What is the recommended post-operative care for an adult patient with childhood-onset strabismus who has undergone surgery?

Post-Operative Management of Childhood-Onset Strabismus Surgery in Adults

Adults who undergo strabismus surgery for childhood-onset misalignment typically adapt well to their new ocular alignment postoperatively, with the majority experiencing successful realignment and a very low risk of persistent diplopia (≤1%), despite pre-existing sensory adaptations like suppression and anomalous retinal correspondence. 1

Expected Postoperative Adaptation

The majority of adult patients with childhood-onset strabismus readily adapt to new ocular alignment after surgery, though some require more time for this adaptation. 1 This favorable adaptation occurs because:

• Patients with early childhood-onset strabismus have pre-existing sensory adaptations (suppression and anomalous retinal correspondence) that nearly always readapt postoperatively. 1
• Torsional anomalous retinal correspondence readapts postoperatively, making persistent torsional diplopia extremely rare in this population. 1
• Even when preoperative prism testing suggests diplopia will occur, surgical correction typically results in rapid readaptation with very low incidence of new long-standing postoperative diplopia. 1

Postoperative Monitoring Protocol

Alignment Assessment

• Monitor ocular alignment using cover-uncover and alternate-cover testing at follow-up visits. 1
• Assess alignment by light reflex testing (e.g., Krimsky) to compare with cover test measurements. 1
• Evaluate for possible duction deficits that might suggest a slipped muscle or stretched scar. 1

Sensory Function Evaluation

• Test for binocular fusion and stereopsis, as some adults may regain these functions postoperatively despite longstanding strabismus. 1
• Assess for expansion of binocular visual fields, which commonly improves even when stereopsis does not fully return. 2

Refractive Management

• Perform manifest refraction to identify any refractive barriers to optimal binocular alignment or fusion. 1
• Consider adjusting optical correction based on dry and cycloplegic refraction findings, including correction of hyperopia and appropriate bifocal or progressive lenses for presbyopic patients. 1

Management of Postoperative Complications

Residual Misalignment

• If alignment is suboptimal but symptoms are mild, occasional, and well-tolerated, observation is appropriate. 1
• For symptomatic residual misalignment, consider prism correction (press-on Fresnel or ground-in prisms) to address diplopia. 1
• In cases of persistent misalignment requiring intervention, botulinum toxin injection may be considered as an alternative to repeat surgery. 1

Diplopia Management

Transient postoperative diplopia is common, but persistent diplopia after successful surgery occurs in 1% or fewer patients. 1 When diplopia persists:

• Reassure patients that even rare cases of persistent diplopia after surgery report improved health-related quality of life due to improved eye alignment. 1
• Consider occlusion therapy (eye patch, occlusive contact lens, or Bangerter foil) for symptomatic relief. 3
• Botulinum toxin injections may prove helpful in select cases of persistent diplopia. 1

Surgical Sequelae to Address

Common sequelae from previous childhood surgery include underaction of recessed muscles, restriction of scarred muscles, and conjunctival scarring. 1 These should be:

• Identified through careful inspection of the ocular surface for conjunctival scars and exposed thinned sclera behind anatomical insertions. 1
• Assessed by examining interpalpebral fissures for evidence of prior muscle resection (smaller fissure) or recession (larger fissure). 1
• Addressed surgically if they compromise optimal postoperative alignment. 1

Expected Outcomes and Success Rates

Surgical success rates for childhood-onset strabismus in adults are favorable, with 63-74% of patients achieving alignment within 15 prism diopters. 1, 4

• Approximately 80% of adult patients achieve satisfactory alignment with one surgical procedure. 2
• Many patients gain some degree of sensory fusion postoperatively, with 29% of congenital esotropia patients demonstrating fusion on Worth 4-Dot or Titmus stereoacuity testing. 5
• Serious complications are anecdotal and rare, making adult strabismus surgery relatively low-risk. 2

Critical Pitfalls to Avoid

Do not rely solely on preoperative prism testing to predict postoperative diplopia risk in childhood-onset strabismus. 1 The response to prism is misleading due to coexistent anomalous retinal correspondence that changes postoperatively—patients often have diplopia with prism but rapidly readapt after surgery. 1

Do not assume poor fusional potential based on longstanding misalignment. 2 Many adults experience improvement in binocular function after surgery, including expansion of binocular visual fields and potential restoration of stereopsis. 5, 2

Ensure experienced ophthalmologic supervision throughout postoperative care. 1 Management of persistent or recurrent childhood strabismus requires the training and clinical judgment of an experienced ophthalmologist, with orthoptists serving as valuable assets under appropriate supervision. 1