ULTIMATE SOFT SHELL TECHNIQUE
Ocular viscoelastic devices(OVD)
USES 
• Floppy iris syndrome,the soft-shell technique can 
hold the iris in place throughout the surgery. 
• cases of broken zonules, the dispersive OVD can 
compartmentalize the eye and keep vitreous 
pushed posteriorly, while the cohesive OVD keeps 
the anterior chamber formed and pressurized. 
• highly myopic eyes, dispersive OVDs protect the 
cornea, while re-application of cohesive OVDs to 
pressurize the anterior segment can minimize 
traction on the vitreous base and decrease retinal 
risk
Ocular viscoelastic devices(OVD)
GLAUCOMA SURGERY 
Visco-canalostomy 
• Means opening of schlemm’s canal by OVD 
• A Nonpenetrating procedure ,independent of 
external filtration 
• Advantages-decrease risk of infection, 
-decrease incidence of cataract 
-hypotony 
-flat AC 
-Excludes risk of late infection & conjunctival 
& episcleral scarring 
• Healon GV and healon5 are used
KERATOPLASTY 
• Used to fill the AC before removing corneal button from 
donor eyes as it helps to protect corneal endothelium 
and provides an even and circular trephination 
• In recipients eyes helps to have even and circular 
trephination,protects other intraocular structures 
maintains IOP and prevents sudden collapse of AC 
during trephination 
• In lamellar keratoplasty helps in the dissection of deep 
stroma during dissection of recipients stroma,called 
viscodelamination of cornea
POSTERIOR SEGMENT SURGERIES
• In strabismus sx Force required to bring the muscle 
to its insertion is significantly less with the use of 
subconjunctival viscoelastic 
• In plastic surgery during DCR helps in identifying 
lacrimal sac 
• Viscoelastics have a role in canalicular repair 
where the uninjured canaliculus is irrigated with 
fluorescein dye tinted viscoelastic , that spills from 
the other end ; helping to locate the proximal end 
of the injured canaliculus 
• In AS trauma helps to separate salvageable tissues 
from damaged tissues during sx
RECENT USES 
VISCOSTAINING OF CAPSULE 
• Techniques-staining from above under an air 
bubble & intracameral subcapsular inj.of Fl.Na ( 
staining from below)with blue-light enhancement. 
• Any instrument entering eye will cause some air to 
escape with rise of lens-iris plane 
• A small amount of high density viscoelastic placed 
near incision prevents air escape & minimizes risk 
of sudden collapse. 
• Alternatively-dye mixed with OVD called as 
viscostaining of ant.lens capsule covers ant capsule 
without coming in contact with corneal endoth.
VISCO ANASTHESIA 
• Mixture of OVD with an anesthetic soln (known 
as VISTHESIA) had advantages of viscosurgery, 
maintainence of ACD, capsular bag expansion, 
protection of corneal endothelium. 
• Prolongs anesthesia 
• No extra surgical step for intracameral inj. Of 
lidocaine 
• Contains topical component -0.3% hyaluronic 
acid with 2% lidocaine in a single dose unit 
• Intracameral component-1.5%hyaluronic acid 
with 1% lidocaine
REMOVAL OF OVD’S 
-Rock & Roll method 
-Two compartment technique 
-Bimanual irrigation & aspiration technique
COMPLICATIONS OF OVD USE 
• Post-op. increase in IOP 
- Occurs in 1st 6-24 hrs & resolves 
spontaneously within 72 hrs 
- Due to mechanical resistance at TM 
• Crystallization of IOL surfaces 
- Due to precipitation or deposition of 
viscoelastic soln. 
- Fern like or amorphous appearance 
- IOL should be explanted & exchanged
Capsular block syndrome or Capsular bag 
distension syndrome (CBS) 
Characterised by accumulation of liquefied 
substance within a closed chamber inside the 
capsular bag, formed because the lens nucleus or 
the PCIOL optic occludes the ant. capsule opening 
created by capsulorhexis 
• Classified as : 
1.Intra-op – time of nucleus luxation following 
hydro-dissection 
2.Early post-op 
3.Late post op. – with liquefied after cataract
• eg.Use of high density viscoelastic agent like 
Healon GV causes late CBS 
• Reduced distance visual acuity and improved 
near acuity due to induced myopia :forward 
shift of IOL. 
