Juvenile myopia progression, risk factors and interventions

Do monocular myopia children need to wear glasses? Effects of monocular myopia on visual function and binocular balance

Objective

This study aims to compare the binocular visual functions and balance among monocular myopic adolescents and adults and binocular low myopic adolescents and explore whether monocular myopia requires glasses.

Methods

A total of 106 patients participated in this study. All patients were divided into three groups: the monocular myopia children group (Group 1 = 41 patients), the monocular myopia adult group (Group 2 = 26 patients) and the binocular low myopia children group (Group 3 = 39 patients). The refractive parameters, accommodation, stereopsis, and binocular balance were compared.

Results

The binocular refractive difference in Group 1, Group 2, and Group 3 was -1.37 ± 0.93, -1.94 ± 0.91, and -0.32 ± 0.27 D, respectively. Moreover, uncorrected visual acuity (UCVA), spherical equivalent (SE) and monocular accommodative amplitude (AA) between myopic and emmetropic eyes in Group 1 and Group 2 were significantly different (all P < 0.05). There was a significant difference in the accommodative facility (AF) between myopic and emmetropic eyes in Group 2 (t = 2.131, P = 0.043). Furthermore, significant differences were found in monocular AA (t = 6.879, P < 0.001), binocular AA (t = 5.043, P < 0.001) and binocular AF (t = -3.074, P = 0.003) between Group 1 and Group 2. The normal ratio of stereopsis according to the random dots test in Group 1 was higher than in Group 2 (χ2 = 14.596, P < 0.001). The normal ratio of dynamic stereopsis in Group 1 was lower than in Group 3 (χ2 = 13.281, P < 0.001). The normal signal-to-noise ratio of the binocular balance point in Group 1 was lower than Group 3 (χ2 = 4.755, P = 0.029).

Conclusion

First, monocular myopia could lead to accommodative dysfunction and unbalanced input of binocular visual signals, resulting in myopia progression. Second, monocular myopia may also be accompanied by stereopsis dysfunction, and long-term uncorrected monocular myopia may worsen stereopsis acuity in adulthood. In addition, patients with monocular myopia could exhibit stereopsis dysfunction at an early stage. Therefore, children with monocular myopia must wear glasses to restore binocular balance and visual functions, thereby delaying myopia progression.

Effect of shape deprivation on retinal thickness in myopic mice using an OCT method

Purpose

The purpose of this study was to study in retina thickness changes in myopic mice using optical coherence tomography (OCT).

Methods

There were 18 mice in the form-deprivation myopia (FDM) group，in which the left eye was not treated as a control;18 untreated mice served as a normal control group. The diopter of all mice was measured 21 days after birth (P21), before form deprivation. After 4 weeks of form deprivation (P49), the refraction, fundus, and retinal sublayer thickness of all mice were measured.

Results

After 4 weeks of form deprivation, the refractive power of the right eye in the FDM group was significantly higher than that in the left eye (p < 0.05). There was no significant change in the refractive power of the left eye in the FDM group compared with the normal control group. The retina, nerve fiber layer (NFL), inner nuclear layer (INL), and outer nuclear layer (ONL) in the right eye of the FDM group were significantly thinner than those of both the FDM and control groups (p < 0.05). There was no significant change in photoreceptor (PR).

Conclusion

Our study highlights that the myopic mice have decreased R thickness, which might reflect the potential pathological mechanism of myopia.

A Clinical Study of the Impact of Soft Contact Lenses on the Progression of Myopia in Young Patients

PURPOSE

To assess the impact of soft contact lenses on the progression of myopia in young patients.

