Advances in myopia control strategies for children.

Myopia has long been a global threat to public health. Timely interventions are likely to reduce the risk of vision-threatening complications. There are both established and rapidly evolving therapeutic approaches to slow myopia progression and/or delay its onset. The effective methods for slowing myopia progression include atropine eye-drops, defocus incorporated multiple segments (DIMS) spectacle lenses, spectacle lenses with highly aspherical lenslets target (HALT), diffusion optics technology (DOT) spectacle lenses, red light therapy (RLT), multifocal soft contact lenses and orthokeratology. Among these, 0.05% atropine, HALT lenses, RLT and +3.00 peripheral addition soft contact lenses yield over 60% reduction in myopia progression, whereas DIMS, DOT and MiSight contact lenses demonstrate at least 50% myopia control efficacy. 0.05% atropine demonstrates a more optimal balance of efficacy and safety than 0.01%. The efficacy of 0.01% atropine has not been consistent and requires further validation across diverse ethnicities. Combining atropine 0.01% with orthokeratology or DIMS spectacles yields better outcomes than using these interventions as monotherapies. Increased outdoor time is an effective public health strategy for myopia prevention while recent studies suggest that 0.05% low-concentration atropine and RLT therapy have promising potential as clinical myopia prevention interventions for high-risk groups. Myopia control spectacle lenses, being the least invasive, are safe for long-term use. However, when considering other approaches, it is essential to ensure proper instruction and regular follow-ups to maintain safety and monitor any potential complications. Ultimately, significant advances have been made in myopia control strategies, many of which have shown meaningful clinical outcomes. However, regular use and adequate safety monitoring over extended durations are imperative to foster confidence that can only come from extensive clinical experience.

Five-Year Clinical Trial of the Low-Concentration Atropine for Myopia Progression (LAMP) Study: Phase 4 Report.

PURPOSE: To evaluate (1) the long-term efficacy of low-concentration atropine over 5 years, (2) the proportion of children requiring re-treatment and associated factors, and (3) the efficacy of pro re nata (PRN) re-treatment using 0.05% atropine from years 3 to 5. DESIGN: Randomized, double-masked extended trial. PARTICIPANTS: Children 4 to 12 years of age originally from the Low-Concentration Atropine for Myopia Progression (LAMP) study. METHODS: Children 4 to 12 years of age originally from the LAMP study were followed up for 5 years. During the third year, children in each group originally receiving 0.05%, 0.025%, and 0.01% atropine were randomized to continued treatment and treatment cessation. During years 4 and 5, all continued treatment subgroups were switched to 0.05% atropine for continued treatment, whereas all treatment cessation subgroups followed a PRN re-treatment protocol to resume 0.05% atropine for children with myopic progressions of 0.5 diopter (D) or more over 1 year. Generalized estimating equations were used to compare the changes in spherical equivalent (SE) progression and axial length (AL) elongation among groups. MAIN OUTCOMES MEASURES: (1) Changes in SE and AL in different groups over 5 years, (2) the proportion of children who needed re-treatment, and (3) changes in SE and AL in the continued treatment and PRN re-treatment groups from years 3 to 5. RESULTS: Two hundred seventy (82.8%) of 326 children (82.5%) from the third year completed 5 years of follow-up. Over 5 years, the cumulative mean SE progressions were -1.34 ± 1.40 D, -1.97 ± 1.03 D, and -2.34 ± 1.71 D for the continued treatment groups with initial 0.05%, 0.025%, and 0.01% atropine, respectively (P = 0.02). Similar trends were observed in AL elongation (P = 0.01). Among the PRN re-treatment group, 87.9% of children (94/107) needed re-treatment. The proportion of re-treatment across all studied concentrations was similar (P = 0.76). The SE progressions for continued treatment and PRN re-treatment groups from years 3 to 5 were -0.97 ± 0.82 D and -1.00 ± 0.74 D (P = 0.55) and the AL elongations were 0.51 ± 0.34 mm and 0.49 ± 0.32 mm (P = 0.84), respectively. CONCLUSIONS: Over 5 years, the continued 0.05% atropine treatment demonstrated good efficacy for myopia control. Most children needed to restart treatment after atropine cessation at year 3. Restarted treatment with 0.05% atropine achieved similar efficacy as continued treatment. Children should be considered for re-treatment if myopia progresses after treatment cessation. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Effects of firsthand tobacco smoking on retinal vessel caliber: a systematic review and meta-analysis.

