High Frequency Deep Sclerotomy (HFDS)

Dr. Dipak GulhaneDr. Rita Dhamankar

HFDS What is it ?

“ Sclerothalamotomy ab interno”Glaucoma filtration surgeryTreatment modality for primary open-angle

glaucoma (POAG)Bypass the resistance of the trabecular

meshworkChannelling aqueous humour directly to

Schlemm’s canal

Surgical Treatment modality for primary open-angle glaucoma (POAG)

Surgical Treatment

Penetrating

Trabeculectomy

Shunt

Nonpenetrating

Ab externo

Ab interno

Surgical anatomy of anatomy anterior chamber

TrabeculectomyFirst described in the 1960’sGold standard glaucoma surgery Bypass the resistance of the trabecular

meshworkChannelling aqueous humour directly to subconjunctival space Success rate of trabeculectomy - 32 and 96% Postoperative complication like hypotony and

choroidal detachment in up to 24% of cases No repeatibility and reproducibility

Trabeculectomy – Complications Intraoperative Complications

Conjunctival buttonholescleral flap tearBleeding

Early PostoperativeShallow anterior chamberLow filtrationChoroidal effusion

Trabeculectomy – Complications

Late Postoperative Late hypotonyLate bleb failureCataract formationLate bleb leaksBlebitis and endophthalmitis

Trabeculectomy – Complications

COMPLICATIONS OF ANTIMETABOLITESWound leak Epithelial erosions Endothelial damage and ciliary body

destruction InfectionScleritisScleral thinning

Nonpenetratingglaucoma surgery Need ?

Low complication ratesElimination / reduction of pressure-reducing

medication

NON-PENETRATING GLAUCOMA SURGERY

ab externo ab interno

ViscocanalostomyCanaloplastyDeep sclerectomy

High frequency deep sclerotomy AqueSysCyPass Micro-StentHydrus MicrostentiStent Inject

NON-PENETRATING GLAUCOMA SURGERY

Nonpenetratingglaucoma surgery

ab externo Canal of Schlemm Viscocanalostomy

Canaloplasty Deep sclerectomy

ab interno

Canal of SchlemmiStent Inject

Hydrus Microstent

HFDS Why ?

Alternative to trabeculectomyLesser complications Less invasive Consistent reduction of IOP

HFDSMinimally invasive, safe and efficacious

technique Avoids damage to episcleral and conjunctival

tissues as in trabeculectomy and conventional non-penetrating surgery

Low rate of postoperative complications

HFDSindications

POAG - mild to moderate

Not controlled with drugs

Non compliance with drugs

Not willing for topical medication

HFDS indications Monocular patient   Large diurnal fluctuations    Pigment dispersion glaucoma   Pseudoexfoliation glaucoma     High risk of choroidal effusions or hemorrhages   

Axial myopia    Previously vitrectomized eye      

History of choroidal effusion or hemorrhage       High risk of postoperative hypotony   

  Young patients    High myopes   

HFDS contraindications

Angle closure glaucoma

Neovascular glaucoma

Occludable angles

The Ideal PatientCOAG

POAG, exfoliation, pigmentary, steroid response

High IOP on maximal medication Target IOP of mid-teensGood visualization of angle structuresNo previous angle surgery/laser

High-Frequency Diathermic Probe (abee® Glaucoma Tip, Oertli Instrumente AG)An inner platinum electrode which is isolated

from the outer coaxial electrode. Tip is 1 mm in length, 0.3 mm height and 0.6

mm width and is bent posteriorly at an angle of 15°

The external diameter - 0.9 mm.Modulated 500 kHz current generates a temperature - 130°C at the tip

High-Frequency Diathermic Probe (abee® Glaucoma Tip, Oertli Instrumente AG)

Surgical Procedure

A clear cornea incision 1.2 mm wide in temporal upper quadrant

A second corneal incision is performed 120° apart

Injection of Healon GVProbe inserted through the

temporal corneal incisionOpposite iridocorneal angle

observed by a 4-mirror gonioscopic lens

Surgical Procedure

Tip penetrates up to 1mm nasal into the sclera through the trabecular meshwork and Schlemm canal

Forms a deep sclerotomy (i.e. “thalami”) of 0.3 mm high and 0.6 mm width

Procedure repeated 6 times within one quadrant

Healon GV evacuated from the anterior chamber with bimanual irrigation/aspiration.

