Combined three-dimensional spectral OCT/SLO topography and microperimetry: Steps toward achieving functional spectral OCT/SLO

Aims: To investigate the combination of 3D optical coherence tomography (OCT) retinal thickness measurements and superimposed scanning laser ophthalmoscopy (SLO) microperimetry obtained using a Spectral OCT/SLO and to test the correlation between retinal thickness and retinal sensitivity in retinal diseases grouped according to anatomic locations. Methods: Patients with various retinal diseases and subjects with normal fundi underwent microperimetry testing and imaging with the Spectral OCT/SLO. Based on the Spectral OCT/SLO findings, the participants were divided into 4 groups: patients with retinal thickening due to the outer retina pathology (group I); patients with retinal thickening due to the cystic changes observed in the inner retina (group II); patients with macular neurosensory retina thinning associated with geographic atrophy or underlying subretinal cicatricial changes (group III), and subjects with unremarkable fundus appearance and normal appearing retina on Spectral OCT/SLO (group IV). The primary outcome was the correlation coefficient (r) between Spectral OCT/SLO-measured macular thickness and microperimetry values. Results: Correlations between retinal thickness and psychophysical thresholds were calculated for each patient, and these values were averaged within groups. The mean correlation values (Pearson product movement) were as follows: for group I (n = 21 eyes) r = 0.04; for group II (n = 24 eyes) r = -0.53; for group III (n = 16 eyes) r = 0.41, and for group IV (n = 15 eyes) r = 0.04. Conclusions: The combination of 3D OCT images and superimposed SLO microperimetry obtained by Spectral OCT/SLO demonstrated that thickening due to cystic changes of the inner retinal layers or thinning of the neurosensory retina on OCT correlated most significantly with decreases in psychophysical threshold sensitivities.