Satinder Pal Singh Grewal MD

1
Safety and Efficacy of OculusGen Biodegradable
Collagen Matrix Implant in Phacotrabeculectomy
Surgery
Satinder Pal Singh Grewal MD Rajeev Jain, MD
Dilraj Grewal MBBS Gagandeep S Brar MD
GREWAL EYE INSTITUTE CHANDIGARH, INDIA
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Financial Disclosures
None of the authors have any financial interest
in this presentation
3
Purpose

• To present the preliminary results of a pilot
  study that evaluating the safety and efficacy of
  OculusGen Biodegradable Collagen Matrix Implant
  designed to improve the regenerating
  tissue-remodeling in glaucoma patients with
  cataract undergoing combined phacotrabeculectomy
  surgery.

This study was registered with ClinicalTrials.gov
Identifier NCT00477685
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Introduction

• Long-term intraocular pressure (IOP) control
  following trabeculectomy may be limited by
  filtration failure, due to scarring at the level
  of the conjunctiva-Tenons-episcleral interface,
  the scleral flap or its overlying episclera, or
  the internal ostium
• Clinically, mitomycin-C (MMC), 5-fluorouracil,
  and corticosteroids have all been used to inhibit
  fibroblast proliferation to prevent scar
  development after glaucoma surgery.However they
  are associated with the risk for late
  postoperative complications, including wound
  leakage, hypotony, and maculopathy.1,2,3

• Sinnreich Z, Barishak R, Stein R. Leaking
  filtering blebs. Am J Ophthalmol.
  197886345349.
• Stamper RL, McMenemy MG, Lieberman MF. Hypotonous
  maculopathy after trabeculectomy with
  subconjunctival 5-fluorouracil. Am J Ophthalmol.
  1992114544553
• Sinnreich Z, Barishak R, Stein R. Leaking
  filtering blebs. Am J Ophthalmol.
  197886345349.

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Introduction

• The use of tissue bioengineering to prevent scar
  prevention has been described.4,5,6,7 The
  application of three-dimensional,
  collagen-glycosaminoglycan copolymers can lead to
  random and relatively loose reorganization of
  regenerating myofibroblasts, fibroblasts, and the
  secreted extracellular matrix (i.e., collagen),
  reducing scar formation.
• These biodegradable implants may simultaneously
  provide physical resistance to overfiltration in
  the early stages and progressively may reduce
  this resistance as the implant degrades and a
  random connective tissue matrix permeates the
  spaces within the implant to create a loosely
  organized bleb structure.

• Yannas IV, Lee E, Orgill DP, Skrabut EM, Murphy
  GF. Synthesis and characterization of a model
  extracellular matrix that induces partial
  regeneration of adult mammalian skin. Proc Nat
  Acad Sci USA. 198986933937.
• Yannas IV. Studies on the biological activity of
  the dermal regeneration template. Wound Repair
  Region. 19986518524.
• Chen HS, Ritch R, Krupin T, Hsu WC. Control of
  filtering bleb structure through tissue
  bioengineering An animal model.Invest Ophthalmol
  Vis Sci. 2006 Dec47(12)5310-4.
• Young MJ, Borras T, Walter M, Ritch R (2005)
  Potential applications of tissue engineering to
  glaucoma. Arch Ophthalmol 1231725173
• Hsu WC, Ritch R, Krupin T, Chen HS. Tissue
  bioengineering for surgical bleb defects an
  animal study. Graefes Arch Clin Exp Ophthalmol.
  2008 Feb 12 Epub ahead of print

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StructureBiodegradable Collagen Matrix Implant

• In this study a three-dimensional biodegradable
  collagen matrix was placed in the subconjunctival
  space and on top of the scleral flap to achieve
  better postoperative IOP control and to reduce
  the risk for early shallow anterior chamber.

A drug-free, biodegradable, porous collagen
matrix of 1 collagen/C-6-S copolymer (OloGen)
with a 7-mm diameter and a 4-mm thickness was
used.
Scanning electron microscopic image of collagen
matrix.
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Methods

• 5 patients underwent combined trabeculectomy
  with the OculusGen Biodegradable Collagen Matrix
  Implant in one eye for refractory glaucoma
• Refractory glaucoma was defined as having
  previously failed medical, laser or surgical
  treatment, and phacoemulsifcation with Acrylic
  IOL impant (AMO AR-40).
• The OculusGen was implanted on the top of the
  scleral flap at the limbus before closing the
  conjunctival wound during trabeculectomy
  operations.
• Intraocular pressure (IOP), bleb characteristics
  and post-operative complications were assessed
  before and after surgery.
• Bleb photographs were analyzed at all
  post-operative visits according to the Moorfields
  Bleb-Grading System for the parameters of area
  (grades 1-5), height (grades 1-4) and vascularity
  (grades 1-5).

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Methods
Inclusion Criteria
Exclusion Criteria

• Known allergic reaction to porcine collagen.
• Subject is on warfarin and discontinuation is not
  recommended.
• Patients with
• Normal tension glaucoma,
• Uveitic glaucoma,
• Sphakic or pseudophakic glaucoma,
• Neovascular glaucoma
• Secondary glaucoma.
• Ocular infection within 14 days prior to
  trabeculectomy.
• Pregnant or breast-feeding women

• Age 30 years or older
• No previous intraocular surgery
• Uncontrolled glaucoma, with failed medical and
  laser treatment, requiring trabeculectomy.

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Surgical Method of Implantation
Graphics from www.oculusgen.com
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Surgical Method of Implantation

• Positioning of implant in respect to the scleral
  flap and the conjunctival wound.
• Double arrow points to Conjunctival defect over
  the area above the implant.

• Hsu WC, Ritch R, Krupin T, Chen HS. Tissue
  bioengineering for surgical bleb defects an
  animal study. Graefes Arch Clin Exp Ophthalmol.
  2008 Feb 12 Epub ahead of print

Graphics from www.oculusgen.com
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Results

• The study population included 4 Males and 1
  Female
• Average age was 56.3 9.6 yrs

• The mean preoperative IOP was 35.7 7.8 mmHg.
• Postoperatively, the mean IOP at 4 months
  follow-up for all eyes had a 54.3 reduction (p lt
  0.05) to 16.3 2.1 mmHg.
• There were no significant intra-operative or
  post-operative complications in any patients.

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Conclusions

• The short-term preliminary results of this
  study indicate that the OculusGen implantation in
  combined phaco-trabeculectomy could potentially
  provide a safe and effective therapeutic
  preventing wound failure following trabeculectomy
  surgery.
• The OculusGen helps to modulate wound healing
  response following glaucoma filtering surgery.
• However a larger study with a longer follow-up
  period is required to confirm these observations.
• Biodegradable Collagen Matrix implants can help
  in achieving a successful trabeculectomy without
  antifibrotic medication,controlling both the
  physical and physiologic aspects of wound
  healing.