New Horizons: “Novel Applications for ologen™ Collagen Matrix” at the 5th WGC, July 2013, Vancouver, Canada

New Horizons: “Novel Applications for ologen™ Collagen Matrix” at the 5th WGC, July 2013, Vancouver, Canada

The Aeon Astron sponsored symposium “New Horizons: Novel Applications for ologen™ Collagen Matrix” held at the fifth World Glaucoma Congress, Vancouver, met with great success.

The symposium featured the US experience with ologen™ Collagen Matrix (Dr David Godfrey, Glaucoma Associates of Texas, USA), the combined Ex-Press®-ologen™ CM technique (Dr. Steven Vold, Vold Vision, Arkansas, USA) and an overview of the surgical options for bleb revision surgery using ologen™ CM (Dr. Ronald Fellman, Glaucoma Associates of Texas, USA). Dr Nigar Hasanova of the National Center of Ophthalmology, Azerbaijan and Dr. Maria Moussalli, Hospital Italiano de Buenos Aires, Argentina presented case reports on respectively congenital glaucoma and non-penetrating deep sclerectomy (NPDS).

Dr. David Godfrey opened the symposium by reviewing the physical mechanisms of ologen™ Collagen Matrix which reduce scarring and maintain surgical success post trabeculectomy. He presented the surgical pearl relating to the trimming of the edge of the collagen matrix and placing it a couple of millimeters back from the limbus, in order to create a more posterior bleb when a fornix-based technique is implemented. Dr. Steven Vold of Vold Vision, Arkansas, shared the opinion that the collagen matrix may allow surgeons to shape the bleb appearance and create a healthy vascular bleb. Having an anti-scarring efficacy similar to MMC[1], the collagen matrix can be applied in combination with other glaucoma filtration devices, such as the Ex-Press® shunt to obtaina controlled outflow of aqueous humor and a minimally penetrating, simple, and precise surgical procedure.

In the retrospective series of 67 eyes treated at the Glaucoma Associates of Texas, where Dr. Godfrey and Dr. Fellman practice, the IOP of the trabeculectomy group with ologen™ CM (44 eyes) went from 20.5 (SD 7.2) mmHg pre-operatively to 11.6 (SD 2.9) mmHg at month 12 post-operatively. Throughout this 12-month follow-up period the patients showed a consistent and well controlled IOP with a stable visual acuity.In the combined phaco emulsification – trabeculectomy group with ologen™ CM (23 eyes), the IOP moved from 14.3 (SD 3.8) mmHg pre-operatively to 11.7 (SD 3.8) mmHg at month 12 post-operatively. At month 18, the cumulative proportion of surgical success was 91.1%*. According to Dr. Godfrey, with comparable results to the MMC-augmented trab, the collagen matrix augmented trab has the potential “to alleviate the long-term side effects typically associated with MMC”.

Dr. Ronald Fellman discussed the use of ologen™ Collagen Matrix in the treatment of refractory bleb dysesthesia and its options for bleb revision surgery. Whilst the traditional method is to revise and resurface the painful bleb using an autologous conjunctival patch (autologous conjunctival bleb resurfacing; ACBR), a second and more recent option could be bleb reduction with the use of ologen™ collagen matrix and subsequent conjunctival advancement. In comparison to ACBR, this method may avoid creating another conjunctival wound at the inferior part of the eye and, as some other surgeons also have proposed, may prevent bleb leak or further hypotony after bleb revision[2]. However, in some of his younger patients, Dr. Fellman, based on the individual’s anatomy and conditions, tends to excise the bleb and close the fistula with a patch graft followed by the implantation of a glaucoma drainage device. The ologen™ Collagen Matrix can be added to the tool kit of an ophthalmic surgeon and may be successfully applied in bleb revision, tube revision[3],[4] and as patch graft.

Dr. Nigar Hasanova, Azerbaijan, presented a number of case reports on combined trabeculotomy-trabeculectomy (CTT) with ologen™ Collagen Matrix in congenital glaucoma. The collagen matrix offers an attractive opportunity for pediatric surgeons to enhance the surgical success in young patients, where adjuvants such as MMC are usually not recommended. In 10 eyes of children aged between 1-14 months, the IOP was 40.4 (SD 6.87) mmHg preoperatively and 13.4 (SD 1.84) mmHg at the last post-operative visit (follow-up range: 3-6 months). The ologen® CM augmented CTT has received good results even in difficult cases including aniridia, neurofibromatosis type I, and CHED type II.

In conclusion, Dr. Maria Moussalli, Argentina, summarized the application of ologen™ Collagen Matrix in trabeculectomy and non-penetrating deep sclerectomy (NPDS). Using a variety of options to position the collagen matrix, Dr. Moussalli – as Dr. Vold – achieved good results by placing the matrix posterior to the (loosely closed) scleral flap. This, despite the more common surgical guideline to put the collagen matrix on top of the scleral flap. Applications and results obtained with ologen™ Collagen Matrix are constantly evolving and may lead to more novel surgical options, combinations and guidelines. For instance as an anti-scarring device in various eye surgeries and eye tissue repair, such as subscleral placement[5],[6],[7], subscleral-to-subconjunctival drainage placement of the material, scleral reinforcement etc.

* The surgical success is defined as a post-operative IOP < 18 mmHg with or without medication. The number of antiglaucoma medication went from 3.0 (SD 1.1) to 0.8 (SD 1.2) in the ologen® CM augmented trab group and from 3.2 (SD 0.7) to 0.2 (SD 0.4) in the ologen® CM augmented phacotrab group.

[1] Cillino S, Pace F Di, Cillino G, Casuccio A. Biodegradable collagen matrix implant vs mitomycin-C as an adjunct in trabeculectomy: a 24-month, randomized clinical trial. Eye 2011; 25(12):1598-606. doi: 10.1038/eye.2011.219.
[2] DietleinT S, Lappas A, Rosentreter A. Secondary subconjunctival implantation of a biodegradable collagen-glycosaminoglycan matrix to treat ocular hypotony following trabeculectomy with mitomycin C. Br J Ophthalmol, 2013 June; e-pub doi:10.1136/bjophthalmol-2013-303357
[3] Stirbu Oana, Jorge Vila. Tube Exposure Repair. Journal of Current Glaucoma Practice, 2012; 6(3): 139-142
[4] Rosentreter A, Mellein AC, Konen WW, Dietlein TS. Capsule excision and ologen implantation for revision after glaucoma drainage device surgery. Graefes Arch Clin Exp Ophthalmol2010; 248: 1319-24
[5] Tanuj D, Amit S, Saptorshi M, Meenakshi G. Combined Subconjunctival and Subscleral Ologen Implant Insertion In Trabeculectomy. Eye, 2013 May; E-pub. doi:10.1038/eye.2013.76
[6] Matthew S J, Sarkisian S, Nathan B, James M R. Initial experience using a collagen matrix implant (ologen) as a wound modulator with canaloplasty: 12 month results. 203 Glaucoma: surgery or wound healing – GL. 2012 ARVO; May 6-10, Ft. Lauderdale, USA