Purpose. This study aimed to evaluate and compare the effect of cycloplegia on keratometric and biometric parameters in keratoconus patients and controls. Materials and methods. A preand post-interventional study was performed on 48 keratoconus (KC) patients diagnosed per Collaborative Longitudinal Evaluation of Keratoconus (CLEK’s) Classification and 41 age-matched controls. Full ophthalmological evaluations included refractive, keratometric, and biometric measurements with an auto kerato-refractometer (Topcon KR-800) and IOL MASTER 700, using 1% cyclopentolate hydrochloride for cycloplegia. Results. The study compared ocular measurements in KC patients and a control group before and after cycloplegia. KC patients exhibited significant changes in flat keratometry K1 (47.52 to 47.34), steep keratometry K2 (52.67 to 52.13), spherical equivalent (SE) (-6.35 to -5.5), lens thickness (LT) (3.49 to 3.44), anterior chamber depth (ACD) (3.75 to 3.84), and central corneal thickness (CCT) (446.78 to 450.72), all significant (p< 0.01), while axial length (AL) remained unchanged (23.5). The control group showed no significant differences in K1, K2, or AL, but SE, LT, ACD, and CCT exhibited significant changes. Conclusion. KC patients have a greater susceptibility to changes in corneal parameters post-cycloplegia compared to controls. These findings highlight the importance of careful evaluation in KC patients due to their distinct ocular responses to cycloplegia.

Cyclopentolate (CYP), an antimuscarinic (anticholinergic) agent, is pharmacologically employed in ophthalmology to induce cycloplegia (temporary paralysis of the ciliary muscle) and mydriasis (pupil dilation) for diagnostic and therapeutic procedures, including ocular examinations and surgeries. This study establishes a spectrofluorimetric method for quantifying CYP in ophthalmic solutions based on Resonance Rayleigh Scattering (RRS) signal modulation. The approach exploits the formation of an ion-associate complex between CYP and the dye erythrosine, which induces a measurable RRS enhancement. Critical experimental parameters governing the complexation and subsequent RRS response were systematically investigated and optimized. Under these established optimal conditions, a linear correlation existed between the enhanced RRS intensity and CYP concentration across the range of 40 to 1500 ng/mL. The method demonstrated a detection limit (LOD) of 13 ng/mL and a quantification limit (LOQ) of 39.5 ng/mL. Successful application to the assay of cyclopentolate in commercial eye drop formulations confirmed the method’s accuracy and precision. This RRS-based methodology utilizing erythrosine presents a straightforward, rapid, cost-effective, and environmentally favorable option for routine quality control and monitoring of CYP in pharmaceutical preparations.

ABSTRACT Clinical Relevance Cycloplegic refraction remains crucial in young adults, where accommodative activity can obscure accurate refractive status. Autorefractor repeatability is essential for precise optical correction and refractive error categorisation in clinical and research settings. Background Cycloplegic autorefraction is recommended for individuals up to 20 years to prevent hyperopia underestimation and myopia overestimation. This study evaluated differences between non-cycloplegic and cycloplegic spherical equivalent refraction following cyclopentolate hydrochloride (cycloplegic agent) administration in young adults. This study also explored whether this difference varied by refractive status (hyperopia (≥1.00D), emmetropia ( >−0.50, <1.00D), myopia (≤-0.50D)) or pre-instillation of proxymetacaine hydrochloride and whether cycloplegia improved autorefractor repeatability. Methods Participants were 182 young adults (17–30 years) (mean (standard deviation): 21.66 (2.86) years). The right eye received 0.5% proxymetacaine hydrochloride and one (blue/green irides) or two drops (brown/hazel irides) of 1.0% cyclopentolate hydrochloride. The left eye received cyclopentolate hydrochloride only. Autorefraction was performed before and after cycloplegia. Analysis included paired t-testing, Deming regression, Bland-Altman analysis and equivalence testing. Results Cycloplegic autorefraction was significantly more hyperopic than non-cycloplegic autorefraction (mean difference: 0.68(0.71) D in right eyes, 0.53(0.53) D in left eyes; p < 0.001) with 48.4% of participants exhibiting clinically significant differences of ≥ 0.50D. Agreement between non-cycloplegic and cycloplegic measurements was poor (limits of agreement: −0.71 D to +2.07 D, right eye). Hyperopes showed the greatest shift (1.39(0.91) D), compared to emmetropes (0.66(0.47) D) and myopes (0.31 (0.34) D). Cycloplegia improved repeatability, narrowing limits of agreement (−0.16 D to +0.15 D vs −0.24 D to +0.21 D). Proxymetacaine hydrochloride pre-instillation enhanced cycloplegic effect (+0.15 (0.07) D), particularly in hyperopic participants. Conclusions A clinically significant difference was observed between non-cycloplegic and cycloplegic autorefraction in young adult participants, particularly among hyperopes. Cycloplegic measurements showed better repeatability, supporting their use for accurate refraction. Further research is needed on potential enhancing effects of proxymetacaine hydrochloride, particularly in diverse populations.

