I recently had the chance to try out the latest advanced spectral domain OCT to hit the UK market.
The Nidek RS-3000 RetinaScan (distributed in the UK by Birmingham Optical Group). The instrument (Figure 1) is capable of very high speed scanning (53,000 A-scans per second) at a resolution of 4 microns. This high resolution means that a retinal cross section has such detail that the various layers are very easy to see (Figure 2).
There are six ways of scanning the retina. The macular line (as in Figure 2) represents a single cross section of the macular area whereas the macular cross gives a vertical and horizontal cross section and the macular multi makes multiple cross-section scans at the macula. A macular map function allows multiple scans to be combined to produce a 3D layered representation of the macular area.
The disc area may be similarly mapped to give a 3D representation that may highlight any topographic change over the years. Also a circular function allows an analysis of the retinal nerve fibre layer. Figure 3 shows the RNFL data for a healthy disc. The instrument now features a normative database which illustrates the data in comparison with an age matched normal database and indicates 'health' with a typical traffic light system. Figure 4 shows a patient where there is some degree of superior nasal thinning as indicated by the amber and red colour. Figure 5 shows the results for a patient who had pressures of 23mmHg. By attachment of a forehead rest and lens cap, anterior sections showing the angle or the corneal thickness are possible (Figure 6).
? For further information contact Birmingham Optical Group on 0845 230 8703