OLOGEN IMPLANT-REPLACING MMC IN TRABECULECTOMY

DR. MANORAMA S. BAHETIDR. VASANTRAO PAWAR MEDICAL COLLEGE,

NASHIK

INTRODUCTION

Trabeculectomy is the standard procedure in penetrating anti-glaucomatous surgery which was introduced by Cairns in 1968. The method was developed further over subsequent decades to address various problems

In 1990, Mitomycin C was applied as an anti-metabolite during trabeculectomy. Various studies demonstrated significant enhancement of success rates and postoperative IOP through intraoperative use of MMC

This was accompanied by an increase in adverse effects such as cataract formation, avascular filtering blebs, thinning of the conjunctiva, subsequent blebitis, and endophthalmitis

The current focus is on the development of less toxic agents and implants to inhibit cicatrisation without adverse effects

One approach is the development of biodegradable implant like the OLOGEN IMPLANT to serve as a placeholder and prevent conjunctiva-sclera adhesions

DESCRIPTION

• Ologen implant is a disc shaped porcine derived biodegradable scaffold collagen matrix implant

• It is composed of more than 90% lyophilized porcine collagen and less than 10% lyophilized glycosaminoglycan with a pore size of 10 – 300 mm

• Ologen implant leads to a non scarring wound healing with a prominent filtering bleb to enable successful surgical outcome after trabeculectomy

• Ologen implant is biodegradable in 90 to 180 days or more leaving a porous skeleton of connective tissue

HOW OLOGEN IMPLANT WORKS

Ologen implant induces a regenerative wound healing process without the need for antifibrotic agent like MMC

It works by guiding fibroblasts to grow through the matrix scaffold in a less random fashion thereby preventing the fibroblasts from laying down in an organised fashion reducing scar tissue formation

When inserted under the conjunctiva at the time of trabeculectomy ,it acts as a reservoir as the aqueous humour is absorbed into its porous structure

It acts as a spacer and mechanically separates the conjunctiva and episcleral surface and prevents adhesions between them

OLOGEN

SURGICAL STEPS

Step 1 : Preparation of conjunctival and scleral flaps• Task description• Task description• Task description• Task description

Step 2 : Fistula is created beneath the scleral flap• Task description• Task description• Task description

Step 3 : The scleral flap is sutured loosely with one single stitch• Task description• Task description

SURGICAL STEPS

Step 4 : Ologen is implanted directly on the top of the scleral flap

• Task description• Task description• Task description• Task description

Step 5 : Conjunctival flap is closed

• Task description• Task description• Task description

Step 6 : Anterior chamber is formed

• Task description• Task description

COMPLICATIONS OF MMC

• BLEB LEAKAGE & HYPOTONY- incidence is 3 to 37%• BLEBITIS & ENDOPHTHALMITIS• CONJUNCTIVAL THINNING• CORNEAL TOXITY• MACULOPATHY- especially in young myopes or with longer

exposure• CYTOTOXIC & TERATOGENIC• NON SELECTIVE CELL DEATH

BLEB POST MMC

BLEB POST USING MMC

MACULOPATHY WITH OPTIC NERVE HEAD OEDEMA POST USING MMC

NEGATIVE ATTRIBUTES OF USING MMC

• Reduces the physiologic barrier• Creates difficult postoperative patient management with

possible late complications that can cause decreased vision• Increased surgical time in the operating room• Preparation and handling time is critical

BENEFITS OF USING OLOGEN IMPLANT

• Prevention of scar formation by guiding fibroblasts to grow through the matrix pore randomly

• Prevention of flat or shallow anterior chamber thus preventing hypotony by creating a buffer system

• Collagen matrix decreases the wound contraction and promotes formation of a nearly normal subconjunctival stroma supporting and maintaining the size of bleb even after partial degradation

• Facilitates proper wound healing and a physiologic functional bleb

• Ologen collagen matrix is fully degradable• Non – teratogenic• No significant risk known• No prior preparation required and saves

operation time

Bleb Post 6 months of ologen implant

Bleb post 12 months of ologen implant

CONCLUSION Various studies demonstrated significant enhancement of success rates and postoperative IOP

through intraoperative use of MMC.[1] This was accompanied by an increase in adverse effects such as cataract formation, avascular filtering blebs, thinning of the conjunctiva, subsequent blebitis, and endophthalmitis. [1-4]

Moreover, the ologen implant will also be adjuvant in repairing postoperative bleb leaks.[5] In human subjects, the ologen implant was tested for augmentation in deep sclerectomy. This study revealed that deep sclerectomy with ologen implantation is an effective and well-tolerated method for reduction of IOP.[6] 

A further pilot study revealed non-significant differences in postoperative IOP after trabeculectomy with ologen and sole trabeculectomy.[7] 

In summary of the previous studies, the use of the ologen implant promises comparable IOP reduction after trabeculectomy and a lower risk profile in comparison with the use of anti-metabolites like MMC and 5-fluorouracil.[7]

The two-year complete succes with ologen collagen matrix (defined as IOP<15mmHg witout medication) was 50% compared to 40% for the MMC group. Longrank test shows ologen collagen matrix to be comparable as MMC in complete success<15mmHg IOP (P>0.05) .[8]

REFERENCES

^1. Wilkins M, Indar A, Wormald R. Intra-operative mitomycin C for glaucoma surgery.Cochrane Database Syst Rev 2005 Issue 4. Art. no.: CD002897 ^2. Mac I, Soltau JB. Glaucoma-filtering bleb infections. Curr Opin Ophthalmol 2003; 14: 91-94^3. Reibaldi A, Uva MG, Longo A. Nine-year follow-up of trabeculectomy with or without low-dosage mitomycin-c in primary open-angle-glaucoma. Br J Ophthalmol 2008; 92: 1666-1670^4. Beckers HJ, Kinders KC, Webers CA. Five-year results of trabeculectomy with mitomycin C. Graefes Arch Clin Exp Ophthalmol 2003; 241: 106-110^5. Hsu WC, Ritch R, Krupin T, Chen HS. Tissue bioengineering for surgical bleb defects: an animal study. Graefes Arch Clin Exp Ophthalmol 2008; 246: 709-717^6. Aptel F, Dumas S, Denis P. Ultrasound biomicroscopy and optical coherence tomography imaging of filtering blebs after deep clerectomy with new collagen implant.Eur J Ophthalmol 2009; 19: 223-230^7. Papaconstantinou D, Georgalas I, Karmiris E, Diagourtas A, Koutsandrea C, Ladas I et al. Trabeculectomy with OloGen versus trabeculectomy for the treatment of glaucoma: a pilot study. Acta Ophthalmol 2010; 88: 80-858. S. Cillino et al. Biodegrable collagen matrix implant VS mitomycin C as an adjuvent in trabeculectomy : a 24 month, randomised clinical trail