Headache associated with refractive errors: Characteristics and risk factors

Impact of stimulant treatment on refractive errors and pupil diameter in attention deficit hyperactivity disorder

PURPOSE

The relationship between attention deficit hyperactivity disorder (ADHD) and visual impairment remains poorly understood, and the impact of visual impairment on the development of ADHD is uncertain. The aim of this study was to investigate the refractive profile and ocular biometric characteristics in patients diagnosed with ADHD and compare them with a control group. Additionally, we aimed to explore the potential influence of sex and medication intake.

METHODS

A cohort of 100 participants, including 50 individuals with ADHD and 50 age- and sex-matched control subjects, was included in this study. Ocular biometric parameters were measured, and refractive error was assessed using cycloplegic and non-cycloplegic autorefraction. Subgroup analyses were performed within the ADHD group based on sex, medication intake and age to investigate potential associations with the ocular findings.

RESULTS

We observed no statistically significant differences in axial length, corneal topography parameters or anterior chamber characteristics between ADHD and control subjects. However, subgroup analysis within the ADHD group revealed that the prevalence of ametropia under cycloplegia was significantly higher in unmedicated (69.6%) compared to medicated (37.5%) (X2(2) = 7.320, p = 0.026) participants. Pupil diameter was significantly larger in medicated (3.91 mm) compared to unmedicated (3.58 mm; p = 0.017) individuals. Males had flatter (p = 0.004) and thicker (p = 0.008) corneas than females. Older ADHD participants had higher refractive error (p = 0.008 for non-cycloplegic and p = 0.0.003 for cycloplegic), axial length (p = 0.002) and corneal astigmatism (p = 0.049).

CONCLUSIONS

Our study provides compelling evidence that individuals diagnosed with ADHD exhibit a similar incidence of refractive errors and ocular parameters compared to normal subjects. Nonetheless, the prevalence of refractive errors appears to be higher in unmedicated ADHD patients, suggesting the potential benefit of stimulant treatment. Additionally, stimulant use is associated with an increase in pupil diameter.

Pharmacologically Induced Accommodation Palsy and the Bioelectrical Activity of the Muscular System: A Preliminary Investigation

The aim of this study was to pharmacologically induce accommodative paralysis and evaluate its effects on the bioelectrical activity of the muscular system. The study included two participant groups: those with myopia and those with normal vision (emmetropes). Electromyographic assessments were performed using the Noraxon Ultium DTS 8-K MR 3 myo Muscle Master Edition system. The muscles analyzed in this study were the temporalis, masseter, sternocleidomastoid, trapezius, abdominal muscles, biceps brachii, and the external oblique muscles of the abdomen. It is important to acknowledge that, based on the current findings, it cannot be definitively stated that the observed effects have clinical significance, and additional studies are encouraged.

Academic performance and musculoskeletal pain in adolescents with uncorrected vision problems

BACKGROUND

Undetected vision problems are common in school children, and a prevalence of up to 40% has previously been reported. Uncorrected vision and lack of optimal eye wear can have a significant impact on almost all aspects of everyday life, such as development and learning, academic performance, pain and discomfort, and quality of life. This study aimed to analyze the relationship between uncorrected vision problems, educational outcomes, and musculoskeletal pain symptoms.

METHODS

A total of 152 school children (15.1 ± 0.8 years, mean ± SD; 40% males) were included in the study. All participants were recruited from a free-of-charge school vision testing program in Kathmandu, Nepal. Academic grades were collected from the school records of the participants' nationwide final grade examinations. A questionnaire was used to record the use of digital devices, screen time, and associated symptoms, including musculoskeletal pain (Wong-Baker FACES Pain Rating Scales).

RESULTS

A total of 61 children (40%) had uncorrected vision, with a cycloplegic refraction of SER - 0.53 ± 0.52 (mean ± SD). Children with uncorrected vision had significantly more third division grades (26 vs. 9%, p = 0.004) and shoulder pain in general/during screen use (66 vs. 43/40%, p = 0.008/0.003; 2.1/1.9 vs. 1.1/1.0 mean pain score, p = 0.002/0.001) compared with children with normal vision. Sex based subanalyses showed that only girls with uncorrected vision had more third division grades (25 vs. 4%, p = 0.006), and only boys with uncorrected vision had more shoulder pain in general/during screen use (76 vs. 28/31%, p < 0.001; 2.2/2.4 vs. 0.7 mean pain score, p < 0.001), compared with children with normal vision.

CONCLUSIONS

The results of this study showed that even small refractive errors may impact educational outcomes and musculoskeletal pain in adolescents. Most of the participating children had low myopia, easily corrected with glasses. This suggests that regular eye examinations are important in school children, and there is a need for raised awareness among parents, and school- and healthcare personnel.

