Review on current concepts of myopia and its control strategies

Myopia Control: Are We Ready for an Evidence Based Approach?

INTRODUCTION

Myopia and its vision-threatening complications present a significant public health problem. This review aims to provide an updated overview of the multitude of known and emerging interventions to control myopia, including their potential effect, safety, and costs.

METHODS

A systematic literature search of three databases was conducted. Interventions were grouped into four categories: environmental/behavioral (outdoor time, near work), pharmacological (e.g., atropine), optical interventions (spectacles and contact lenses), and novel approaches such as red-light (RLRL) therapies. Review articles and original articles on randomized controlled trials (RCT) were selected.

RESULTS

From the initial 3224 retrieved records, 18 reviews and 41 original articles reporting results from RCTs were included. While there is more evidence supporting the efficacy of low-dose atropine and certain myopia-controlling contact lenses in slowing myopia progression, the evidence about the efficacy of the newer interventions, such as spectacle lenses (e.g., defocus incorporated multiple segments and highly aspheric lenslets) is more limited. Behavioral interventions, i.e., increased outdoor time, seem effective for preventing the onset of myopia if implemented successfully in schools and homes. While environmental interventions and spectacles are regarded as generally safe, pharmacological interventions, contact lenses, and RLRL may be associated with adverse effects. All interventions, except for behavioral change, are tied to moderate to high expenditures.

CONCLUSION

Our review suggests that myopia control interventions are recommended and prescribed on the basis of accessibility and clinical practice patterns, which vary widely around the world. Clinical trials indicate short- to medium-term efficacy in reducing myopia progression for various interventions, but none have demonstrated long-term effectiveness in preventing high myopia and potential complications in adulthood. There is an unmet need for a unified consensus for strategies that balance risk and effectiveness for these methods for personalized myopia management.

Quality of life and depression among patients with high myopia in Nigeria: a cross sectional study

AIM

To evaluate the quality of life (QOL) and level of depression among participants with high myopia in Nigeria and the demographic factors associated with these outcomes.

METHODS

This cross-sectional study was conducted on 100 adult participants with high myopia (defined as refractive error ≤-5.00 D or worse, and uncorrected visual acuity worse than 6/18 in the better seeing eye) attending ophthalmology centres in Nigeria from 2 October 2021 to 30 August 2022. The means and standard deviations were calculated for each of the four domains of World Health Organization Quality of life scale (WHOQOL-BREF) using the transformed scores. The Beck Depression Inventory (BDI) scale was used to assess the level of depression.

RESULTS

The highest and the lowest mean scores of WHOQOL-BREF domains were found for the psychological and physical health domains (mean percentage scores were 67.0 [95% confidence intervals (CI) 64.1-68.9] and 55.3 (95%CI 51.8-58.8, P<0.001), respectively. One-way analysis of variance (ANOVA) revealed significant differences in physical health with educational status (higher among those with tertiary education: mean difference 0.9, 95%CI -0.2-2.1; P=0.049), differences in psychological health with working status (higher among those who were working 1.2, 95%CI 0.3-2.1; P=0.012). Also, the result showed a statistically significant association between environmental health and marital status (higher among non-married: 1.7, 95%CI -0.9-2.3; P=0.012) while overall health was associated with place of residence (higher in urban areas: 2.3, 95%CI 1.2-3.5; P=0.024). For depression, one in every nine participants reported major depressive symptom, mostly younger people (aged 16-29 vs 30-49y: 17.0% vs 0, P=0.019), and slightly more women than men (14.3% vs 0, P=0.064). There were significant negative correlations between the depression scores and psychological health (r=-0.48, P<0.001), physical health (r=-0.29, P=0.002), social and relationship (r=-0.49, P<0.001), environmental (r=-0.48, P<0.001) and overall health (r=-0.49, P<0.001).

CONCLUSION

People with high myopia have a relatively moderate QOL, but poor physical health, particularly the younger age group, and women who are more likely to experience clinically relevant depression. Eye care professionals should consider possible referrals for counselling for people with high myopia.

Control of myopia using diffusion optics spectacle lenses: 12-month results of a randomised controlled, efficacy and safety study (CYPRESS)

BACKGROUND

Mutations in the L/M cone opsin gene array cause abnormally high perceived retinal contrast and the development of myopia. Environmental factors may also lead to high visual contrast and cause myopia. Diffusion optics technology (DOT) lenses are designed to reduce contrast signalling in the retina and slow myopia progression.

METHODS

The Control of Myopia Using Peripheral Diffusion Lenses Efficacy and Safety Study (CYPRESS, NCT03623074) is a 36-month, multicentre, randomised, controlled, double-masked trial evaluating two investigational spectacle lenses versus control lenses in myopic children aged 6-10, with a planned interim analysis at 12 months. The primary endpoints are change from baseline in axial length (AL) and spherical equivalent refraction (SER).

RESULTS

256 children (58% female; mean age at screening, 8.1 years) were dispensed spectacles. Across all groups, baseline averages were AL 24.02 mm (SD±0.77 mm), SER -2.01 D (SD±0.9 D) using manifest refraction, and SER -1.94 D (SD±1.0 D) using cycloplegic autorefraction. At 12 months, mean difference in SER progression for test 1 versus control was -0.40 D (p<0.0001), representing a 74% reduction and -0.32 D for Test 2 (p<0.0001), representing a 59% reduction. The difference in AL progression for test 1 versus control was 0.15 mm (p<0.0001) and test 2 versus control was 0.10 mm (p=0.0018).