HFDS Video animation

HFDS Video

Schematic – HFDS Opening

SL-OCT - HFDS POST OP

Complications Hypotony not severeHyphaema - disappears within the first 2

weeks after surgeryTransient fibrin formation – clears within

early post op after frequent application of topical Dexamethasone

Case SK64 years Male5 yearsBCVA 6/9 , N6 Gonioscopy - open angles Intraocular pressure OD 20 OS 16 mm of Hg Anterior segment - Posterior Polar Cataract Fundus - C:D OD 0.6 OS 0.5 Inf notching Perimetry – Suprior paracentral defect OCT ONH – Thinning of inf rim

CaseImpression – OU Posterior Polar Cataract primary open-

angle glaucomaTreatment – OU Timolet e/d BD BE Cataract surgery done 2008

2010OD 20 OS 16 mm of HgC:D OD 0.7 OS 0.75OU Brimonidine + Timolol e/d BD

Case2012C:D OD 0.8 OS 0.8Intraocular pressure 14 18 mm of Hg AdviceBE HFDS Post op

Pilocatpine e/d BD

CaseIntraocular

pressure OD mm of Hg

Intraocular pressure OSmm of Hg

Pre op 14 18

Post op1 week

14 08

Post op1 month

8 12

Post op3 month

10 10

Study Of Effect Of High Frequency Deep Sclerotomy &

Intraocular Pressure In Glaucoma Patients.

Inclusion criteria-

Patient of either sex of age group 18-80 yrs

Uncontrolled IOP with primary open angle

glaucoma & juvenile glaucoma

Non compliance of patient to medical therapy

Methodology-Design: prospective studySet-up: Laxmi Eye Institute and Laxmi Charitable

Trust hospitalSample size: 30 eyes Duration : 1 year

MethodologyThe parameters assessed for the purpose of research

includes DemographicsVisual acuity IOP by Applanation tonometryCup disc changesAngles (gonioscopy)

This parameters to be assessed at pre operatively as well as post operatively on Day 1 , 7 , 30, 90

POD visit I II III IV

Results

Pre op POD I POD II POD III POD IV

IOP 14.18[7.52] 13.64[4.62] 18.65[13.55]

In this study data of 18 patients is analysed, 13 –males, mean age- 57.54[12.08]5 females,mean age- 60.51[24.7]

22.89[8.19]

14.73[6.86]

Results

pre op post op visit1 post op visit 2 post op visit 3 post op visit 40

5

10

15

20

2522.89

14.8113.64

18.04

14.73

IOP

Results

Discussion-According to our observation at 3 months follow

up ,mean reduction in IOP is 8.16 [6.86] mm Hg& observed complication was hyphema which got resolved in 7 days post operatively

Akafo SK et al,in 1990 Longterm post trabeculectomy intraocular pressure, success rate of IOP range[32 and 96%] postoperative complications like hypotony and choroidal detachment are reported in 24%

Literature on non-penetrating deep sclerectomy by Demailly P, Lavat P, Kretz G et al indicates a success rate of 58–74% without a collagen implant and 74–90% with collagen implantation post operative filtering complication

NON-PENETRATING GLAUCOMA SURGERY ViscocanalostomyCanalplastyAqueSysCyPass Micro-StentHydrus MicrostentiStent InjectSolx Gold Shunt

ViscocanalostomyDescribed by StegmannA fornix-based conjunctival flap A second near-full thickness flap 1 mm inside this flap and slowly extended into Schlemms

canalStripping thin layers of deep tissue overlying Schlemm's

canal and Descemet's membrane Gentle dilation of the cut ends of Schlemm's with Healon

GV Superficial flap was secured in as watertight fashion as

possible with 10/0 Vicryl

Video Viscocanalostomy

NON-PENETRATING AB EXTERNO GLAUCOMA SURGERY

Canaloplasty

Microcatheter or tube placed in the Canal of

Schlemm

250-µm fiber-optic OM catheter is guided by

fibreoptic light source

Opens up collapsed Schlemm’s canal

Used to treat congenital glaucoma

Steep learning curve

Video Canalplasty

GoniotomyTreatment for congenital glaucomaInstrument - goniotomy knife90–120 degrees of arc incisions in the anterior trabecular

meshwork10% of a recurrence rate Complications – hyphema , damage to iris / ciliary

body , cataract formation , inflammation in the anterior chamber; scarring of the cornea , subluxation or dislocation of the lens , retinal detachment

