Mark Saeger1, Jan Heckmann1, Konstantine Purtskhvanidze1, Amke Caliebe2, Johann Roider1, Stefan Koinzer3. 1. Department of Ophthalmology, University Hospital of Schleswig-Holstein, Campus Kiel, House 25, Arnold-Heller-Str. 3, 24105, Kiel, Germany. 2. Institute of Medical Informatics and Statistics, University Hospital of Schleswig-Holstein, Campus Kiel, House 31, Arnold-Heller-Str. 3, 24105, Kiel, Germany. 3. Department of Ophthalmology, University Hospital of Schleswig-Holstein, Campus Kiel, House 25, Arnold-Heller-Str. 3, 24105, Kiel, Germany. koinzer@auge.uni-kiel.de.
Abstract
BACKGROUND: Photocoagulation lesion intensity relies on the judgement of retinal blanching. Lesions turn out variable due to observer-dependent judgement and time dependency of blanching. We investigated lesion variability per patient and per physician in clinical routine treatments. METHODS: In this observational clinical trial, different physicians performed panretinal photocoagulation for diabetic retinopathy. Study eyes received 20-30 study lesions at 20 ms (three physicians, nine eyes) and 200 ms (four physicians, 12 eyes) irradiation time (532 nm continuous wave photocoagulator, 300 μm spot size). Lesions were imaged after 1 hour with photography and optical coherence tomography (OCT). We measured lesion diameters in fundus and OCT images, and graded intensities according to a previously published six-step classifier. RESULTS: 200-ms lesions were larger and more severe (568, 474-625 μm [median, IQR], predominantly class 6) than 20-ms lesions (397, 347-459 μm, predominantly classes 3-4). The impact of laser power was small compared to other factors. Lesion intensities and diameters in fundus and OCT images varied significantly between patients and between physicians. Median photographic lesion diameters varied by up to a factor of 1.61 (20 ms) or 1.5 (200 ms) respectively. CONCLUSIONS: In this study, the treated area of retina varied by up to a factor of 1.612 = 2.59 for a given spot number. As clinical efficacy depends on the treated area, which is a function of lesion number by area per lesion, our results implicate poor control of the overall treatment effect if treatments are administered according to lesion number or spacing alone. Better ways of laser effect control should be sought.
BACKGROUND: Photocoagulation lesion intensity relies on the judgement of retinal blanching. Lesions turn out variable due to observer-dependent judgement and time dependency of blanching. We investigated lesion variability per patient and per physician in clinical routine treatments. METHODS: In this observational clinical trial, different physicians performed panretinal photocoagulation for diabetic retinopathy. Study eyes received 20-30 study lesions at 20 ms (three physicians, nine eyes) and 200 ms (four physicians, 12 eyes) irradiation time (532 nm continuous wave photocoagulator, 300 μm spot size). Lesions were imaged after 1 hour with photography and optical coherence tomography (OCT). We measured lesion diameters in fundus and OCT images, and graded intensities according to a previously published six-step classifier. RESULTS: 200-ms lesions were larger and more severe (568, 474-625 μm [median, IQR], predominantly class 6) than 20-ms lesions (397, 347-459 μm, predominantly classes 3-4). The impact of laser power was small compared to other factors. Lesion intensities and diameters in fundus and OCT images varied significantly between patients and between physicians. Median photographic lesion diameters varied by up to a factor of 1.61 (20 ms) or 1.5 (200 ms) respectively. CONCLUSIONS: In this study, the treated area of retina varied by up to a factor of 1.612 = 2.59 for a given spot number. As clinical efficacy depends on the treated area, which is a function of lesion number by area per lesion, our results implicate poor control of the overall treatment effect if treatments are administered according to lesion number or spacing alone. Better ways of laser effect control should be sought.
Authors: Stefan Koinzer; Kerstin Schlott; Lars Ptaszynski; Marco Bever; Susanne Kleemann; Mark Saeger; Alexander Baade; Amke Caliebe; Yoko Miura; Reginald Birngruber; Ralf Brinkmann; Johann Roider Journal: Invest Ophthalmol Vis Sci Date: 2012-06-14 Impact factor: 4.799
Authors: Daniel Lavinsky; Jose A Cardillo; Yossi Mandel; Philip Huie; Luiz A Melo; Michel E Farah; Rubens Belfort; Daniel Palanker Journal: Acta Ophthalmol Date: 2013-04-05 Impact factor: 3.761
Authors: Mahiul M K Muqit; Jane C B Gray; George R Marcellino; David B Henson; Lorna B Young; Niall Patton; Stephen J Charles; George S Turner; Andrew D Dick; Paulo E Stanga Journal: Arch Ophthalmol Date: 2010-04