India as leading country in the application of ologen™ Collagen Matrix and its combined use
2013 APAO-AIOS symposia recognize India as leading country in the application of ologen™ Collagen Matrix and its combined use with other compounds.
The Aeon Astron sponsored symposium at the 2013 APAO-AIOS Joint Congress1 “Breakfast Debate: ologen™ Collagen Matrix or MMC for Glaucoma Surgery? (GL-SP01)” recognizes India as leading country in the application of ologen™ Collagen Matrix and its use in combination with other compounds. Followed by Dr. Robert Ritch’s scientific program on: “The Use of ologen™ in Filtration Surgery (GL-SS08)”, the debate further introduced to a video-assisted skill transfer presented by AIOS and ISGS2 “Trabeculectomy: Pearls & Pitfalls; Cipla” in which the collagen matrix implant was recommended by a number of highly recognized Indian members of the national presenting panel3,4,5. According to the audience’s response, a large number of the attendees were convinced of the outstanding qualities ofologen™ Collagen Matrix and willing to try or continue using the collagen matrix.
Dr. L Vijaya opened the debate by reviewing the phases of wound healing and the role of Mitomycin-C (MMC) in glaucoma filtration surgery. As MMC-associated complications are dose-dependent, Dr. Vijaya recommended an application with the minimal required dose of MMC with the shortest exposure time possible, as opposed to a localized, high-dose MMC implementation.
In response, Dr. B S Rao brought up the aspect of ologen™ Collagen Matrix implant as an anti-scarring adjuvant and alternative to MMC: with physiological wound modulation and the prevention of wound adhesion and formation of dense scarring, the collagen matrix implant may reduce the chemo toxic hazard – both for the patients and for the surgeons – of applying and disposing of MMC.
In the second round of the debate, Dr. Sathyan P and Dr. Sirisha S reviewed the clinical evidence available to date. In a two-year randomized controlled trial (RCT) by Dr. Cillino et al. (2011), ologen™ Collagen Matrix was used as an adjuvant in trabeculectomy. In agreement with Aravind Eye Hospital’s experiences presented by Dr. Sathyan at the debate, the study tentatively concluded that “The implant could be a new, safe, and effective alternative to MMC, with similar long-term success rate.”
More RCT’s were reviewed with regard to the MMC use. Despite the more-established effectiveness in killing cells and the non-conclusive results on MMC’s safety issues, a number of studies do suggest that MMC may increase the chances of post-operative complications. This safety issue is especially significant in treating young patients as “the bleb-related complications are going to be more… the longer you follow them up. (Dr. Sirisha)”*6 A solution to the unmet need for the optimization of filtration surgery – especially in pediatricglaucoma – was yet to be found.
The debate peaked when a new application modality of the ologen™ Collagen Matrix was discussed: the pros and cons of combining collagen matrix implant with low-dose MMC (separate procedures; 0.1 mg/mL MMC or below; in comparison to the commonly used dose of 0.2 mg/mL up) and whether there would be conflicting mechanisms. While ologen™ Collagen Matrix alone may be enough in general situations as proven by the evidence, the implant and the antimetabolites may nevertheless be active during the different phases of wound healing and thus achieving some kind of synergism for scar prevention. This especially could be the case in patients requiring more complicated care, for instance, during repeated or revision surgery post failed trabeculectomy. Some preliminary reports have been published by Dr. Dada et al. (J Glaucoma 2012), Dr. Bordeianu (ESCRS abstract, 2012), Dr. Rosentreter et al. (2010) and Dr. Kohlhaas (2012; 2008), supporting the idea of this combined use of a collagen matrix and an anti-metabolite in the special cases.
To summarize, the combined use of ologen™ Collagen Matrix implant with low-dose antimetabolites (separate procedures) raises the question as to how low an effective dose of MMC could be in order to obtain the desired results with optimal wound healing and reduced bleb-related complications. Further research is also required for new possible combinations, such as the effectiveness of ologen™ Collagen Matrix together with Bevacizumab (separate procedures)7, an anti-VEGF adjuvant presumably suitable for glaucoma surgery patients with AMD or neovascular glaucoma. The exploration of these approaches may help optimize the practice of filtration surgery as well as other glaucoma related surgeries (GDD, revision surgery and NPGS), when a delicate consideration is made between the welfare of patients with more difficult glaucoma situations and the economy of health care.
(Click to see the photos of the events.)
1. Asia Pacific Academy of Ophthalmology (APAO) and All India Ophthalmological Society (AIOS) Joint Congress
2. International Society of Glaucoma Surgery (ISGS)
3. Dr. Murali Ariga (Swamy Eye Clinic and Chennai Glaucoma Foundation) on “Same site phacotrab with ologen implant”.
4. Dr. R Ramakrishna (Aravind Eye Hospital; author, co-editor of “Diagnosis & Management of Glaucoma, Jaypee 2013”) on “Trabeculectmy with ologen”.
5. Dr. Tanuj Dada (Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS; ISGS) on “Trabeculectomy with ologen subconjunctival & subscleral (with subscleral crater)”, “ologen subconjunctival with releasable sutures”, “ologen subslceral (NPDS with low-dose MMC; separate procedures)”.
6. Some abstracts on the application of collagen matrix implant in pediatric glaucoma are to be presented in 2013 SOE, Copenhagen, and 2013 WGC, Vancouver.
7. Other candidates include Ranibizumab, Aflibercept, or small molecular anti-VEGF (TKI), such as Pegaptanib (soaked or intraocular injection).