CONCLUSION

12-month results from this ongoing trial demonstrate the safety and effectiveness of DOT spectacles for reducing myopic progression.

Assessment of biosafety and implantation feasibility of novel phakic refractive lens

Purpose

We investigated the biosafety and implantation feasibility of a new phakic refractive lens (PRL) in rabbit eyes.

Methods

Short PRLs (S-PRLs), large PRLs (L-PRLs), and large-grooved PRLs (LG-PRLs), were prepared by molding medical-grade liquid silicon. The cytotoxicity and cellular adhesion of the PRLs was assessed in vitro. To assess implantation feasibility, the S-PRL, L-PRL, and LG-PRL were implanted in the posterior chamber of rabbit eyes and the relative position was assessed by optical coherence tomography. The intraocular pressures (IOP) were compared between the S-PRL, L-PRL, LG-PRL, and control groups to evaluate the PRL biosafety after implantation.

Results

The in vitro assays showed that cell viability and cellular adhesion in the S-PRL, L-PRL and LG-PRL groups was not significantly different to those in the control group throughout the study. After implantation into the posterior chamber of rabbit eyes, there were no obvious signs of inflammation or increases in IOP at each time point relative to the control group, demonstrating good biosafety of the PRL. The relative positions of the L-PRLs and LG-PRLs in the posterior chamber were appropriate and the retention frequencies were high.

Conclusions

The newly developed LG-PRL showed good biosafety with negligible in vitro cytotoxicity, ocular inflammation, or fluctuations in IOP. The LG-PRL provided the best implantation feasibility. The grooves on the LG-PRL provided channels for aqueous humor circulation. The LG-PRL is a promising type of PRL with an appropriate size and surface structure for effective correction of refractive errors in rabbit eyes.

Age-Related Effects on the Spectrum of Cerebral Visual Impairment in Children With Cerebral Palsy

Background

Cerebral Visual Impairment (CVI) is a very common finding in children affected by Cerebral Palsy (CP). In this paper we studied the characteristics of CVI of a large group of children with CP and CVI, describing their neurovisual profiles according to three different age subgroups (subgroup 1: infants 6 months–2 years; subgroup 2: pre-school age 3–5 years; subgroup 3: school age ≥ 6 years).

Methods

We enrolled 180 subjects (104 males, mean age 66 ± 42.6 months; range 6–192 months) with CP and CVI for the study. We carried out a demographic and clinical data collection, neurological examination, developmental or cognitive assessment, and a video-recorded visual function assessment including an evaluation of ophthalmological characteristics, oculomotor functions, and basic visual functions. In school-aged children, we also performed an evaluation of their cognitive-visual profiles.

Results

There were signs of CVI in all the three subgroups. Subgroup 1 (62 children) and subgroup 2 (50 children) were different for fixation (p = 0.02), visual acuity (p = 0.03) and contrast sensitivity (p < 0.01), being more frequently impaired in younger children. Comparing subgroup 2 with subgroup 3 (68 children), the older children presented more frequently myopia (p = 0.02) while the younger ones esotropia (p = 0.02) and alteration in smooth pursuit (p = 0.03) and saccades (p < 0.01). Furthermore, fixation, smooth pursuit, visual acuity, contrast sensitivity and visual filed (p < 0.01) were more frequently impaired in younger children (subgroup 1) compared to the older ones. Multiple correspondence analysis (MCA) confirmed the different neurovisual profiles according to age: younger children with CP showed more signs of CVI compared to the older ones. 34 out of 68 children belonging to subgroup 3 underwent the cognitive visual evaluation; an impairment of cognitive visual skills was detected in 21 subjects.

Conclusion

Younger children with CP showed more signs of CVI compared to the older ones, likely for the physiological maturation of visual system and mechanisms of neuroplasticity. In this direction, we suggest an early neurovisual evaluation to detect any weak visual functions.

Choroidal Thickness in Correlation with Axial Length and Myopia Degree

Background: Myopia is a condition in which the visual images come to a focus in front of the retina of the eye. This disease is a major cause of visual disability, which presents in 108 million persons globally. Purpose: This study aims to determine the relationship between the degree of myopia, the axial length, and the choroidal thickness (CT). Methods: This is an observational analytical study that made use of a cross-sectional design. A total of 59 participants with refractive errors underwent treatment at Hasanuddin University Hospital and 116 eyes were measured and analyzed. The choroidal thickness was measured using the Enhance Depth Imaging OCT (EDI-OCT) tool, which is divided into nine observational areas. Furthermore, all data obtained were compared using statistical analysis, such as the one-way ANOVA and Pearson correlation test (p < 0.05). Results: There was a significant relationship between the choroidal thickness with axial length (p < 0.05) and myopia degrees (p < 0.05). Conclusions: The thickness of the choroid decreases with an increase in the axial length and degree of myopia, which further indicates that the higher the myopia degree, the thinner the choroidal vasculature.