PURPOSE: To review the effects of firsthand tobacco smoking on central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) of firsthand tobacco smokers. METHODS: We performed a search on EMBASE and PubMed for studies up to 15th July 2022. Two independent reviewers selected studies with baseline data of CRAE and CRVE of current smokers, nonsmokers, and former smokers. Initial search identified 893 studies, of which 10 were included in the meta-analysis. Two independent reviewers extracted data from the included studies. The quality of studies was assessed by the Newcastle-Ottawa Scale. RESULTS: In this meta-analysis, 7431 nonsmokers, 2448 current smokers and 5786 former smokers, as well as 7404 nonsmokers, 2430 current smokers and 5763 former smokers were included in CRAE and CRVE analysis respectively. Nonsmokers had narrower CRVE (Weighted mean difference [WMD], -12.15; 95% CI, -17.33 - -6.96) and CRAE (WMD, -4.77; 95% CI, -7.96 - -1.57) than current smokers, and narrower CRVE (WMD, -3.08; 95% CI, -6.06 - -0.11) than former smokers. Current smokers had wider CRVE (WMD, 10.42; 95% CI, 7.80 - 13.04) and CRAE (WMD, 7.05; 95% CI, 6.65 - 7.46) than former smokers. Subgroup analysis and sensitivity analysis were performed. CONCLUSION: Firsthand tobacco smoking resulted in wider CRAE and CRVE in current and former smokers, particularly in CRVE, and such changes may not be reversible after smoking cessation. Therefore, retinal vessel caliber may reflect the effects of firsthand tobacco smoking and be used to estimate the risk of cardiovascular diseases.

Iris depigmentation and cytomegalovirus in aqueous humor as predictors of uveitic activity and recurrence in chronic and recurrent anterior uveitis.

PURPOSE: To examine the clinical outcomes in chronic or recurrent anterior uveitis in the presence or absence of cytomegalovirus (CMV) and investigate the predictive factors for uveitic activity and recurrence. METHODS: Polymerase chain reaction (PCR) was performed in a prospective cohort of immunocompetent adults with recurrent or chronic anterior uveitis to detect CMV in aqueous humor. The clinical outcomes were compared between eyes with and without CMV DNA. Logistic regression was performed to evaluate associations between iris depigmentation, CMV-PCR status, uveitic activity, and recurrence. RESULTS: Thirty-eight eyes of 38 subjects with a mean age of 61.1 ± 11.2 years old were analyzed. Fifteen eyes were positive for CMV. More eyes with CMV developed recurrences and remained actively inflamed at 6, 12, and 24 weeks though the differences were insignificant. The presence of iris depigmentation was predictive of a greater odd of uveitic recurrences by 12 and 24 weeks (Odds ratio (OR) = 9.17 and 5.72, P = 0.007 and 0.034 respectively), whereas positive CMV-PCR predicts a greater odd of uveitic activity at postoperative 12 and 24 weeks (OR = 13.08, 34.30; P = 0.027, 0.007). CONCLUSION: Eye with and without detectable CMV behaved similarly in their clinical course. Our findings suggested that iris depigmentation was predictive of more frequent uveitic recurrence, regardless of the PCR status, whereas the presence of CMV in aqueous humor was associated with persistent uveitic activity. Iris changes may be present during the earlier phase of the disease and precede the detection of virus from the aqueous humor at a later stage of CMV infection.

Interocular Symmetry in Retinal Nerve Fiber Layer Thickness in Children: The Hong Kong Children Eye Study.

INTRODUCTION: The aim of this work is to determine the interocular differences in peripapillary retinal nerve fiber layer (p-RNFL) thickness and its associations among school children in Hong Kong. METHODS: We conducted a population-based study including 4034 children aged 6-8 years from the Hong Kong Children Eye Study (HKCES). All participants received comprehensive ocular examinations where p-RNFL thickness was measured using spectral-domain optical coherence tomography (SD-OCT). The degree of symmetry between both eyes was analyzed and represented by intraclass correlation coefficient (ICC) values. Multivariable linear regression analysis was used to investigate the associations between ocular and systemic factors with p-RNFL thickness difference. RESULTS: The study included 4034 children with a mean age of 7.61 ± 0.98 years. The mean global p-RNFL thickness was 106.60 ± 9.41 µm in right eyes and 105.99 ± 9.30 µm in left eyes. The ICC for global p-RNFL difference was 0.866 (95% CI 0.858-0.873, p < 0.001). The symmetry displayed the largest values in nasal inferior quadrant with the ICC value of 0.736 (95% CI 0.721-0.749); and the smallest degree of symmetry was found to be in the superior temporal quadrant with the ICC value of 0.567 (95% CI 0.546-0.588). Axial length (AL) difference was found to have more pronounced correlation to interocular symmetry in p-RNFL thickness with the coefficient of 0.514 (p < 0.001). CONCLUSIONS: Normal variation in interocular symmetry exists in children. Our results can contribute to the establishment of a standard reference for interocular differences in OCT parameters in children. The interocular differences in AL should be considered in the interpretation of RNFL symmetry, in terms of identifying children at risk of developing glaucoma or other ocular disorders.