PATIENTS AND METHODS

The observational study included 102 patients divided into 3 groups: MFCL (multifocal contact lenses) group: 15 girls and 9 boys, aged 8-20 (= 14.12 ± 2.863) with soft multifocal contact lenses with myopia: = -3.12 D ± 1.776 D and mean myopia progression -0.23 ± 0.233D after 2 years; SVCL (single vision contact lenses) group: 30 girls and 5 boys, 11-20 years old (=15.5 ± 2.24) with myopia = -2.88 ± 2.122 D at admission and mean myopia progression -0.54 ± 0.464 D after 2 years; the spectacle (single vision glasses) group: 25 girls and 18 boys, aged 8-18 years ( = 13.65 ± 2.448) with single vision glasses with myopia: = -1.74 ± 1.412 D at admission and mean myopia progression -0.86 ± 0.489D after 2 years. Medical history and physical examination were performed every 6, 12, 18 and 24 months. Refractive error was examined using the autorefractometry after cycloplegia.

RESULTS

The analysis of myopia correction after 2 years showed differences between MFCL and spectacle correction. The change in myopia progression after 2 years was statistically significant for MFCL vs SVCL and MFCL vs spectacle correction when the myopia occured before the period of intensive growth. When myopia occurred during the period of intensive growth, difference was noted for MFCL vs spectacle correction and SVCL vs spectacle correction. When myopia occurred after a period of intensive growth, no significant differences between the groups were observed.

CONCLUSION

1) Multifocal contact lenses and some single vision contact lenses (Biofinity) may be useful in the control of myopia in younger patients, slowing the progression of nearsightedness; therefore, they can be a therapeutic option in inhibiting the progression of myopia. 2) The best effects of using multifocal contact lenses occur if myopia is diagnosed before the period of intensive growth.

Associations Between Fetal Growth Trajectories and the Development of Myopia by 20 Years of Age

Purpose

To evaluate the contribution of genetic and early life environmental factors, as reflected by fetal anthropometric growth trajectories, toward the development of myopia during childhood and adolescence.

Methods

This analysis included 498 singleton Caucasian participants from the Raine Study, a pregnancy cohort study based in Western Australia. Serial fetal biometric measurements of these participants were collected via ultrasound scans performed at 18, 24, 28, 34, and 38 weeks’ gestation. At a 20-year follow-up, the participants underwent a comprehensive ophthalmic examination, including cycloplegic autorefraction and ocular biometry measurements. Using a group-based trajectory modeling approach, we identified groups of participants with similar growth trajectories based on measurements of fetal head circumference (HC), abdominal circumference, femur length (FL), and estimated fetal weight (EFW). Differences between trajectory groups with respect to prevalence of myopia, axial length (AL), and corneal radius of curvature measured at the 20-year follow-up were evaluated via logistic regression and analysis of variance.

Results

Prevalence of myopia was highest among participants with consistently short or consistently long FLs (P = 0.04). There was also a trend toward increased prevalence with larger HC in late gestation, although not at a statistically significant level. Trajectory groups reflecting faster HC, FL, or EFW growth correlated with significantly flatter corneas (P = 0.03, P = 0.04, and P = 0.01, respectively) and a general, but not statistically significant, increase in AL.

Conclusions

Environmental or genetic factors influencing intrauterine skeletal growth may concurrently affect ocular development, with effects persisting into adulthood.

Accommodation and binocular vision changes after wearing orthokeratology lens in 8- to 14-year-old myopic children

PURPOSE

The study aimed to observe and analyze the dynamic accommodation and binocular vision changes in myopic children after they switched from spectacles to orthokeratology (ortho-k) lenses.

METHODS

Thirty-six myopic children aged 8-14 years were enrolled in this prospective, self-controlled study from West China Hospital. General information was gathered, and examinations were performed at baseline and at 1, 3, 6, and 12 months after switching to ortho-k lenses. The examination included assessments of distance/near visual acuity, distance/near horizontal and vertical ocular alignment, distance/near horizontal vergence range, accommodative amplitude, monocular/binocular accommodative facility, accommodative response, positive and negative relative accommodation (PRA/NRA), accommodation convergence/accommodation (AC/A), stereopsis, and reading ability.

