When a patient presents with symptoms that cannot be explained by an abnormality of the refracting media and the anterior eye segment, an examination of the eye fundus is indicated. Even when the symptom does originate from the former, it is often still necessary to examine the fundus because the cause of the patient’s symptom may also be traced back to here. In addition, there are several systemic diseases that may have a negative impact on the fundus of the eye. Examples are, amongst others, hypertension and diabetes. The examination of the eye fundus forms part of the routine check-up in patients with those diseases.
Again, the history-taking here is based on the prediagnosis.
History-taking
- How old is the patient?
- How long have the problems existed?
- Have the problems developed suddenly or gradually?
- Are both eyes equally affected?
- Does covering one eye change the situation?
- Do the problems occur when looking into the distance, close up, or both?
- Apart from what the patient describes, do they also see blotches, flies, light flashes, stars, imagery, or curtain-like phenomena?
- Prior to the start of the symptoms, did the patient e.g. see circles around lamps, complain of headache localised around or above the eyes?
- Does the patient require strong positive or negative correction because of a refractive error?
- Does high eye pressure (glaucoma) run in the family?
Required materials
- mydriatics (dilating drops)
- battery tube and funduscopy piece [Figure 71]
Figure 71
The funduscopy piece
Looking from the connection mechanism used to place the piece on the battery tube, we see a wheel or handle on the front [Figure 72-1] that can be used to vary the shape of the light beam (slit-shaped, half moon-shaped, small full moon, large full moon, and on some models also a full moon with a “target” depicted inside it). On the same side there is also a handle to change the colour of the light (white or green). Above it you will find a small round opening [Figure 72-2], through which the light beam leaves the funduscope, and its position is in line with the opening on the back that you look through, the ocular. On the side of the funduscope piece a small wheel is visible, the diopter dial [Figure 72-3]. On the other side of the piece, on newer models made by Heine, a handle is located with the numbers 10 and 20 beside it; with this you can place a lens of +10 or +20 diopter, respectively, in front of the ocular above it. Above this handle you can see a circle in which the numbers 0 to 10 inclusive are visible when you turn the dioper dial [Figure 72-4]; the numbers are either black or red. These correspond with lenses that are turned in front of the ocular to correct a possible refractive error of the examiner’s or patient’s eye. The red numbers correspond to a negative correction, the back numbers with positive corrections.
Figure 72