Pages

Tuesday, 22 September 2015

Is this a case of White Coat Myopia?

A 6-year-old girl was referred to the ophthalmology clinic by the School Health Service of the Health Promotion Board. She had been referred for a re-assessment at the Board after she was identified as myopic in a mass vision test performed at her primary school. The results of her vision test during the mass screening was 6/18 and 6/9, for the right and left eye, respectively. As her right eye vision test result was greater than 6/9, she was then referred to do a re-assessment at the Board. The results of her vision re-assessment were 6/18 correctable to 6/9 and 6/12 correctable to 6/6, for the right and left eye, respectively. The attending optometrist was contemplating on giving her a prescription for glasses or to refer her to the ophthalmology clinic. The point of concern was that the girl’s vision could not be corrected to 6/6 with the appropriate lenses. To err on the side of caution, she was referred to the National University Hospital Medical Centre.

She was born following a normal full-term pregnancy by vacuum-assisted delivery. There were no neonatal problems and her development was normal. She was often described as a very lively child but timid and fearful of doctors, teachers and other seemingly authoritative figures.
Both her parents do not have myopia though her grandmother had amblyopia, commonly known as lazy eye.

At the ophthalmology clinic, though her visual acuity test indicated that one of her eyes has poorer vision than the other, her 3-D vision test was ‘normal’. Her vision test was found to be 6/6 for both her eyes and her dilated eye examination did not reveal any significant findings. She was discharged as having normal vision and does not need any glasses.


The question now is that how was she assessed as having myopia on two earlier occasions? Wouldn’t the prescribed glasses have worsened her vision since it was not needed in the first instance? The ophthalmologist clarified that vision tests for children could sometimes be inaccurate as they rely heavily on the child’s responses and the subjective interpretation of the optometrist. A child that is uncooperative because she/he is shy might end up with a poor test vision result. Upon further discussion with the girl’s mother, it was found the mother was absent on the two earlier ‘failed’ vision assessments and was only present at the last eye-examination session. Could the girl had been so anxious that she could not read aloud the letters flashed before her, only to be calm enough to do so when her mother is present?  Is this a case of anxiety-induced myopia or what I like to call it White Coat Myopia?

No comments:

Post a Comment