High Frequency Deep Sclerotomy

1. High Frequency Deep
Sclerotomy (HFDS)
Dr. Dipak Gulhane
Dr. Rita Dhamankar

2. HFDS What is it ?
“ Sclerothalamotomy ab interno”
 Glaucoma filtration surgery
 Treatment modality for primary open-angle
glaucoma (POAG)
 Bypass the resistance of the trabecular meshwork
 Channelling aqueous humour directly to Schlemm’s
canal

3. Surgical Treatment modality for primary open-
angle glaucoma (POAG)
Surgical
Treatment
Penetrating
Trabeculectomy
Shunt
Nonpenetrating
Ab externo
Ab interno

4. Surgical anatomy of anatomy anterior
chamber

5. Trabeculectomy
 First described in the 1960’s
 Gold standard glaucoma surgery
 Bypass the resistance of the trabecular meshwork
 Channelling 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

6. Trabeculectomy – Complications
 Intraoperative Complications
 Conjunctival buttonhole
 scleral flap tear
 Bleeding
 Early Postoperative
 Shallow anterior chamber
 Low filtration
 Choroidal effusion

7. Trabeculectomy – Complications
 Late Postoperative
 Late hypotony
 Late bleb failure
 Cataract formation
 Late bleb leaks
 Blebitis and endophthalmitis

8. Trabeculectomy – Complications
 COMPLICATIONS OF ANTIMETABOLITES
 Wound leak
 Epithelial erosions
 Endothelial damage and ciliary body destruction
 Infection
 Scleritis
 Scleral thinning

9. Nonpenetrating
glaucoma surgery Need ?
 Low complication rates
 Elimination / reduction of pressure-reducing
medication

10. NON-PENETRATING GLAUCOMA
SURGERY
ab externo ab interno
Viscocanalostomy
Canaloplasty
Deep sclerectomy
High frequency deep sclerotomy
AqueSys
CyPass Micro-Stent
Hydrus Microstent
iStent Inject

11. NON-PENETRATING GLAUCOMA
SURGERY
Nonpenetrating
glaucoma surgery
ab externo
Canal of Schlemm
Viscocanalostomy
Canaloplasty
Deep sclerectomy
ab interno
Suprachoroidal space
iStent Supra
Solx Gold Shunt
Canal of Schlemm
iStent Inject
Hydrus Microstent

12. HFDS Why ?
 Alternative to trabeculectomy
 Lesser complications
 Less invasive
 Consistent reduction of IOP

13. HFDS
 Minimally 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

14. HFDSindications
 POAG - mild to moderate
 Not controlled with drugs
 Non compliance with drugs
 Not willing for topical medication

15. 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

16. HFDS contraindications
 Angle closure glaucoma
 Neovascular glaucoma
 Occludable angles

17. The Ideal Patient
 COAG
 POAG, exfoliation, pigmentary, steroid response
 High IOP on maximal medication
 Target IOP of mid-teens
 Good visualization of angle structures
 No previous angle surgery/laser

18. 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

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

20. 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 GV
 Probe inserted through the temporal
corneal incision
 Opposite iridocorneal angle
observed by a 4-mirror gonioscopic
lens

21. 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.

22. HFDS Video animation

23. HFDS Video

24. Schematic – HFDS Opening

25. SL-OCT - HFDS POST OP

26. Complications
 Hypotony not severe
 Hyphaema - disappears within the first 2 weeks after
surgery
 Transient fibrin formation – clears within early post
op after frequent application of topical
Dexamethasone

27. Case
 SK
 64 years Male
 5 years
 BCVA 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

28. Case
 Impression – OU Posterior Polar Cataract primary open-
angle glaucoma
 Treatment – OU Timolet e/d BD
 BE Cataract surgery done 2008
2010
 OD 20 OS 16 mm of Hg
 C:D OD 0.7 OS 0.75
 OU Brimonidine + Timolol e/d BD

29. Case
 2012
 C:D OD 0.8 OS 0.8
 Intraocular pressure 14 18 mm of Hg
 Advice
 BE HFDS
 Post op
Pilocatpine e/d BD

30. Case
Intraocular
pressure OD
mm of Hg
Intraocular
pressure OS
mm of Hg
Pre op 14 18
Post op
1 week
14 08
Post op
1 month
8 12
Post op
3 month
10 10