Headache Attributed to Refractive Error: Improvement after Topography-Guided Photorefractive Keratectomy with Corneal Cross-Linking in Patients with Keratoconus

PURPOSE

To investigate if topography-guided photorefractive keratectomy (TGPRK) alleviates headache, particularly headache attributed to refractive errors (HARE) in keratoconus.

METHODS

Patients diagnosed with keratoconus undergoing TGPRK for refractive correction were included. Best spectacle corrected visual acuity (BSCVA) using the logMAR scale and refractive error were measured. Patients answered a questionnaire exploring headaches, characteristics, treatment, and the Headache Impact Test (HIT-6) before and 6 months after the surgery.

RESULTS

40 patients were included. Preoperatively, 24 patients (60%) met criteria for headaches: five for migraine, 14 for HARE, and five for tension-type headache (TTH). Patients with headaches preoperatively were more likely to require bilateral TGPRK, and the mean sphere and cylindrical power were higher. Postoperatively, 15 out of the 24 patients of the headache group experienced complete resolution of headaches, and only nine patients met diagnostic criteria for headaches: two for migraine, six for HARE, and one for TTH. The number of headaches reduced from 4.4 ± 2.4 to 0.5 ± 0.7 days/week (p < 0.001). Headache duration decreased from 108.5 ± 100.7 min to 34.4 ± 63.5 min (p = 0.002). Postoperatively, the consumption of analgesia decreased. The HIT-6 revealed an improvement in the quality-of-life post-procedure (p < 0.001).

CONCLUSIONS

Surgical correction of irregular astigmatism in patients with keratoconus can alleviate or resolve headaches in a large proportion of patients, resulting in an improvement in their quality of life. Physicians should consider keratoconus in patients fitting criteria for HARE not alleviated by spectacle correction and suboptimal vision in glasses.

High Myopia and Thickness of Extraocular and Masticatory Muscles-7T MRI, Preliminary Study

(1) Background: Myopia is one of the most common refractive errors in the world. The aim of this study was to evaluate the transverse dimensions of selected masticatory muscles (temporalis muscle and masseter muscle) versus the transverse dimensions of selected extraocular muscles (superior rectus, inferior rectus, medial rectus and lateral rectus) in emmetropic and high myopic subjects. (2) Methods: Twenty-seven individuals were included in the analysis, resulting in 24 eyeballs of patients with high myopia and 30 eyeballs of emmetropic subjects. A 7 Tesla resonance was used to analyze the described muscles. (3) Results: Statistical analysis showed differences in all analyzed extraocular muscles and all analyzed masticatory muscles between emmetropic subjects and high myopic subjects. In the high myopic subject group, statistical analysis showed four correlations. The three negative correlations were between the lateral rectus muscle and an axial length eyeball, refractive error and an axial length eyeball, and the inferior rectus muscle and visual acuity. The positive correlation was between the lateral rectus muscle and the medial rectus muscle. (4) Conclusions: The high myopic subjects are characterized by a larger cross-sectional area of extraocular muscles and masticatory muscles compared to the emmetropic subjects. Correlations were observed between the thickness of the extraocular muscles and the masticatory muscles. The lateral rectus muscle was related to the length of the eyeball. The phenomenon requires further study.

Fixation disparity and refractive error among first-year optometry students

PURPOSE

To determine the fixation disparity and refractive error of first-year optometry students to ascertain any relationship between them and also identify any association between fixation disparity and visual symptoms at near.

METHOD

It was an analytical cross-sectional study involving 85 participants aged 17 to 27 years (18.60 ± 1.37), 41% of whom were males. Subjective refraction was done at 3 m and fixation disparity was measured with and without spectacle correction using the Wesson Fixation Disparity Card. All analysis was set within a 95% confidence interval with a p-value ≤ 0.05 considered statistically significant.

RESULTS

Refractive error ranged from 0.25 SEQ (spherical equivalent) to 5.50 SEQ. Mean fixation disparity ranged from 2.9 ± 2.6 to 3.9 ± 2.8 min arc. There was no statistically significant correlation between refractive error and fixation disparity without correction (r = -0.180, p = 0.098) and with correction (r = 0.155, p = 0.157). For fixation disparity in the ortho and exo direction, mean fixation disparity with correction of participants who experienced headaches during or after reading (5.1 ± 2.6 min arc) was significantly higher (p = 0.032) than participants who did not (2.0 ± 2.6 min arc).

CONCLUSION

Myopia is common among first-year optometry students. Refractive error has no significant effect on fixation disparity. Headache is significantly associated with exo fixation disparity at near.

