From the Guidelines
Strabismus in an older adult is most commonly caused by a variety of factors including recurrent, decompensated, or unresolved childhood strabismus, sensory strabismus, convergence insufficiency, divergence insufficiency, and other conditions such as Graves’ disease, orbital trauma, and neurologic disorders 1. When evaluating an older adult with strabismus, it is essential to consider the numerous potential causes of this condition. Some key factors to consider include:
- Recurrent, decompensated, or unresolved childhood strabismus
- Sensory strabismus
- Convergence insufficiency
- Divergence insufficiency
- Sagging eye syndrome
- Strabismus associated with high axial myopia, including strabismus fixus
- Graves’ disease
- Orbital trauma
- Strabismus associated with other ophthalmic surgery
- 4th nerve palsy
- Skew deviation
- 6th nerve palsy
- 3rd nerve palsy
- Myasthenia gravis
- Fixation switch diplopia
- Foveal misregistration (binocular central diplopia) As noted in the adult strabismus preferred practice pattern 1, accurate diagnosis of the etiology of strabismus in an adult requires expertise to recognize associated signs and symptoms and familiarity with studies that may confirm the diagnosis. The goal of treatment should be broad and include not only motor alignment but also sensory recovery, as well as gains in psychosocial and functional domains of vision-related quality of life 1. Treatment options may include prism glasses, botulinum toxin injections, or surgery, and success rates vary widely depending on the type of strabismus and underlying conditions 1.
From the Research
Causes of Strabismus in Older Adults
The causes of strabismus in older adults can be attributed to various factors, including:
- Acquired underlying etiology of misalignment, such as neurological, non-neurological, thyroid eye disease, or myotoxic conditions, as reported in 2
- Idiopathic strabismus, which is more common in the elderly, as noted in 3
- Small-angle horizontal strabismus (HT), esotropia (ET), exotropia (XT), and palsies, including trochlear palsy, as identified in 3
- Other conditions, such as Graves' disease, which can cause strabismus, as mentioned in 4
Etiology of Strabismus
The etiology of strabismus in older adults can be classified into different categories, including:
- Neurological causes, such as cranial nerve paresis, as discussed in 2 and 4
- Non-neurological causes, such as thyroid eye disease, as reported in 2
- Myotoxic causes, as mentioned in 2
- Idiopathic causes, as noted in 3
Prevalence of Strabismus
The prevalence of strabismus in older adults is significant, with a study reporting that 87.9% of patients had an acquired underlying etiology of misalignment, as found in 2. Another study reported that most cases of diplopia in adults can be classified into a few categories based on their type of strabismus, as noted in 3.