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Satinder Pal Singh Grewal MD

Rajeev Jain, MD

Dilraj Grewal MBBS

Gagandeep S Brar MD

Safety and Efficacy of OculusGen Biodegradable

Collagen Matrix Implant in Phacotrabeculectomy

Surgery

GREWAL EYE INSTITUTECHANDIGARH, INDIA

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Financial Disclosures

None of the authors have any financial interest in this presentation

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• 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.

Purpose

This study was registered with ClinicalTrials.gov: Identifier NCT00477685

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• Long-term intraocular pressure (IOP) control following trabeculectomy may be limited by filtration failure, due to scarring at the level of the conjunctiva-Tenon’s-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. 1978;86:345–349.• Stamper RL, McMenemy MG, Lieberman MF. Hypotonous maculopathy after trabeculectomy with subconjunctival 5-fluorouracil. Am J Ophthalmol.

1992;114:544–553• Sinnreich Z, Barishak R, Stein R. Leaking filtering blebs. Am J Ophthalmol. 1978;86:345–349.

Introduction

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• 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.

Introduction

• 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. 1989;86:933–937.

• Yannas IV. Studies on the biological activity of the dermal regeneration template. Wound Repair Region. 1998;6:518–524. • Chen HS, Ritch R, Krupin T, Hsu WC. Control of filtering bleb structure through tissue bioengineering: An animal model.Invest Ophthalmol Vis Sci. 2006

Dec;47(12):5310-4.• Young MJ, Borras T, Walter M, Ritch R (2005) Potential applications of tissue engineering to glaucoma. Arch Ophthalmol 123:1725–173• 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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Structure:Biodegradable Collagen Matrix Implant

Scanning electron microscopic image of collagen matrix. 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.

• 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.

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• 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).

Methods

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•Age 30 years or older

•No previous intraocular surgery

•Uncontrolled glaucoma, with failed

medical and laser treatment, requiring

trabeculectomy.

•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

Inclusion Criteria: Exclusion Criteria:

Methods

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Surgical Method of Implantation

Graphics from www.oculusgen.com

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Surgical Method of Implantation

Graphics from www.oculusgen.com

1. 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]

•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.

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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 < 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.