An analysis of high myopia in a pediatric population less than 10 years of age

IMI-Management and Investigation of High Myopia in Infants and Young Children

Purpose

The purpose of this study was to evaluate the epidemiology, etiology, clinical assessment, investigation, management, and visual consequences of high myopia (≤-6 diopters [D]) in infants and young children.

Findings

High myopia is rare in pre-school children with a prevalence less than 1%. The etiology of myopia in such children is different than in older children, with a high rate of secondary myopia associated with prematurity or genetic causes. The priority following the diagnosis of high myopia in childhood is to determine whether there is an associated medical diagnosis that may be of greater overall importance to the health of the child through a clinical evaluation that targets the commonest features associated with syndromic forms of myopia. Biometric evaluation (including axial length and corneal curvature) is important to distinguishing axial myopia from refractive myopia associated with abnormal development of the anterior segment. Additional investigation includes ocular imaging, electrophysiological tests, genetic testing, and involvement of pediatricians and clinical geneticists is often warranted. Following investigation, optical correction is essential, but this may be more challenging and complex than in older children. Application of myopia control interventions in this group of children requires a case-by-case approach due to the lack of evidence of efficacy and clinical heterogeneity of high myopia in young children.

Conclusions

High myopia in infants and young children is a rare condition with a different pattern of etiology to that seen in older children. The clinical management of such children, in terms of investigation, optical correction, and use of myopia control treatments, is a complex and often multidisciplinary process.

Factors associated with reduced visual acuity in myopes with and without ocular pathologies after optical correction

PURPOSE

Considering that a certain proportion of high myopes have reduced visual acuity even after full optical correction, this study aimed to investigate the association between various refractive error components (sphere, cylinder and axis orientation) and reduced visual acuity in individuals with low to high myopia with and without pathologic myopia lesions.

METHODS

We analysed data from randomly selected eyes of 11,258 individuals with myopia (mean ± SD spherical equivalent (SE) -3.2 ± 2.9D; range: -0.5D to -21.5D). In total, 10,528 individuals had no pathologic myopia lesions. Sphere, cylinder and SE refraction were classified into mild, moderate and high categories. Astigmatism was defined as with-the-rule, against-the-rule or oblique based on the axis orientation. Reduced best-corrected visual acuity was defined as ≥0.18 logMAR. Logistic regression was performed to test factors associated with reduced visual acuity with and without pathologic myopia lesions.

RESULT

Overall, 6.4% (N = 720/11,258) of myopes had reduced best-corrected visual acuity. High sphere (≤-6.0D; Odd ratios [OR]: 16.1; 95% CI: 2.1-126.5), high cylinder (<-2.0 DC; OR: 2.5; 95% CI: 1.8-3.4), against-the-rule (OR: 1.5; 95% CI: 1.1-2.0) and oblique astigmatism (OR: 1.6; 95% CI: 1.2-2.1) were significantly (p ≤ 0.008) associated with reduced visual acuity in the absence of pathologic myopia lesions. Both moderate SE and high myopic SE were also associated with reduced visual acuity. In the presence of pathologic myopia lesions, tessellated fundus (OR: 6.9; 95% CI: 3.5-14.1), chorioretinal atrophy (OR: 7.7; 95% CI: 2.6-19.9) and choroidal neovascularisation (OR: 37.4; 95% CI: 3.3-419.3) were significantly (p ≤ 0.003) associated with reduced visual acuity.

CONCLUSION

Even after full optical correction, both refractive components and pathologic myopia lesions can independently cause reduced visual acuity, regardless of the degree of myopia.

A systematic review of Amblyopia prevalence among the children of the world

Objective: to assess the prevalence of Amblyopia disease in the children of the world. Methods: In order to perform this systematic review, PICO was considered as the research question. Then, the preferred keywords were searched in Medline (via PubMed), Embase, Scopus, Web of Science, and ProQuest databases. The retrieved citations were reviewed by two independent inspectors in a three-step process in terms of the title, abstract, and full-text, based on the inclusion criteria. The studies included in the review were critically evaluated and then were extracted by two dependent expert reviewers. Finally, the prevalence of Amblyopia disease in the children of the world was pooled by meta-analysis CMA v.2 software. The heterogeneity of the selected studies was evaluated using I2 and chi-square. Also, subgroup-analysis was performed using designs and continents. Results: Out of 952 retrieved citations, 131 studies were included. The total prevalence of Amblyopia in the children of the world was calculated to be 4.3% [Pooled Prevalence: 4.3%, 95% CI: 2.6%-7.00%, P-value 0.0001]. In addition, the heterogeneity of the studies was reported to be high (Q: 48281.18, df: 56, p-value 0.001, I-square: 99.88). The subgroup analysis showed that America had the highest (5.57%, 95% CI: 2.23%-13.94%, P-value 0.0001) prevalence, and the lowest prevalence of Amblyopia in the children of the world was seen in Africa (7.1%, 95% CI: 0.003%-172.53%, P-value 0.05). Conclusion: It can be concluded that the total prevalence of Amblyopia is 3.4%, but this estimate varies in all continents, especially in Africa. The major reason for this variation was reported to be the heterogeneity of studies. These assessments have investigated different populations in terms of severity of illness, age, and gender. Therefore, further worldwide high-quality and valid studies should be carried out to allow the calculation of the real prevalence of Amblyopia among children of the world. Abbreviations: VA = visual acuity, ALSPAC = Avon Longitudinal Study of Parents and Children, JBI = Joanna Briggs Institute, PRISMA = Systematic Review and Meta-analysis, CMA = Comprehensive Meta-analysis Software.

