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LETTER TO THE EDITOR |
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Year : 2019 | Volume
: 67
| Issue : 8 | Page : 1381-1382 |
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Refractive errors and the red reflex- Bruckner test revisited
Amber A Bhayana, Priyanka Prasad, Shorya V Azad
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi, India
Date of Web Publication | 22-Jul-2019 |
Correspondence Address: Dr. Shorya V Azad Dr. R P Centre, AIIMS, New Delhi - 110 029 India
Source of Support: None, Conflict of Interest: None | Check |
DOI: 10.4103/ijo.IJO_2107_18
How to cite this article: Bhayana AA, Prasad P, Azad SV. Refractive errors and the red reflex- Bruckner test revisited. Indian J Ophthalmol 2019;67:1381-2 |
Sir,
Kothari MT has described the use of Bruckner test[1] as a method for screening refractive errors[2] by documenting that a bright crescent is seen superiorly in hyperopes and inferiorly in myopes. But neither has this been verified with any other equipment nor has any explanation been given for the formation of crescent. We did a similar red reflex test with an indirect ophthalmoscope to find out any difference against direct ophthalmoscope and found results to be exactly opposite.
We found when a dilated eye is seen through an indirect ophthalmoscope at distance of 50-75 cm, hypermetropes formed a bright crescent inferiorly and myopes superiorly. Formation of crescents in refractive error depended on relative positioning of the illumination and visualization systems of equipment [Figure 1], [Figure 2], [Figure 3]. It was difficult to demonstrate these crescents on retro-illumination with slit lamp as it has perfectly co-axial systems. Hypermetrope displaced bright crescent away from illumination axis towards visualization axis; opposite in case of myopes. As per Kothari MT,[2] the bright crescent is superior in hypermetropes and inferior in myopes with direct ophthalmoscope. But we found opposite results with indirect ophthalmoscope due to exact opposite placements of visualization and illumination systems with respect to each other [Figure 4]. | Figure 1: Case 1: A 27-year-old female; BCVA OD 6/6 OS 6/36; slit lamp, fundus examination within normal limit (WNL); cycloplegic refraction OD emmetrope and OS + 3.75DS/+0.75DC @100° (acceptance 6/18). (a) OS hypermetropia with bright glow down and right when visualizing through right eyepiece which is down and right relative to illumination (inset shows position of camera by red arrow). (b) OS hypermetropia with bright glow down and left when seen through left eyepiece. (c) Emmetropic right eye. So crescent is towards eyepiece and away from illumination for hypermetrope
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| Figure 2: Case 2: A 10-year-old male; BCVA OD 6/24 OS 6/6; anterior segment, fundus WNL; cycloplegic refraction OD + 4/+0.5 @75° (acceptance 6/12) OS emmetrope. (a) OD hypermetropia with bright glow displaced left when seen by a camera placed left to illumination of ophthalmoscope (inset showing position of camera by red circle). (b) OD hypermetropia with bright glow displaced right when seen by camera place right to illumination of ophthalmoscope and OS emmetropia. So crescent is towards camera and away from illumination for hypermetrope
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| Figure 3: Case 3: A 8-year-old female; BCVA OD 6/9 OS finger count at 20 cm; anterior segment bilaterally normal and posterior segment OD WNL and OS showing myopic fundus; cycloplegic refraction OD + 1.5DS OS -11DS (no acceptance). (a) OS myopia with bright glow up and left when seen through right eyepiece of indirect ophthalmoscope (inset shows position of camera by red arrow). (b) OD hyperopia with bright glow down and left when seen through left eyepiece of indirect ophthalmoscope (inset shows position of camera by red arrow). So crescent is away from eyepiece and towards illumination for myope
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| Figure 4: Comparison of optical systems of direct and indirect ophthalmoscope (opposite relative placements of illumination and visualization systems)
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*Note: All displacements of crescents (right/left) have been described from the examiner's view.
We conclude by saying that refractive errors cannot only be screened by direct ophthalmoscope but also by indirect ophthalmoscope or any other equipment that has adjacent visualization and illumination systems close enough to allow formation of reflex but also at same time having some distance to allow formation of crescents.
Kothari MT has added to the value of the classical Bruckner test as a screening tool for refractive errors using direct ophthalmoscope. We would just like to add that the findings are not rigid to exactly what he described and can vary according to the equipment used. The position of reflex depends as much on relative position of visualization and illumination systems of the instrument used as on refractive status of the eye.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References | | |
1. | Tongue Ac, Cibis GW. Bruckner test. Ophthalmology 1981;88:1041-4. |
2. | Kothari MT. Can the Bruckner test be used as a rapid screening test to detect significant refractive errors in children? Indian J Ophthalmol 2007;55:213-5. [ PUBMED] [Full text] |
[Figure 1], [Figure 2], [Figure 3], [Figure 4]
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