A significant improvement in sustainability and efficiency is achievable through green and white chemistry. As part of this study, sustainability assessment tools were used to assess the environmental impact and practicality of an innovative, straightforward RP-UPLC method to analyze cyclopentolate (CLO) and its organic impurities simultaneously in pure and ophthalmic solutions at the same time. An optimization strategy based on Box–Behnken design was employed to minimize experimental runs while optimizing chromatographic conditions. Using this design, four critical variables were evaluated comprehensively—ethanol percentage in the mobile phase, pH, column temperature, and flow rate—on chromatographic responses such as retention time, resolution between CLO and impurity, and theoretical plate count. As a result of desirable and overlay plots, an optimal condition was selected: 65:25, v/v, ethanol and buffer, pH 4.25, 0.3 mL/min flow rate, and 4°C and 25°C sample and column oven temperatures, respectively, and the main peak retained for a little more than 3 min. The calibration curves for CLO and impurities at concentrations from 5 to 50 μg/mL and 1 to 20 μg/mL showed a correlation value of 0.9998. Recoveries are ±15% of the actual amounts, which is acceptable. RP-UPLC has been extensively designed for the coincidental estimation of anticholinergic drugs and their impurities. A combination of white and green tools was used to assess the method's environmental impact. ICH guidelines have been followed to validate the suggested strategy. This approach offers a reliable, fast, and eco-friendly solution for routine pharmaceutical quality control of anticholinergic agents.

Abstract In veterinary medicine, 1% Cyclopentolate hydrochloride (CP) has emerged as an intermediate-term cycloplegic and mydriatic agent. This study evaluated the pupillary dilation time and systemic effects related to the use of 1% CP eye drops in cats. Fifteen cats, aged 1 to 6 years and weighing 2.5 to 7 kg, were included in the study. After receiving written consent from the owners, each cat was administered two drops of 1% Cyclopentolate, 10 minutes apart, into both eyes. Data on pupil dilation, systemic symptoms, and behavioral changes were collected and analyzed using frequency and descriptive statistics. Pupillary dilation was observed 30 minutes after administering the second drop of 1% CP. The duration of pupillary dilation was 36 hours for 26.6% of the eyes, 48 hours for 53.4%, and 60 hours for 20%. Within the first hour after medication administration, seven cats exhibited episodes of salivation and vomiting, and four displayed behavioral changes, including aggressiveness and increased vocalization. Results suggest that 1% CP eye drops cause mydriasis for at least 36 hours and can lead to temporary adverse effects on the gastrointestinal and nervous systems.

Green and white chemistry are vital to revolutionizing the chemical industry through their unparalleled potential to enhance sustainability and efficiency. In this study, nine sustainability tools of both green and white metrics, including green analytical procedure index (GAPI), ComplexGAPI, analytical greenness, analytical greenness metric for sample preparation, Analytical Eco-Scale (ESA), analytical method greenness score, high-performance liquid chromatography- environmental assessment tool (HPLC-EAT), analytical method volume intensity, and blue applicability grade index (BAGI), have been developed for appraising environmental friendliness for both innovative and straightforward mean centering of ratio spectra (MCR) and reversed-phase high-performance liquid chromatography (RP-HPLC)strategies utilized for concurrent analysis and separation of cyclopentolate (CYC) and C12 and C14 homologs of benzalkonium chloride (BNZ) in pure and ophthalmic solution. The mobile phase, formed of buffer phosphate and acetonitrile (35:65, v/v), was adjusted to pH 6.3, and 215-nm UV detection was used. The experimental flow rate was 2.0 mL min-1, and the analytical column was L11 Inertsil Ph-3 (150 mm × 4.6 mm, 5 µm). All sequences were run at 25°C in the column oven. The MCR approach effectively resolved the drug's spectral overlapping. CYC and BNZ employed this approach at 227.5 and 220.4 nm, respectively. As part of the HPLC analysis, an isocratic method was employed with phosphate buffer and acetonitrile in the mobile phase at 35:65. A correlation coefficient greater than 0.999 was observed between the calibration curves for the HPLC and MCR methods in the ranges of 20-320 µg mL-1 and 5-30 µg mL-1 for all drugs. The technique yields excellent primary recovery rates, ranging from 97.2% to 100.5%. The recommended approach has been validated according to International Council for Harmonizationguidelines.

