To investigate the visualization of cystoid macular edema (CME) using noninvasive retromode imaging by a new scanning laser ophthalmoscope (SLO) and compare to previous imaging modalities.

The authors of the present study retrospectively reviewed the medical records of 21 eyes of 20 patients with CME due to various etiologies. All eyes were examined with fundus camera, fluorescein angiography (TRC-50EX, Topcon, Tokyo, Japan), SLO (F-10, Nidek, Gamagori, Japan), and spectral-domain optical coherence tomography (OCT) (3D OCT-1000, Topcon, Tokyo, Japan). In the present study the SLO was used in the retro-mode with an infrared laser.

Previous fundus photography could not detect CME adequately although SLO retro-mode could show numerous oval or polygonal cystoid spaces more readily. Furthermore, each individual small cystoid space could be detected and the area of each cystoid space could be measured. The area of the largest cystoid space showed a correlation with its height, as measured with OCT (R = 0.606, p = 0.004). The area of the whole foveal cystoid space showed a correlation with central macular thickness, as measured with OCT (R = 0.493, p = 0.023).

A new commercially available SLO (F-10) in the retro-mode can allow us to detect each cystoid space non-invasively and to measure the extent of CME.