New Laser Technologies

Chapter

Abstract

Glaucoma laser surgery was initially intended and practiced as a less invasive modification of standard filtration surgery. Pulsed and continuous-wave (CW) laser beams were used to create new outflow paths to lower the intra ocular pressure (IOP). The patency of laser-made openings proved short lasting, but the realization that the reduction of IOP persisted long after their failure prompted the investigation of new techniques and protocols. Lasers were used to produce shrinking burns in the trabecular meshwork (laser trabeculoplasty or LT), to stretch or perforate the iris (laser iridoplasty or laser iridotomy), and to replace diathermy and cryotherapy in cyclodestructive procedures to reduce the production of aqueous humor (laser cyclophotocoagulation or CPC). Treatment endpoint of all laser surgeries was always a discernable photothermal, photoacoustic, or photomechanical tissue effect, such as stretching, blanching, burning, bubbling, popping, perforating, or cutting. Although destructive in nature, the iatrogenic damage and collateral effects associated with these endpoints have been universally accepted as necessary for a useful treatment. Lately, almost by serendipity, it has been found that some procedures result equally effective and more beneficial when performed without destructive endpoint, by eliciting similar mechanisms of action with fewer or no collateral effects. This chapter will briefly review past and current glaucoma laser-surgery procedures and discuss new laser technologies that allow performing novel subthreshold laser-therapy treatments with no discernable tissue reaction endpoint.

Effective subthreshold laser therapies, with less or no iatrogenic damage, can be administered pro re nata (PRN) and play an important complementary role with emerging microinvasive glaucoma surgeries (MIGS) in the long-term management of glaucoma.