31. Study Of Effect Of High Frequency
Deep Sclerotomy & Intraocular
Pressure In Glaucoma Patients.

32. 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

33. Methodology-
 Design: prospective study
 Set-up: Laxmi Eye Institute and Laxmi Charitable Trust
hospital
 Sample size: 30 eyes
 Duration : 1 year

34. Methodology
 The parameters assessed for the purpose of research includes
 Demographics
 Visual acuity
 IOP by Applanation tonometry
 Cup disc changes
 Angles (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

35. Results
Pre op POD I POD II POD III POD IV
IOP 14.18[7.52] 13.64[4.62] 18.65[13.5
5]
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]

36. Results

37. 22.89
14.81
13.64
18.04
14.73
0
5
10
15
20
25
pre op post op visit1 post op visit 2 post op visit 3 post op visit 4
IOP
Results

38. 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

39. NON-PENETRATING GLAUCOMA
SURGERY
 Viscocanalostomy
 Canalplasty
 AqueSys
 CyPass Micro-Stent
 Hydrus Microstent
 iStent Inject
 Solx Gold Shunt

40. Viscocanalostomy
 Described by Stegmann
 A fornix-based conjunctival flap
 A second near-full thickness flap
 1 mm inside this flap and slowly extended into Schlemms canal
 Stripping 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

41. Video Viscocanalostomy

42. NON-PENETRATING AB EXTERNO
GLAUCOMA SURGERY

43. 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

44. Video Canalplasty

45. Goniotomy
 Treatment for congenital glaucoma
 Instrument - goniotomy knife
 90–120 degrees of arc incisions in the anterior trabecular
meshwork
 10% 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

46. Video Goniotomy

47. Trabeculotomy ab interno
 Directs 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

48. Video Trabeculotomy

49. iStent
 Inserted through a small temporal clear corneal
incision
 Placed 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)

50. 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

51. 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

52. AqueSys contd .

53. 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

54. 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.

55. The Hydrus Microstent
 It is made of nitinol a nickel-titanium alloy
 Safe and biocompatibile
 Under topical anesthesia
 Dimensions and curvature similar as Schlemm canal.
 Loaded inside handheld injector
 Placed in nasal iridocorneal angle under direct
gonioscopy

56. The Hydrus Microstent
The Hydrus Microstent is designed to dilate 3 clock
hours of Schlemm canal. The inlet at the right is positioned
in the anterior chamber to facilitate aqueous flow across the
trabecular meshwork and through Schlemm canal into the
collector channels.

57. The Hydrus Microstent
.
.The device 30 days after its implantation into
Schlemm canal.

58. The Hydrus Microstent

59. iStent Inject
 Single-piece, heparin-coated titanium stent
 Length of 360 µm , width of 230 µm
 Designed for retention within the trabecular meshwork
 Single-use injector system
 Injector - insertion sleeve retraction button and a stent release
button
 Penetrates the trabecular meshwork
 Several clock hours of distance between the two stents
 Get into the canal of Schlemm


60. iStent Inject
Two stents positioned with 2
clock hours of separation
between them
The flanged end penetrates the trabecular
meshwork and stops with the thicker, flat
end in the anterior chamber

61. 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

62. iStent Supra
 Stent is implanted right below the scleral spur
 Combination with cataract surgery or alone
 Visibility of the angle structures and a knowledge of
the angle landmarks IMPORTANT

63. Solx Gold Shunt
 Made of biocompatible gold
 GMS and the GMS Plus
 Width 25 µm
 Height
 GMS model is 44 µm
 GMS Plus 68 µm
 Two leaflets fused together

64. Solx Gold Shunt
 Outflow into the suprachoroidal
space
 Placed at the level of the scleral
spur
 Enhance uveoscleral outflow
 Size 5.2mm long
 2.4mm wide anteriorly
 3.2mm wide posteriorly

65. Video Solx Gold Shunt

66. Animation Solx Gold Shunt

67. Take home message
 High 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

68. THANK YOU