Makindo Medical Notes

Related Subjects: |OSCE Eye Exam |OSCE Ear Exam |OSCE Abdominal Exam |OSCE Ascites Exam |OSCE Jaundice Exam |OSCE Testicular Exam |OSCE Inguinal Exam |OSCE Upper limb Neurology |OSCE Lower limb Neurology |OSCE Face Neurology |OSCE Visual Fields

Introduction

• Hand Hygiene: Wash your hands thoroughly before starting the examination.
• Patient Introduction: Introduce yourself, confirm the patient’s name and date of birth, and explain that you will be assessing their visual fields.
• Consent & Explanation: Obtain informed consent and explain the purpose and steps of the examination to the patient to ensure they are comfortable and understand what is required.

Equipment Needed

• Snellen chart (for visual acuity, if needed) – though primarily for central vision.
• A pen or small target (for confrontation testing).
• A well-lit room with a plain background.
• A fixation target (e.g., examiner’s nose or a small letter at center).

The commonest error is not testing each eye separately. CovEr the eye not being tested. Usually a cooperative patient can cover the eye not being tested for you with their hand. Commonest cause of a Homonymous hemianopia is a stroke on the other side of the brain to the side with no vision. Commonest cause of a bitemporal hemianopia is a large pituitary macroadenoma

Background Knowledge

Step-by-Step Examination

• Preparation & Positioning:
  • Seat the patient comfortably at eye level in a well-lit room.
  • Ensure the patient is looking straight ahead at a fixed central target (e.g., your nose or a marked central point on the wall).
  • Explain that you will test their peripheral vision by asking them to report when they see your moving target.
• Testing Each Eye Separately (Confrontation Test):
  • Cover one eye: Ask the patient to cover one eye with an occluder or their hand without pressing on the globe.
  • Fixation: Instruct the patient to keep their uncovered eye fixed on your central target.
  • Visual Field Assessment:
    • Stand about 1 metre in front of the patient.
    • Using your free hand or a pen, slowly move your finger or target from the periphery towards the center in each quadrant (upper, lower, nasal, and temporal) of the visual field.
    • Ask the patient to say “now” or to raise a finger when they first see your moving target.
    • Repeat this process for all four quadrants.
  • Document any areas where the patient fails to detect the target (visual field defects) and note if the defect is unilateral or bilateral.
• Repeat for the Other Eye:
  • Switch the occluder and repeat the same procedure for the other eye.
  • Compare the findings between both eyes to identify any asymmetry or specific field deficits.
• Additional Observations:
  • Note the patient’s response time and consistency in detecting the stimulus.
  • If available, use a confrontation grid or automated perimetry as adjuncts, though the basic confrontation method is usually expected in OSCEs.

Documentation & Communication

• Record the patient’s performance, including any missed quadrants or asymmetrical visual field defects.
• Document the method used (confrontation test) and any relevant comments (e.g., “right superior quadrant defect observed”).
• Explain your findings to the patient and discuss if further formal visual field testing (e.g., automated perimetry) is necessary.

Key Points for OSCE

• Follow a systematic approach: Preparation → Testing Each Eye Separately → Comparison → Documentation.
• Ensure clear communication throughout the examination to keep the patient at ease.
• Maintain proper positioning and fixation to obtain reliable results.
• Be observant and note any inconsistencies or delays in the patient’s responses.

Common Pitfalls

• Not explaining the procedure adequately, leading to patient confusion or anxiety.
• Failing to maintain consistent fixation during testing, which can lead to inaccurate results.
• Rushing through the examination without systematically assessing each quadrant.
• Neglecting to compare the visual fields of both eyes for asymmetry.

References & Further Reading

• Geeky Medics: Visual Field Examination OSCE Guide
• Clinical Methods: The History, Physical, and Laboratory Examinations
• OSCEstop – Online OSCE practice resources.