Confocal blue reflectance imaging in type 2 idiopathic macular telangiectasia

To report the characteristics of confocal blue reflectance imaging in type 2 idiopathic macular telangiectasia (type 2 IMT).

In a prospective observational cross-sectional study, both eyes of 33 patients with type 2 IMT were examined by means of fundus biomicroscopy, fundus photography, fluorescein angiography, and optical coherence tomography (OCT). Confocal blue reflectance (CBR) imaging was performed using a confocal scanning laser ophthalmoscope (HRA2; Heidelberg Engineering, Heidelberg, Germany). To compare the results derived from different imaging modalities, an analysis was performed using image analysis software (Heidelberg Eye Explorer; Heidelberg Engineering).

CBR imaging revealed a parafoveal area of increased reflectance that was slightly larger than the area of hyperfluorescence in late-phase fluorescein angiography. The area usually encompassed an oval parafoveal area, but sectors could be spared. A parafoveal area of increased CBR was detected in 98% of eyes that showed angiographic evidence for type 2 IMT.

CBR imaging is a new, noninvasive, and sensitive method that may contribute to differentiate type 2 IMT from other diseases. Abnormalities of macular pigment distribution and Müller cell pathology may contribute to the phenomenon of increased CBR and thus the pathophysiology of type 2 IMT.