Endothelin-1 Serum Concentration is Lower in Children and Adolescents with High Myopia, a Preliminary Study

The aim of this study is to evaluate the levels of enothelin-1 (ET-1) in children and adolescents with high myopia and its association with the axial length of the eye and the presence of myopic retinal degeneration. The cross-sectional study was carried out in 57 patients with high myopia and 29 control subjects. Serum concentrations of ET-1 were measured using enzyme-linked immunosorbent assay (ELISA) kit. A significantly lower concentration of ET-1 in highly myopic patients compared to controls was found (1.47 (0.91; 1.87) vs. 1.94 (1.1; 2.69) pg/mL, p = 0.005). In patients with high myopia, a weak negative correlation between ET-1 concentration and the longest axial length out of the two eyes was found (r = −0.255, p = 0.0558). Further analysis revealed statistically significant differences in ET-1 concentration between patients with the axial length of the eye > 26 and ≤ 26 mm (p < 0.041) and patients with the axial length of the eye > 26 mm and controls (p < 0.001). ET-1 expression is disturbed in highly myopic children and adolescents. Lower ET-1 concentration in patients with the axial length of the eye > 26 mm may co-occur with high myopia and should be considered a risk factor in the pathophysiology of high myopia progression.

Morphogenetic defects underlie Superior Coloboma, a newly identified closure disorder of the dorsal eye

The eye primordium arises as a lateral outgrowth of the forebrain, with a transient fissure on the inferior side of the optic cup providing an entry point for developing blood vessels. Incomplete closure of the inferior ocular fissure results in coloboma, a disease characterized by gaps in the inferior eye and recognized as a significant cause of pediatric blindness. Here, we identify eight patients with defects in tissues of the superior eye, a congenital disorder that we term superior coloboma. The embryonic origin of superior coloboma could not be explained by conventional models of eye development, leading us to reanalyze morphogenesis of the dorsal eye. Our studies revealed the presence of the superior ocular sulcus (SOS), a transient division of the dorsal eye conserved across fish, chick, and mouse. Exome sequencing of superior coloboma patients identified rare variants in a Bone Morphogenetic Protein (Bmp) receptor (BMPR1A) and T-box transcription factor (TBX2). Consistent with this, we find sulcus closure defects in zebrafish lacking Bmp signaling or Tbx2b. In addition, loss of dorsal ocular Bmp is rescued by concomitant suppression of the ventral-specific Hedgehog pathway, arguing that sulcus closure is dependent on dorsal-ventral eye patterning cues. The superior ocular sulcus acts as a conduit for blood vessels, with altered sulcus closure resulting in inappropriate connections between the hyaloid and superficial vascular systems. Together, our findings explain the existence of superior coloboma, a congenital ocular anomaly resulting from aberrant morphogenesis of a developmental structure.

Ocular coloboma is a disease characterized by gaps in the lower portion of the eye and can affect the iris, lens, or retina, and cause loss of vision. Coloboma arises from incomplete closure of a transient fissure on the underside of the developing eye. Therefore, our identification of patients with similar tissue defects, but restricted to the superior half of eye, was surprising. Here, we describe an ocular developmental structure, the superior ocular sulcus, as a potential origin for the congenital disorder superior coloboma. Formation and closure of the sulcus are directed by dorsal-ventral eye patterning, and altered patterning interferes with the role of the sulcus as a pathway for blood vessel growth onto the eye.

The differences in level of trait anxiety among girls and boys aged 13-17 years with myopia and emmetropia

Background

A significant increase in myopia among children and teenagers can be observed all over the world. Yet at the same time, there is still an insignificant number of studies concerning this health problem.

The aim of this study was to assess the level of trait anxiety among myopic group of teenagers in comparison to teenagers with emmetropia, and to confirm whether the level of trait anxiety relates to age and gender.

Methods

Two hundred thirty-nine students aged 13–17 years were included in the study. The study group comprised 114 persons with myopia (81 girls and 33 boys), while the control group comprised 125 persons without refractive error (79 girls and 46 boys). Volunteers completed a set of questionnaires including: personal data, State-Trait Anxiety Inventory for Children (STAIC) (13–14 year-olds), or State-Trait Anxiety Inventory (STAI) (15–17 year-olds). The trait anxiety subscales were thus analyzed.

Results

Among younger adolescents (13–14 years of age) with myopia there was a significantly higher incidence of pathological intensification of anxiety as a constant trait. After taking into account the distribution of gender, there was a higher level of trait anxiety in the group of boys with myopia than in the control group aged 13–17 years and 13–14 years. There was also a higher level of trait anxiety detected in males than in females.