• IOP is normal, despite shallow anterior 
chamber. 
• Treatment is done by yag laser application to 
anterior capsule to allow OVD to escape 
anteriorly or posterior capsule may be lasered 
with escape of OVD posteriorly.
Pre treatment - Accumulation of turbid 
fluid in the space between IOL and 
posterior capsule 
Pre treatment UBM - UBM showing in 
the bag IOL and posterior bowing of 
posterior capsule 
Post treatment UBM - UBM confirming 
disappearance of retro IOL space following 
YAG laser 
Post treatment - Following YAG laser 
capsulotomy disappearance of turbid fluid
• Calcific band keratopathy 
- Occurs with chondroitin sulphate containing 
OVDs 
• Pseudo Anterior uveitis 
- Due to OVDs viscous nature & the electrostatic 
charge of it 
- RBCs & inflammatory cells remain in AC giving 
it appearance of uveitis 
- Spontaneously resolves within 3 days 
- Intra ocular hemorrhage may be trapped 
between vitreous space & OVD in AC mimicking 
VH
THANK YOU

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Ocular viscoelastic devices(OVD)

  • 2. INTRODUCTION Substances having dual properties 1.Viscocity of fluid 2.Elasticity of gel or solid
  • 3. HISTORY • Viscosurgery was a term coined by Balazs • Sodium Hyaluronate was 1st used in ophthalmic surgery as viscoelastic in 1972 as a replacement for vitreous & aqueous humor
  • 4. IDEAL VISCOELASTIC • Ease of infusion • Retention under +ve pressure in eye • Retention during phaco • Easy removal/no removal needed • Doesnt interfere with instruments/IOL placement • Protects endothelium • Nontoxic • Does not obstruct aq.outflow
  • 5. PROPERTIES RHEOLOGICAL PROPERTIES viscoelasticity viscosity Pseudo plasticity surface tension
  • 6. VISCOELASTICITY • Elasticity refers to the ability of a solution to return to its original shape after being stressed • Elasticity allows the anterior chamber to reform after deformation by depression on the cornea when external forces are released.
  • 7. VISCOSITY • Viscosity reflects a solution's resistance to flow, • A function of the molecular weight of the substance. • Viscosity of OVDs is measured in centipoise (cPs) or centistokes (cSt), which are measures of the resistance to flow relative to a given shear force. • The higher the solution's molecular weight, the more it resists flow
  • 8. PSEUDOPLASTICITY • Pseudoplasticity refers to a solution's ability to transform when under pressure, from a gel-like substance to a more liquid substance • More pseudoplastic a material is, the more rapidly it changes from being highly viscous at rest to a thin, watery solution at high shear rates.
  • 9. SURFACE TENSION - The coating ability of an OVD is determined not only by the surface tension of material itself but also by the surface tension of the contact tissue, surgical instrument or IOL. - By measuring the angle formed by a drop of OVD on a flat surface (contact angle),the coating ability is estimated. - At lower surface tension & lower contact angle, better ability to coat.
