Characteristics and long-term surgical outcomes of horizontal strabismus

Prevalence and characteristics of amblyopia, strabismus, and refractive errors among patients aged 3-16 years in Shanghai, China: a hospital-based population study

BACKGROUND

Functional visual impairments in children are primarily caused by amblyopia or strabismus. This study aimed to determine the prevalence and clinical profile of amblyopia and strabismus among individuals aged 3-16 years in Shanghai, China.

METHODS

From February 2023 to February 2024, this hospital-based, cross-sectional study included data of children who visited the Ophthalmology Department of Shanghai General Hospital. Comprehensive ocular examinations included visual acuity measurement after cycloplegic refraction, slit lamp examination, cover test, and dilated fundus examination. Descriptive statistics were performed to estimate the proportion and clinical characteristics of amblyopia and strabismus.

RESULTS

A total of 920 children were enrolled in our study. Among them, 223 (24.24%) children were identified as amblyopia. Unilateral amblyopia occupied 57.85%, and bilateral amblyopia occupied 42.15%. Most participants were within the age range of 5-10 years (75.97% for unilateral amblyopia, and 70.21% for bilateral amblyopia). Anisometropia was the primary cause of unilateral amblyopia (68.99%). Most amblyopic children have high hyperopia (38.76% for unilateral amblyopia, and 39.89% for bilateral amblyopia). 30 (3.26%) children were diagnosed with strabismus, and 19 (63.3%) of them were aged 5-10 years. Seven of the children had both strabismus and amblyopia.

CONCLUSION

The proportion of patients with amblyopia and strabismus was determined as 24.24% and 3.26% in our study. Anisometropia was the leading cause of unilateral amblyopia, whereas high hyperopia was a crucial refractive error in the amblyopic population. These findings shed light on further longitudinal studies targeting the age-related changes in amblyopia, strabismus and refraction errors. Therefore, efforts should be made to manage uncorrected refractive errors, amblyopia, and strabismus among children in Shanghai.

Long-term surgical outcomes of one-muscle vs. two-muscle horizontal strabismus surgery

PURPOSE

While horizontal strabismus surgery is generally considered to have favorable outcomes, success rates can vary by type of procedure. Our purpose is to compare the long-term outcomes of patients who underwent one-muscle vs. two-muscle horizontal strabismus surgery.

METHODS

This is a retrospective study comparing one-muscle to two-muscle strabismus surgery for small to moderate angle horizontal strabismus. Demographic data and eye exam parameters were compared at baseline and postoperatively (6 months up to 6 years). Surgical success was defined as a post-operative angle of 10 PD or less. We also compared outcomes by strabismus type: esotropia vs exotropia and adjusted the analysis for previous strabismus surgery.

RESULTS

Out of 89 patients with moderate angle horizontal strabismus (25 PD or less), 17 patients had a one-muscle operation, and 72 patients had two-muscle surgery. The mean age was 14.12 ± 9.30 years and 11.70 ± 11.30 years for the one-muscle and two-muscle groups, respectively (p = .74). The baseline characteristics of both groups were comparable. Follow-up time was 32.82 ± 26.93 months in one-muscle and 37.67 ± 23.81 in two-muscle groups (p = .29). Success rate was 70.6% for the one-muscle group and 68.10% for the two-muscle group (p = .69). Outcomes were similar when divided into esotropia and exotropia. The success rate was not affected by previous strabismus surgeries nor by the initial angle of deviation.

CONCLUSION

One-muscle and two-muscle horizontal strabismus surgery had similar long-term outcomes and did not differ by strabismus type nor by angle of deviation.

Community Knowledge, Attitude, and Practices Related to Strabismus and Strabismus Treatment and Surgery in Al-Jouf Region, Saudi Arabia

BACKGROUND

Strabismus is the misalignment of the visual axis of both eyes caused by abnormalities in binocular vision or anomalies of neuromuscular control of ocular motility. This study aimed to assess the community knowledge, attitude, and practices related to strabismus and strabismus treatment and surgery in the Al-Jouf region of Saudi Arabia.

