The gap between parental knowledge and children practice of myopia control and challenge under COVID-19: a web-based survey in China.

Objective: To evaluate parental knowledge of myopia control, investigate its association with children's practice and refractive status, and explore their change under the outbreak of COVID-19 pandemic. Methods: In this web-based survey, a self-administered questionnaire was made online available during the COVID-19 outbreak between February 1th, 2022 and August 31th, 2022 in China. Participants were recruited via social media by convenience and snowball sampling. Parents of both sexes whose children aged between 3 and 18 were eligible. The overall questionnaire was composed of four categories: demographic information, parental knowledge of myopia, children's myopia-related behaviors and their change after the COVID-19 pandemic, and children's refractive status. SPSS version 18.0 was applied to perform the statistics analysis and p < 0.05 was considered to be statistically significant. Results: A total of 423 eligible families were included in our online survey. The average age of children was 11.37 ± 2.83y (male 46.1%; female 53.9%), with a myopia incidence of 83.9% (355/423). Both children's age (OR = -0.6; 95%CI = -1.12 to -0.07; p = 0.026) and family income (OR = 2.60; 95%CI = 1.13 to 4.07; p = 0.001) had independently significant impacts on parental knowledge. Unexpectedly, parental knowledge was negatively correlated with children's onset age of myopia (p = 0.002, r = -0.165) and positively correlated with spectacles wearing (p = 0.014, r = 0.131), and no correlation was found between parental knowledge and the occurrence of children myopia, current diopter, annual myopia progression and the diopter of the first glasses (all p > 0.05). We found discordance phenomenon between parents' knowledge and children's behaviors, with parental knowledge being irrelevant to children's sleeping time (p = 0.159, r = 0.069), the frequency of lying reading (p = 0.462, r = -0.036) and keeping nutrition diet (p = 0.142, r = 0.072), and positively correlated with daily homework time (p = 0.012, r = 0.123). After the outbreak of COVID-19, 77.8% (329/423) of parents admitted that their children's daily routine had been changed, with children spending more time on sleeping (p < 0.001) and electronic products (p < 0.001), and taking less time to do outdoor activities (p < 0.001). Conclusion: The ideal interaction mode that establishing positive impact between parental knowledge and children practice has not been reached in China, which might be the result of insufficient parents' cognition and discordance phenomenon between parental knowledge and children's behaviors. The pandemic of COVID-19 has obviously changed children's daily routine. More efforts should be made to narrow the gap between knowledge and behaviors of myopia control, and stay alert to the potential increased risk of myopia during COVID-19.

The effects of refractive status on the outcomes of strabismus surgery in patients with esotropia.

BACKGROUND: The success of the strabismus surgery can hinge on several factors. One of these factors is refractive condition like hyperopia or myopia. Our study seeks to evaluate the surgical outcomes in patients with esotropia and myopia. METHODS: This case-control study encompassed all surgical cases of esotropia at Torfe and Negah Hospital between 2016 and 2021, which satisfied our specified inclusion criteria. The initial variables from electronic medical records were collected, including demographic, clinical, and surgery-related factors. At the final follow-up appointment, the level of eye deviation, both at distance and near, was recorded. We considered the operation a "success" for patients with a post-surgery distance eye deviation of 10(Pd) or less. Patients with greater deviation were classified as surgery failure. Statistical analyses were executed using SPSS software (version 16.0), and a P-value less than 0.05 was considered significant. RESULTS: Of the 194 patients evaluated, 112 were incorporated into the study. Surgical failure was observed in 14.29% of myopic patients, 29.79% of hyperopic patients, and 31.82% of emmetropic patients. The myopia group displayed a 0.19 odd ratio for surgical failure compared to the combined hyperopia and emmetropia groups, not statistically significant (OR: 0.19, CI 95%: 0.03-1.02). Additionally, patients diagnosed with Lateral Rectus Under-action were found to be 6.85 times more likely to experience surgery failure(OR: 6.85, CI 95%: 1.52-30.94). An elevated risk of surgical failure was also identified in patients who underwent Inferior Oblique Weakening procedure, indicated by a 3.77-fold increase in the odds ratio for failure(OR: 3.77, CI 95%: 1.08-13.17). CONCLUSION: In our study, despite numerical disparities, there was no statistical difference among the success rates of all esotropia patients with different refractive errors. The patients with LRUA or IOOA showed lower success rates. Myopic patients had higher post-op overcorrection with lower reoperation rates compared to hyperopic or emmetropic patients.

