New research published in Medicine (Baltimore) investigated a potential link between spinal and vision problems.
Give me some background first.
Scoliosis is a disorder classified as a deformed curvature of the spine that can lead to cardiopulmonary diseases if left untreated. Adolescent idiopathic scoliosis (AIS) is the most common type, progressing most rapidly during puberty. In China, over 5 million students in primary and secondary schools have scoliosis.
Interestingly, myopia and scoliosis are part of the top 3 diseases that affect adolescents in China.
Go on…
Previous research has found indications that scoliosis may be linked to various vision problems, including myopia, ophthalmic torticollis, horizontal gaze palsy, and Goldenhar syndrome amongst other conditions.
Despite this, vision and spinal health are rarely viewed in the literature as relevant to each other.
Now, talk about the study.
Data from 17 studies was collected from PubMed, China National Knowledge Infrastructure, and Web of Science.
Studies with the following characteristics were included:
- Adolescent scoliosis and vision problems
- Abstracts in Chinese or English
- Time frame
- Published full text availability
Findings?
In the study conducted by Zeming Cai et al, over 5,000 students in Chaozhou City, China, were enrolled to observe the incidence of scoliosis.
The investigators utilized multiple logistic regression analyses to demonstrate that students with myopia were 1.49 times more likely to develop scoliosis than those without myopia.
The study authors concluded in a separate study in Yunnan Province, China the possibility that poor vision in those students may prompt a more sedentary lifestyle and overall decreased outdoor activity that could increase the chances of or worsen idiopathic scoliosis.
What about ocular torticollis?
Torticollis may result from sternocleidomastoid spasms characterized by involuntary head tilting. The disease can further be divided into two subsets—true and false torticollis.
The latter condition is referred to as "ocular torticollis" since it is not related to sternocleidomastoid muscle spasming, rather it is caused by extraocular muscle (EOM) deficiencies leading to diplopia and abnormal head posture to maintain binocularity.
And secondary scoliosis?
Secondary scoliosis often may occur in patients with torticollis, but there seems to be a paucity of research exploring the relationship between these diseases.
Subsequently, ocular torticollis can be often misdiagnosed in the advanced stages as just scoliosis, potentially delaying treatment.
How about diseases related to vision and spinal problems?
Horizontal gaze palsy and Goldenhar syndrome are diseases with ocular and spinal implications.
Horizontal gaze palsy
Horizontal gaze palsy with progressive scoliosis (HGPPS) is a genetic disease often occurring during childhood, characterized by an inability to move eyes horizontally, progressive scoliosis, and ametropia.
Goldenhar syndrome
Goldenhar syndrome is an inherited disease related to the eyes, ears, and spine—exhibiting the following signs and symptoms of dermoid ocular cysts, strabismus, epicanthus, small or accessory ears, and scoliosis.
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Researchers believe that these congenital defects may originate from abnormal development of the first and second branchial arches, the first branchial fissure, and the temporal bone. Additionally, there has been some evidence pointing towards a lack of separation between the ectoderm and mesoderm in early embryonic development of those suffering from Goldenhar syndrome.
Of note, there appears to be a limited amount of Chinese literature regarding Goldenhar syndrome due to the rarity of presentation in their clinics. It is important to call out that not all patients with Goldenhar syndrome have both visual and spinal problems.
Meaning…
Although the underlying mechanism is still unclear, these diseases demonstrated a pattern of scoliosis linked with vision problems.
Any connections to spinal surgery?
Vision loss after spinal surgery is very rare, happening in 0.028% to 0.2% of cases.
However, spinal surgery has become the leading cause of postoperative blindness, surpassing cardiac surgery. Digging a bit deeper, among postoperative vision disease entities, ischemic optic neuropathy was the most frequent and typically occurred secondary to lumbar spine surgery.
The causes of vision loss are complex, and the exact mechanisms that lead to vision loss remain unclear. Previous studies suggest that excessive fluid replacement, vasopressors, globe compression, and prolonged use of a horseshoe headrest during spinal surgery may be linked to vision loss.
Limitations?
According to the authors, many relevant studies did not meet the study criteria and, therefore, were unable to be included.
Further, the results of the bibliometric analysis differed from those in the actual research due to the low number of citations.
Expert opinion?
The authors concluded that while there is evidence to correlate scoliosis and vision problems from previous studies, there has not been a specific mechanism identified yet..
They suggested that future research regarding this topic should include a “case-control study, genetic study, and long-term follow up.”
Take home.
Fully understanding the pathogenesis of a disease is highly recommended to effectively treat patients. The ocular factors relating to spinal problems can often be overlooked.
While previous research has established a link between scoliosis and visual problems, the authors have suggested further studies to explore both the disease mechanism and overarching relationships.