Booklet  Examining PWLD: Section three

The Examination

This section will concentrate on determining vision and visual skills in a patient with learning disabilities.

We must not forget that some adults with learning disabilities are able to take part in a full eye examination in a similar fashion to our conventional patients, that is, they can describe history and symptoms, can read a letter chart and can answer the questions in a subjective evaluation. As we learned in the previous section, our approach may require some modification to provide a simpler structure to our questions, with short sentences and extra time given to the patient to reply. Nevertheless, the techniques for measurement may not differ remarkably from our usual routine.

For this section, we will concentrate on patients who are less able and who require quite different techniques. The carers will provide history and symptoms (but remember to include the patient in the discussion; talk to the patient, not about them). Take careful notes of the carers’ concerns and remember to address these in your report, even if you discover additional defects or encounter no visual problems. Sometimes carers have very little prior information about the patient, or are very unsure about level of vision. This is particularly so if the patient has multiple disabilities. The lack of ability to carry out a visual function may be due to physical or cognitive difficulties instead of, or as well as, a visual defect.

Consent

The issue of consent for any intervention or examination with a person with learning disabilities is complex and beyond the scope of this article. However, the practitioner should bear in mind that it is essential that the patient gives consent for all of our procedures. Be aware of consent issues and be guided by the carer. 

General Observation

 
We can sometimes learn a great deal about a patient’s level of vision from simply observing their responses to the visual world. It is useful to have the patient come to your testing area and to watch their entrance, rather than have the patient in place before your arrival. Watch the patient’s reactions carefully as they approach the area. If they look around carefully, noting where they are going and where things are, we can assume a useful level of vision. If the patient makes direct eye contact with you and particularly if they can respond to your facial expressions, this too indicates quite a good acuity. The reverse is not necessarily true. If a patient does not explore their surroundings and does not make eye contact, we cannot assume poor vision, since cognitive factors are also important in these functions.

Look for eye movement control at this stage – are the eyes deliberately targeting objects of interest and are the two eyes aligned as the patient explores their visual environment? Good alignment with normal eye movements and direct fixation will indicate reasonable vision. Uncontrolled roving eye movements, on the other hand are common in patients with very limited vision. For the inexperienced, it may be difficult to distinguish these roving eye movements from nystagmus, which can accompany good (but usually below-normal) vision.

Once the patient is in position, it can be useful to hand them an item (an unbreakable torch, the record card, a communication card); this allows us to check hand-eye co-ordination, eye alignment for a near target and to some extent, asymmetry in visual fields. These informal approaches are useful in establishing a ball-park for vision but also in settling the patient and creating a friendly atmosphere at the outset of the examination, before we move on to more formal procedures. 

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