RESULTS

After the children switched to ortho-k lenses, distance and near ocular alignment showed an exophoric shift (distance: p = 0.001, near: p = 0.002), and the horizontal vergence range decreased by different degrees (convergence: distance blur point (p = 0.002), distance break point (p = 0.005), near blur point (p = 0.011), near break point (p = 0.043); divergence: distance break point (p < 0.001), distance recover point (p < 0.001), near recover point (p = 0.005)). The stereopsis ability (p < 0.001), monocular/binocular accommodative facility (p < 0.001), and PRA (p = 0.010) increased. The accommodative lag (p < 0.001), accommodative amplitude (p < 0.001), and calculated and gradient AC/A (calculated: p = 0.001, gradient: p = 0.025) decreased. The adjusted horizontal and vertical reading times and their ratio decreased (all p < 0.001).

CONCLUSION

The subjects showed distance and near exophoric shifts after switching to ortho-k lenses; improvements in accommodative function, stereopsis, and ocular motility; and a decrease in the binocular horizontal vergence range. The relationships between these changes and the ortho-k myopic control effects require further investigation.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Visual impairment and associated factors among primary school children in Gurage Zone, Southern Ethiopia

Background

Visual impairment is one of the major public health problems worldwide, especially in developing countries.

Objective

To determine the prevalence of visual impairment and its associated factors among school children in Gurage Zone, Southern Ethiopia

Methods

A cross sectional study was conducted in eight primary schools of Gurage Zone. A total of 1064 pupils, of whom589 boys and 475 girls were selected using multistage sampling technique. Socio-demographic characteristics of the participants were collected using structured questionnaires and visual acuity was measured using Snellen's chart. Logistic regression analysis was used to determine the associated factors of visual impairment.

Results

The prevalence of visual impairment was 5.2%. Factors significantly associated with visual impairment were age group of 13–18 years (AOR = 9.44, 95% CI = 3.83 – 23.25), school grade level of 5- 8 (AOR = 2.97, 95% CI = 1.23 – 7.17), rural residents (AOR = 2.59, 95% CI = 1.22 – 5.54), family's monthly income of less than 2000 Ethiopian Birr (AOR = 2.87, 95% CI = 1.08 – 7.61) and visually impaired parents (AOR = 2.16, 95% CI = 1.06 – 4.39).

Conclusion

This study found that the prevalence of visual impairment was 5.2%.

Relationship between Aquaporin-1 Protein Expression and Choroidal Thickness during the Recovery of Form-deprivation Myopia in Guinea Pigs

Purpose: The purpose of this study was to investigate the relationship between aquaporin-1 (AQP-1) protein expression in the choroid and choroid thickness (CT) during the recovery of form-deprivation (FD) myopia in guinea pigs.Materials and Methods: Seventy-two guinea pigs were randomly assigned to the normal control (NC) group, FD 21 group (animals wore a latex facemask in the right eye for 21 days to induce FD myopia) and four recovery (REC) groups. Guinea pigs in the REC groups also wore the facemask for 21 days to induce myopia; then, the facemask was removed, and the eye was re-exposed to the normal environment for 12 hours (REC ½ group), 1 day (REC 1 group), 2 days (REC 2 group), and 7 days (REC 7 group). All animals underwent biometric measurements (refraction, axial length, and CT), and the protein expression of AQP-1 in the choroid was determined using western blotting.Results: The protein expression of AQP-1 and CT were significantly decreased in the FD 21 group as compared with those in the NC group (p = .007 and p < .001). Both AQP-1 protein expression and CT gradually increased and peaked in the REC 2 group. Additionally, there were significant differences in AQP-1 protein expression and CT between the REC 2 group and all other groups (all p < .05). We observed a complete recovery in the in REC 7 group as compared with the NC group (p > .05). AQP-1 protein expression was significantly associated with CT (p = .001) in all groups; however, there was a significant negative correlation (p = .029) between AQP-1 protein expression and axial length in the REC groups.Conclusions: AQP-1 protein expression in the choroid was upregulated following recovery of FD myopia in guinea pigs, and these changes correlated with alterations in CT and axial length.

