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• Re: Surgery for glaucoma in the 21st century
  Andre Mermoud
  Published on: 22 March 2016
• Reply to editorial "Surgery for Glaucoma in the 21st Century"
  Richard J. Fugo
  Published on: 22 March 2016

• Published on: 22 March 2016

  Re: Surgery for glaucoma in the 21st century

  • Andre Mermoud
  • Other Contributors:
    • Emilie Ravinet

  Dear Editor

  Regarding the editorial by Khaw et al.[1] we are surprised that after quite a few years now non- penetrating filtering surgery (NPFS) remains only partly understood by many ophthalmologists. There are at present two main NPFS: viscocanalostomy as described by Stegmann, in which outflow filtration is at least in theory not subconjunctival, and deep sclerectomy with or without an implant or even wi...

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  Dear Editor

  Regarding the editorial by Khaw et al.[1] we are surprised that after quite a few years now non- penetrating filtering surgery (NPFS) remains only partly understood by many ophthalmologists. There are at present two main NPFS: viscocanalostomy as described by Stegmann, in which outflow filtration is at least in theory not subconjunctival, and deep sclerectomy with or without an implant or even with viscoelastics, the success of which depends on several outflow routes - an important one being subconjunctival. Careful postoperative follow up becomes therefore mandatory and is at least as important as the procedure itself. If needed subconjunctival injection of antimetabolites, needling or use of lasers for goniopuncture, iris desincarceration and attempts of possible bleb reduction or closure of possible seidel may be required. It also becomes evident that antimetabolites play an important role in high risk cases for filtration failure undergoing NPFS (apart from viscocanolostomy as describd by Stegmann). Furthermore in our hospital we have been using antimetabolites also in cases requiring low postoperative IOP such as normal tension glaucoma since 1994. We do not understand the comment made stating that greater care should be taken with antimetabolites used during NPFS, since we intraoperatively use these agents before the deeper scleral flap is being excised or even created. Thus at this stage this does not differ with trabeculectomy. Later on the anterior chamber is not entered and furthermore the deep scleral flap which has been exposed to antimetabolites is being excised making the danger of intraoperative intraocular penetration considerably less than with trabeculectomy (even with unintended macroperforation during NPFS).

  Additional sutures are added in cases of accidental macroperforaton so that the incidence of early significant hypotony in the hands of experienced surgeons with NPFS is not high. Moreover postoperative suturelysis may then be required in these cases if the sutures have been made too tight or too numerous.

  References are being made to the article by Brart et al. However how reliable is it to compare the efficacy of two procedures without giving the same chances of success to both? Intraoperative antimetabolites were used for all trabeculectomies and yet never with NPFS. Yet strangely enough, postoperative antimetabolites as well as needling with an attempt to lift the scleral flap in some, were used in both groups. The author also writes in the discussion that patients with successful drainage at 6 and 12 months following viscocanalostomy had evidence of subconjunctival drainage of aqueous as opposed to eyes without successful drainage. Later on he further states that 'with our viscocanalostomy technique, the subconjunctival route is the main pathway' and 'observation of the disappearance of subconjunctival blebs in our patients with drainage failure after viscocanalostomy appears to suggest that subconjunctival fibrosis is responsible'. Clearly, if antimetabolites are being used in trabeculectomies, it should be used in NPFS before any reliable conclusions can be drawn. Goniopunture was also only done after 18 months which of course will not be of great help if the outflow route after the trabeculodescemet's membrane has scarred down. Thus to promote good filtration in addition to intraoperative and postoperative use of antimetabolites, goniopuncture can help in enhancing and thus in maintaining a flow under the scleral flap. Using lasers for suturelysis in trabeculectomies or for goniopuncture in NPFS is part of the armementarium we have in glaucoma surgery. The final aim for the patient is not to know whether the procedure is penetrating or not, but rather how effective it is so that the discussion on whether or not to use goniopunture is futile.

  For ophthalmologists performing NPFS, the later is compared to trabeculectomy what phacoemulsification was to extracapsular cataract extraction. They will never go back to it unless obliged to do so. However it is clear that there is a learning curve to this surgery and that it is not as forgiveful as is trabeculectomy.

  E. Ravinet, MD
  A. Mermoud, MD
  

  Reference

  (1) Khaw PT, Wells AP, Lim KS. Surgery for glaucoma in the 21st century. Br J Ophthalmol 2002;86: 710-711.

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  Conflict of Interest:
  None declared.

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• Published on: 22 March 2016

  Reply to editorial "Surgery for Glaucoma in the 21st Century"

  • Richard J. Fugo, Medical Doctor

  Dear Editor

  I found your editorial on glaucoma in the 21st century to be fascinating.[1] Not only did you give us insight as to where we are in the field, but you certainly give us provocative insight into where we might be headed in the pursuit of the perfect glaucoma procedure.

  I would like to state at the onset that I have a financial interest in product involved in this discussion, having develop...

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  Dear Editor

  I found your editorial on glaucoma in the 21st century to be fascinating.[1] Not only did you give us insight as to where we are in the field, but you certainly give us provocative insight into where we might be headed in the pursuit of the perfect glaucoma procedure.

  I would like to state at the onset that I have a financial interest in product involved in this discussion, having developed the device which is presently FDA approved in the United States for anterior capsulotomy called the Fugo Blade™. In many other parts of the world, this device is referred to as the Plasma Blade.