Physiological adaptation of the eye to the visual perception of near objects consists of the "near triad": convergence, accommodation, and pupil miosis. Normally, these tend to revert when one stops fixating on a near object. Spasm of the near reflex (SNR) is a pathological phenomenon, which manifests itself by the persistence of the above-mentioned adjustments, which prevents the eye from returning to its relaxed state. In this narrative review, we aim to summarize the etiology, diagnostics, treatment, and prevention of SNR. The literature review was performed by searching online databases. The clinical presentation of SNR is diverse; it presents as isolated accommodative spasm more frequently than impairment of all three components of the near triad. Patients usually present with fluctuations in visual acuity, blurred vision, diplopia, and asthenopia. The etiology is not fully understood. Potential causes include neuroanatomic, organic, and psychogenic disorders. The diagnosis is clinical, based on the constellation of symptoms and assessment of the near triad. The diagnostic golden standard is a cycloplegic examination of refraction, preferably using cyclopentolate hydrochloride (1%, 0.5%, or 0.1% solution). The first-line treatment requires the administration of a cycloplegic drug in combination with plus lenses, flipper lenses, optical fogging, or miotics. For secondary cases, causal treatment should be implemented. Prevention of SNR should be based on eliminating modifiable risk factors. We propose including screening for SNR symptoms in every ophthalmic examination, especially among patients with psychogenic or neural disorders, after brain trauma, or young adults spending much time in front of computer screens.

Cycloplegic refraction is considered the gold standard method when examining children and for ensuring accurate refractive error assessment within epidemiological studies. Recent reports underline that cycloplegia is equally important for ensuring accurate refractive error assessment in Chinese adolescents and young adults (Sun et al., 2018). The aim of this study was to assess whether cycloplegia is of equal importance for refractive error assessment in Norwegian adolescents and young adults. Non-cycloplegic and cycloplegic autorefraction (Huvitz HRK-8000A), and cycloplegic ocular biometry (IOLMaster 700), were undertaken in 215 Norwegian adolescents (101 males) aged 16–17 years. Topical cyclopentolate hydrochloride 1% was used for cycloplegia. Two years later, autorefraction and ocular biometry were repeated in 93 of the participants (34 males), both non-cycloplegic and cycloplegic. Non-cycloplegic spherical equivalent refractive errors (SER = sphere + 1⁄2 cylinder) were more myopic (less hyperopic) than cycloplegic SER in 93.6% of the participants (overall mean ±SD difference in SER: -0.59 ±0.50 D, 95% limit of agreement: -1.58 – 0.39 D). Refractive error classification by non-cycloplegic SER underestimated the hyperopia frequency (10.4% vs. 41.4%; SER ≥ +0.75 D) and overestimated the myopia frequency (12.1% vs. 10.7%; SER ≤ -0.75 D), as compared with refractive error classification by cycloplegic SER. Mean crystalline lens thickness decreased and mean anterior chamber depth increased with cycloplegia, with the largest changes in the hyperopes compared with the emmetropes and myopes (p ≤ 0.04). The individual differences between non-cycloplegic and cycloplegic SER varied by more than ±0.25 D between first and second visit for 31% of the participants. Accurate baseline measurements — as well as follow-up measurements — are imperative for deciding when and what to prescribe for myopic and hyperopic children, adolescents, and young adults. The results here confirm that cycloplegia is necessary to ensure accurate measurement of refractive errors in Norwegian adolescents and young adults.

