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Accommodation paralysis
Last reviewed: 04.07.2025

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Only that which should move can paralyze, and paralysis of eye accommodation is no exception, since accommodation is the process of changing the curvature of the lens, due to which the clarity of the projection of images on the retina of the eye is corrected, and we see well what is close.
This sharp change in the refractive power of the eye (refraction) lasts only 350 milliseconds, and is provided by a reflex contraction of a special ciliary muscle. When it is disrupted, accommodation paralysis (cycloplegia) develops - a pathology in which a person cannot clearly see closely located objects.
Causes accommodation paralysis
In modern ophthalmology, the causes of accommodation paralysis are associated with eye diseases (anterior uveitis, glaucoma, iridocyclitis) and general infections (flu, diphtheria, infectious mononucleosis, tuberculosis, meningitis, encephalitis, syphilis, damage by botulinum toxin or its spores).
Also, the etiology may be due to:
- damage to the oculomotor nerve (3rd pair of cranial nerves) due to hemorrhage or tumor (optic nerve glioma);
- swelling of the disc of the optic nerve (papilloedema), which develops due to persistent increase in intracranial pressure;
- trigeminal neuralgia;
- Adie-Holmes syndrome (ciliary muscle dysfunction);
- ciliary body aplasia;
- rupture of zonular fibers and partial subluxation of the lens;
- Kurshman-Steinert syndrome (myotonic dystrophy);
- tumors of the brain (for example, a tumor of the pineal gland);
- upper acute hemorrhagic polioencephalitis (Gaye-Wernicke syndrome);
- intoxication with exogenous poisons (snake and insect bites) and poisoning with organophosphorus compounds, carbamate insecticides and fungicides, lead, arsenic, carbon monoxide.
Risk factors
The following risk factors for the development of cycloplegia have been noted: diabetes mellitus and alcoholism; general decreased adaptability of the organism; ocular and orbital eye injuries; damage to the brain stem or ciliary ganglion in traumatic brain injury; multiple sclerosis and Parkinson's disease.
There is a whole list of pharmacological agents that cause accommodation paralysis. It includes: atropine, amphetamine, amitriptyline, antazoline, belladonna, betamethasone, vincristine, dexamethasone, diazepam, diphenhydramine, diphenylpyralin, dicyclomine, captopril, carbamazepine, clemastine, isoniazid, naproxen, oxazepam, pilocarpine, pentazocine, scopolamine, temazepam, trichlormethiazide, cimetidine, chloramphenicol, etc.
Pathogenesis
Accommodation paralysis consists of a complete blockade of contractions of the ciliary muscle, which is located in the ciliary body of the eye, and the ciliary body - in the form of a ring - holds the lens and is located under the sclera. From the inner part of the ciliate body towards the lens, ciliary nerve processes and the thinnest, radially located muscle fibers - zonular ones - extend. Their totality is the ciliary ligament.
To clarify the pathogenesis of accommodation paralysis, it should be borne in mind that the process of eye accommodation is provided by nerve impulses transformed in the retina from light impulses - when a person looks at a nearby object. Afferent impulses go to the central nervous system, entering the structures of the thalamus in the occipital lobes of the brain, more specifically, to the cortical visual centers of the 18th Brodmann area (it turned out that they are responsible for accommodation). From there, along the parasympathetic fibers of the oculomotor nerve - with a switch in the ciliary ganglion innervated by the processes of the trigeminal nerve - the corresponding return signal reaches the ciliary muscle, and it contracts. This relaxes the zonular fibers of the ciliary ligament, which allows the lens of the eye to become more rounded and correctly focus the image of a nearby object.
The next tension (tension) of the zonular fibers and the entire ligament is the result of the next relaxation of the ciliary muscle, and this happens when a person looks at distant objects. With paralysis of accommodation, the state of the ciliary muscle is relaxed, which reduces the accommodative amplitude to almost zero.
Ophthalmologists distinguish between paralysis and spasm of accommodation, which is also called false myopia; with spasm of accommodation, the ciliary muscle contracts in a tense state, which reduces the quality of distant vision.
Symptoms accommodation paralysis
According to specialists and complaints of patients with accommodation paralysis, the first signs are manifested in blurring (unclearness) of near vision: in order to read text printed in standard font, a person has to increase the distance between the eyes and the page, stretching the hand with the book or magazine forward. And this can continue until even at a distance of a fully extended arm a person cannot read a single line of small font.
Other symptoms of accommodation paralysis are described as difficulty writing (the person cannot see the text they have written); reading with one eye; squinting when they need to see something close up.
There are also complaints about rapid eye fatigue and slight burning in them (after exercise) and headaches. And doctors also call such a symptom as mydriasis, that is, dilation of the pupil.
Complications and consequences
The consequences and complications of cycloplegia for initially normal vision and in farsightedness (hyperopia) are expressed in the often irreversible weakening of the clinical refraction of the eyes and the loss of the ability to clearly see close up without the help of optics. In the case of initial myopia (nearsightedness), paralysis of accommodation can pass almost without consequences for visual acuity.
Diagnostics accommodation paralysis
A comprehensive medical history and a thorough ophthalmologic and neuro-ophthalmologic examination are the foundation upon which the diagnosis of accommodation paralysis is based.
Instrumental diagnostics include hardware refractometry, rheophthalmography, ophthalmoscopy, perimetry, and slit-lamp microscopic examination. If neurocerebral etiology of the disorder is suspected, examination of the brain and/or spine using ultrasound sonography, CT, or MRI will be required.
Differential diagnosis
Differential diagnostics – involving specialized specialists – is designed to identify or exclude optic neuritis or its infiltration in glioma and sarcoidosis; cavernous sinus thrombosis or Chiari syndrome; Foster-Kennedy syndrome; drug intoxication; Lyme disease (with increased intracranial pressure); medulloblastoma or lymphoblastic leukemia.
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Treatment accommodation paralysis
Considering the causes of this visual pathology, the treatment of accommodation paralysis can go far beyond the scope of ophthalmology itself: just look again at the relevant section of this publication.
As for ophthalmology, doctors say that there is no therapy in cases of drug-induced accommodation paralysis: discontinuing the offending drug will lead to spontaneous restoration of near vision.
If after treatment of systemic diseases (which is prescribed and carried out by doctors of the appropriate profile) paralysis remains, then ophthalmologists prescribe lenses (with plus diopters) to correct farsightedness.
The indications for surgical treatment – laser vision correction (by changing the curvature of the cornea with a laser) – include refractive anomalies of the eye: myopia, hyperopia, astigmatism and presbyopia (age-related farsightedness). Accommodation paralysis is not listed as an indication.
Forecast
And the fact that the real prognosis is absolutely dependent on the causes of the pathology is obvious. Accommodation paralysis, as a violation of the contractions of the ciliary muscle, can lead to amblyopia - weakening of vision that cannot be corrected with glasses or contact lenses, as well as to accommodative esotropia (adaptive strabismus) or closed-angle glaucoma.
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