- -7,50 (+1,75 à 60°)
- -5,25 (+0,75 à 135°)
- -13 (+3 à 70°)
- -10,75 (+1,75 à 100°)
- Axial length measurement
- Corneal topography
- Slit lamp examination after full pupil dilation
Clinical situation
A 9-year-old child is referred for a second opinion for progressive myopia despite myopia-control spectacle lenses.
Refraction under cycloplegia performed 6 months previously:
Visual Acuity (VA): 8/10 RE and LE (0.1 Log MAR)
When seen in the clinic, new refraction under cycloplegia reveals:
Visual Acuity (VA): 7/10 RE and LE (0.2 Log MAR), i.e. + 5 / + 4,5 Spherical equivalent
At that stage, the most crucial examinations to perform are :
Title Axial lenght measurement: 23,83 / 23,66
Title Not an axial myopia… Refractive myopia => cornea, or lens
Patient’s eye after cyclopentolate: Good cycloplegia, but suboptimal pupil dilation
Title Refractive myopia
cornea, or lens Fully dilate the pupils…
cornea, or lens Fully dilate the pupils…
- An NGS panel for lens ectopia can be performed
- The myopia-control spectacle lenses can be discontinued
Considering the child has no dysmorphic features, no psychomotor delay, and no family or personal history apart from his visual symptoms:
Visual acuity remains good; surgery is not indicated at that stage.
Mild forms of homocystinuria can present with such a phenotype; metabolic tests are compulsory.
An NGS panel can be performed in addition.
Axial length is normal, and therefore myopia-control interventions aiming to slow down length elongation are not indicated
Plasmatic homocysteinemia = 342 µmol/L (abnormally elevated)
The child was diagnosed with homocystinuria due to cystathionine beta-synthase (CBS) deficiency, requiring a metabolic follow up, with a risk of thrombosis and the necessity to get a plasmatic homocysteinemia < 50 µmol/L before any surgical intervention
