Comments on: Using Brückner's test for gross keratometry screening.

Dear Editor,

We were impressed by the ophthalmic image[1] published in the past issue of Indian Journal of Ophthalmology for the unique use of indirect ophthalmoscope for performing Brückner test.

The Brückner test is classically performed using a direct ophthalmoscope in an undilated pupil in a dark or semi-darkened room to assess amblyogenic factors in young children. Nevertheless, it can be performed with any bright coaxial light source that is capable of obtaining pupillary trans-illumination reflex.

We found indirect ophthalmoscope could elicit the reflex only when the pupil was well dilated. In comparison with direct ophthalmoscope [Fig. 1], the transpupillary reflex obtained with indirect ophthalmoscope were dull, the pattern of the crescent was inverted, laterally reversed, and large magnitude of ametropia was needed (in excess of 5D) to create abnormal crescent. Hence, ophthalmologists must continue to use a direct ophthalmoscope to perform the Brückner test. Nonetheless, if an abnormal transillumination pattern is incidentally detected using the indirect ophthalmoscope, a prompt referral is needed for detailed refractive evaluation for apparently large ametropia.

Figure 1

Comparison of Brückner test using a direct ophthalmoscope (1.1–1.4) and indirect ophthalmoscope (1.A–1.D) in a child with right eye -1.5d myopia. Note easily appreciable change in the pattern of transpupillary illumination with change in the refractive status of the eye when using direct ophthalmoscope in the upper panel in comparison with poorly appreciable effect of changes in the transpupillary illumination with refractive differences when an indirect ophthalmoscope was used to perform the Brückner test

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