Conclusions

Myopia may affect the level of trait anxiety among 13–14-year-olds. In both age groups of girls, a higher percentage of patients with high level of anxiety was discovered (≥7 sten), as compared to their peers without vision defects. Our results can contribute to a more accurate analysis of young teenagers’ psychological problems, especially among boys diagnosed with myopia.

Refractive Changes in Amblyopic Children with High Anisometropia

PURPOSE

To demonstrate the refractive changes of amblyopic children attributed to high anisometropia in the myopia endemic in Taiwan.

METHODS

Amblyopic children younger than 10 years with myopic or hyperopic anisometropia 3 diopters (D) or more who had follow-up for more than 2 years and had final visual acuity of 20/30 or better in the amblyopic eye were included.

RESULTS

The average age on the first visit was similar for the 13 myopic children (5.5 years) and 17 hyperopic children (5.3 years). Initially, the mean anisometropia was significantly different (myopic, 7.25 D vs. hyperopic, 3.89 D), but the visual acuity of the amblyopic eye (logarithm of the minimum angle of resolution) was similar between both groups at baseline (0.50 vs. 0.57). Myopization of the sound eye surpassed that of the amblyopic eye in the myopic group, which resulted in a yearly reduction of anisometropia of 0.51 D. However, hyperopia decreased synchronously in both eyes of the hyperopic children. The final degree of anisometropia was not significantly different between the two groups (4.07 D vs. 3.62 D).

CONCLUSIONS

Growing up in a country with a high prevalence of myopia, children with myopic and hyperopic anisometropia in this study inevitably had myopization in both eyes. Myopic anisometropia decreases significantly over time, but hyperopic anisometropia remains constant.

Severe anisometropic myopia in identical twins

High anisometropic myopia is a rare condition in twins. Genetic factors have been implicated in its development and there may be an association with vision-threatening complications. A pair of 11-year-old twins presented with poor distance vision in both eyes. Detailed ocular examination was performed including slit lamp examination, dilated funduscopy, cycloplegic refraction, keratometry and axial length measurement. The objective refraction was -6.50DS -2.00DC × 180 (right eye), -1.00DS (left eye) for the first twin; -13.75DS -2.25DC × 180 (right eye), -0.50DS -0.75DC × 04 (left eye) for the second twin. This case suggests an underlying genetic defect in the development of myopia.

Peripheral retinal findings in highly myopic children < or =10 years of age

PURPOSE

The purpose of this study was to characterize the peripheral retinal findings in highly myopic young children without other known risk factors for retinal detachment.

METHODS

A retrospective review of all cases of children < or =10 years of age with high myopia (>6.00 diopters) who were evaluated for presumed risk of retinal detachment by either an examination under anesthesia or office examination by a single retina specialist from January 2001 through December 2008. Patients with regressed retinopathy of prematurity, retinal detachment in the fellow eye, or known Stickler syndrome were excluded.

RESULTS

Fifty-four eyes of 30 patients with high myopia were examined. Twenty-six eyes of 14 patients were examined under anesthesia because of the examiner's inability to adequately visualize the peripheral retina during an office examination. Mean age at examination was 6 +/- 3 (range, 1-10) years. Mean spherical equivalent refractive error was -13.88 +/- 3.79 (range, -6.00 to -25.00) diopters. Peripheral retinal findings were identified in 33% of eyes, the most common being lattice degeneration (20%), white without pressure (11%), and retinal holes with subretinal fluid (4%).

CONCLUSION

Approximately one third of highly myopic children in our study showed peripheral retinal findings. If the peripheral retina is not adequately visualized during an office evaluation, examination under anesthesia should be considered.

Effect of myopia on visual acuity measured with laser interference fringes

The aim was to determine how visual acuity is affected by myopia when optical factors of the eye are controlled. Grating acuity was measured with interference fringes to avoid the effects of aberrations, and ocular biometry was used to compensate for differences in retinal image size among subjects. Distance spectacle refractions ranged from +2.25 to -14.75 D. The retinal magnification factor (RMF) in mm/deg was computed for each eye from the distance refraction, central corneal power and ultrasound biometry. A forced-choice orientation discrimination method was used to measure acuity for high-contrast 543 nm laser interference fringes in three retinal locations: the fovea, and at 4 deg and 10 deg eccentricity in the temporal retina. Acuity, expressed in c/deg and adjusted for spectacle magnification, was not significantly correlated with refraction at any of the three retinal locations. When acuity was converted to retinal spatial frequency units (c/mm) via the RMF, acuity decreased with increasing myopia at all three retinal locations (significantly at the fovea and at 10 deg eccentricity). Retinal acuity values in highly myopic subjects (>6 D) are consistent with retinal sampling distances that are larger than published values of human cone or ganglion cell spacing. The results imply that a highly myopic eye has retinal neurons that are more widely spaced than normal, but the increased axial length enlarges the retinal image enough to compensate for the retinal stretching. The data are consistent with a retinal stretching model that primarily affects the posterior pole.