Association of Polymorphisms in ZFHX1B and PAX6 With Anisometropia in Chinese Children: The Hong Kong Children Eye Genetics Study.

Purpose: To identify gene variants associated with anisometropia development in children. Methods: This is a population-based, cross-sectional, and longitudinal genetic association study involving 1057 children aged 6 to 10 years with both baseline and 3-year follow-up data. Six single nucleotide polymorphisms (SNPs), ZC3H11B rs4373767, ZFHX1B rs13382811, KCNQ5 rs7744813, SNTB1 rs7839488, PAX6 rs644242, and GJD2 rs524952 were analyzed in all children. Anisometropia was defined by an interocular difference in SE of ≥1 diopter (D) (Aniso-SE) and an interocular difference in axial length (AL) of ≥0.3 mm (Aniso-AL), respectively. Genetic associations of individual SNPs and joint SNP effects were analyzed. Results: ZFHX1B rs13382811 was associated nominally with Aniso-AL (odds ratio [OR], 1.66; P = 0.003) at baseline. At 3 years, rs13382811 was significantly associated with Aniso-AL (OR, 1.49; P = 0.001) and became nominally associated with Aniso-SE (OR, 1.40; P = 0.01). In addition, PAX6 rs644242 was significantly associated with Aniso-AL at 3 years (OR, 1.45; P = 0.002). At the 3-year follow-up, PAX6 rs644242 was associated significantly with Aniso-AL development (OR, 1.61; P = 0.0003) and nominally with Aniso-SE development (P = 0.03) in children who were not anisometropic at baseline, whereas ZFHX1B rs13382811 was associated nominally with Aniso-AL development (P = 0.02). An additive SNP analysis indicated children carrying the risk allele T of ZFHX1B rs13382811 and allele A of PAX6 rs644242 might have a 4.33- and 6.90-fold of increased risk of Aniso-SE and Aniso-AL development by 3 years, respectively. Conclusions: This study identified two susceptible gene variants, ZFHX1B rs13382811 and PAX6 rs644242, for anisometropia development in Hong Kong Chinese children, implicating their role in imbalanced refractive change and axial elongation between both eyes.

Analysis of Secondhand Smoke Exposure and Myopia Among Children Aged 6 to 8 Years in Hong Kong.

Importance: Secondhand smoke (SHS) exposure potentially threatens ocular health; however, its association with myopia is unknown. Objective: To examine the association between SHS exposure and childhood myopia. Design, Setting, and Participants: Cross-sectional data from the population-based Hong Kong Children Eye Study were used. Data were collected from March 5, 2015, to September 12, 2021, at The Chinese University of Hong Kong Eye Center. Participants included children aged 6 to 8 years. Secondhand smoke exposure was evaluated using a validated questionnaire. All participants underwent comprehensive ophthalmic and physical examinations. Exposure: Secondhand smoke exposure. Main Outcomes and Measures: Generalized estimating equations were constructed to examine the association of SHS exposure with spherical equivalent and axial length; logistic regression models, with myopia rate; and linear regression models, with myopia onset. Results: A total of 12 630 children (mean [SD] age, 7.37 [0.88] years; 53.2% boys) were included in the analysis. Among the participants, 4092 (32.4%) had SHS exposure. After adjusting for age, sex, parental myopia, body mass index, near-work time, outdoor time, and family income, SHS exposure was associated with greater myopic refraction (ß = -0.09 [95% CI, -0.14 to -0.03]) and longer axial length (ß = 0.05 [95% CI, 0.02-0.08]). Children with SHS exposure were more likely to develop moderate (odds ratio [OR], 1.30 [95% CI, 1.06-1.59]) and high myopia (OR, 2.64 [95% CI, 1.48-4.69]). The association of SHS exposure with spherical equivalence and axial length was magnified in younger children. For each younger year of a child's exposure to SHS, SHS exposure was associated with a 0.07-D decrease in spherical equivalence (ß = 0.07 [95% CI, 0.01-0.13]) and a 0.05-mm increase in axial length (ß = -0.05 [95% CI, -0.08 to -0.01]). Exposure to SHS was associated with an earlier mean (SD) age at onset of myopia (72.8 [0.9] vs 74.6 [0.6] months; P = .01). Every increase in SHS exposure in units of 10 cigarettes per day was associated with greater myopic refraction (ß = -0.07 [95% CI, -0.11 to -0.02]), axial length (ß = 0.04 [95% CI, 0.01-0.06]), and likelihood of developing moderate (OR, 1.23 [95% CI, 1.05-1.44]) and high myopia (OR, 1.75 [95% CI, 1.20-2.56]), and earlier myopia onset (ß = -1.30 [95% CI, -2.32 to -0.27]). Conclusions and Relevance: The findings of this cross-sectional study suggest that SHS exposure was associated with greater myopic refraction, longer axial length, greater likelihood of developing moderate and high myopia, and earlier myopia onset. The larger the quantity of SHS exposure and the younger the child, the more advanced myopia development and progression with which SHS exposure is associated.