Prevalence of Myopia among Children Attending Pediatrics Ophthalmology Clinic at Ohud Hospital, Medina, Saudi Arabia

Introduction

Around half of the visually impaired population has uncorrected refractive errors (URE), and myopia constitutes a high proportion of them. URE should be screened and treated early to prevent long-term complications. The aim of this study was to determine the prevalence of myopia among all patients attending a pediatric outpatient clinic at Ohud Hospital in Medina, Saudi Arabia (KSA).

Method

This study was conducted using a convenience sample of all patients attending the clinic (1500 patients) aged between 3 and 14 years, and they were enrolled in the study during the period from May 2017 until September 2017.

Result

Of 1215 subjects, only 43 (3.54%) were diagnosed with myopia. Out of the study participants, 56.8% were female and the mean age was 9.7 ± 3.6. Myopia was more prevalent in male participants than female participants (n = 525, 4%, n = 690, 3.1%, p=0.5). Low myopia was the most common form among the screened individuals. The level of myopia was associated with the degree of the strabismus angle. Approximately 22% of patients with myopia had >25° strabismus angle. There was a statistically significant association with both near work indoor and outdoor activities on weekends and the level of myopia.

Conclusion

The prevalence of myopia among pediatrics patients in Medina is 3.54%. We hope that the results of this study will contribute to a better understanding of this public health issue in Saudi Arabia in order to implant a strict screening program for early detection and interventions to reduce the risk of further progression of visual impairment.

Breastfeeding and myopia: A cross-sectional study of children aged 6-12 years in Tianjin, China

This study aimed to determine whether an association existed between breastfeeding and myopia in children aged 6-12 years in Tianjin, China, using a cross-sectional study of 527 children. The spherical equivalent refraction (SER) and axial length (AL) were determined by ocular examination, and information regarding the children's demographics, breastfeeding history and other myopia-related risk factors were investigated using a questionnaire. The myopia prevalence rate, mean SER, and mean AL were 53.9%, -0.99 ± 1.69 D, and 23.56 ± 1.11 mm, respectively. In total, 442 (83.9%) participants were breastfed; among the breastfed participants, 132 (29.9%) were breastfed <6 months. Children who were breastfed were less likely to have myopia (breastfeeding duration <6 months: OR = 0.399, P = 0.011; >6 months: OR = 0.502, P = 0.033, multiple logistical regression). The mean SER of children breastfed <6 months was 0.653 D more hyperopic than that of non-breastfed children (P = 0.008, multiple linear regression). No significant association was observed between breastfeeding and AL. In conclusion, breastfeeding was associated with a decreased risk of myopia among children aged 6-12 years in Tianjin. Breastfeeding during the first 6 months of infancy was associated with more hyperopic SER. Furthermore, breastfeeding was associated with myopic refraction and was not related to AL, and this association could exist in childhood.

Prevalence and risk factors for myopia among school children in Aba, Nigeria

Aim: To study the prevalence of myopia among school children in Aba, Nigeria.Methods: This cross-sectional study was conducted in public and private (primary and secondary) schools. A multi-stage random sampling technique was used for selecting participants aged between 8 and 15 years from 12 schools in Aba, Nigeria. Data were analysed for 1197 children who underwent a comprehensive eye examination. The children were divided according to the following criteria: age groups (group 1 [8–11 years] or group 2 [12–15 years]), gender (male or female), level of education (primary or secondary) and type of school (public or private). Myopia was defined as spherical equivalent refraction (SER) ≤ -0.50 D in the poorer eye.Results: The prevalence of myopia was estimated to be 2.7%. Of the 96 children with refractive error, 78.1% were uncorrected. In using logistic regression analysis, risk of developing myopia was associated with older age groups (odds ratio [OR]: 1.20; 95% confidence interval [CI], 0.16–9.11; p < 0.010) and higher level of education (OR: 1.73; 95% CI, 1.05–2.86; p < 0.030). There was no significant difference in myopia prevalence between male and female children (p = 0.89).Conclusion: Although the prevalence of myopia and overall prevalence of refractive error in school children in Aba were low, the high prevalence of uncorrected refractive error is a significant public health problem. An effective and sustainable children’s vision screening programme is needed to prevent visual impairment and blindness.