Controlled cyclophotocoagulation with the 940 nm laser for primary open angle glaucoma in African eyes
- 135 Downloads
“Controlled cyclophotocoagulation” is a real-time dosage control which reduces the complications of transscleral cyclophotocoagulation to a negligible amount in European eyes. Applied to a few African eyes, however, the method failed. Obviously, the physical parameters of the laser procedure need adjustment to African eyes.
Method and material
After theoretical investigations and tests in African cadaver eyes, 940 nm laser wavelength instead of 810 nm and a different fiber coupling had solved the problem of physical differences between European and African eyes to a large extent. The method was then applied to 272 eyes of 188 patients with primary open-angle glaucoma, of which it was possible to follow 26 eyes of 18 patients for at least 1 year. Median age of the patients was 63.7 years, with the youngest 16.8 years, the oldest 88.8 years. Either 16 or 24 laser spots were applied at random. If both eyes were treated, they were treated in the same session.
The average intraocular pressure (IOP) reduction after 1 year was 7.5 mmHg, with average glaucoma drug reduction from 1.5 to 1.2 substances. At least one pop spot occurred in 32% of the eyes. No statistically significant difference between 16 and 24 spots was found. No severe complications such as intraocular bleeding, hypotony <7 mmHg, choroidal detachment or phthisis were observed.
Controlled cyclophotocoagulation with the 940 nm laser is a safe method which can be applied as the first-choice treatment to African primary open-angle glaucoma eyes. Individual IOP prediction, however, is very difficult.
KeywordsCyclophotocoagulation Wavelength dependence Real-time control Radiation transport
- 2.Beckman H, Kinoshita A, Rota AN, Sugar HS (1972) Transscleral ruby laser irradiation of the ciliary body in the treatment of intractable glaucoma. Trans Am Acad Ophthal Otol 76:423–436Google Scholar
- 10.Hamard P, Kopel J, Valtot F, Quesnot S, Hamard H, Haut J (1995) Traitement des glaucomes réfractaires par cyclophotocoagulation au laser à diode. J Fr Ophthalmol 18:447–454Google Scholar
- 13.Omofolasade K, Gaasterland DE, Pollack IP, Enger CL (1996) Long-term outcome of initial ciliary ablation with contact diode laser transscleral cyclophotocoagulation for severe glaucoma. Ophthalmology 103:1294–1302Google Scholar
- 16.Hamada M, Suzuki R, Kurimoto S (1991) Transient complete visual loss during transscleral cyclophotocoagulation. Jap J Clin Ophthalmol 45:949–951Google Scholar
- 17.Edwards DP, Brown SV, Higginbotham E (1989) Sympathetic ophthalmia following Nd:YAG cycloptherapy. Ophthalmic Surg 20:544–546Google Scholar
- 21.Sabry K, Vernon SA (1999) Scleral perforation following transscleral cyclodiode. Br J Ophthalmol 83:502–503Google Scholar
- 26.England C, Van der Zypen E, Fankhauser F, Kwasniewska S (1988) A comparison of optical methods used for transscleral cyclophotocoagulation in rabbit eyes produced with the Nd:YAG laser: a morphological physical and clinical analysis. Lasers Light Ophthalmol 2:87–102Google Scholar
- 27.Kwasniewska S, Fankhauser F, Van der Zypen E, Rol P, Henchoz PD, England C (1988) Acute effects following transscleral contact irradiation of the ciliary body and the retina/choroid with the cw Nd:YAG laser. Lasers Light Ophthalmol 2:25–34Google Scholar
- 29.Takahashi H, Okisaka S (1991) Safety and effectiveness of contact trans-scleral cyclophotocoagulation with continuous-wave Nd:YAG laser. Jap J Clin Ophthalmol 45:1233–1237Google Scholar
- 39.Schroder G (1990) Technische Optik. Kamprath-Reihe, Vogel, Würzburg, ISBN 3-8023-0067-XGoogle Scholar
- 40.Rol P, Niederer P, Dürr U, Henchoz PD, Fankhauser F (1990) Experimental investigations on the light scattering properties of the human sclera. Laser Light Ophthalmol 3:201–212Google Scholar
- 42.Holbach M, Fiadoyor S, Preußner PR. Controlled cyclophotocoagulation for the therapy of primary open angle glaucoma in African eyes. Presentation to the 101st Congress of the Deutsche Ophthalmologische Gesellschaft (DOG), Berlin, 25-28.09.2003Google Scholar