Prevalence and Characteristics of Peripapillary Gamma Zone in Children With Different Refractive Status: The Hong Kong Children Eye Study.

Purpose: This study aimed to assess the prevalence and characteristics of the peripapillary gamma zone in myopic, emmetropic, and hyperopic eyes of Chinese children. Methods: Overall, 1274 children aged 6 to 8 years from the Hong Kong Children Eye Study underwent ocular examinations, including measurements of cycloplegic auto-refraction and axial length (AL). The optic disc was imaged using a Spectralis optical coherence tomography (OCT) unit and a protocol involving 24 equally spaced radial B-scans. The Bruch's membrane opening (BMO) was identified in over 48 meridians in each eye. The peripapillary gamma zone was defined as the region between the BMO and the border of the optic disc, identified by the OCT. Results: The prevalence of the peripapillary gamma zone was higher in myopic eyes (36.3%) than in emmetropic (16.1%) and hyperopic eyes (11.5%, P < 0.001). AL (per 1 mm; odds ratio [OR]) = 1.861, P < 0.001) and a more oval disc shape (OR = 3.144, P < 0.001) were associated with the presence of a peripapillary gamma zone after adjusting for demographic, systemic, and ocular variables. In the subgroup analysis, a longer AL was associated with the presence of a peripapillary gamma zone in myopic eyes (OR = 1.874, P < 0.001), but not in emmetropic (OR = 1.033, P = 0.913) or hyperopic eyes (OR = 1.044, P = 0.883). A peripapillary zone was not observed in the region nasal to the optic nerve in myopic eyes, in contrast to its presence in the same region in 1.9% of emmetropic eyes and 9.3% of hyperopic eyes; these intergroup differences were statistically significant (P < 0.001). Conclusions: Although peripapillary gamma zones were observed in the eyes of both myopic and non-myopic children, their characteristics and distribution patterns were substantially different.

A review on drug-induced dry eye disease.

Dry eye disease encompasses a broad range of etiologies and disease subtypes which have similar clinical manifestations. Medications can cause dry eye disease or symptoms of dryness as a side effect by either interfering with the lacrimal gland or meibomian gland function, or both, and by other mechanisms that affect the ocular surface homeostasis. This is important to know and recognize as eliminating the offending medication can reverse the symptoms and, in many cases, prevent further deterioration of the ocular surface inflammation. This review focuses on drugs like systemic isotretinoin and taxanes, which cause meibomian gland dysfunction; immune checkpoint inhibitors that cause lacrimal gland dysfunction; gliptins and topical antiglaucoma medications that cause cicatrizing conjunctivitis; and epidermal growth factor receptor inhibitors, fibroblast growth factor receptor inhibitors, and belantamab mafodotin, which cause mucosal epitheliopathy. Many of these medications, particularly the newer anticancer agents, have only recently been introduced for clinical use, and knowledge and awareness of their ocular side effects are still evolving. This review aims to update ophthalmologists on the drug-induced causes of dry eye disease or symptoms of dryness, which is avoidable by discontinuation of the incriminating agent or can be mitigated by reducing the dose or frequency of usage.

Myopia control and prevention: From lifestyle to low-concentration atropine. The 2022 Josh Wallman Memorial Lecture.

The purpose of this study was to explore the findings from the Hong Kong Children Eye Study and the Low Concentration Atropine for Myopia Progression (LAMP-1) Study. The incidence of myopia among schoolchildren in Hong Kong more than doubled during the COVID-19 pandemic, with outdoor time decreased significantly and screen time increased. The change in lifestyle during the COVID-19 pandemic aggravated myopia development. Low-concentration atropine (0.05%, 0.025% and 0.01%) is effective in reducing myopia progression with a concentration-related response. This concentration-dependent response was maintained throughout a 3-year follow-up period, and all low concentrations were well tolerated. An age-dependent effect was observed in each treatment group with 0.05%, 0.025% and 0.01% atropine. Younger age was associated with a poor treatment response to low-concentration atropine. Additionally, low-concentration atropine induced choroidal thickening along a concentration-dependent response throughout the treatment period. During the third year, continued atropine treatment achieved a better effect across all concentrations compared with the washout regimen. Stopping treatment at an older age and receiving lower concentration were associated with a smaller rebound effect. However, differences in the rebound effect were clinically small across all the three concentrations studied.

