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Retina Sessions I.M.O 2009

Retina Sessions I.M.O 2009. Leyla Asgarova, MD Illumination and light toxicity in vitreoretinal surgery. Light toxicity. Verhoeff , 1916 Noell , 1966 Light source intensity Spectral content of the light Exposure time. F ocal D iffuse S pecular R etroillumination

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Retina Sessions I.M.O 2009

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  1. Retina SessionsI.M.O 2009 Leyla Asgarova, MD Illumination and light toxicity in vitreoretinal surgery

  2. Light toxicity • Verhoeff, 1916 • Noell, 1966 • Light source intensity • Spectral content of the light • Exposure time

  3. Focal • Diffuse • Specular • Retroillumination • Slitlamp attachment for the OM

  4. Evolutionary and Revolutionary Trends in Vitreoretinal Surgery • Bullet light probes • Shielded bullet probes (provide up to 180Þ of illumination while controlling glare) • Chandelier lighting systems

  5. ILLUMINATED INSTRUMENTS, CHANDELIER LIGHTING • Dual-mode cannula • Tornambe Torpedo (Insight Instruments, Stuart, Fla) • Synergetics Awh Chandelier • Tissue manipulator • Viscodelamination light probes

  6. Evolutionary and Revolutionary Trends in Vitreoretinal Surgery • Tungsten halogen system Alcon Accurus: Fort Worth, Texas • Short-arc Xenon illumination system: Alcon Accurus Synergetics’ Photon box (O’Fallon, Mo) • Metal halide system Millennium, Bausch & Lomb, (Rochester, N.Y.) • Mercury vapor

  7. Evolutionary and Revolutionary Trends in Vitreoretinal Surgery

  8. Evolutionary and Revolutionary Trends in Vitreoretinal Surgery

  9. Evolutionary and Revolutionary Trends in Vitreoretinal Surgery

  10. Spectral content of the light

  11. Spectral content of the light

  12. Function and morphology of the retinal pigment epithelium after light-induced damage • Purpose: To determine the threshold energy for light-induced functional damage of the retinal pigment epithelium at various wavelengths • Broadband blue light (400-520 nm) Yellow light (510-740 nm) Narrowband blue light (408, 417, 439, 455, 485, 501) • 58 pigmented rabbit eyes, 21 albino rabbits. • Blue light 30 times more efficient than yellow light in causing dysfunction of the blood-retinal barrier. • Melanin seemed to play no role. No influence on the threshold energy.

  13. Endoillumination during vitrectomy and phototoxicity thresholds Br J Ophthalmol 2000;84:1372–1375 • Not safe with respect to photochemical retinal damage • International Commission on Non-Ionizing Radiation Protection (ICNIRP) • 1 min - 10 mm working distance

  14. Histology of the Vitreoretinal Interface after Indocyanine Green Staining of the ILM, with Illumination Using a Halogen and Xenon Light Source • 10 human eyes • 6 pig eyes • 3 min light exposure: xenon and halogen CONCLUSIONS: Care should be taken when comparing results obtained in human eyes and porcine eyes. Investigative Ophthalmology and Visual Science. 2005;46:1468-1472

  15. Light toxicity Three general mechanisms: • Thermal (thermal confinement) • Mechanical (stress confinement) • Photochemical effects

  16. Retinal vessel abnormalities of phototoxic retinopathy in rats • Progressive loss of outer retina • Approximation deep capillary bed • Vaso – obliterative changes • Extensive pyknosis and reduction of nuclei in the outer nuclear layer, damage to ganglion cells, and edema formation.

  17. Newer Endoilluminators Ease 25-Gauge Surgery (Retina today, Allen C) Normal and 1.5-hour light exposed retina with a fixed position endoilluminator. Images show a normal rabbit retina (A), a Tungsten-halogen exposed retina (B), a xenon-bipass exposed retina (C) and a metal-halide exposed retina (D).

  18. Light toxicity and BIO • Exposure to the indirect ophthalmoscope for more than 15 minutes is necessary to cause retinal lesions. Robertson DM, Erickson GJ. The effect of prolonged indirect ophthalmoscopy on the human eye. Am J Ophthalmol 1979;87:652-661. Ts'o MOM, Fine BS, Zimmerman LE. Photic maculopathy produced by the indirect ophthalmoscope. 1. Clinical and histopathologic study. Am J Ophthalmol 1972

  19. Long-term follow-up of iatrogenic phototoxicity. Arch Ophthalmol 1998;116:753-7. • Iatrogenic phototoxicity following either cataract or vitrectomy surgery average duration of surgery - 109 minutes - 0.9% longer - 39% (Khwarg et all)

  20. 6 patients • 3% - 7% of cataract cases (0-28%) • Light duration (?) – 11 min McDonald HR, Irvine AR. Light-induced maculopathy from theoperating microscope in the extracapsular cataract extraction and intraocular lens implantation. Ophthalmology. 1983;90:945-951.

  21. Symptomatic vs asymptomatic • Visible vs invisible • The early finding: deep retinal whitening +/- serous retinal detachment • Oval shaped vs round homogenous • Resolution 48 hours after surgery • Mottling RPE in late postop • IVFA: window defect • Autoflurescence (!) • OCT Kleinmann G, Hoffman P, Schechtman E, Pollack A. Microscope-induced retinal phototoxicity in cataract surgery of short duration. Ophthalmology. 2002;109:334-338.

