Interuser accuracy, intermachine variation

I was lucky enought to spend an excellent day in snowy Silverastone on Monday organised by the National Eyecare Group. Ostensibly the day was a chance for delegates to have a look at and consider purchase of an OCT. Advice was on hand to explain how they pay for themselves in no time at all and as a adjunct to any clinic they are becoming increasingly essential if you want to differentiate yourself as a specialised clinician. 16 companies were present and the variety of OCTs available appear endless and ever-increasing (Optos, for example, are a new player here). I was asked many times which one I would recommend. My answer is always the same. All the modern ones have excellent resolution and each has a variety of features worth investigating. I would want an anterior scan (and like the integrated lens of the Topcon for this), i would want ease of focusing including establishing the z-plane for reference of measurement (all make this esasy now though that did not use to be the case), I would want a ganglion cell complex thickness measure (Optovue first here but other catching up. Spectralis has the Blue Peak autofluorescence enabling useful assessment of dead RPE (for example when assesssing the extent of atrophy of an AMD patient), easy interface of data, a trustworthy normative database (an ever changing area and we should NEVER solely rely on them). Cirrus has good en face layer displays and excellent tracking for repeat use. Copernicus and Topcon are easy to use for me. Ultimately you will find one which you intuitevly find easiest to use and this will vary from person to person. All the current one have excellent resolution and graphic display.