Explaining cortical visual impairment and environmental adaptation — OSCE

Candidate instructions (8-minute station)

You are the paediatric registrar in the neurodisability clinic. A 10-month-old girl born at 26 weeks gestation, who has spastic diplegia, does not reliably fix and follow or reach for toys held in front of her. She turns toward the window light but ignores faces held close. Her external eye exam, red reflexes and dilated fundus are normal, with clear media and a healthy retina. [6]

Your tasks are: [1]

1. Explain the diagnosis of cortical visual impairment in plain language, including why the baby sees poorly despite a healthy eye. [2]
2. Describe the paradoxical behaviours the parent may have noticed, and what they mean. [2]
3. Explain the habilitative approach — why there is no drug or surgery for the cortex, the hope of improvement through the brain rewiring, and the practical environmental adaptations at home. [11]
4. Outline the team that will support the family and the plan ahead. [7]

You are not expected to order new investigations in this station or to discuss urgent imaging — the eye is normal and the diagnosis is being explained. [1]

Examiner prompt to the actor (parent)

"But the eye doctor said her eyes are completely healthy — so how can she not see? Is there something wrong with her brain? And if there is no medicine or operation for it, what exactly are we supposed to do at home?" [2]

Marking domains

• Frame and explanation (3): explains cortical visual impairment in plain, reassuring language as a visual difficulty caused by the brain's visual processing rather than the eye; names that the eyes are healthy and the signal from the eye is not the problem; uses an accessible analogy rather than jargon; sets a realistic and hopeful tone. [1]
• Paradoxical behaviours (2): validates what the parent has seen — the light-gazing, the distance-better-than-near pattern, the fluctuation with tiredness — and explains that these are expected features of CVI, not signs of fabrication or decline. [2]
• Habilitative approach and prognosis (3): explains honestly that no drug or surgery repairs the cortex but that the developing brain rewires and many children improve over years; gives three concrete home adaptations (reduce clutter, present single high-contrast objects in the best field, control lighting) and frames visual stimulation as consistent, meaningful experience. [11] [7]
• Team and plan (2): names the multidisciplinary team — ophthalmology, neurology and neurodisability, education and therapy — and frames the family as the constant across settings, with a shared written plan and regular review as the child grows. [7]

Model answer — the explanatory script

"Thank you for bringing her, and thank you for noticing how she uses her vision — what you have described is really helpful. Let me explain what we think is going on, because it is a bit different from what you might expect." [1]

"You are absolutely right that her eyes are healthy — the eye doctor checked them carefully and the retina, the lens and all the structures are perfect. The reason she does not see as well as we would expect is not in the eyes. It is in the brain. Seeing does not just happen in the eye — the eye takes the picture, but the brain has to process it, and because she was born very early, the part of the brain that handles vision had a bit of an injury early on. So the message from the healthy eye is not being processed properly. We call this cortical visual impairment." [1] [2]

"The things you have noticed all fit this. The way she turns toward the window light, the fact she sometimes seems to see things further away better than things right in front of her face, and how it changes when she is tired — these are the patterns we see when the brain's visual processing is affected, not when the eye is the problem. None of this means you are imagining it or that she is getting worse. These are the hallmarks of this condition." [2]

"Now, I want to be honest with you about the treatment. There is no medicine or operation that fixes the injured part of the brain. But here is the hopeful part — a baby's brain is incredibly adaptable, and it can rewire itself, finding new pathways to take over some of the visual processing. Many children with this condition gain vision over months and years. So this is not a fixed picture. Our job is to give her brain the best chance to do that rewiring." [7] [11]

"There are three things you can do at home that make a real difference straight away. First, reduce the clutter — when you show her a toy, do it against a plain background, not a busy pattern, because her brain finds crowded scenes overwhelming. Second, show her one thing at a time, in a bright, strong colour and with good contrast, and give her a moment to find it. Third, notice the lighting — she seems drawn to light, so use good natural light when you play together, and see whether she does better at a particular distance. These sound simple, but they change how much she can use the vision she has." [11]

"You will not be doing this alone. We will bring together a team — the eye doctor to keep checking her eyes, the neurology and developmental team to support her movement and learning, teachers and therapists who specialise in vision, and you, because you spend the most time with her and you know her best. We will write down a plan that goes with her between home and any nursery or therapy, so everyone is doing the same thing. And we will review her regularly as she grows, because her vision will change and the plan will change with it." [7] [1]