Fungal keratitis is a medical emergency that is among the most common causes of blindness in developing countries. The type of the agent may vary depending on the geographical conditions under which the patient lives, trauma exposure, the use of contact lenses and profession. Curvularia spp. is a saprophytic genus that rarely causes systemic disease in humans and has 250 species identified to date. They proliferate in soil and plants and spread to the environment with their spores and the formation of blackish and fluffy colonies is its most well-known morphological feature. There may be difficulties in cultivating brown (dematiaceous) fungi. Due to the similarity between the genera, conventional methods remain inadequate for diagnosis. In this report, a case of fungal keratitis associated with C.lunata was presented. Seventy-five years-old female patient admitted to the hospital with the symptoms of stinging pain, blurred vision, and swelling in the right eye. Her symptoms had begun four days ago after her eye was hit by a plant. The patient who had a history of peripheral neuropathy due to diabetes mellitus (DM) was hospitalized with a preliminary diagnosis of keratitis, and in the cultures of the patient's corneal scraping samples, the filamentous, black pigment-forming colonies of the pathogen growing on 5% sheep blood agar and potato dextrose agar showing an aerial hyphal structure, were stained with lactophenol cotton blue and examined under the microscope. The microscopic examination revealed geniculate conidiophores with brown pigmentation. On top of these structures were tetralocular macroconidia, one of which appeared to be larger than the main axis. The fungus was subjected to molecular identification with the prediagnosis of Curvularia/Bipolaris. DNA extraction of the ITS region polymerase chain reaction amplification and Sanger sequencing were performed for molecular identification. Sanger sequencing identified the agent to be Curvularia lunata with a similarity rate of 99.79% (NCBI-GenBank Nucleotide ID: OR365075). In vitro antifungal susceptibility of C.lunata was evaluated by microdilution method. Itraconazole and amphotericin B showed higher activity against C.lunata compared to other antifungals while fluconazole was the least active antifungal. Intrastromal and subconjunctival voriconazole injection was applied to the patient who was unresponsive to empirically initiated oral moxifloxacin and different topical treatments (vancomycin, ceftazidime, flucanozole, ganciclovir, cyclopentolate hydrochloride, hyaluronic acid and trehalose). After injection, right penetrating keratoplasty was applied due to increased thinning of the ulcerated area. No pathogen was detected in cultures taken after keratoplasty. Rare fungi should be considered in cases of keratitis that are difficult to treat. Fungal keratitis caused by brown fungi are clinically similar to each other and effective treatment protocols cannot be implemented without a species identification. Identification of the pathogen will enable genus-specific treatment. This will also help prevent complications that may occur. This article aims to present a case of fungal keratitis associated with C.lunata.

Objective: The study aimed to evaluate the effect of cycloplegia on the ocular biometric parameters and intraocular lens (IOL) power calculated by Sanders–Retzlaff–Kraff/Theoretical (SRK/T) formula in the cataractous eyes. Materials and Methods: This cross-sectional study included 68 senile cataractous eyes of 68 patients scheduled to undergo cataract surgery. Measurements of anterior chamber depth (ACD), axial length (AL), white-to-white (WtW) diameter, keratometry (K1, K2, Kmean), central corneal thickness (CCT), and pupil size (PS) were obtained with AL-Scan (Nidek Co., Ltd, Gamagori, Japan) before and after cycloplegia. The SRK/T formula was used to calculate IOL power with target refraction of 0 D. Cycloplegia induced by cyclopentolate hydrochloride %1. Results: The mean age of the patients was 70.60±4.07 years (range 65 to 80). A significant increase was observed in ACD after cycloplegia (p&amp;lt; 0.001). There was no statistically significant difference between pre-dilation and post-dilation AL, WtW, CCT, K1, K2, Kmean, and IOL power readings (p&amp;gt; 0.05). Two cases observed a decrease above 0.5 D of IOL power after cycloplegia. Conclusions: Cycloplegia induced by cyclopentolate hydrochloride %1 does not affect the measurement of the AL, WtW, CCT, keratometry, and SRK/T calculated IOL power except ACD in senile cataractous eyes.

