OBJECTIVE: To investigate whether photocoagulation of the retinal pigment epithelium is possible with sparing of the photoreceptors. METHODS: Mild laser effects of a neodymium:yttrium-lithium-fluoride (Nd:YLF) laser (527 nm) were applied to 17 patients. To establish the necessary energy, test exposures were performed to the lower macula (laser variables: 1.7 microseconds, 100 and 500 pulses applied in a train at 500 Hz, 20-130 microJ, 160 microm). Of 179 test lesions, 73 were followed up at various time intervals up to 1 year by performing microperimetry directly on top of the laser lesions. RESULTS: All of the test lesions were at the threshold of retinal pigment epithelial disruption, and none of the laser effects were visible by ophthalmoscopy during photocoagulation; they were detectable only by fluorescein angiography. After exposure with 500 pulses, retinal defects were detected in up to 73% of the patients (100 microJ) after the first day. Most of these defects were no longer detectable after 3 months. After exposure with 100 pulses, no defects could be detected with 70 and 100 microJ after 1 day. The absence of microscotomas in the follow-up period suggests that retinal damage was minimal or, if it occurred, was functionally repaired. CONCLUSION: By choosing proper energy and number of pulses, it is possible to produce retinal pigment epithelial effects with no subsequent retinal damage detectable by microperimetry.
OBJECTIVE: To investigate whether photocoagulation of the retinal pigment epithelium is possible with sparing of the photoreceptors. METHODS: Mild laser effects of a neodymium:yttrium-lithium-fluoride (Nd:YLF) laser (527 nm) were applied to 17 patients. To establish the necessary energy, test exposures were performed to the lower macula (laser variables: 1.7 microseconds, 100 and 500 pulses applied in a train at 500 Hz, 20-130 microJ, 160 microm). Of 179 test lesions, 73 were followed up at various time intervals up to 1 year by performing microperimetry directly on top of the laser lesions. RESULTS: All of the test lesions were at the threshold of retinal pigment epithelial disruption, and none of the laser effects were visible by ophthalmoscopy during photocoagulation; they were detectable only by fluorescein angiography. After exposure with 500 pulses, retinal defects were detected in up to 73% of the patients (100 microJ) after the first day. Most of these defects were no longer detectable after 3 months. After exposure with 100 pulses, no defects could be detected with 70 and 100 microJ after 1 day. The absence of microscotomas in the follow-up period suggests that retinal damage was minimal or, if it occurred, was functionally repaired. CONCLUSION: By choosing proper energy and number of pulses, it is possible to produce retinal pigment epithelial effects with no subsequent retinal damage detectable by microperimetry.
Authors: H Elsner; E Pörksen; C Klatt; A Bunse; D Theisen-Kunde; R Brinkmann; R Birngruber; H Laqua; J Roider Journal: Graefes Arch Clin Exp Ophthalmol Date: 2006-12 Impact factor: 3.117
Authors: H Elsner; C Klatt; S H M Liew; E Pörksen; A Bunse; M Rudolf; R Brinkmann; R P Hamilton; R Birngruber; H Laqua; J Roider Journal: Ophthalmologe Date: 2006-10 Impact factor: 1.059