Corneal nerve changes in herpes zoster ophthalmicus: a prospective longitudinal in vivo confocal microscopy study.

PURPOSE: To study the changes in corneal nerves and corneal sensitivity over a 6-month period in patients with herpes zoster ophthalmicus (HZO) compared with healthy subjects. METHODS: This was a prospective longitudinal study on patients with newly diagnosed HZO. In vivo confocal microscopy (IVCM) corneal nerve parameters and corneal sensitivity were measured and compared between eyes with HZO, contralateral eyes and controls at baseline, 2 and 6 months. RESULTS: Fifteen subjects with HZO and 15 healthy age and sex matched controls were recruited. HZO eyes revealed a reduction in corneal nerve branch density (CNBD) from baseline to 2 months (9.65 ± 5.75 vs. 5.90 ± 6.87/mm2, p = 0.018), and decreased corneal nerve fibre density (CNFD) at 2 months when compared with control (p = 0.025). However, these differences resolved by 6 months. HZO fellow eyes demonstrated increased corneal nerve fibre area (CNFA), corneal nerve fibre width (CNFW) and corneal nerve fractal dimension (CNFrD) at 2 months compared with baseline (p = 0.025, 0.031, 0.009). There was no change in corneal sensitivity for both HZO affected and HZO fellow eyes from baseline or over time, nor was it different from sensitivity in controls. CONCLUSION: Corneal denervation was present at 2 months in HZO eyes, with an observed recovery by 6 months. HZO fellow eyes demonstrated increased corneal nerve parameters at 2 months, which could represent a proliferative response to nerve degeneration. IVCM is useful in monitoring corneal nerve changes, and is more sensitive in detecting nerve alterations than esthesiometry.

Prevalence of Myopia in Children Before, During, and After COVID-19 Restrictions in Hong Kong.

Importance: Childhood myopia increased during the COVID-19 pandemic. Limited evidence exists about whether myopia development was reversed or worsened after the lockdown. Objective: To determine the prevalence of myopia and its associated factors before, during, and after COVID-19 restrictions. Design, Setting, and Participants: This population-based, repeated cross-sectional study evaluated children aged 6 to 8 years from the Hong Kong Children Eye Study between 2015 and 2021 in 3 cohorts: before COVID-19 (2015-2019), during COVID-19 restrictions (2020), and after COVID-19 restrictions were lifted (2021). Exposures: All the children received ocular examinations, including cycloplegic autorefraction and axial length. Data about the children's lifestyle, including time spent outdoors, near-work time, and screen time, were collected from a standardized questionnaire. Main Outcomes and Measures: The main outcomes were the prevalence of myopia, mean spherical equivalent refraction, axial length, changes in lifestyle, and the associated factors over 7 years. Data were analyzed using descriptive statistics, logistic regression, and generalized estimating equations. Results: Of 20 527 children (mean [SD] age, 7.33 [0.89] years; 52.8% boys and 47.2% girls), myopia prevalence was stable from 2015 to 2019 (23.5%-24.9%; P = .90) but increased to 28.8% (P < .001) in 2020 and 36.2% (P < .001) in 2021. The mean (SD) time spent outdoors was much lower in 2020 (0.85 [0.53] h/d; P < .001) and 2021 (1.26 [0.48] h/d; P < .001) compared with pre-COVID-19 levels (1.40 [0.47]-1.46 [0.65] h/d). The trend was reversed for total near-work time and screen time. High myopia prevalence was associated with the COVID-19 pandemic (odds ratio [OR], 1.40; 95% CI, 1.28-1.54; P < .001), younger age (OR, 1.84; 95% CI, 1.76-1.93; P < .001), male sex (OR, 1.11; 95% CI, 1.03-1.21; P = .007), lower family income (OR, 1.05; 95% CI, 1.00-1.09; P = .04), and parental myopia (OR, 1.61; 95% CI, 1.52-1.70; P < .001). During the pandemic, mean (SD) near-work and screen times in children from lower-income families were 5.16 (2.05) h/d and 3.44 (1.97) h/d, more than from higher-income families (4.83 [1.85] and 2.90 [1.61] h/d, respectively). Conclusions and Relevance: The findings of this cross-sectional study revealed that after COVID-19 restrictions were lifted in Hong Kong, myopia prevalence among children was higher than before the pandemic, and lifestyle did not return to pre-COVID-19 levels. Younger children and those from low-income families were at a higher risk of myopia development during the pandemic, suggesting that collective efforts for myopia control should be advocated for these groups.

