First Author: M.Richardson UK
Co Author(s): R. Mathew S. Sivaprasad 0 0 0 0 0 0 0 0 0
Back to previous
To determine the most efficient Optical Coherence Tomography (OCT) scanning protocol for Diabetic Macular Oedema (DMO) by balancing the number of scans acquired, with the efficiency of capturing pathology in the retina.
The Advanced Imaging Referral (AIR) clinic at King’s College Hospital, London is the photographer managed clinic for mild diabetic maculopathy.
During the visit, patients undergo an OCT of the macula (Spectralis HRA+OCT, Heidelberg Engineering, Heidelberg, Germany). The parameters of the scan were set to 200 x 200 macular cube, with Automatic Real Time (ART) function of 24, high speed and scan density of 97 raster lines. The centre of the scan was positioned on the white reflex of the foveal depression. Only eyes that did not display pathology on the central scan were eligible. 50 Eyes of 28 patients were scanned and analysed. Analysis was conducted for each individual scan looking principally for the presence of exudates and cysts. By analysing the spacing of the scans containing pathology, we tried to determine if a coarser scan pattern would have yielded the same results for pathology detection in each case.
Of the 50 eyes that were analysed, 20% were found to have cysts that averaged at 3% of individual scan lines. The 25 line protocol (spacing 240µm) was equally effective at detecting pathology as the 97 line (spacing 60µm) scans in 100% of cases. The volume of pathology that could remain undetected increased logarithmically as the distance between scans increases.
The 25 line protocol was recommended for use in virtual clinics, saving time and increasing efficiency of the virtual clinics. More research is needed into determining the optimum settings for the other OCT parameters.