Laboured reading and musculoskeletal pain in school children - the role of lifestyle behaviour and eye wear: a cross-sectional study

Background

Lifestyle behaviour in children and adolescents has become increasingly sedentary and occupied with digital work. Concurrently, there has been an increase in the prevalence of headache, neck- and low back pain, which are leading causes of disability globally. Extensive near work and use of digital devices are demanding for both the visual system and the upper body head-stabilizing musculature. Uncorrected vision problems are present in up to 40% of Nordic school children, and a lack of corrective eye wear may cause eyestrain, musculoskeletal pain and headache. The aim of this study was to investigate associations between laboured reading, musculoskeletal pain, uncorrected vision, and lifestyle behaviours in children and adolescents.

Methods

This was a cross-sectional study with a total of 192 Norwegian school children aged 10–11 and 15–16 years. As a part of a school vision testing program, the children completed an online questionnaire about general and ocular health, socioeconomic status, academic ambition, near work and related symptoms, upper body musculoskeletal pain, and physical and outdoor activities.

Results

The 15–16-year-olds had a more indoor, sedentary, digital-based lifestyle with higher academic demands, compared with the 10–11-year-olds. Concurrently, reading became more laboured and upper body musculoskeletal pain increased with age. Girls reported more symptoms, higher academic ambitions, and more time spent on schoolwork and reading, compared with boys. Non-compliance in wearing prescribed eye wear (glasses or contact lenses), increased use of near digital devices, and experiencing visual stress (glare) were positively associated with laboured reading and upper body musculoskeletal pain.

Conclusions

A screen-based lifestyle with high academic demands challenges the ability to sustain long hours of static, intensive near work. Extensive near work tires the visual system and upper body musculature and provokes laboured reading and musculoskeletal pain symptoms. This study emphasizes the importance of regular eye examinations in school children, and the need to raise awareness among children, parents, and school- and health personnel about the importance of optimal vision and visual environment for academic performance and health.

Characteristics of Headache in Children Presenting to Ophthalmology Services in a Tertiary Care Center of South India

Introduction: Headache is a common cause of disability worldwide and can disrupt the education and social life of children. Children regularly present to ophthalmologists with headache. So, we aimed to describe the characteristics of headache in children presenting to the ophthalmology outpatient department (OPD) in our center.

Methodology: We conducted this cross-sectional, prospective study in Bangalore, India. We included all children aged 5-18 years, presenting with headache to the ophthalmology OPD, from September 2018 to September 2020, and excluded nonverbal children, those with prior head trauma, diagnosed psychiatric illnesses, or epilepsy. We provided each child with a headache questionnaire, following which they received a detailed ophthalmologic evaluation. We performed relevant descriptive and inferential analyses.

Results: We included 311 children, with a mean age of 11.1 years. Sixty-eight percent were males. Fifty-one percent reported holocranial headache, and 28% reported frontal headache. Sixty-nine percent reported screen time of ≥2 hours/day. The most common refractive error (RE) was myopia, seen in 48%. The most common type of headache was headache associated with refractive errors (HARE), seen in 64%, followed by migraine, in 19%. Children with HARE were more likely to be males, have daily screen time of >2 hours/day, or have myopia. Their headache was more likely to be for >1 month, or have frontal localization. Children with headache due to other causes were more likely to be adolescents.

Discussion: We found that almost two-thirds of children presenting to our ophthalmology OPD had HARE. Our findings support the association of REs with headache. Children with HARE had a longer history and predominantly frontal localization. Further, they reported longer screen time, a significant finding in today’s world. Ophthalmologists must be aware of the various etiologies of headache and ensure that each child with headache receives a full ophthalmologic evaluation.

The Organ of Vision and the Stomatognathic System-Review of Association Studies and Evidence-Based Discussion

The stomatognathic system is a functional complex of tissues and organs located within the oral and craniofacial cavities. The craniofacial anatomical factors and the biomechanics of the temporomandibular joints affect many systems throughout the body, including the organ of vision. However, few scientific reports have shown a relationship between the organ of vision and the stomatognathic system. The purpose of this review is to provide an overview of connections along neural, muscle-fascial, and biochemical pathways between the organ of vision and the stomatognathic system. Based on the literature presented in this review, the connections between the organ of vision and the stomatognathic system seem undeniable. Understanding the anatomical, physiological, and biochemical interrelationships may allow to explain the interactions between the mentioned systems. According to the current knowledge, it is not possible to indicate the main linking pathway; presumably, it may be a combination of several presented pathways. The awareness of this relationship among dentists, ophthalmologists, physiotherapists, and optometrists should increase for the better diagnosis and treatment of patients.