Quantification of Retinal Pigment Epithelium Tear Area in Age-Related Macular Degeneration

In Brief Purpose: To compare different quantification tools based on confocal scanning laser ophthalmoscopy for assessment of retinal pigment epithelium (RPE) tear area size. Methods: Confocal scanning laser ophthalmoscopy fundus autofluorescence (FAF) and near-infrared reflectance (IR) images were retrospectively evaluated in 23 patients with RPE tear after intravitreal injection for pigment epithelium detachment due to exudative age-related macular degeneration at baseline and additionally in 11 patients after 5.1 ± 1.8 months of follow-up. Retinal pigment epithelium tear area was measured by three independent readers using three methods: manually on confocal scanning laser ophthalmoscopy FAF images, manually on confocal scanning laser ophthalmoscopy IR images, and using an FAF-based semiautomated software. Results: Confidence intervals were 0.08 and 0.12 for FAF, 0.11 and 0.09 for FAF-based semiautomated software, and 0.25 and 0.27 for IR for intraobserver (Reader 1) and interobserver agreements (Readers 1 and 2), respectively. The average values of the square errors of the quantification methods were 0.040 ± 0.033 mm2 (FAF), 0.035 ± 0.060 mm2 (software), and 0.187 ± 0.219 mm2 (IR). Mean area of RPE tears at baseline given as the average measurement of all 3 readers using FAF-based semiautomated software was 5.77 ± 4.62 mm2 (range, 0.13–14.74 mm2). Follow-up measurements of unilobular RPE tears (8 patients) showed no change in lesion area size (0.14 ± 0.33 mm2); in contrast, multilobular RPE tears (3 patients) showed a progression in lesion area size of 1.80 ± 0.74 mm2. Conclusion: Manual FAF-based and semiautomated FAF-based quantifications of RPE tear area are accurate and reproducible and superior to manual IR-based measurement. Retinal pigment epithelium tear area quantification is clinically relevant regarding further intravitreal treatment, particularly in multilobular RPE tears. The aim of this study was to compare different quantification tools for assessment of area sizes of retinal pigment epithelium tears using a manual area measurement tool based on confocal scanning laser ophthalmoscopy near-infrared reflectance images, fundus autofluorescence, and using a semiautomated fundus autofluorescence–based software tool. Manual fundus autofluorescence–based and semiautomated fundus autofluorescence–based quantification of retinal pigment epithelium tear area proved to be accurate and reproducible. Results of manual infrared reflectance–based quantification, however, showed a much higher statistical spread. Retinal pigment epithelium tear area quantification is clinically relevant regarding intravitreal treatment, particularly in cases of multilobular retinal pigment epithelium tears.