The National Institute for Health and Clinical Excellence (NICE) has issued full guidance to the NHS in England, Wales, Scotland and Northern Ireland on tenotomy of horizontal eye muscles for nystagmus (with reattachment at their original insertions).


Nystagmus is the involuntary movement of the eyes (most commonly from side to side) and is usually associated with impaired vision. Tenotomy involves cutting the horizontal muscles of the eye (which move the eye from side to side) and reattaching them at the same place. The aim of the procedure is to improve vision.

Coding recommendations

C34.7 Tenotomy of combinations of muscles of eye

Z17.1 Medial rectus muscle of eye

Z17.2 Lateral rectus muscle of eye

Note: A code from Z94. - Laterality of operation would also be recorded to identify left, right or bilateral operation.

This would also be recorded with the ICD-10 code H55.X Nystagmus and other irregular eye movements.

Your responsibility

This guidance represents the view of NICE, arrived at after careful consideration of the evidence available. When exercising their judgement, healthcare professionals are expected to take this guidance fully into account. However, the guidance does not override the individual responsibility of healthcare professionals to make decisions appropriate to the circumstances of the individual patient, in consultation with the patient and/or guardian or carer.

Commissioners and/or providers have a responsibility to implement the guidance, in their local context, in light of their duties to have due regard to the need to eliminate unlawful discrimination, advance equality of opportunity, and foster good relations. Nothing in this guidance should be interpreted in a way that would be inconsistent with compliance with those duties.

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