Clinical Examination, Investigation and Instrumentation
What this domain tests
This domain tests technique, interpretation and safe use of slit lamps, tonometers, gonioscopes, ophthalmoscopes, perimeters and imaging devices. Questions reward correct calibration, infection control and recognition of artefact.
Core rules and concepts
- Goldmann applanation tonometry requires fluorescein, cobalt-blue illumination and a calibrated prism; avoid excessive eyelid pressure.
- Gonioscopy uses a mirrored lens to assess the angle; indentation distinguishes appositional from synechial closure.
- Ophthalmoscopy should be systematic: media, disc, macula, vessels and periphery.
- Perimetry requires reliable fixation and attention to false-positive and false-negative rates.
- Slit-lamp and contact equipment need disinfection between patients; follow manufacturer and infection-control guidance.
Worked example
A Goldmann reading is 26 mmHg in one eye and 14 mmHg in the other. Reasoning: repeat after checking calibration, prism cleanliness and eyelid pressure. If the high reading persists, examine the angle and optic disc, compare with previous readings and refer urgently if acute angle closure is suspected. A single high reading is not a diagnosis.
Traps that cost marks
Not calibrating the tonometer; pressing on the eyelid during applanation; misreading the Goldmann scale; ignoring unreliable visual fields; failing to disinfect a gonioscopy lens.
Key points
- Goldmann tonometry needs calibration, fluorescein and cobalt-blue light.
- Eyelid pressure falsely raises applanation readings.
- Gonioscopy assesses angle closure and synechiae.
- Visual fields must be interpreted with reliability indices.
- Disinfect shared contact equipment between patients.