A systematic review of validation studies of the International Classification of Disease (ICD) coding system, ICD-9 and ICD-10 is presented by the authors. Three searches were conducted based on three concepts, firstly health administration claims and ICD codes, secondly diagnostic validity and lastly nine neuro-ophthalmic conditions: idiopathic intracranial hypertension (IIH), giant cell arteritis, optic neuritis, neuromyelitis optica, cranial nerve palsy, myasthenia gravis, non-arteritic ischaemic optic neuropathy (NAION), thyroid eye disease (TED) and blepharospasm. From an initial 2820 unique records, 31 abstracts met the inclusion criteria and 11 papers were included in the review. The papers included in the review covered six of the nine neuro-ophthalmic conditions deemed of interest, therefore identifying gaps in the validation literature for administrative claims databases for NAION, TED and blepharospasm. There were also only single papers for neuromyelitis optica and ocular motor cranial neuropathies. This systematic review highlights future research that is required and the considerations of diagnostic accuracy and validity of coding which should be taken when using large datasets in neuro-ophthalmology.