More time spent on near tasks has consistently been associated with the promotion of myopia. The World Health Organization advises limiting daily screentime to less than 2h for children aged five and over. This study explored the relationship between time spent on screens and reading/writing with refractive status, ocular biometric and anthropometric factors in 6- to 7-year-olds in Ireland. Participants were 723 schoolchildren (377 boys [51.8%]), mean age 7.08 (0.45) years. The examination included cycloplegic autorefraction (1% cyclopentolate hydrochloride), ocular biometry (Zeiss IOLMaster), height (cm) and weight (kg). Screentime and reading/writing time were reported by parents/legal guardians by questionnaire. Myopia (≤-0.50D) and premyopia (>-0.50D ≤ 0.75D) risk assessments were performed using logistic regression, and multivariate linear regression was used to analyse continuous variables. Reported daily screentimes were 31% <1h, 49.5% 1-2h, 15.6% 2-4h and 3.9% >4h. Reading/writing times were 42.2% frequently, 48.0% infrequently and 9.8% seldom/never. Linear regression, controlling for age and ethnicity, revealed >2h/day on screens was associated with a more myopic spherical equivalent [β=-1.15 (95% confidence intervals {CIs}: 1.62-0.69, p < 0.001)], increased refractive astigmatism (β=0.29, CI: 0.06-0.51, p=0.01), shorter corneal radius (β=0.12, CI: 0.02-0.22, p=0.02), higher axial length/corneal radius (β=0.06, CI: 0.03-0.09, p < 0.001), heavier weight (β=1.60, CI: 0.76-2.45, p < 0.001) and higher body mass index (BMI) (β=1.10, CI: 0.28-1.12, p < 0.001). Logistic regression, controlling for age and ethnicity, revealed daily screentime >2h was associated with myopia (OR=10.9, CI: 4.4-27.2, p=0.01) and premyopia (OR=2.4, CI: 1.5-3.7, p < 0.001). Frequent reading/writing was associated with screentime ≤2h/day (OR=3.2, CI: 1.8-5.8, p < 0.001). Increased screentime was associated with a more myopic refraction, higher axial length/corneal radius ratio, increased odds of myopia, premyopia, higher degrees of astigmatism, increased weight, BMI and decreased reading/writing time. Dedicated education programmes promoting decreased screentime in children are vital to prevent myopia and support eye and general health.

ABSTRACT Clinical Relevance Reducing the time between drop instillation and refraction reduces the time paediatric patients and young adults spend in practice, facilitating more eye examinations daily. Background The current procedure for paediatric cycloplegic refraction is to wait for at least 30-minutes post-instillation of a cycloplegic before measuring spherical equivalent refraction. This study compared cycloplegia at 20- and 30-minutes following 0.5% proxymetacaine and 1.0% cyclopentolate in 12-13-year-olds. Methods Participants were 99 white 12-13-year-olds. One drop of proxymetacaine hydrochloride (Minims, 0.5% w/v, Bausch & Lomb, UK) followed by one drop of cyclopentolate hydrochloride (Minims, 1.0% w/v, Bausch & Lomb, UK) was instilled into both eyes. Spherical equivalent refraction was measured by autorefraction (Dong Yang Rekto ORK-11 Auto Ref-Keratometer) at 20- and 30-minutes post-instillation. Data were analysed through paired t-testing, correlations, and linear regression analysis. Results There was no significant difference in level of cycloplegia achieved at 20- (Mean spherical equivalent refraction (standard deviation) 0.438 (1.404) D) and 30-minutes (0.487 (1.420) D) post-eyedrop instillation (t (98) = 1.667, p = 0.099). The mean spherical equivalent refraction difference between time points was small (0.049 (0.294) D, 95% confidence interval =-0.108 ̶ 0.009D). Agreement indices: Accuracy = 0.999, Precision = 0.973, Concordance = 0.972. Spherical equivalent refraction at 20- and 30-minutes differed by ≤0.50D in 92% of eyes, and by <1.00D in 95%. Conclusions There was no clinically significant difference in spherical equivalent refraction or level of cycloplegia at 20- and 30-minutes post-eyedrop instillation. The latent time between drop instillation and measurement of refractive error may be reduced to 20 minutes in White 12-13-year-olds and young adults. Further studies must determine if these results persist in younger children and non-White populations.

In this study, it is aimed to investigate the effects of intracameral mydriatic combinations on the pupil dilation (PD), intraocular pressure (IOP), heart rate (HR) and mean arterial pressure (MAP). In this study 35 animals were divided into 5 groups. The first group (MSic) was phenylephrine hydrochloride (Mydfrin) and cyclopentolate hydrochloride (Sikloplejin), the second group (TLic) was tropicamide (Tropamid) and 2% lidocaine, the third group (BSS) was balanced salt solution. Cats were anesthetized, and all solutions were injected intracamerally. The fourth group (MSt) was phenylephrine hydrochloride (Mydfdrin) and cyclopentolate hydrochloride (Sikloplejin) and the fifth group (TLt) tropicamide (Tropamid) and 2% lidocaine were given by topically. During this research, the fastest onset of the mydriasis was numerically formed by first group. All intracameral groups were seen having longer duration of mydriasis compared to topical groups. Intraocular pressure decreased after anterior camera paracentesis in all intracameral procedures. In our study, time dependent changes of heart rate were found to be statistically significant in all groups. Our research observed that first and second group successfully created enough mydriasis (&gt;10mm). In terms of pupil diameter, it has been proven that first and second group are usable alternatives administration, and no side effects on intraocular pressure, heart rate or mean arterial pressure.