  The device operates on flashlight size rechargeable batteries and with this minute power can cut sharper than a diamond blade with a total cut time of one hour duration. Best stated by Dr I. Howard Fine, the device operates "like a miniature eximer laser" . Namely, the device creates an ablation path by employing a focused photon ablation of tissue with quanta of electromagnetic energy. This does sound incredible but to quote the last sentence in your editorial "Impossible? Only if you think so."

  There are over 500 doctors trained and certified in the United States in this technology. The doctors on our certification list include such notable surgeons such as I Howard Fine, F. Hampton Roy, Luther Fry, Gregory Scimeca, David Schanzlin, Jan Worst and Dr Daljit Singh. Dr Jan Worst of the Netherlands has stated, "This device can change the entire field of surgery, not just ophthalmic surgery. " Dr Daljit Singh of Amritsar, India has stated, "This is the greatest cutting device that I have ever used".

  There are those who have not used this device who state that it is merely another electro-cautery unit. The Fugo Blade™ absolutely has nothing to do with electro-cautery or diathermy. Consider that it can be operated on batteries as small as coin size, wristwatch batteries. Yes, this is a new approach to electrosurgery. Such a new device allows us to perform surgeries, which heretofore were considered to be impossible just as you discuss in your article. Incisions are resistance free and bloodless . You can ablate through highly vascularized tissue such as uveal tissue which will be resistance free and bloodless. This opens up incredible possibilities for glaucoma surgery.

  Dr Daljit Singh of Amritsar, India is presently performing what you mentioned in the last paragraph of your editorial namely a 5-minute glaucoma procedure. This is called Transciliary Filtration or Singh Filtration. We do not have 95% of the patients achieving pressures of 10-12 mm Hg for several decades. However, we do have an impressive success rate with not a single collapsed anterior chamber in approximately 200 cases in our clinicals. No iridotomy is needed and a 1 cm conjunctival flap is required. We also are obtaining penetrating insight into the homeostatic mechanisms in the eye and an enhanced understanding of how the eye works.

  Employing the Fugo Blade™, Dr Daljit Singh has been able to demonstrate stunning videos of an extensive lymphatic system that exists subconjunctivally. He showed these videos at the most recent meeting of ACES, ASCRS and ISRS. He has obtained these findings in human subjects employing vital stain and based on data obtained by Fugo Blade™ histologic sections.

  We have seen that this subconjunctival lymphatic system is imperative for homeostasis of tissue fluid in the globe. The exact microanatomy of this lymphatic system is being worked out. However, we see a highly suggestive correlation between the lymphatic feeder channels and Schlemm's canal. These feeder channels sit above Schlemm's canal. We are beginning to believe that this lymphatic system plays a major role in the management of extracellular fluid in any pathologic process such an inflammation or infection but also rules highly in the management of aqueous fluid exiting from Schlemm's canal.

  Also, we find that our studies demonstrate that a filtration track placed through sclera in an area which has deficient lymphatics will produce a large bleb, however will not produce anticipated drop in IOP. Initially, this was confusing; however, it appears that the mechanism here is that the intraocular aqueous is escaping through the filtration tract and accumulates under the conjunctiva. Since the conjunctiva lacks appropriate lymphatics, there is a large accumulation of aqueous under the conjunctiva thereby creating a large filtering bleb that lacks the ability to drain the aqueous fluid back through the orbit and into the vascular system . Dr. Singh's work will force us to rethink not only our surgical approach to glaucoma but also, as you suggest in your editorial, our thoughts and concepts about how the eye functions.

  The number of applications that are presently under study in humans include bloodless plastic surgery, bloodless squint surgery, Fugo Blade™ phacofragmentation, bloodless ablation of fibrovascular bands that exist in severe retinopathy, and a new procedure coined by Dr. Singh as " Peep Hole" DCR . This procedure takes about 3-5 minutes wherein a micropore ablation path is placed through the medial cathal conjunctiva and into the dacryocyst, providing a port for evacuation of necrotic debris from the dacryocyst. Also, the ablation path allows probing and flushing of the area with antibiotic. This has produced excellent results to date on the 10 operated patients. We also are working on exciting protocols for DLEK and lamellar corneal grafts. Likewise, we now have a marvelous tool which may bring a quick, repeatable and efficacious presbyopia reversal surgery into the realm of reality in the foreseeable future. A senior executive of one of our large ophthalmic companies has called this technology: "the greatest fundamental technology since the implementation of the laser".

  Numerous articles have appeared on this device in the USA since this device is FDA approved and over 500 American ophthalmologists have taken a course in this technology and have been certified to use the technology. Dr I. Howard Fine chose the Fugo Blade as one of the top eight technologies at the 2002 ASCRS Meeting.2 The technology will be introduced into the European market and into Japan in 2003. Only a few lectures on this topic have been given to date outside of the USA and those include lectures given by Dr I. Howard Fine and Dr Daljit Singh. Dr David Apple has performed Fugo Blade capsulotomy margin histologic analysis and presented this data in his Keynote Innovators Lecture at the 2002 ASCRS meeting in Philadelphia. He explained why the Fugo Blade capsule margin is "desirable" based on his analysis as well as the authoritative studies of Assia.

  Your editorial correctly points out that surgical techniques must be accompanied by improved understanding. This new technology may help greatly in this quest. Dr Daljit Singh calls the Plasma Blade "the great leveler". He firmly believes that this technology may provide an opportunity to deliver much needed ophthalmic care to the 3rd World. If this comes to pass, wouldn't it be grand!

  Richard J. Fugo MD, PhD

  Reference

  (1) P T Khaw, A P Wells, and K S Lim. Surgery for glaucoma in the 21st century. Br J Ophthalmol 2002; 86: 710-711.

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  Conflict of Interest:
  None declared.

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