Ophthalmological Instruments and Procedures

The number and type of instruments varies in different offices but the following instruments are involved in many clinical examinations: slit lamp, retinoscope, phoropter and/or trial lenses in trial frames, ophthalmoscope (both direct and indirect), fixation targets, prisms, tests for binocularity like Worth's four dot test, Maddox's rod, Bagolini's striate glasses, TNO and Titmus stereo tests and some of the instruments discussed in Part III of this text.

It is usually best to arrange an introduction to the various functions in the office so that the locations and the use of different instruments are known by the interpreter as well as which instruments usually dazzle the patient and interfere with their vision afterwards.

Most instruments are used without much active involvement of the patient. The direction of the gaze, however, is often critical for a correct measurement or for thorough examination. The interpreter must be located so that visual communication is possible if something has to be said during the test situation to a patient who is not accustomed to tactile communication. During slitlamp examination and examination of the inside of the eye with an ophthalmoscope the patient has to change the direction of gaze several times and sometimes to extreme positions. The different directions of the gaze can be described to the patient before the examination. The patient can be informed about where to look during the examination by gently tapping at the corresponding area around the eye. This can usually be done by the doctor but if his hands are busy examining, the interpreter can give this tactile information.

Interpreting during surgery under local anaesthesia requires more than routine interpreting skills. The interpreter needs to be instructed on sterility rules and on the strict limitations on moving in the operating room when going to his place close to the patient's communicating hand. Visual communication is usually impossible. Since the interpreter needs the patient's hand for communication, the intravenous drip should be placed so that it does not interfere with the interpreter's work.

The procedure has to be rehearsed well in advance, especially if the patient is not accustomed to tactile information. Then the information given during the operation is reduced to a few simple tactile cues. The interpreter must be informed about the possible effects of premedications on communication. If the interpreter has no previous experience with similar operations he should be present during another operation a few days prior to the surgery of the deaf patient. It is wise to test whether he tolerates the excitement without fainting or any other unpleasant reactions that would be disruptive.

When deaf patients are operated on under general anaesthesia, an interpreter is needed both before and especially after the operation in the recovery area. Again, some instructions on the post-operative care are usually necessary for the interpreter.

Laboratory examinations involve instructions by technicians who may not be very good at describing the test. It is usually best that the interpreter is tested briefly so he knows what the patient is going to see and when and to what he is expected to react. If the patient is going to press on a button, it is important to instruct the patient that the button cannot be pressed more than once. The typical "yes, yes" answer of a deaf person might disrupt the test.

Measurement of vestibulo-ocular response (VOR) of deaf patients is usually performed in the ENT department but most probably the same interpreter is involved. Communication with a deaf patient in pitch dark without interfering with the test itself is quite a challenge.

The test situation seems to be best understood when the test itself is described first and after that the calibration procedure by saying: "In order to be able to make the measurement we first have to do some preliminary measurements of your eye movements". When the room, the movements of the chair and the fixation lights are carefully described before testing, communication can be reduced to three different kinds of tactile information, for example, one tap meaning that the patient has to fixate on the light or the imaginary light in front of him, two taps that he has to do the calibration procedure and a slight sweep to "erase" information that was started at a wrong moment. The interpreter is in charge of the lights that have to be switched on and off during the test. The role of the interpreter in this test situation is expanded toward that of a research assistant, but this works better than if an additional person is present to switch the lights in the usually very small room.