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Accommodative excess is a prevalent accommodation abnormality in children and adults. This condition results in blurred vision for near and distance, and it is frequently found in patients with extended near-work demand. Symptoms of accommodative excess include eye strain, fatigue, and concentration loss. Clinical tests, such as accommodative amplitude, accommodative facility, and near-point-of-convergence assessments, are used to evaluate accommodative excess. These tests often reveal a reduced ability to relax accommodation. Management options for accommodative excess include glasses, vision therapy, and pharmacological agents, including cycloplegic drugs. The prognosis is generally good with appropriate and timely treatment, including vision therapy, corrective lenses, and addressing underlying causes like visual stress or prolonged near work. This activity for healthcare professionals is designed to enhance learners' competence in evaluating and managing accommodative excess. Participants will gain a broader grasp of the condition's risk factors, etiology, pathophysiology, and presentation. The best diagnostic and therapeutic practices will also be discussed. Improved recognition and management skills will empower healthcare professionals to collaborate meaningfully in an interprofessional setting when caring for individuals with accommodative excess. Objectives: Differentiate accommodative excess from other vision disorders in terms of etiology, epidemiology, and pathophysiology. Identify patients with accommodative excess based on clinical presentation and diagnostic evaluation results. Implement individualized management approaches to alleviate accommodative excess and prevent complications or recurrence. Collaborate with the interprofessional team to educate, treat, and monitor patients with accommodative excess to improve patient outcomes. Access free multiple choice questions on this topic.

The human eye adjusts its focus to see objects at varying distances by altering the curvature of the anterior lens surface, a process known as accommodation.[1] Accommodative dysfunction, which includes accommodative insufficiency and excess, encompasses a group of common vision disorders affecting the pediatric population, with or without associated visual disturbances or binocular dysfunction.[2] Accommodative excess, or excessive accommodation, occurs when the eye exerts greater accommodation effort or power than necessary for a given visual stimulus at a particular distance or cannot relax accommodation.[3] Accommodative spasm, a form of accommodative excess, is defined as prolonged contraction of the ciliary muscle, often leading to varying degrees of pseudomyopia when the lens remains in a state of near-sightedness.[4] Accommodative excess is characterized by blurred distance vision, particularly after extended near work, and difficulty shifting focus from near to far. Headache, eyeache, and asthenopia are common manifestations of accommodative spasms.[5]

Excessive Accommodation Extended near work is key to the development of accommodative excess. Several other factors contribute to the condition. Young individuals with hyperopia often rely on excessive accommodation to achieve clear vision without refractive correction.[6] Additionally, young myopes engaged in prolonged near activities may experience excessive accommodative effort, which is often accompanied by excessive convergence.[7] Astigmatic errors in early childhood may also be associated with excessive accommodation.[8] Furthermore, presbyopes may engage in excessive accommodation to attain clearer vision for near tasks.[9] Accommodation Spasms This visual disorder is a spontaneous spasm of accommodation in children with refractive anomalies, such as hypermetropia, astigmatism, and, sometimes, myopia, that impair their vision.[10] Accommodation spasms may occur bilaterally or unilaterally. Affected children often engage in excessive near work in poor environments, such as places with insufficient illumination, and may experience mental stress, depression, or anxiety. Overstimulation of the parasympathetic nervous system is associated with muscle fatigue, contributing to excessive accommodation, excessive convergence, and mitotic pupils, resulting in what is called "spasm of near reflex" (SNR) or "spasm of the near synkinetic reflex."[11][12] Aggravating factors include the following: Topical medications, particularly parasympathomimetic or cholinergic drugs, including pilocarpine [13][14] Myasthenia gravis [15] Psychological conditions, including anxiety [16][17] Effect of refractive procedures, including laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) [18][19] Head trauma [20] Opioid use disorder [21] Toxic reaction to certain drugs, including sulphonamides and antipsychotics, such as haloperidol and biperiden [22][23]

Various studies have reported the prevalence of accommodative dysfunction in nonstrabismic and nonpresbyopic populations, but few have focused on the prevalence of accommodative excess. A study of South African students found that the prevalence of accommodative excess was 2.8% among individuals aged 13 to 19.[24] In a survey of university students, 10.8% had accommodative excess, while 32.3% experienced binocular dysfunction.[25] Another study conducted in South India on binocular vision anomalies in nonstrabismic populations aged 7 to 17 showed that accommodative excess accounted for 0.8% of nonstrabismic binocular vision anomalies in rural schools.[26] Additionally, a 2019 study on opioid use disorder among 80 male individuals in Iran found a prevalence of accommodative excess of 3.75%.

