Ophthalmoplegia refers to abnormal eye movements and possibly disturbed adaptation and accommodation resulting from paralysis of the extraocular muscles involved in these processes. Ophthalmoplegia may indicate cranial nerve palsy, but may also be related to a variety of other diseases.
Any combination of abnormal eye movements may be presented:
OP patients often claim visual impairment, mainly diplopia. The degree of diplopia is dependent on the current direction of gaze. Patients may "learn" to compensate for OP by adopting abnormal head positions. This condition is commonly referred to as ocular torticollis  .
OP is diagnosed clinically and has to be associated with an underlying disorder. Demographic parameters, symptom onset and disease progression, the presence of unilateral or bilateral complaints and concomitant pathologies should be considered when establishing a list of differential diagnoses. With regards to cranial nerve palsies, extensive knowledge regarding the course of cranial nerves coordinating eye muscle contractions is required to deduce the site of injury from clinical symptoms . Brain imaging may be indicated to visualize lesions of the central nervous system and in this context, magnetic resonance imaging is generally the most sensitive technique. However, computed tomography is usually preferred for an evaluation of orbital tissues . Images obtained by means of computed tomography may, for instance, depict spindle-shaped, enlarged extraocular muscles, as is characteristic of Graves disease. Other entities may be associated with abnormally thin, atrophic ocular musculature. Laboratory analyses of blood samples are usually carried out to assess the patient's general condition and to reveal the underlying pathology. Cerebrospinal fluid specimens may be obtained for similar reasons.
Ophthalmoplegia (OP) generally refers to the presence of eye movement alterations that are caused by paralysis of the extraocular musculature. Because cranial nerve palsies account for considerable shares of OP cases , extraocular muscles shall be enumerated according to their respective innervation:
In the broader sense, OP may also describe clinical symptoms arising from internal muscle paralysis. In detail, pupillary sphincter and dilator and/or the ciliary muscle may be affected. These muscles mediate narrowing and widening of the pupil, a means of adaptation to light intensity, and changes of lens shape, thus adapting the eye to short range focus. The pupillary sphincter and ciliary muscle are innervated by the oculomotor nerve.
Cranial nerve palsies may be caused by space-occupying lesions such as a cerebral aneurysm or brain tumors or may be triggered by an increased intracranial pressure, inflammation , infection or stroke. Intrinsic muscle dysfunction is less common but may be observed in cases of multiple sclerosis , myasthenia gravis, and diabetes mellitus , among others. These are systemic disorders not usually restricted to ocular muscles. Congenital OP may indicate developmental defects  or hereditary disorders such as congenital muscle dystrophy . Additionally, mutations of mitochondrial DNA are commonly associated with myopathy, including but not limited to OP .