ObjectiveThe NETRA (Near Eye Tool for Refractive Assessment) is a smartphone-based refractive tool that allows for self-evaluation of refractive error. This study investigates the validity of the NETRA with and...

The main aim of this study was to compare refraction measurements with and without cycloplegia from two refractors devices, (TRK-2P autorefractometer (TRK-2P) and wavefront-based refraction Visionix 130 (VX130)) in children and adolescents. This descriptive observational study included 20 myopic eyes and 40 hyperopic eyes measured in two different Spanish hospitals. Cycloplegia was carried out by three drops of cyclopentolate hydrochloride 1% (Colircusí cycloplegic, Alcon Healthcare S.A., Barcelona). The mean age of the myopia group was 12.40 ± 3.48 years; for the hyperopia group, the mean age was 7.37 ± 2.47 years. In the myopia group, autorefraction and wavefront-based refraction did not show clinically significant differences in any components between with and without cycloplegia. The hyperopia group showed statistical and clinically significant differences in sphere and SE components between relaxed and non-relaxed states of accommodation, although the cylindrical components were not clinically different. In this study, we considered a value of ≥0.50D as a clinically significant difference in refraction. Therefore, both devices were capable of obtaining accurate refractions without cyclopegia in myopia children, although they did not avoid instrument myopia and accommodation involved in hyperopia children. Moreover, both refractometers could be useful for astigmatism monitoring in children without the need for cycloplegic drops.

Cyclopentolate hydrochloride (CH) is a topical agent used in ophthalmological examinations for mydriasis whose both ocular and systemic side effects can occur after administration. In children, the risk of intoxication increases depending on many risk factors such as smaller body mass index or being severely ill. After the administration of CH ophthalmic solution in the ophthalmology outpatient clinic, an 8-year-old patient with complaints of speaking difficulties and flushing was admitted to the pediatric emergency department. Tachycardia, bilateral mydriasis, and dysarthria were detected and she was diagnosed with the anticholinergic syndrome. Neurological findings improved after 3 hours and mydriasis after 30 hours. It should be taken into consideration that systemic effects may occur as a result of cyclopentolate topical drug application, especially in children, even at an appropriate dose.

Comparison of the Effects of 1% Atropine and 1% Cyclopentolate Hydrochloride on Refractive Errors and Anterior Chamber Depth in Horses

Objective: To investigate the longitudinal epidemiological characteristics of myopia in primary school students from grade one to grade three in Hubei province, and to analyze the main factors affecting the occurrence and development of myopia, so as to provide the direction and theoretical basis for the prevention and control of myopia in children and adolescents. Methods: Longitudinal study. A total of 13, 244 primary school students from grade one to grade three in 17 prefectures and forest districts of Hubei province were included in the study by means of random stratified cluster sampling. Among them, there were 7, 331 boys and 5, 913 girls with an age of (7.7±1.0) years. The same group of students were followed up for two years from October 2017 to October 2019 to complete three data collections. All included subjects underwent visual acuity examination, which required further automatic computer optometry after using cyclopentolate hydrochloride eye drops if the visual acuity was less than 1.0. In the questionnaire, the general situation and eye behavior of the included subjects were collected. The Chi-square test was used to compare the prevalence of myopia among different genders,different reproductive history and grades. The Kruskal-Wallis H test was used to compare the difference in the mean spherical equivalent refraction, and logistic regression was used to analyze the influencing factors of myopia. Results: The prevalence of myopia was 23.10% at baseline in 2017, 28.67% after one year's follow-up and 33.26% after two years' follow-up among primary school students in grade one to grade three in Hubei province. The overall prevalence of myopia increased with time (χ²=307.47, P<0.05). It also increased with the increase of grades. After two years of follow-up, the myopia rate of students in grades one through three was 25.62%, 35.07% and 41.05%, respectively (χ²=200.98, P<0.05). In 2017, the prevalence of myopia was 21.62% in boys and 24.93% in girls, and it increased to 31.20% and 35.69% after 2 years of follow-up, respectively. Both the prevalence of myopia and the spherical equivalent refraction were higher in girls than in boys. Moreover, myopia was associated with parents' myopia (OR=1.17), less time for outdoor activities (OR=1.06), no rest after half an hour's study (OR=1.18), more time for daily exposure to electronic products (OR=1.07), longer time for extracurricular study (OR=1.09), and higher grades (OR=1.78). Children whose parents were more myopic and who ate sweets and fizzy drinks more often had greater levels of myopia. Conclusions: Myopia occurs early in primary school students of grade one to grade three in Hubei province and increases rapidly. More attention should be paid to good habits for eyes, regular screening, outdoor activities and girls. (Chin J Ophthalmol, 2021, 57: 749-756).