Effect of Low-Concentration Atropine Eyedrops vs Placebo on Myopia Incidence in Children: The LAMP2 Randomized Clinical Trial.

Importance: Early onset of myopia is associated with high myopia later in life, and myopia is irreversible once developed. Objective: To evaluate the efficacy of low-concentration atropine eyedrops at 0.05% and 0.01% concentration for delaying the onset of myopia. Design, Setting, and Participants: This randomized, placebo-controlled, double-masked trial conducted at the Chinese University of Hong Kong Eye Centre enrolled 474 nonmyopic children aged 4 through 9 years with cycloplegic spherical equivalent between +1.00 D to 0.00 D and astigmatism less than -1.00 D. The first recruited participant started treatment on July 11, 2017, and the last participant was enrolled on June 4, 2020; the date of the final follow-up session was June 4, 2022. Interventions: Participants were assigned at random to the 0.05% atropine (n = 160), 0.01% atropine (n = 159), and placebo (n = 155) groups and had eyedrops applied once nightly in both eyes over 2 years. Main Outcomes and Measures: The primary outcomes were the 2-year cumulative incidence rate of myopia (cycloplegic spherical equivalent of at least -0.50 D in either eye) and the percentage of participants with fast myopic shift (spherical equivalent myopic shift of at least 1.00 D). Results: Of the 474 randomized patients (mean age, 6.8 years; 50% female), 353 (74.5%) completed the trial. The 2-year cumulative incidence of myopia in the 0.05% atropine, 0.01% atropine, and placebo groups were 28.4% (33/116), 45.9% (56/122), and 53.0% (61/115), respectively, and the percentages of participants with fast myopic shift at 2 years were 25.0%, 45.1%, and 53.9%. Compared with the placebo group, the 0.05% atropine group had significantly lower 2-year cumulative myopia incidence (difference, 24.6% [95% CI, 12.0%-36.4%]) and percentage of patients with fast myopic shift (difference, 28.9% [95% CI, 16.5%-40.5%]). Compared with the 0.01% atropine group, the 0.05% atropine group had significantly lower 2-year cumulative myopia incidence (difference, 17.5% [95% CI, 5.2%-29.2%]) and percentage of patients with fast myopic shift (difference, 20.1% [95% CI, 8.0%-31.6%]). The 0.01% atropine and placebo groups were not significantly different in 2-year cumulative myopia incidence or percentage of patients with fast myopic shift. Photophobia was the most common adverse event and was reported by 12.9% of participants in the 0.05% atropine group, 18.9% in the 0.01% atropine group, and 12.2% in the placebo group in the second year. Conclusions and Relevance: Among children aged 4 to 9 years without myopia, nightly use of 0.05% atropine eyedrops compared with placebo resulted in a significantly lower incidence of myopia and lower percentage of participants with fast myopic shift at 2 years. There was no significant difference between 0.01% atropine and placebo. Further research is needed to replicate the findings, to understand whether this represents a delay or prevention of myopia, and to assess longer-term safety. Trial Registration: Chinese Clinical Trial Registry: ChiCTR-IPR-15006883.

Association of SIX1-SIX6 polymorphisms with peripapillary retinal nerve fibre layer thickness in children.

PURPOSE: Association of SIX1-SIX6 variants with peripapillary retinal nerve fibre layer (p-RNFL) thickness had been reported in adults. This study aimed to investigate these associations in children, with further explorations by spatial, age and sex stratifications. METHODS: 2878 school children aged between 6 and 9 years were enrolled from the Hong Kong Children Eye Study. Three single-nucleotide polymorphisms (SNPs) at the SIX1-SIX6 locus were genotyped. The association of each SNP with p-RNFL thickness (including global and sectoral thickness) were evaluated using multiple linear regression. RESULTS: SNPs rs33912345 (p=7.7×10-4) and rs10483727 (p=0.0013) showed significant associations with temporal-inferior p-RNFL thickness. The C allele of rs33912345 was associated with a thinner temporal-inferior p-RNFL by an average of 2.44 µm, while rs10483727-T was associated with a thinner temporal-inferior p-RNFL by 2.32 µm. The association with temporal-inferior p-RNFL was the strongest in the 8-9 year-old group for rs33912345 (p=5.2×10-4) and rs10483727 (p=3.3×10-4). Both SNPs were significantly associated with temporal-inferior p-RNFL thickness in boys (p<0.0017), but not in girls (p>0.05). In contrast, rs12436579-C (ß=1.66; p=0.0059), but not rs33912345-C (ß=1.31; p=0.052) or rs10483727-T (ß=1.19; p=0.078), was nominally associated with a thicker nasal-inferior p-RNFL. CONCLUSIONS: Both rs33912345 and rs10483727 at SIX1-SIX6 were associated with p-RNFL thickness in children, especially at the temporal-inferior sector, with age-dependent and sex-specific effects. SNP rs12436579 was associated with nasal-inferior p-RNFL thickness. Our findings suggested a role of SIX1-SIX6 in RNFL variation during neural retina development in childhood.

