What are the treatment options for binocular vision disorders?

Treatment Options for Binocular Vision Disorders

Treatment of binocular vision disorders is symptom-directed and aims to reduce diplopia, restore binocular vision, and reconstruct ocular alignment through a stepwise approach starting with observation and optical management, progressing to prism correction, fogging techniques, and ultimately surgical intervention when conservative measures fail. 1

Initial Assessment and Conservative Management

Observation and Monitoring

• Patients with mild or occasional symptoms, or those opposed to treatment, should be monitored without immediate intervention. 1
• This approach is appropriate when symptoms do not significantly impact quality of life or daily function. 1

Refractive Correction

• Proper sphere-cylindrical correction is the first-line treatment, as adequate refractive correction can reduce heterophoria and binocular vision disorders. 2
• Refractive correction is particularly important in fixation switch diplopia, where attempting to "switch" fixation back to the dominant eye through refractive means can gradually reduce diplopia. 1
• Patients will experience less diplopia if dominance is re-established in the previously dominant eye. 1

Optical Management with Prisms

Prism Correction

• Prism lenses represent a primary non-surgical treatment option for binocular diplopia, aiming to restore the largest area of single binocular vision. 3
• Prisms can reduce symptoms in patients with binocular retinal diplopia and various forms of strabismus. 4
• In cases where fixation cannot be switched back due to permanent vision loss, vision in the newly dominant eye should be optimized with refractive correction and prisms. 1

Fogging Techniques

Monocular Fogging

• Fogging one eye is the most successful long-term treatment for binocular central diplopia, as it eliminates foveal conflict by creating a central scotoma. 5, 4
• Fogging can be achieved through multiple methods:
  • Bangerter foils 5, 4
  • Scotch Satin tape 5, 4
  • Occlusive contact lenses 5, 4
  • Surgical tape 4
• Combination therapy using small prism plus Bangerter foil may be considered for selected cases. 5

When Fogging is Indicated

• Fogging is particularly effective for binocular retinal diplopia caused by macular disease, epiretinal membranes, or foveal displacement. 1, 5
• This approach is appropriate when central and peripheral fusion are in conflict (central-peripheral rivalry). 1

Occlusion as Last Resort

• Occlusion must be contemplated only as a last resort when fixation switch diplopia cannot be alleviated by other means. 1
• This represents the most extreme non-surgical option when all other conservative measures have failed. 1

Surgical Management

Strabismus Surgery

• Eye muscle surgery is indicated when conservative measures fail and there is a significant angle of misalignment with demonstrated ability to relieve diplopia through prism correction. 1, 3
• Surgery aims to establish a different alignment at which the patient can suppress diplopia. 1
• For divergence insufficiency, sagging eye syndrome, and strabismus fixus, surgical intervention may be necessary as these conditions will not resolve spontaneously. 1
• Strabismus surgery should be approached with caution and considered only in selected cases. 5

Retinal Surgery

• Surgical peeling of epiretinal membranes may be effective for treating binocular central diplopia in some patients, but carries the risk of causing new diplopia in others. 5, 4
• Patients with suspected retinal pathology should be referred to a retina specialist. 5

Specialized Management by Disorder Type

Fixation Switch Diplopia

• Management should be performed by an ophthalmologist with expertise in longstanding childhood strabismus and abnormalities of binocular function. 1
• Orthoptists can assist in examination, diagnosis, and nonsurgical management under ophthalmologist supervision. 1
• Patients have an excellent prognosis if fixation can be switched back to the dominant eye. 1

Binocular Retinal Diplopia

• Coordinated care between a retina specialist and a strabismus specialist (pediatric ophthalmologist, orthoptist, or neuro-ophthalmologist) is recommended. 5
• Treatment focuses on managing the underlying macular pathology while addressing diplopia symptoms. 1, 5

Convergence Insufficiency and Heterophoria

• Convergence insufficiency (prevalence 19%) and simple esophoria (17%) are among the most frequent non-strabismus binocular vision disorders requiring specific treatment beyond refractive correction. 2
• Accommodative and fusional vergence abnormalities should be assessed and treated accordingly. 6, 7

Critical Pitfalls to Avoid

Diagnostic Errors

• Do not assume all "double vision" complaints represent true diplopia—many patients use this term to describe blurred vision or visual distortion rather than actual image separation. 5
• Always distinguish monocular versus binocular diplopia by asking the patient to cover each eye separately. 3

Treatment Failures

• Missing binocular central diplopia can result in failed surgical treatment, as addressing small-angle deviation surgically without treating retinal distortion will not resolve the condition. 5
• Do not overlook treatable coexisting causes such as concurrent strabismus. 5

Preventive Counseling

• Patients should be counseled to avoid procedures or refractive corrections that result in a switch of fixation to their nondominant eye, as this can precipitate fixation switch diplopia. 1
• This is particularly important before monovision correction, refractive surgery, or cataract surgery. 1

Comprehensive Examination Requirements

All adult strabismus and binocular vision disorder patients require: 1

• Detailed sensorimotor evaluation
• Assessment of refractive status
• Dilated fundus examination
• Amsler grid testing to detect metamorphopsia and macular distortion 5
• Awaya test to quantify aniseikonia when maculopathy is suspected 5