It has always been best practice in our field of visual impairment to assess children with any visual impairment at least yearly if they have a possibility of changing visual skills.
For kids with ocular impairments (degenerative conditions, damage to the eye or surgeries), sadly this change is usually a reduction in vision. You need the assessment to make sure the materials and methods match the current visual skills to ensure that learning has the optimal visual access.
For kids with CVI, the possibility of visual improvement changes warrant an assessment yearly so the materials and methods match the current visual skill. Waiting for the typical three year re-evaluations might miss a positive vision changes and materials and methods might not match the new visual skills.