Differential compensatory role of internal astigmatism in school children and adults: The Hong Kong Children Eye Study.

BACKGROUND: To compare the prevalence of refractive (RA), corneal (CA), and internal astigmatism (IA) in Hong Kong children and adults and evaluate the role of IA in compensating for total astigmatism and its relations to myopic traits. METHODS: The Hong Kong Children Eye Study is a population-based cross-sectional study. Totally 3704 school children (mean age 7.5 ± 1.0 years) and 5577 adults (mean age 41.1 ± 7.5 years), who were their parents, were recruited. Cycloplegic and non-cycloplegic refractive cylinders were obtained from children and adults, respectively. Spearman correlation was applied to detect associations between astigmatism, ocular biometrics, refraction, and lens power. Astigmatism compensation factor (CF) was derived from the power vector analysis J0 and J45. RESULTS: The prevalence of RA (≤-1.0 D), CA (≥+1.0 D) and IA (≥+1.0 D) was 21.9%, 63.9%, and 9.9% in children, and 30.9%, 39.5%, and 23.7% in adults respectively. The mean RA, CA and IA values in children and adults were -0.69 ± 0.66 D, +1.14 ± 0.61 D, +0.62 ± 0.32 D, and -0.80 ± 0.74 D, +0.97 ± 0.69 D, and +0.76 ± 0.43 D, respectively. In adults and children, IA was negatively correlated with axial length (p < 0.0001), but positively correlated with spherical values and equivalent (p < 0.0001), suggesting an association of astigmatism with myopic traits. A greater proportion of children exhibited compensation by IA than adults in J0 (86.6% vs. 66.0%, p < 0.0001) and J45 components (55.5% vs. 41.7%, p < 0.0001). CONCLUSIONS: Chinese children in Hong Kong exhibit a higher prevalence of RA and CA than in other cities. Children displayed a greater compensation by IA than adults, suggesting an age-related attenuation of IA compensation. IA is associated with myopic traits.

Increase in Bruch's membrane opening minimum rim width with age in healthy children: the Hong Kong Children Eye Study.

BACKGROUND/AIMS: To identify normative values and determinants for Bruch's membrane opening (BMO) and the minimum rim width of BMO (BMO-MRW) among healthy children. METHODS: A population-based cross-sectional study from the Hong Kong Children Eye Study, recruiting 1, 226 children aged 6-8 years. Spherical refractive error, axial length (AL), body mass index and intraocular pressure (IOP) were measured. The optic nerve head and the peripapillary retinal nerve fibre layer (p-RNFL) were imaged through spectral domain-optical coherence tomography, using 24 equally spaced radial B-scans. Global and sectoral BMO-MRW values, BMO area and fovea-to-BMO (FoBMO) angle were calculated. Multiple regression analysis was performed to define the determinants of BMO area and BMO-MRW in relation to demographic and ocular parameters. RESULTS: The mean values for global BMO-MRW, BMO area and FoBMO angle among children were 345.76±54.08 µm, 2.34±0.49 mm2 and -5.45±4.36°, respectively. Global and sectoral values for BMO-MRW correlated with p-RNFL thickness (r=0.11-0.35, p<0.001). After adjusting for demographic and ocular parameters, global BMO-MRW increased with age (ß=6.4, p<0.001) and greater global p-RNFL thickness (ß=1.41, p<0.001), but decreased with larger BMO area (ß=-47.46, p<0.001) and higher IOP (ß=-1.73, p<0.001). Global BMO-MRW did not associate with AL, whereas both BMO area and FoBMO angle associated with AL (ß=0.04, p=0.02 and ß=0.31, p=0.03, respectively), but not with age. CONCLUSION: We observed that BMO-MRW increases with age among children. Our results provide normative values and the determinants of BMO parameters among Chinese children.

Acute postoperative endophthalmitis after cataract operation: result of early vitrectomy within 24 hours of presentation.