The history is critical to identifying accommodative excess, as not all visual and asthenopic symptoms are solely due to refractive issues.[27] Asthenopia refers to eye strain or fatigue, often caused by activities like reading, prolonged near work, or extended screen time. Symptoms of accommodative excess are common and include blurred vision at both near and distance. The condition initially manifests with headache, eyestrain, brow ache, ocular deviation (esotropia), and, occasionally, diplopia associated with excessive near work.[28] In cases of accommodative spasms, asthenopic symptoms are often more pronounced than visual symptoms. Individuals with accommodative spasms may experience macropsia, an optical illusion where both the near and far points appear closer to the eye. In this condition, the near point is abnormally close. Additionally, the pupillary diameter may become smaller (miosis).[29][30]

A thorough evaluation is crucial for diagnosing accommodative excess. Consequently, a range of tests is required to assess refractive status, ocular mobility, and binocular function. These diagnostic methods help identify underlying issues and tailor treatment approaches for affected individuals. Visual Acuity Visual acuity should be measured monocularly and binocularly, at a distance and near, for both uncorrected and best-corrected vision. Patients with accommodative excess may report fluctuations in their visual acuity. Refraction The patient's refractive status should be evaluated objectively and subjectively. Cycloplegic refraction is the best option for evaluating true refractive status. Patients with accommodative excess, hyperopia, and astigmatism often rely on about 1 diopter of ciliary muscle tone, the excess accommodative effort, to compensate for some degree of refractive error. Ocular Mobility Ocular movements should be assessed in all 9 gazes, and any difficulty in movement should be noted. This test is performed to rule out the overaction and underaction of a muscle. Cover-Uncover Test The cover-uncover test should be performed using a small target. Any deviation observed should be corrected with prisms during the test. Near-Point-of-Convergence The near-point-of-convergence (NPC) test is essential for evaluating binocular function. This test involves gradually bringing a small target closer to the patient in the midsagittal plane. The distance is measured using a scale, typically the Royal Air Force (RAF) ruler. The scale includes a dot on a vertical line, a section of the general post office (GPO) telephone directory, a reduced Snellen chart, and a Times Roman typeface. The patient should wear their refractive correction during the test. The NPC is reached when an eye begins to deviate outward or when the patient reports diplopia. The target is then moved away from the patient to determine the distance at which the patient can once again see a single image or fixate with both eyes. This point is known as the convergence recovery point (CRP). The test should be repeated to confirm the measurements and ensure the patient understands the procedure. Typical NPC and CRP values range from 6 to 10 cm and approximately 15 cm, respectively. In cases of convergence weakness, both NPC and CRP values are increased. Amplitude of Accommodation

The patient should wear their refractive correction during the test. The NPC is reached when an eye begins to deviate outward or when the patient reports diplopia. The target is then moved away from the patient to determine the distance at which the patient can once again see a single image or fixate with both eyes. This point is known as the convergence recovery point (CRP). The test should be repeated to confirm the measurements and ensure the patient understands the procedure. Typical NPC and CRP values range from 6 to 10 cm and approximately 15 cm, respectively. In cases of convergence weakness, both NPC and CRP values are increased. Amplitude of Accommodation The amplitude of accommodation (AA) refers to the dioptric power required to focus an object from infinity to the nearest point. Using data from Diane, Hoffstetter proposed the following equations to calculate AA based on age: Mean AA = 18.5 – 0.3 × age Minimum AA = 15 – 0.25 × age Maximum AA = 25 – 0.4 × age [31][32] In clinical practice, the amplitude of accommodation can be measured using the push-up (or "Donder push-up") and minus lens methods.[33][34] The Donder push-up method uses the RAF ruler to calculate the near point of accommodation, which helps determine the amplitude. In the minus lens method, concave lenses are added while the subject focuses on a target 6 feet away, both monocularly and binocularly. The lens power used when the subject reports blur is considered the amplitude of accommodation. Relative Accommodation The amount of accommodation required to increase or relax in order to focus an object binocularly at a specific distance, with fixed convergence, is known as relative accommodation. This parameter can be either positive (positive relative accommodation, PRA) or negative (negative relative accommodation, NRA).[35] "NRA" refers to the minimum amount of accommodation or the maximum relaxation of accommodation needed to focus on an object at a fixed distance. Meanwhile, "PRA" refers to the maximum accommodation required for that distance. A low NRA indicates accommodative excess, while a low PRA suggests accommodative insufficiency. Accommodative Facility

