We have had the Optos system at the City clinic for most of this year and it has proved a useful adjunct to ophthalmoscopy.
A good illustration of its application is shown by this patient case. Having been recommended to come to us for a 'thorough examination', this high myope was duly dilated and a thorough indirect ophthalmoscopic view undertaken.
It was immediately apparent that a whole swathe of inferior temporal retina was heavily pigmented, along with some peripapillary changes related to the patient's myopia.
We then took images on the Optos system. Figure 1 shows the right and left maps displayed on screen simultaneously and clearly shows the area of pigmentation. The appearance suggests previous damage, such as an earlier detachment, but interestingly the patient reported no such incident.
A closer view of the right eye (Figure 2) showed two points of more concern to us. There appeared to be a small break in the retina (shown by the thin arrow) surrounded by what looked to be elevated retina (the boundary of which is shown by the thicker arrow). By removing either the red or the green component, it was possible to reveal the lesion to be at the retinal level (Figure 3) rather than the choroidal level (Figure 4).
We decided that an opinion using the Optos email service would be useful in this case. It might be that the small circular lesion was a longstanding atrophic patch and the surrounding paler area either artefactual or something other than oedema. Users of the system are able to attach images to an email which goes to William Jones, well-known US optometrist and expert in the peripheral retina.
The response was received, impressively, in a matter of hours and confirmed 'temporal tilted disc with choroidal crescent, RPE hyperplasia, retinal degeneration and chorioretinal atrophy in the inferior temporal (retina). This is usually seen in trauma. There is pigment cuffing of a vessel seen nasally'.
The email clearly states that this is an opinion provided 'as an aid to deciding whether to refer and cannot be regarded as a diagnosis of the patient's condition, since the reviewer has neither had access to the full history nor examined the patient directly'.
As we had had such access, it was decided that, bearing in mind the conflict between the patient history (or, rather, lack of it) and the unusual fundus appearance, that referral for a full peripheral retinal assessment by an ophthalmologist was appropriate. The patient was told of our findings and all relevant information regarding relevant symptoms to be aware of. We await the results of her referral.
The pigment spread was clearly visible with a Volk lens assessment but the small atrophic hole and surrounding pale area were not. Our view was that the P200 helped us to obtain a more thorough picture of this patient's unusual peripheral retinal changes, but more experience in interpreting the Optos images will be useful.
? Bill Harvey is clinical editor of Optician and Umesh Rupralia is visiting clinican at City University