  • 11. SODIUM HYALURONATE • Biopolymer, disaccharide • occurring in many connective tissues throughout the body, including both the aqueous and vitreous humors • Hyaluronate has a half-life of approximately 1 day in aqueous and 3 days in vitreous. • Mainly present in visco cohesives
  • 12. CHONDROITIN SULFATE • Chondroitin sulfate (CDS) is another viscoelastic biopolymer that is found as one of the three major mucopolysaccharides in the cornea. • Obtained from shark fin cartilage • Eliminated from the anterior chamber in approximately 24 to 30 hours • Coats tissues but poor space maintainer
  • 13. HYDROXYPROPYL METHYL CELLULOSE • Does not occur naturally in animals but is distributed widely in plant fibers • Easy availability • Ease of preparation • Storage at room temperature • Ability to with stand autoclaving • Main component in dispersives
  • 14. HYALURONATE PRODUCTS Healon, Healon5, Healon GV, Healon D Amvisc, Amvisc plus, Provisc HA+CS PRODUCTS Viscoat, Discovisc HPMC PRODUCTS Occucoat, Cellugel
  • 15. CLASSIFICATION OF OVDS High viscosity-cohesive OVDs Lower viscosity-dispersive OVDs Viscoadaptive OVDs 1 2 3
  • 16. COHESIVES VS DISPERSIVES COHESIVES DISPERSIVES High viscocity Low viscocity Low mol wt High mol wt Long chain molecules Short chain molecules Adhere to themselves through intramolecular bonds, resists breaking apart. They adhere well to external surfaces, e.g., tissues and instruments.These materials tend to break apart easily High degree of pseudoplasticity and high surface tension Lower surface tension and lower pseudoplasticity
  • 19. HIGH VISCOSITY--COHESIVES SUPER VISCOUS VISCOUS 1.Healon GV(1.4%) 2.Ivisc plus 1.Ivisc 2.Provisc 3.Healon(1%) 4.Amvisc
  • 20. • All products contain Na.hyaluronate • Indications of highviscous cohesive OVD- -To deepen the AC -To enlarge small pupils -to dissect adhesions -during IOL implantation
  • 21. ADVANTAGES 1.Maintain space at low shear rates 2.Easily displaced at high shear rates 3.Sticks together,aspirated out easily 4.Low risk of post op IOP rise even if retained DISADVANTAGES 1.Minimal coating,so less endothelial protection
  • 22. LOWER VISCOSITY-- DISPERSIVES MEDIUM VISCOCITY VERY LOW VISCOCITY 1.Viscoat 2.Vitrax 3.Cellugel 4.Biovisc 1.Occucoat 2.Ocuvis 3.I-cell 4.Hymecel 5.Viscilon Most of them are Hydroxypropyl methyl cellulose
  • 23. ADVANTAGES 1.Excellent coating and gives superior endothelial protecton DISADVANTAGES 1. Complete removal of dispersive OVDs is difficult because the molecules do not tend to join together and do not aspirate as a unit, 2. Do not maintain or stabilise spaces 3. Can form microbubbles and obscure view 4. High risk of post op IOP rise
  • 24. VISCOADAPTIVES • Behaviour changes at different flow rates • Acts as a viscous cohesive agent at lower flow rate & as a pseudo-dispersive agent at higher flow rates • Adapts its behaviour to surgeon’s needs during surgery • Highly purified non inflammatory high mol.wt. Na Hyaluronate at a 2.3% conc. dissolved in a physiological buffer • Example  HEALON 5
  • 26. ADVANTAGES • 1. Crystal clear & has higher refractive index than aq.humor, so increases clarity within surgical field. • Ability to bind to & to protect delicate corneal endoth. cells from debris & turbulence during phaco • Helpful in small pupil as it causes viscomydriasis • Neutralises the +ve vitreous pressure & prevents the capsulorrhexis extension DISADVANTAGES 1.Risk of post op IOP rise if retained
  • 29. CLINICAL USES  Cataract surgery • Protection of endothelium • Maintaining of AC • CAPSULAR RHEXXIS • Cleavage of lens structure • Visco ecpression of lens • Phacoemulsification of nucleus • IOL implantation • dilate the pupil & maintain a good intraoperative mydriasis
  • 30. SOFT SHELL TECHNIQUE • Developed by Arshinoff • Use of both lower viscosity dispersive & high viscosity cohesive OVDs together to minimise their drawbacks & to get best properties of both
  • 33. ULTIMATE SOFT SHELL TECHNIQUE
  • 35. USES • Floppy iris syndrome,the soft-shell technique can hold the iris in place throughout the surgery. • cases of broken zonules, the dispersive OVD can compartmentalize the eye and keep vitreous pushed posteriorly, while the cohesive OVD keeps the anterior chamber formed and pressurized. • highly myopic eyes, dispersive OVDs protect the cornea, while re-application of cohesive OVDs to pressurize the anterior segment can minimize traction on the vitreous base and decrease retinal risk
