Association of sleep timings, duration, consistency, and chronotype with premyopia and myopia among Indian children.

BACKGROUND: To explore the association of sleep timings, duration, consistency, and chronotype with premyopia and myopia among Indian children. METHODS: This hospital-based cross-sectional study included 453 children, aged 6-12 years. Two myopia participants were selected for each individual with the corresponding premyopia or emmetropia. All children underwent cycloplegic autorefraction and ocular biometric tests. The Children's Sleep Habits Questionnaire (CSHQ) and parental information on behavioral habits were used to assess the association of sleep parameters with myopia and premyopia using logistic regression models. RESULTS: Both myopia and premyopia exhibited significant late bedtime, short sleep duration, early wakeup time on only weekdays, and longer weekend catch-up sleep than emmetropia children (p < 0.05). In multivariate analysis, late bedtime (more than 24:00 a.m.) on weekdays (Odds ratio, OR = 3.63, 95% CI [0.74, 8.68]) as well as on free days (OR = 1.04, 95% CI [0.02, 8.08]); and early wake-up time only on weekdays (5:00-6:00 a.m., OR = 2.16, 95% CI [0.24, 6.76] and 06:00-07:00 a.m., OR = 2.42, 95% CI [0.51, 8.44]) were associated with increased risk of myopia (all p < 0.05) but not premyopia. After adjusting the confounding factors, when each of the eight CSHQ subscale components was analyzed, only bedtime resistance, night waking, and daytime sleepiness scores were significantly associated with a higher risk for premyopia and myopia (p < 0.05). CONCLUSIONS: The sleep quality components, including bedtime resistance, night waking, and daytime sleepiness, equally involve a higher risk for myopia as well as premyopia.

Associations between systemic melatonin and human myopia: A systematic review.

PURPOSE: Experimental models have implicated the role of melatonin circadian rhythm disruption in refractive error development. Recent studies have examined melatonin concentration and its diurnal patterns on refractive error with equivocal results. This systematic review aimed to summarise the literature on melatonin circadian rhythms in myopia. RECENT FINDINGS: PubMed, EMBASE, Web of Science, Scopus, ProQuest Central, LILACS, Cochrane and Medline databases were searched for papers between January 2010 and December 2022 using defined search terms. Seven studies measured melatonin and circadian rhythms in three biological fluids (blood serum, saliva and urine) in both myopes and non-myopes. Morning melatonin concentrations derived from blood serum varied significantly between studies in individuals aged 10-30 years, with a maximum of 89.45 pg/mL and a minimum of 5.43 pg/mL using liquid chromatography and mass spectrometry. The diurnal variation of salivary melatonin was not significantly different between myopes and emmetropes when measured every 4 h for 24 h and quantified with enzyme-linked immunosorbent assay. Significantly elevated salivary melatonin concentrations were reported in myopes compared with emmetropes, aged 18-30 years when measured hourly from evening until their habitual bedtime using liquid chromatography. However, the relationship between dim light melatonin onset and refractive group was inconsistent between studies. The 6-sulphatoxymelatonin concentration derived from overnight urine volume, measured using a double antibody radioimmunoassay, was found to be significantly lower in myopes (29.17 pg/mL) than emmetropes (42.51 pg/mL). SUMMARY: The role of melatonin concentration and rhythm in myopia has not been studied extensively. This systematic review confirms conflicting findings across studies, with potential relationships existing. Future studies with uniform methodological approaches are required to ascertain the causal relationship between melatonin dysregulation and myopia in humans.

Progression pattern of non-amblyopic Anisomyopic eyes compared to Isomyopic eyes.

This study aimed to determine the progression pattern of non-amblyopic anisomyopic children from ages 6 to 16 years. This retrospective study analyzed the electronic medical records of 8680 myopic children who visited Sankara Nethralaya, Chennai, India over eight years (2009 to 2017). A total of 711 records were retrieved based on inclusion criteria. In addition, 423 records out of 711 had consecutive follow-up for three years (baseline plus three follow-up visits) and were considered to determine the progression pattern. The cycloplegic sphero-cylindrical refraction was taken for analysis and converted to vector notation of M (SE), J0, and J45. Anisomyopia referred to the interocular difference of myopic SE of ≥ 1 D whereas isomyopia referred to the interocular difference of myopic SE of < 1 D. Based on the refraction of the less ametropic eye, anisomyopes were further categorized into bilateral anisometropic myopia (BAM) and unilateral anisometropic myopia (UAM). The isomyopic cohort showed a mean annual progression of -0.49 ± 0.54 D (median [IQR] -0.38 D [{-0.75}-0.00]). In BAM, the mean annual progression of the more myopic eye was -0.45 ± 0.55 D (median [IQR] -0.38 D [{-0.75}-0.00]), and the less myopic eye was -0.37 ± 0.55 D (median [IQR] -0.25 D [{-0.63}-0.00]). This difference was significant (t (212) = -2.14, p < 0.05). In UAM, the myopic eyes (-0.39 ± 0.51 D; median [IQR] -0.25 D [{-0.75}-0.00]) showed a statistically significant higher mean annual progression compared to emmetropic eyes (-0.22 ± 0.36 D; median [IQR] 0.00 D [{-0.44}-0.00]; t (96) = -3.30, p < 0.001). In terms of progression trend, in the BAM group, the rate of change of mean SE between the more myopic and the less myopic eyes were similar (-1.12 ± 1.20 D; median [IQR] -1.13 D [{-2.00}-{-0.38}] vs. -1.05 ± 1.25 D; median [IQR] -0.88 D [{-1.75}-{-0.13}]; t (138) = -0.64, p > 0.05). However, the more myopic eyes of UAM showed a higher myopic trend compared to the emmetropic eyes (-1.37 ± 1.06 D; median [IQR] -1.32 D [{-2.13}-{-0.50}] vs. -0.96 ± 1.11 D; median [IQR] -0.75 D [{-1.56}-{-0.25}]; t (61) = -2.74, p < 0.05).   Conclusion: Children with BAM and UAM eyes exhibit different progression patterns from each other. While the rate of the refractive shift in myopic eyes of UAM is similar to isomyopic eyes, BAM eyes present a slower rate of progression than isomyopic eyes. What is Known: • The rate of change of refraction in anisomyopes is higher compared to isomyopic children. • Less myopic eyes tend to shift towards more myopia while more myopic eyes show stable refraction. What is New: • The progression pattern of bilateral anisometropic myopia and unilateral anisometropic myopia differ from one another. • While the rate of the refractive shift in myopic eyes of unilateral anisometropic myopia is similar to isomyopic eyes, bilateral anisometropic myopia eyes present a slower rate of progression than isomyopic eyes. • The pattern of change in the interocular difference of anisometropia depends on the laterality (bilateral or unilateral ametropia), and degree of spherical equivalent in the more ametropic eye.

