Long-term results of deep sclerectomy with collagen implant : Journal of Cataract & Refractive Surgery

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Long-term results of deep sclerectomy with collagen implant

Dahan, Elie MD, MmedOphth

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Journal of Cataract & Refractive Surgery: May 2005 - Volume 31 - Issue 5 - p 868-869
doi: 10.1016/j.jcrs.2005.03.048
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The long-awaited report of long-term results1 shows clearly the benefits and advantages of nonpenetrating glaucoma surgery (NPGS).2–5 The opponents of NPGS have argued that there were no publications of long-term results of this promising technique.4,5 The article by Shaarawy et al. shows that long-term results exist, and they are not disappointing. At 96 months (8 years postoperatively), a qualified success rate of 91% and a complete success rate of 57% are remarkable. For the more demanding glaucoma surgeons, this article also shows that 49% of the 105 eyes had a complete success rate (without medications), achieving an intraocular pressure of 125 mm Hg or less at 96 months. This is by all measures an unbeatable achievement.

However, 1 important detail in the report was not elaborated sufficiently: All surgery was performed by the same surgeon. I presume the surgeon was Andre Mermoud, who is the head of the Glaucoma Unit in the Hôpital Ophtalmique Jules Gonin in Lausanne, Switzerland. Mermoud probably performs more than 500 NPGS procedures annually. Nonpenetrating glaucoma surgery has a long learning curve and is notoriously difficult to master; the more one does, the better the results.2,4 Shaarawy et al. should have emphasized this point and maybe compared their results with those of the rest of the department.

“Deep sclerectomy” is a misnomer for an excellent glaucoma operation. Although it has gained popularity and most ophthalmologists worldwide understand its meaning, it describes only part of the procedure: the creation of a deep scleral bed beneath the superficial scleral flap. To the layman, the term does not necessarily refer to a glaucoma operation. The term nonpenetrating glaucoma surgery is more descriptive, more precise, and more complete. Nonpenetrating glaucoma surgery encompasses all the variants (trabeculectomy ab externo, deep sclerectomy, viscocanalostomy) of the same glaucoma operation, which allows filtration through a naturally occurring membrane, the trabeculo-Descemet's membrane.4

Elie Dahan MD, MmedOphth

Johannesburg, South Africa


1. Shaarawy T, Mansouri K, Schnyder C, et al. Long-term results of deep sclerectomy with collagen implant. J Cataract Refract Surg 2004; 30:1225-1231
2. Dahan E, Drusedau MUH. Onpenetrating filtration surgery for glaucoma: control by surgery only. J Cataract Refract Surg 2000; 26:695-701
3. Dahan E, Ravinet E, Ben-Simon GJ, Mermoud A. Comparison of the efficacy and longevity of nonpenetrating glaucoma surgery with and without a new nonabsorbable hydrophilic implant. Ophthalmic Surg Lasers Imaging 2003; 34:457-463
4. Dahan E, Shaarawy T, Mermoud A, Freedman J. Nonpenetrating glaucoma surgery. In: Yanoff M, Duker JS, eds, Ophthalmology, 2nd ed. St Louis, MO, Mosby, 2004; 1577-1585
5. Tan JCH, Hitchings RA. Non-penetrating glaucoma surgery: the state of play. Br J Ophthalmol 2001; 85:234-237
© 2005 by Lippincott Williams & Wilkins, Inc.