METHODS

This study utilized a quantitative cross-sectional design. The consented volunteering adult participants were randomly selected through sequential enrollment to the completion of the target sample size from five population groups constituting the Al-Jouf region of Saudi Arabia. The data were collected through an online validated self-administered questionnaire. The collected data were analyzed using descriptive and inferential statistics.

RESULTS

The study included 340 participants; 67.6% of them were females and 32.4% were males. Only 66.8% of participants correctly defined strabismus. Symptoms of strabismus were identified as double vision (58.5%), blurred vision (48.2%), headache (31.8%), eye fatigue (41.5%), and difficulty reading (47.1%). Regarding risk factors of strabismus, 48.5% reported family history, 39.4% reported uncorrected refractive errors, and 23.2% reported long screen time. Complications of untreated strabismus were reported as low self-confidence (39.1%), vision loss (27.6%), poor interpersonal relationships (25.9%), amblyopia (42.6%), and cosmetic stigma (14.1%). Only 45.6% of the participants agreed to marry someone with strabismus or allow their relatives to do so. The majority of participants (72.6%) would advise a strabismus patient to visit an ophthalmologist. Despite a higher knowledge regarding strabismus among females, younger agers, higher education, single persons, workers/students, and those inhabiting the capital city of the region, such association did not reach significance.

CONCLUSION

The study shows a moderate level of knowledge, attitude, and practices among the general population of Al-Jouf Saudis toward strabismus. There was no significant relationship between knowledge of strabismus and any of the demographic characteristics of the participants. This might prove detrimental to the early detection and treatment of strabismus to prevent its complications and improve its outcomes and the quality of patients' lives. Institution of correlation plans are mandated by the Ministry of Health and interested stakeholders.

Gender differences in horizontal strabismus: Systematic review and meta-analysis shows no difference in prevalence, but gender bias towards females in the clinic

Background

Strabismus is a misalignment of the visual axis that affects 2-3% of the population and can lead to loss of binocular vision. It is currently controversial whether there is a gender difference in the most common form of visual misalignment: horizontal strabismus. Some studies claimed that more females than males have an outward deviation (exotropia), while others concluded that there is no significant gender difference. No previous work has systematically explored gender differences in horizontal strabismus or has compared the results of population-based studies with those of clinic-based studies.

Methods

We conducted a systematic review and meta-analysis of studies reporting the prevalence of horizontal strabismus. We included 73 population-based studies and compared their disclosed gender population with that in 141 comparable clinical-based studies. We analysed the data according to gender, strabismus type (esotropia, exotropia), and geographic region/ethnicity.

Results

Summary statistics showed a nearly identical prevalence of horizontal strabismus (2.558% for males, 2.582% for females), esotropia (1.386% males vs. 1.377% females), and of exotropia (1.035% males vs. 1.043% females). Meta-analysis results showed that these differences between males and females were not statistically significant (odds ratio (OR) = 1.01; 95% confidence interval (CI) = 0.97-1.10), but that females were significantly more frequent (by 7.50%) in clinic-based studies than males, with 5.00% more females for esotropia, and 12.20% more females for exotropia when adjusted for the population's sex ratio. The extent of the female gender bias differed between geographic regions/societies, with Asians having the lowest bias towards females and Latin American countries having the strongest bias.

Conclusions

Males and females have the same prevalence of horizontal strabismus, including exotropia. Females with strabismus seek health care or are brought to clinics significantly more often than males. This is an example of gender bias in health care in favour of females rather than males, apparently because parents - erroneously fearing only cosmetic consequences - are more concerned about strabismus in their daughters than their sons. Societal attitudes towards females, as well as economic factors (insurance status), appear to be relevant factors that determine the magnitude of the gender bias in horizontal strabismus.