The child who stumbled
Keya was two years old when her parents brought her in for an eye examination. This charming kid was however born with a large squint. Parents were keen that the squint be rectified before starting school. They were concerned about teasing or other social issues because of her appearance.
I examined Keya who was very playful as one can expect a two year old to be. Her visual responses were normal. She did not have any need for glasses. The parents and I discussed the next steps to plan the surgery to correct her squint. The surgery was performed on both eyes (squint surgeries can be performed safely on both eyes at the same time) a month later. The surgery and the postoperative course were uneventful.
I saw Keya six weeks later and found that the small incisions that were made for the surgery had healed well. She was well aligned and the parents were satisfied.
I did not see them for a while as they had decided to follow up with a local ophthalmologist in their town. About 18 months later they came back looking worried. They had noticed that while Keya was academically bright she appeared to be distracted and clumsy. Upon further questioning they had noticed that the child stumbles when walking and has difficulty copying from the board. She has a tough time locating her mother when she comes to pick the child up from school.
She probably had cerebral visual impairment (CVI) due to hypoglycaemia. We confirmed this with an MRI. She also underwent a few more tests which looked at her visual field, color, contrast and functional vision. In the next few months Keya was given therapy to overcome these visual difficulties and slowly became better.
We did a detailed test this time asking the child to read alphabets on the vision chart which she did very well. Her alignment was good and I could not find anything else wrong.
I was perplexed and then went back to the very beginning and asked mother a few questions about the child’s birth. Mother volunteered the history that the child had poor feeding soon after birth and that Keya’s blood glucose had dropped and she had a small episode of seizure. She was treated promptly and recovered fully.
Now the picture became clearer. Keya probably had cerebral visual impairment (CVI) due to hypoglycaemia. We confirmed this with an MRI. Keya also underwent a few more tests which looked at her visual field, color, contrast and functional vision. In the next few months Keya was given therapy to overcome these visual difficulties and slowly became better.
CVI due to hypoglycaemia in the newborn as an entity is becoming increasingly recognized. It is well known that the first breast milk is called colostrum. Traditionally the child is fed the colostrum as it is rich in nutrients. Sometimes there is a delay in the production of the colostrum from the mother but the neonate is kept fasting. This result in a drop in blood sugar and this can affect the sensitive newborn’s brain especially the visual cortex. It is important to feed the child after birth without delay. Midwives, neonatologists, obstetricians should be aware of this.
Ophthalmologists and optometrists need to watch out for visual difficulties in the presence of good visual acuity.
More on the topic of CVI and easy screening questions that any parent or eye care professionals could ask to identify these patients in the next blog.