Earlier in the year, Optician (January 27) reported on the new Zeiss Visucam Pro NM which was launched onto the UK market late last year.
As we reported, the camera boasts some nice new features, so we had the systems installed at the Fight for Sight clinic, City University, and captured images from as wide a range of patients as possible. The aim was to do so without mydriasis, bearing in mind that the manufacturers state quite clearly that this non-mydriatic system allows ‘totally non-mydriatic examination of even problematic patients with exceptionally small pupils’.
Setting Up
The system itself has the hard drive and software integrated within the camera unit itself so all the table supports is the camera and a 17 inch flat screen monitor (Figure 1). A printer is also provided, though we were able to attach one of those ‘ready to go’ photo printers which allows an immediate print out of a five inch photograph which can be given immediately to a patient for the required fee
Having an internal hard drive means that any image may be stored rapidly but it is also possible to configure the system such that images are immediately stored on to a DVD (something many prefer to do so they have a hard copy back up) or, as in our case, directly onto an external drive or memory pen. I found that the storage straight to a memory pen only added seconds to the capture sequence but allows easy transfer of data. This was a very simple operation and very user friendly.
I tend to use jpegs but the system also offers the larger tiff files and also Codec files. These are becoming standard in the medical field as the image is encoded with all the relevant patient data. For transfer between clinics and also from a medicolegal standpoint, this storage mode is likely to become the norm in future.
Once the system has booted up you are directed to the patient data field as with most systems. Once details are entered, the capture button is depressed and an external shot of the patient’s eye is seen, assuming they are set up appropriately. This can just be seen on the screen in Figure 1 where you will also note the circle.
The patient’s pupil should be at least as large as the central circle for best quality and a 45º capture. For smaller pupils, the camera may be set to a 30º capture of a special SP or small pupil setting. As I shall explain, we managed a 45º capture in almost all the patients we examined, some with pupils smaller than 4mm.
With the patient fixating a central target, the instrument is moved toward them and a clunk is 
heard as the condensing lens falls into place. The fixation target may be made larger or set to flash, something useful for our macular disease patients.
A black and white image appears on screen, the brightness of which may be adjusted using an infra red rheostat which has no influence on the pupil diameter. Two white dots are aligned with the lines on screen and a small pair of vernier markers are aligned to a single horizontal line for a focussed image. Once set, the focusing only needs to be readjusted if changing the view to peripheral retina. Multiple central shots remain in focus from the first adjustment, so freeing up your hand.
Images
A typical central 45º shot is shown in Figure 2 Another straightforward patient was happy for me to try out multiple images. By setting the fixation target to manual setting it is possible to 
get the patient to look in adjacent directions.
Each shot may then be shown on the proofsheet screen.
By selcting ones you are happy with, a ‘merge’ button may then be depressed and a multiple image is saved.
As seen in Figures 3, 4 and 5, the ‘join’ is invisible. If individual images have too much shadowing, say if the pupil was too small, the merging is not possible.
I have to say, however, that this was the easiect composite image creation I have ever used.
This would be excellent for diabetics with widespread 
multiple lesions. A patient with a history of retrobulbar neuritis in the right eye was captured again using the manual fixation to ensure the discs were central to the image. 
This allowed us to present the two discs side by side and the atrophy of the right becomes clear (figure 6 a and b).
As with most systems, a red free option is offered during capture which gives better contrast than if the red is 
removed later by a graphics package (figure 6 a and b). A patient with very small pupils (3mm) was examined using the SP setting and the quality of the resultant image was sufficient to reveal clinical details (figure 7). Interestingly, this patient had a degree of exophthalmos which required him being positioned with his head away from the brow rest before a focussed image was achievable. The only time dilation was deemed necessary was when attempting to view some lattice way out in the periphery on a young patient. This just could not be imaged on the 45 degree setting and displaced fixation.
Recommended
Overall, I have to say for ease of use, ease of image transfer, image manipulation and image quality, I like this system very much and would recommend it.