OBJECTIVES: To evaluate result of early pars plana vitrectomy (PPV) within 24 hours of presentation for acute postoperative endophthalmitis after cataract operation, and to determine factors that predict visual outcome. METHODS: Consecutive patients who developed acute postoperative endophthalmitis within 6 weeks after cataract operation were reviewed. Patients were divided into two groups for analysis: (1) those receiving PPV within 24 hours of presentation (early PPV group), and (2) those receiving initial intravitreal antibiotics only without PPV within 24 hours of presentation (IVA group). RESULTS: Out of 41,411 cataract operations, 22 eyes developed acute postoperative endophthalmitis. Presenting VA was hand-movement or worse in 72.7%. The most common organisms were Staphylococcus (40.9%), Streptococcus (13.6%) and Enterococcus (13.6%). 22.7% of eyes had good final VA ≥ 20/30 and 27.3% had poor final VA < 20/400. Early PPV group had significantly lower rate of requiring additional treatments to control infection (25% versus 80%, P = 0.030), higher rate of retinal detachment (25% versus 0%, P = 0.221) and similar final logMAR VA (1.08 ± 1.08 versus 0.80 ± 0.80, P = 0.489) compared to IVA. Multivariate linear regression analysis showed that worse final VA was significantly associated with Streptococcus (ß = 1.92, P = 0.007) and retinal detachment (ß = 1.72, P = 0.005) but not with early PPV (P = 0.225). CONCLUSION: Early PPV was superior to initial intravitreal antibiotics alone as it required fewer additional treatments to control infection. Visual outcome was similar between early PPV and initial intravitreal antibiotics alone despite high number of poor presenting VA of light-perception in early PPV group. Streptococcal infection and retinal detachment were major poor prognostic factors for vision.

Effect of Myopic Undercorrection on Habitual Reading Distance in Schoolchildren: The Hong Kong Children Eye Study.

INTRODUCTION: This study aimed to evaluate the habitual reading distance among non-myopic children and also myopic children with undercorrection and with full correction. METHODS: This was a population-based cross-sectional study with a total of 2363 children aged 6-8 years who were recruited from the Hong Kong Children Eye Study. Cycloplegic autorefraction, subjective refraction, habitual visual acuity, and best corrected visual acuity were measured. The entire reading process (9 min) was recorded using a hidden video camera placed 5 m away from the reading desk. Reading distances were taken at 6, 7, 8, and 9 min after the child began reading and were measured using a customized computer program developed in MATLAB. The main outcome was the association of habitual reading distances with refraction status. Habitual reading distances of children were documented via video camera footage. RESULTS: The habitual reading distances of undercorrected myopic children (23.37 ± 4.31 cm) were the shortest when compared to non-myopic children (24.20 ± 4.73 cm, P = 0.002) and fully corrected myopic children (24.81 ± 5.21 cm, P < 0.001), while there was no significant difference between the last two children groups (P = 0.17). A shorter reading distance was associated with myopia (OR 1.67; 95% CI 1.11-2.51; P = 0.013) after adjusting for age, sex, height, near work time, outdoor time, and parental myopia. The association of reading distance with myopia did not hold after undercorrected myopic children were excluded (OR 0.97, 95% CI 0.55-1.73; P = 0.92). A shorter reading distance correlated with poorer vision under habitual correction (ß = - 0.003, P < 0.001). CONCLUSION: A shorter reading distance was present among undercorrected myopic children. Myopia undercorrection is not recommended as a strategy for slowing myopic progression.

Light exposure therapy for myopia control: a systematic review and Bayesian network meta-analysis.

AIMS: To compare and rank the myopia control effects of different light wavelengths in children using a systematic review and Bayesian network meta-analysis (Bayesian NMA). METHODS: The review protocol was registered with PROSPERO. We searched PubMed, EMBASE and MEDLINE for relevant clinical and animal studies published as of 2 February 2023. We included studies comparing red, violet or full-spectrum light with controls. Data extracted included descriptive statistics and study outcomes (axial length (AL) elongation and progression of spherical equivalent (SE) refraction). After quality assessment, estimates of treatment effect outcomes (mean differences (MDs) and 95% CIs) were first pooled for the animal and clinical studies in a traditional meta-analysis. To compare and rank the different light wavelengths, the Bayesian NMA was then conducted for all the included clinical studies (12 studies) and separately for only randomised controlled trials (8 studies). MDs, 95% credible intervals (CrIs) and ranks of the various light wavelengths were estimated in the Bayesian NMA. RESULTS: When all clinical studies were included in the Bayesian NMA (12 studies), only red-light significantly slowed AL elongation, MD (95% CrI), -0.38 mm (-0.59 mm to -0.16 mm)/year and SE refraction progression, 0.72D (0.35D to 1.10D)/year compared with controls. It remained the only significant intervention when effect sizes from only RCTs (eight studies) were separately combined, (-0.28 mm (-0.40 mm to -0.15 mm)/year and 0.57D (0.22D to 0.92D)/year, for AL and SE refraction, respectively). CONCLUSION: Myopia control efficacy varied among different wavelengths of light, with red light ranked as the most effective. PROSPERO REGISTRATION NUMBER: Clinical studies: CRD42022368998; animal studies: CRD42022368671.