Video Goniotomy

Trabeculotomy ab internoDirects flow of aqueous into the canal and then into the collector channels Direct visualization with a gonioscopy lens Removes a 60-to 120-degree strip of the

trabecular meshwork and the inner wall of Schlemm’s canal with electrocautery

Video Trabeculotomy

iStentInserted  through a small temporal clear

corneal incisionPlaced in Schlemm's canal at the lower nasal

quadrant. By creating a patent bypass through

Schlemm's   re-establishes physiologic outflow In vitro - iStent® can improve facility of

outflow by 84% (p<.003)

AqueSys

Collagen-derived gelatin.To create outflow of aqueous from the

anterior chamber subconjunctival space.Gelatin - well tolerated and noninflammatory.Soft, and this pliabile allows the device to

conform to the ocular tissue

AqueSys contd .

The gelatin material is cross-linked - makes it permanent.

Clear corneal incision via a preloaded IOL-like inserter using an ab interno approach

Can be placed over the course of the patient’s lifetime

AqueSys contd .

CyPass Micro-Stent Implanted in the supraciliary space to

establish a permanent passage via uveoscleral outflow

Negative pressure gradient between the suprachoroidal space and the anterior chamber - driving force

Fenestrated, miniature stent Biocompatible, nonbiodegradable polyimide

material 6.35 mm long and has an external diameter of

510 μm Inserter for the stent consists of a handpiece

and a releasable guidewire

Optical coherence tomography image of a CyPass Micro-Stent in the supraciliary space.

Stent loaded on the guide wire implanted in the supraciliary space.

The surgeon views the device through a goniolens after implantation.

The Hydrus MicrostentIt is made of nitinol a nickel-titanium alloy Safe and biocompatibileUnder topical anesthesia Dimensions and curvature similar as

Schlemm canal.Loaded inside handheld injectorPlaced in nasal iridocorneal angle under

direct gonioscopy

The Hydrus Microstent

The Hydrus Microstent is designed to dilate 3 clockhours of Schlemm canal. The inlet at the right is positionedin the anterior chamber to facilitate aqueous flow across thetrabecular meshwork and through Schlemm canal into thecollector channels.

The Hydrus Microstent.

.The device 30 days after its implantation intoSchlemm canal.

The Hydrus Microstent

iStent Inject

Single-piece, heparin-coated titanium stentLength of 360 µm , width of 230 µmDesigned for retention within the trabecular

meshworkSingle-use injector system Injector - insertion sleeve retraction button and a stent

release buttonPenetrates the trabecular meshworkSeveral clock hours of distance between the two stentsGet into the canal of Schlemm  

iStent Inject

Two stents positioned with 2 clock hours of separationbetween them

The flanged end penetrates the trabecular meshwork and stops with the thicker, flat end in the anterior chamber

iStent Supra • Shunting aqueous to suprachoroidal space, the aqueous exits either via a transscleral route or by choroidal absorption• Made of poyethersulfone and has a coloured titanium sleeve• Heparin coated (Duraflo) and is biocompatible• Curved to match the suprachoroidal space• Has retention rings to provide stability at the site of implantation• Clear visibility of the angle structures and a knowledge of the angle landmarks

iStent Supra

Stent is implanted right below the scleral spur

Combination with cataract surgery or aloneVisibility of the angle structures and a

knowledge of the angle landmarks IMPORTANT

Solx Gold ShuntMade of biocompatible goldGMS and the GMS Plus Width 25 µmHeight

GMS model is 44 µm GMS Plus 68 µm

Two leaflets fused together

Solx Gold ShuntOutflow into the

suprachoroidal spacePlaced at the level of the

scleral spur Enhance uveoscleral

outflowSize 5.2mm long

2.4mm wide anteriorly 3.2mm wide posteriorly

Video Solx Gold Shunt

Animation Solx Gold Shunt

Take home messageHigh frequency deep sclerotomy is conjunctival sparing

minimally invasive nonpenetrating glaucoma surgery with lesser complications .

HFDS can be considered as primary line of treatment for primary open angle glaucoma

Non compliant , non willing for topical medication Combined with cataract surgery Trabeculectomy is always there to take care of

failure cases

THANK YOU