Effectiveness of 0.01% atropine in anisomyopic children.

Purpose: To investigate the change in ocular parameters of anisomyopic children treated with 0.01% atropine. Methods: This retrospective study analyzed the data of anisomyopic children who underwent comprehensive examination at a tertiary eye center in India. Anisomyopic subjects (difference of ≥1.00 D) of age 6-12 years who were treated with 0.01% atropine or prescribed regular single vision spectacle and had follow-ups of more than 1 year were included. Results: Data from 52 subjects were included. No difference was observed in the mean rate of change of spherical equivalent (SE) of more myopic eyes between 0.01% atropine (-0.56 D; 95% confidence interval [CI]: -0.82, -0.30) and single vision lens wearers (-0.59 D; 95% CI: -0.80, -0.37; P = 0.88). Similarly, insignificant change in the mean SE of less myopic eyes was noted between the groups (0.01% atropine group, -0.62 D; 95% CI: -0.88, -0.36 vs. single vision spectacle wearer group, -0.76 D; 95% CI: -1.00, -0.52; P = 0.43). None of the ocular biometric parameters showed any difference between the two groups. Though anisomyopic cohort treated with 0.01% atropine revealed a significant correlation between the rate of change of mean SE and axial length in both eyes (more myopic eyes, r = -0.58; P = 0.001 and less myopic eyes, r = -0.82; P < 0.001) compared to single vision spectacle wearer group, the change was not significant. Conclusion: Administration of 0.01% atropine had minimal effect on reducing the rate of myopia progression in anisomyopic eyes.

RETRACTED: Young adults with myopia have lower concentrations of neuromodulators-dopamine and melatonin in serum and tear.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors, as questions have arisen in the interim regarding the validity of some of the methods and therefore the results. The authors have provided the following statement: "We have addressed a question raised by the reader on the higher levels of dopamine and melatonin in serum and tear levels reported in this study in Myopia along with controls. Serum and tear levels of dopamine and melatonin in Myopia cases were estimated by HPLC (UV detector) is reported by us in a higher order of magnitude (ng/mL) in both specimens compared to most of the reported data (pg/mL) that are reported based on LC/MS/MS or kit based immunoassay(pg/mL). The sample extraction protocol that we followed before estimation of the analytes was based on removing protein by precipitation methods with no further purification by liquid/liquid extraction/use of SPE cartridges as reported in other published reports. This could have possibly extracted related compounds, such as the closely related indoles in the case of melatonin extraction; the other Dopamine related metabolites respectively. The possibility of confounding by other metabolites in our estimation has not been ruled out by any targeted analysis. This we agree is a limitation in the specificity of the protocol we have followed that may have contributed to the nmol range of detection. We have done the HPLC method of analysis and detection (UV) and not LC-MS/MS or immunoassays by kit method whose sensitivity and specificity are reportedly higher based on the range of testing reported in serum. The lower detection limit of our protocol was not in pg/mL but in ng/mL. Parity in the levels reported was discussed in the manuscript attributing to the analytical method adopted and interpretation based on relative changes. Amongst ocular fluids, Aqueous humor by similar HPLC analysis reportedly shows up to 200 ng/ml in literature (Alkozi, H. et al 2017). However, based on our serum data, we feel that further validation studies and method comparisons are required. The method of estimation of the neurotransmitters HPLC (UV detection) seems to have influenced the absolute levels of dopamine and melatonin in the cases and controls studied and therefore casts doubts on the validity of these data. Though further interpretations can be made on relative changes, we decide to withdraw our paper, to work further on the method comparison. We sincerely apologize for the inconvenience to the readers."