To evaluate related factors with the change of spherical equivalents (ΔSE) and determine the suitable predictor of clinically significant ΔSE (≥0.50 D) with cyclopentolate hydrochloride on Chinese children. A total of 145 right eyes of 145 children aged 4 to 15y were enrolled. Intraocular pressure, axial length and lag of accommodation (LOA) were assessed before cycloplegia induced by 3 drops of 1% cyclopentolate at 5-minute intervals. SE was measured before and 1h after the first drop of cyclopentolate. ΔSE was compared between different gender groups and among refractive groups. Multivariate linear regression analysis was performed to find related factors with ΔSE. ROC analysis was used to figure out the suitable predictor of clinically significant ΔSE. For the total 145 eyes, the mean SE reached up to -0.70±1.86 D from -1.30±1.62 D, with the mean ΔSE of 0.60±0.55 D. The mean ΔSE were 0.63±0.55 D and 0.57±0.56 D respectively in the male and female group (P=0.40). The mean ΔSE was significantly different among different refractive groups (P<0.0001), with the ΔSE of hyperopia group (1.12±0.64 D) larger than that of the emmetropia (0.56±0.43 D, P=0.001) and myopia group (0.32±0.28 D, P<0.0001). The ΔSE was correlated with LOA (B=-0.54, P<0.0001), cycloplegic SE (B=0.10, P<0.0001) and age (B=-0.04, P=0.015). ROC curve indicated that LOA predicted clinically significant ΔSE by 82% [area under the curve (AUC)=0.82] alone, while the value was slightly improved to 85% (AUC=0.85) in combination with axial length and 86% (AUC=0.86) in association with axial length as well as age. After cycloplegia with cyclopentolate, the ΔSE decreases with larger LOA, longer axial length and older age. Specifically, LOA plays a more vital role in predicting clinically significant ΔSE.

This study aims to assess the effects of topical tropicamide 1% versus cyclopentolate hydrochloride 1% on the main numerical anterior chamber angle parameters using anterior segment optical coherence tomography (AS-OCT) in myopic, emmetropic, and hyperopic pediatric populations. One hundred eight healthy and non-amblyopic children were enrolled in this prospective study. The children were assigned into three refractive groups of myopia, emmetropia, and hyperopia for both tropicamide and cyclopentolate administrations. Half of the children in three groups were instilled tropicamide 1%, and the remaining halves were instilled cyclopentolate hydrochloride 1%. AS-OCT measurements of the anterior chamber angle in three groups were performed at the temporal areas of the right eyes under similar conditions at baseline, 30min after tropicamide, and 45min after cyclopentolate instillations. Main measurements including the angle-opening distance at 500µm anterior to the scleral spur (AOD500), trabecular iris space area at 500µm anterior to the scleral spur (TISA500), and scleral spur angle (SSA) were compared between three refractive groups. The groups were age and gender-matched. The mean baseline spherical equivalents were similar in hyperopia groups of the tropicamide (+2.34 ± 0.44) and cyclopentolate (+2.18 ± 0.32) administrations (p = 0.284), as well as the myopic children administered with tropicamide (-2.68 ± 0.40) and cyclopentolate (-2.74 ± 0.38), (p = 0.406). All baseline measurements of AOD500, TISA500, and SSA measurements were similar in three refractive groups for both tropicamide and cyclopentolate as well as the final measurements and thus measurement changes between two sessions (P >0.05 for all). Both drops induced an increase of AOD500, TISA500, and SSA measurements in three refractive groups (p <0.05 for all). Cycloplegic effects of topical instillations of tropicamide and cyclopentolate lead to a significant increase in anterior chamber angle measurements of AS-OCT. This similar effect of the drops should be considered for proper clinical assessment in children.