"NRA" refers to the minimum amount of accommodation or the maximum relaxation of accommodation needed to focus on an object at a fixed distance. Meanwhile, "PRA" refers to the maximum accommodation required for that distance. A low NRA indicates accommodative excess, while a low PRA suggests accommodative insufficiency. Accommodative Facility Accommodative facility assesses the ability to change accommodative power rapidly and may be performed monocularly or binocularly. Clinically, this property is measured using an accommodative flipper (+/- 2 diopters or other combinations of plus-minus lenses).[36] The flipper consists of 2 plus and 2 minus lenses of equal strength. The patient focuses through a pair of lenses on an object at a fixed distance (typically 40 cm). When the object is clearly focused, the flipper is flipped, and the subject refocuses. The number of cycles completed per minute is recorded, and the examiner notes which lens causes more difficulty. Difficulty focusing with the plus lens monocularly may suggest accommodative excess. Monocular Estimated Method The monocular estimated method (MEM) objectively determines a patient's accommodative response, assessing for the presence of a lead or lag in accommodation.[37] MEM retinoscopy is performed at a 40-cm distance using a near-paragraph text card. The examiner observes and neutralizes the horizontal retinoscopy reflex in each eye separately. The typical range of MEM values is +0.25D to +0.75D. A lower MEM value indicates accommodative excess. Ocular and Systemic Health Assessment An external ocular examination should be performed to rule out conditions such as exophthalmos, typically associated with Graves disease, and ptosis. Slit-lamp biomicroscopy should be used to identify any media abnormalities. A history of refractive procedures should be documented, and a dilated fundus examination should be conducted to check for retinal abnormalities. A systemic examination is necessary to rule out conditions frequently associated with impaired vision, such as multiple sclerosis, diabetes mellitus, Graves disease, myasthenia gravis, and mental health issues. Neuroimaging Studies Magnetic resonance imaging (MRI) or computed tomography (CT) scans may be needed, especially in cases of recent head trauma. Imaging modalities can help rule out any organic causes of accommodation problems.

The management strategy for accommodative excess focuses on addressing the underlying cause, whether functional or organic. Improving visual hygiene is crucial in cases with a functional etiology. Treatment options for accommodative excess include optical correction, vision therapy, and pharmacological therapy. Some individuals may require a combination of these approaches. Optical Correction Refractive error correction with appropriate spectacles is the first step in managing accommodative excess, as uncorrected refractive errors can lead to accommodative fatigue. Spectacles should be prescribed after cycloplegic refraction, and near work should be restricted for a period.[38] Adding a plus lens alone may not be effective due to low NRA and MEM values. Cycloplegic therapy with a plus lens may improve near vision.[39] The maximum plus lens that does not cause visual disturbance should be prescribed. Vision Therapy Vision therapy for accommodative excess aims to improve accommodative amplitude and facilities.[40] Common vision therapy techniques include the accommodative flipper, Hart chart, Rock chart, computer applications, and home exercises.[41] Vision therapy aims to normalize accommodative amplitude and enhance the speed of response to accommodative stimulation. The goal is to restore accommodative and vergence reflexes and ensure the subject can maintain these functions. Pharmacological Treatment Cycloplegic drugs are the most effective treatment for relaxing ciliary muscle spasms. Atropine 1% has shown superior results compared to other cycloplegic medications, such as homatropine 2%, cyclopentolate 1%, and tropicamide 1%, which are often associated with ocular discomfort and near-vision problems.[42] Cycloplegic eye drops should be tapered after 4 weeks of use or switched to a weaker formulation. Neuropsychiatric Referral Patients with coexisting anxiety or neuropsychiatric disorders should be referred for expert evaluation and management by neurologists or psychiatrists. This measure ensures comprehensive care that addresses both the ocular and psychological aspects of the condition.

Accommodative excess may be misdiagnosed as myopia without cycloplegic refraction or bilateral 6th nerve palsy. A careful clinical and diagnostic evaluation helps determine the appropriate management and prevent recurrence or complications.

The prognosis for accommodative excess is usually good with early diagnosis and treatment. However, if left untreated, the condition can lead to headaches, eye strain, and blurred vision. Increased accommodation efforts and near work can potentially lead to the development or worsening of childhood myopia.[43]

Accommodative excess is both a refractive and neuromuscular problem. Treatment options extend beyond spectacles and should include vision therapy, visual hygiene, and mental health care. Individuals with accommodative excess, particularly pseudomyopes, may feel discouraged from wearing corrective spectacles, and parents may be dissatisfied with this recommendation for their children.[44] The most effective management approaches include cycloplegic medication use, in-office vision therapy, and home treatment. After successful intervention, patients with accommodative excess should be monitored every 6 months, with those wearing spectacles following up every 3 to 6 months.

The main therapeutic goal is to provide patients with good vergence and accommodative facility. Appropriate refractive error correction should be prescribed, and patient counseling on visual hygiene is critical. Where anxiety is a cause of accommodative excess, coordination with a psychiatrist may be required as part of an interprofessional approach to care.