  22. OCT Y FOTOTOXICIDAD MACULAR ARCH SOC ESP OFTALMOL 2008; 83: 267-272

  23. Light toxicity after cataract surgery

  24. Light toxicity after cataract surgery

  25. Light toxicity and ECCE

  26. Light toxicity in MH surgery • In a controlled clinical trial for macular hole repair surgery 7% of patients had presumptive photo- chemical retinal toxicity with a significantly worse visual outcome. Banker AS, Freeman WR, Kim JW, et al. Vision-threating complications of surgery for full-thickness macular holes. Ophthalmology 1997;104:1442–53.

  27. Light toxicity by fiber light probe

  28. Iatrogenic phototoxicity during vitrectomy • . • 3 cases • one week after surgery • size - 2-5 DD • 2 eyes fovea spared Macular phototoxicity caused by fiberoptic endoillumination during pars plana vitrectomy.Am J Ophthalmol. 1992 Sep 15;114(3):287-96 A2e mediated phototoxic effects of endoilluminators, Br. J. Ophthal, 2006 Michels M, Lewis H, Abrams GW, et al. Macular phototoxicity caused by fiberoptic endoillumination during pars plana vitrectomy. Am J Ophthalmol 1992; 114:287-96.,

  29. Xenon light induced phototoxicity lesions Arch Soc Espanola de Oftalmologia, Febr 2000

  30. Xenon light induced phototoxicity lesions

  31. Long-term Follow-up of Iatrogenic Phototoxicity • 24 eyes(20 ant. segment surgeries, 4 – vitrectomy) • 50-220 min, aver. surgical time - 109 min. • Follow-up - 34 months • Lesions spared to fovea – ant. segment surgeries involved fovea – after vitrectomy • Inferior the fovea – 9 superior – 5 20/20 – 20/25 temporal – 3 subfoveal - 5 20/400 Arch Ophthal, Vol. 116 No. 6, June 1998

  32. Long-term Follow-up of Iatrogenic Phototoxicity

  33. Long-term Follow-up of Iatrogenic Phototoxicity • Decreasing in size – 21% • No correlation age - visual outcome. (VO) change in lesion size - VO • Symptomatic – 33%

  34. Long-term Follow-up of Iatrogenic Phototoxicity

  35. Predisposing conditions and light toxicity • 39 years old F • Systemic lupus erythematosus (SLE) + hydroxychloroquine treatment Phototoxic maculopathy following uneventful cataract surgery in a predisposed patient. Br J Ophthalmol. 2002 June; 86(6): 705–706

  36. Phototoxicity to the retina: mechanisms of damage. Int J Toxicol. 2002 Nov-Dec;21(6):473-90. • Antibiotics • Nonsteroidal anti-inflammatory drugs (NSAIDs) • Psychotherapeutic agents (Amitrityline, Chlorpromazine, Imipramine, Iprindol, Prozac Thioridazine) • Herbal medicine

  37. D/D • Applying aspiration to macular holes for drying purposes when using adjuvants • ICG and other dyes used to visualize the ILM • Aminoglycoside antibiotic toxicity • Unrecognized mechanical trauma to RPE

  38. Light toxicity and ICG assisted ILM peeling • 72 years old man • MH stage III • Xenotron II, Geuder, Germany • 2 times 0.05 % ICG • 10-15 attempts – 10 min + 2 min • Post op: MH closed • Vis postop – HM + centra (12 weeks) Severe retinal damage after macular hole surgery with extensive indocyanine green-assisted internal limiting membrane peeling (Eye (2004) 18, 538–539

  39. Banker AS, Freeman WR, Kim JW, Munguia D, Azen SP. Vision-threatening complications of surgery for full-thickness macular holes. Vitrectomy for Macular Hole Study Group. Ophthalmology 1997; 104: 1442–1452

  40. SURGICAL CONSIDERATIONS • Any illumination system can be phototoxic, therefore usually precautoins apply. • Surgical time shortened (?) • Various filters are introduced during surgery. • Try to vary the directionality and intensity of light throughout the case; combining diffuse and tangential "spot" lighting • No use illuminated forceps or scissors in macular surgery (small gauge surgery)

  41. To reduce the risk of retinal phototoxicity:

  42. 420nm cut-off: standard 435nm cut-off: for core vitrectomy and general membrane removal 475nm cut-off: for removal of membranes adherent to the retina 515nm cut-off: for macular repair Xenon BrightStar - 1266-XIII, DORC

  43. SURGICAL CONSIDERATIONS • Illuminating just the area between the vascular arcades, which has a diameter of about 10 mm, would correspond with a fibre- optic distance of only 5 mm • Minimize the time that the fiber optic tip is less than 8-10 mm from the retinal surface • Not to use the light probe as an instrument to manipulate the detached retina (photochemical damage) • Exposure to the operating microscope light should be minimized as much as possible by either turning off the illumination source or placing a small shield or cover on the cornea when not using the microscope

  44. To reduce the risk of retinal phototoxicity:

  45. SURGICAL CONSIDERATIONS • Use of intraoperative dyes, such as indocyanine green, or systemic medications, such as tetracycline, may alter the threshold for damage. • Be aware of the output power from the fiber optic; ideally aim for 10-20 mW. • Power output range from 24 lumens for stiff 25- gauge light probes to over 80 lumens on some chandeliers. • Remember that a fresh bulb will increase the power output. • Surgical video!

  46. GRACIAS Festival Grec Ennogata, Sylvie Guillem July 2009

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