Keywords

Burning Filtration Argon Shrinkage Prostaglandin 

References

  1. 1.
    Krasnov MM. Laseropuncture of the anterior chamber angle in glaucoma. Am J Ophthalmol. 1973;75:674–8.PubMedGoogle Scholar
  2. 2.
    Hager H. Besondere mikrochirurgische Eingriffe. II. Erste Erfahrungen mit dem Argon-Laser-Gerat 800. Klin Monatsbl Augenheilkd. 1973;162:437–50.PubMedGoogle Scholar
  3. 3.
    Worthen DM, Wickam MG. Argon laser trabeculotomy. Trans Am Acad Ophthalmol Otolaryngol. 1974;78:OP371–5.PubMedGoogle Scholar
  4. 4.
    Wickam MG, Worthen DM. Argon laser trabeculotomy: long-term follow-up. Ophthalmology. 1979;86:495–503.CrossRefGoogle Scholar
  5. 5.
    Wise JB, Witter SL. Argon laser therapy for open-angle glaucoma. A pilot study. Arch Ophthalmol. 1979;97:319–22.PubMedCrossRefGoogle Scholar
  6. 6.
    Gaasterland D, Kupfer C. Experimental glaucoma in the rhesus monkey. Invest Ophthalmol. 1975;14:455.Google Scholar
  7. 7.
    Ticho U, Zauberman H. Argon laser application to angle structures in glaucoma. Arch Ophthalmol. 1976;94:61–4.PubMedCrossRefGoogle Scholar
  8. 8.
    Ticho U, Cadet JC, Mahler J, et al. Argon laser trabeculotomies in primates: evaluation by histological and perfusion studies. Invest Ophthalmol. 1978;17:667–74.Google Scholar
  9. 9.
    Ticho U. Laser applications to the angle structures in animal and in the human glaucomatous eye. Adv Ophthalmol. 1977;34:201.PubMedGoogle Scholar
  10. 10.
    Glaucoma Laser Trial Research Group. The Glaucoma Laser Trial (GLT) and glaucoma laser trial follow-up study: 7. Results. Am J Ophthalmol. 1995;120:718–31.Google Scholar
  11. 11.
    Musch DC, et al., for the CIGTS Study Group. The collaborative initial glaucoma treatment study. Study design, methods, and baseline characteristics of enrolled patients. Ophthalmology. 1999;106:653–62.Google Scholar
  12. 12.
    Lichter PR, et al., for the CIGTS Study Group. Interim clinical outcomes in the collaborative initial glaucoma treatment study comparing initial treatment randomized to medications or surgery. Ophthalmology. 2001;108:1943–53.Google Scholar
  13. 13.
    Heijl A, et al., for the Early Manifest Glaucoma Trial Group. Reduction of intraocular pressure and glaucoma progression. Results from the Early Manifest Glaucoma Trial. Arch Ophthalmol. 2002;120:1268–79.Google Scholar
  14. 14.
    Leske MC, et al., for the Early Manifest Glaucoma Trial Group. Factors for glaucoma progression and effect of treatment. The Early Manifest Glaucoma Trial. Arch Ophthalmol. 2003;121:48–56.Google Scholar
  15. 15.
    Ederer F, Gaasterland DA, Dally LG, Kim J, VanVeldhuisen PC, Blackwell B, Prum B, Shafranov G, Allen RC, Beck A, AGIS Investigators. The Advanced Glaucoma Intervention Study 13. Comparison of treatment outcomes within race 10 years results. Ophthalmology. 2004;111(4):651–64.Google Scholar
  16. 16.
    Shigleton BJ, Richter CU, Dharma SK, et al. Long-term efficacy of argon laser trabeculoplasty. A 10-year follow-up study. Ophthalmology. 1993;100:1324–9.CrossRefGoogle Scholar
  17. 17.
    Rachmiel R, Trope GE, Chipman ML, et al. Laser trabeculoplasty trends with the introduction of new medical treatments and selective laser trabeculoplasty. J Glaucoma. 2006;15(4):306–9.PubMedCrossRefGoogle Scholar
  18. 18.
    American Academy of Ophthalmology. Committee on Ophthalmic Procedures Assessment. Laser trabeculoplasty for primary open-angle glaucoma. Ophthalmology. 1996;103(10):1706–12.Google Scholar
  19. 19.
    Park CH, Latina MA, Schuman JS. Developments in laser trabeculoplasty. Ophthalmic Surg Lasers. 2000;30(4):315–22.Google Scholar
  20. 20.
    Olivier MMG. Glaucoma laser treatment: where are we now? Tech Ophthalmol. 2004;2(3):118–23.CrossRefGoogle Scholar
  21. 21.
    Fea AM, Bosone A, Rolle T, et al. Micropulse diode laser trabeculoplasty (MDLT): a phase II clinical study with 12 months follow-up. Clin Ophthalmol. 2008;2(2):247–52.PubMedCentralPubMedCrossRefGoogle Scholar
  22. 22.
    Ingvoldstad DD, Krishna R, Willoughby L. Micropulse diode laser trabeculoplasty versus argon laser trabeculoplasty in the treatment of open angle glaucoma. Invest Ophthal Vis Sci. 2005;46:ARVO E-Abstract 123.Google Scholar
  23. 23.
    Fea AM, Dorin G. Laser treatment of glaucoma: evolution of laser trabeculoplasty techniques. Tech Ophthalmol. 2008;6(2):45–52.CrossRefGoogle Scholar
  24. 24.
    Goldenfeld M, Melamed S, Simon G, Ben Simon GJ. Titanium:sapphire laser trabeculoplasty versus argon laser trabeculoplasty in patients with open-angle glaucoma. Ophthalmic Surg Lasers Imaging. 2009;40:264–9.PubMedCrossRefGoogle Scholar
  25. 25.
    Gaasterland DE. Diode laser cyclophotocoagulation. Technique and results. Glaucoma Today. 2009;7(2):35–8.Google Scholar
  26. 26.
    Wilensky JT, Krammer J. Long-term visual outcome with transscleral laser cyclotherapy in eyes with ambulatory vision. Ophthalmology. 2004;111:1389–92.PubMedCrossRefGoogle Scholar
  27. 27.
    Ansari E, Gandhewar J. Long-term efficacy and visual acuity following transscleral diode laser photocoagulation in cases of refractory and non-refractory glaucoma. Eye. 2007;21(7):936–40.PubMedCrossRefGoogle Scholar
  28. 28.
    Gedde SJ, Sciffman JC, Feuer WJ, et al. Three-year follow-up of the tube versus trabeculectomy study. Am J Ophthalmol. 2009;148(5):670–84.PubMedCrossRefGoogle Scholar
  29. 29.
    Tan AM, Chockalingam M, Aquino MC, et al. Micropulse transscleral diode laser cyclophotocoagulation in the treatment of refractory glaucoma. Clin Experiment Ophthalmol. 2010;38:266–72.PubMedGoogle Scholar
  30. 30.
    Aquino MC, Tan AW, Xiang L, et al. Micropulse versus continuous wave transscleral diode cyclophotocoagulation in the treatment of refractory glaucoma: a randomized comparison trial. (submitted for publication).Google Scholar
  31. 31.
    Liu GJ, Mizukawa A, Okisada S. Mechanism of intraocular pressure decrease after contact transscleral continuous-wave Nd:YAG laser cyclophotocoagulation. Ophthalmic Res. 1994;26(2):65–79.PubMedCrossRefGoogle Scholar
  32. 32.
    Ho CL, Wong EYM, Chew PTK. Effect of diode laser contact transscleral pars plana photocoagulation on intraocular pressure in glaucoma. Clin Exper Ophthalmol. 2002;30:343–7.CrossRefGoogle Scholar
  33. 33.
    Ho CL. Micropulse diode transscleral cyclophotocoagulation. Asian J Ophthalmol. 2002; nos 3,4, 2001 Supplement.Google Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Clinical Applications DevelopmentIRIDEX CorporationMountain ViewUSA

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