  • 37. GLAUCOMA SURGERY Visco-canalostomy • Means opening of schlemm’s canal by OVD • A Nonpenetrating procedure ,independent of external filtration • Advantages-decrease risk of infection, -decrease incidence of cataract -hypotony -flat AC -Excludes risk of late infection & conjunctival & episcleral scarring • Healon GV and healon5 are used
  • 38. KERATOPLASTY • Used to fill the AC before removing corneal button from donor eyes as it helps to protect corneal endothelium and provides an even and circular trephination • In recipients eyes helps to have even and circular trephination,protects other intraocular structures maintains IOP and prevents sudden collapse of AC during trephination • In lamellar keratoplasty helps in the dissection of deep stroma during dissection of recipients stroma,called viscodelamination of cornea
  • 40. • In strabismus sx Force required to bring the muscle to its insertion is significantly less with the use of subconjunctival viscoelastic • In plastic surgery during DCR helps in identifying lacrimal sac • Viscoelastics have a role in canalicular repair where the uninjured canaliculus is irrigated with fluorescein dye tinted viscoelastic , that spills from the other end ; helping to locate the proximal end of the injured canaliculus • In AS trauma helps to separate salvageable tissues from damaged tissues during sx
  • 41. RECENT USES VISCOSTAINING OF CAPSULE • Techniques-staining from above under an air bubble & intracameral subcapsular inj.of Fl.Na ( staining from below)with blue-light enhancement. • Any instrument entering eye will cause some air to escape with rise of lens-iris plane • A small amount of high density viscoelastic placed near incision prevents air escape & minimizes risk of sudden collapse. • Alternatively-dye mixed with OVD called as viscostaining of ant.lens capsule covers ant capsule without coming in contact with corneal endoth.
  • 42. VISCO ANASTHESIA • Mixture of OVD with an anesthetic soln (known as VISTHESIA) had advantages of viscosurgery, maintainence of ACD, capsular bag expansion, protection of corneal endothelium. • Prolongs anesthesia • No extra surgical step for intracameral inj. Of lidocaine • Contains topical component -0.3% hyaluronic acid with 2% lidocaine in a single dose unit • Intracameral component-1.5%hyaluronic acid with 1% lidocaine
  • 43. REMOVAL OF OVD’S -Rock & Roll method -Two compartment technique -Bimanual irrigation & aspiration technique
  • 44. COMPLICATIONS OF OVD USE • Post-op. increase in IOP - Occurs in 1st 6-24 hrs & resolves spontaneously within 72 hrs - Due to mechanical resistance at TM • Crystallization of IOL surfaces - Due to precipitation or deposition of viscoelastic soln. - Fern like or amorphous appearance - IOL should be explanted & exchanged
  • 45. Capsular block syndrome or Capsular bag distension syndrome (CBS) Characterised by accumulation of liquefied substance within a closed chamber inside the capsular bag, formed because the lens nucleus or the PCIOL optic occludes the ant. capsule opening created by capsulorhexis • Classified as : 1.Intra-op – time of nucleus luxation following hydro-dissection 2.Early post-op 3.Late post op. – with liquefied after cataract
  • 46. • eg.Use of high density viscoelastic agent like Healon GV causes late CBS • Reduced distance visual acuity and improved near acuity due to induced myopia :forward shift of IOL. • IOP is normal, despite shallow anterior chamber. • Treatment is done by yag laser application to anterior capsule to allow OVD to escape anteriorly or posterior capsule may be lasered with escape of OVD posteriorly.
  • 47. Pre treatment - Accumulation of turbid fluid in the space between IOL and posterior capsule Pre treatment UBM - UBM showing in the bag IOL and posterior bowing of posterior capsule Post treatment UBM - UBM confirming disappearance of retro IOL space following YAG laser Post treatment - Following YAG laser capsulotomy disappearance of turbid fluid
  • 48. • Calcific band keratopathy - Occurs with chondroitin sulphate containing OVDs • Pseudo Anterior uveitis - Due to OVDs viscous nature & the electrostatic charge of it - RBCs & inflammatory cells remain in AC giving it appearance of uveitis - Spontaneously resolves within 3 days - Intra ocular hemorrhage may be trapped between vitreous space & OVD in AC mimicking VH