Bruckner Test (Fundus Red Reflex Test)- Everything you need to know

What is Bruckner Test or Fundus Red Reflex Test?

• The Bruckner Test is a test which is performed with a direct ophthalmoscope to identify gross ametropia and other abnormalities of the eye.
• A large circle aperture of Direct Ophthalmoscope is used to illuminate both eye simultaneously and reflex of both eyes are observed and compared.
• Eye with brighter reflex is abnormal and eye with dimmer reflex is normal.
• Being an objective test, it can be used among preverbal children and uncooperative patients.
• Both eyes of the patient are simultaneously illuminated from approximately 1 meter distance.

Basic Mechanism of Buckner’s Test Principle:

Why is the Dimmer Reflex Normal?

• When eyes are aligned rays focus on the fovea which has tightly packed photoreceptor cells which absorb light thus reflex is dimmer.

Why is Brighter Pupillary Reflex Abnormal?

• When eye is deviated the rays focus an extra foveal area (peripheral retina) where photoreceptors cells are less and light reflected more, thus a bright pupillary is seen in strabismic eye.

Requirements to perform Bruckner Test:

• Direct ophthalmoscope.
• Patient.
• Dim light Conditions
• Test Distance: Generally, 1M but main purpose is to illuminated both pupil simultaneously.

Procedure of Bruckner Test:

1. Positioning:

• The examiner sits at a distance of approximately 1 meter from the patient.
• The patient is instructed to look straight at the examiner.

2. Preparing the Ophthalmoscope for Bruckner Test:

• Turn on the ophthalmoscope, setting it to emit a large white spot of light.

3. Illumination:

• Direct the light from the ophthalmoscope at the patient’s eyes, ensuring both eyes are illuminated within the circle of ophthalmoscopic light.

4. Focusing:

• Focus the ophthalmoscope on the pupillary area of both eyes.

5. Assessment of Red Reflex:

• Quality and Intensity:
  • Observe and compare the quality and intensity of the red reflex in both eyes.
• Size of the Pupil:
  • Check and compare the size of the pupils.
• Position of the Light Reflex:
  • Note the position of the light reflex in each eye.
• Quality of Corneal Light Reflexes:
  • Assess the corneal light reflexes for symmetry and quality.

6. Comparison red reflex in Bruckner Test:

• Ensure that the reflexes are mirror images of each other.
• This symmetry is important for accurate assessment.
• A brighter reflex in one eye compared to the other may indicate an abnormality.

Interpretations of Bruckner Test:

1. In hyperopia:

• The lighter crescent is visible at the top of the red reflex.
• With increasing degrees of hyperopia, the overall red reflex will become dimmer.

2. In myopia:

• The lighter crescent is at the bottom of the red reflex.
• With increasing degrees of Myopia, the overall red reflex will become dimmer.

3. In astigmatism:

• Red reflex flattens into a straight line across the pupil rather than a crescent.
• This occurs due to an increase converging in one meridian as compared to other.

4. In Anisometropia:

• Anisometropia is condition where dioptric power of two eyes is different.
• Higher the refractive error dimmer the reflex, thus in anisometropia the color of the red reflexes is different.
• The size, position, and color of the crescents are also clearly different in each eye.

5. Media Opacities:

• Media opacities will be seen as black against fundus reflex.
• Corneal abrasions and corneal scars will appear as black marks on the red reflex.

6. Retinoblastoma:

• Loss of the red reflex and development of leukocoria/ Glucocoria, or “white reflex,”

7. Strabismus:

• Asymmetry of the red reflex.
• Unequal pupil sizes; and
• Displacement of the central corneal light reflex.

8. Esotropia:

• The red reflex will be brighter on the eye that goes inward.
• The white corneal reflex will be moved outward toward the exocanthus.

9. Exotropia

• The red reflex will be brighter on the eye that turns outward.
• The white corneal reflex will be moved inward toward the nose.

Questions for You:

1. Which Instrument is used to performed Bruckner Test?

• A. Streak Retinoscope.
• B. Direct Ophthalmoscope.
• C. Indirect Ophthalmoscope.
• D. Manual Keratometer.

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2. The eye with Brighter Reflex is ……………… .

• A. Normal Eye.
• B. Abnormal Eye.

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3. While performing Bruckner Test, you observe there is a crescent in upward position of pupillary reflex in both eyes. What is the refractive status of this patient?

• A. Myopia.
• B. Hyperopia.
• C. Astigmatism.
• D. Emmetropia.

Type your answer in Comment Box

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