Abstract
Purpose: :
Type 2 macular telangiectasia (MacTel) affects the central vision in both eyes and can lead to loss of driving and reading abilities. In its early stages, diagnosis of the disease requires high index of clinical suspicion and the aid of imaging techniques. During the MacTel Project, patients enrolled in the study had multiple imaging carried out in order to establish diagnosis. This included colour fundus imaging (CFI), fluorescein angiography (FFA), autofluorescence imaging (AF), optical coherence tomography (OCT) and indocyanine green angiography (ICG). The aim of this study was to establish if ICG was helpful in establishing the diagnosis of MacTel.
Methods: :
All images taken for patients enrolled in the MacTel Study with the clinical diagnosis of MacTel were sent to the Reading Centre at Moorfields Eye Hospital, UK where the diagnosis was confirmed using CFI, FFA, OCT and AF. For those patients where diagnosis was confirmed, ICG imaging was also graded. Two experienced medical retinal specialists who were not involved grading the other imaging modalities read the ICGs and then adjudication was carried out by an expert on the field (ACB).
Results: :
Out of 276 patients enrolled in the MacTel study, 153 patients -264 eyes- had gradable quality indocyanine green angiography on presentation. 32 eyes of 24 patients had choroidal neovascularisation secondary to MacTel. In CNV cases, no ICG findings specific to MacTel were identified; findings were not different of those already known to be characteristic of CNV. In the rest of the eyes, no specific ICG findings were identified related either to the condition or to the stage of the disease.
Conclusions: :
ICG did not show specific MacTel findings in our group of 153 confirmed MacTel patients. Our study suggests that ICG does not exhibit unique findings in MacTel; therefore in clinical practice it might not be useful in aiding the diagnosis or the grading of the non-end stage disease. In late stage, the findings do not differ from that found in CNV and its use in clinical practice for these cases is yet to be proven. Based on our findings, ICG is to be removed from the MacTel imaging protocol.
Keywords: macula/fovea • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)