Characteristics of cystoid spaces in type 2 idiopathic macular telangiectasia on spectral domain optical coherence tomography images.

Purpose: To investigate the morphologic and topographic characteristics of intraretinal cystoid spaces in eyes with Type 2 idiopathic macular telangiectasia (MacTel 2).
Methods: Using B-scan and en face images of eyes with MacTel 2 taken from a spectral domain optical coherence tomography database, the circularities and mean gray values of the cystoid spaces were measured to determine their boundaries and reflectivity. The characteristics of cystoid spaces in MacTel 2 eyes were compared with those in eyes with Type 1 idiopathic macular telangiectasia (MacTel 1), retinal vein occlusion, and diabetic macular edema, which are caused by vascular leakage. The cystoid spaces of en face optical coherence tomography images were matched with fluorescein angiographic images.
Results: The circularity of the cystoid spaces in B-scan and en face optical coherence tomography images of 16 eyes with MacTel 2 was lower than that of eyes with MacTel 1 (P = 0.004 and P = 0.003, respectively), retinal vein occlusion (P < 0.001 and P < 0.001, respectively), and diabetic macular edema (P < 0.001 and P < 0.001, respectively). The mean gray value ratio of the cystoid spaces of eyes with MacTel 2 was lower than that of eyes with MacTel 1 (P = 0.002) and diabetic macular edema (P < 0.001). In eyes with MacTel 2, the cystoid spaces were located in the foveal center or parafoveal area.
Conclusion: Characteristics of cystoid spaces of eyes with MacTel 2 were different from those in eyes with MacTel 1, retinal vein occlusion, and diabetic macular edema. The irregular boundaries and low reflectivity of the cystoid spaces in MacTel 2 may represent the degenerative origin of the disease.