Impact of Refractive Status on Presbyopia Progression among Patients with Presbyopia.

PURPOSE: To explore the impact of refractive status on presbyopia progression among patients with presbyopia. METHODS: This retrospective observational study included patients with presbyopia who visited the Seventh Affiliated Hospital of Sun Yat-sen University and Shenzhen Polytechnic Medical College between May 2018 and August 2022. The amplitude of accommodation (AMP) and near addition power (ADD) at 6 months and 1 year were collected. RESULTS: A total of 103 patients with presbyopia were included in this study: 42 patients with myopia, 23 patients with emmetropia, and 38 patients with hyperopia. There were significant differences in ΔAMP(6-month) and ΔADD(6-month) among patients with different refractive statuses, and the values of emmetropic patients and hyperopic patients were higher than in myopic patients (all P < 0.001). The ΔAMP(1-year) and ΔADD(1-year) of hyperopic patients were significantly higher than in emmetropic patients and myopic patients (all P < 0.001). The ΔADD(1-year) of emmetropic patients was greater than in myopic patients (P = 0.045), but there were no significant differences in ΔAMP(1-year) between patients with emmetropia and myopia (P = 0.090). CONCLUSIONS: The progression of presbyopia in hyperopic patients was relatively more significant than for emmetropia, followed by myopia. The prescription of presbyopia glasses might need to be replaced more frequently in patients with hyperopia.

Study of myopia progression and risk factors in Hubei children aged 7-10 years using machine learning: a longitudinal cohort.

BACKGROUND: To investigate the trend of refractive error among elementary school students in grades 1 to 3 in Hubei Province, analyze the relevant factors affecting myopia progression, and develop a model to predict myopia progression and the risk of developing high myopia in children. METHODS: Longitudinal study. Using a cluster-stratified sampling method, elementary school students in grades 1 to 3 (15,512 in total) from 17 cities in Hubei Province were included as study subjects. Visual acuity, cycloplegic autorefraction, and height and weight measurements were performed for three consecutive years from 2019 to 2021. Basic information about the students, parental myopia and education level, and the students' behavioral habits of using the eyes were collected through questionnaires. RESULTS: The baseline refractive errors of children in grades 1 ~ 3 in Hubei Province in 2019 were 0.20 (0.11, 0.27)D, -0.14 (-0.21, 0.06)D, and - 0.29 (-0.37, -0.22)D, respectively, and the annual myopia progression was - 0.65 (-0.74, -0.63)D, -0.61 (-0.73, -0.59)D and - 0.59 (-0.64, -0.51)D, with the prevalence of myopia increasing from 17.56%, 20.9%, and 34.08% in 2019 to 24.16%, 32.24%, and 40.37% in 2021 (Χ2 = 63.29, P < 0.001). With growth, children's refractive error moved toward myopia, and the quantity of myopic progression gradually diminished. (F = 291.04, P = 0.027). The myopia progression in boys was less than that in girls in the same grade (P < 0.001). The change in spherical equivalent refraction in myopic children was smaller than that in hyperopic and emmetropic children (F = 59.28, P < 0.001), in which the refractive change in mild myopia, moderate myopia, and high myopia children gradually increased (F = 73.12, P < 0.001). Large baseline refractive error, large body mass index, and high frequency of eating sweets were risk factors for myopia progression, while parental intervention and strong eye-care awareness were protective factors for delaying myopia progression. The nomogram graph predicted the probability of developing high myopia in children and found that baseline refraction had the greatest predictive value. CONCLUSION: Myopia progression varies by age, sex, and myopia severity. Baseline refraction is the most important factor in predicting high myopia in childhood. we should focus on children with large baseline refraction or young age of onset of myopia in clinical myopia prevention and control.

Refractive associations with corneal biomechanical properties among young adults: a population-based Corvis ST study.

PURPOSE: To assess the associations of corneal biomechanical properties as measured by the Corvis ST with refractive errors and ocular biometry in an unselected sample of young adults. METHODS: A total of 1645 healthy university students underwent corneal biomechanical parameters measurement by the Corvis ST. The refractive status of the participants was measured using an autorefractor without cycloplegia. Ocular biometric parameters were measured using the IOL Master. RESULTS: After adjusting for the effect of age, sex, biomechanical-corrected intraocular pressure and central corneal thickness, axial length was significantly associated with A1 velocity (A1v, ß = -10.47), A2 velocity (A2v, ß = 4.66), A2 deflection amplitude (A2DeflA, ß = -6.02), HC deflection amplitude (HC-DeflA, ß = 5.95), HC peak distance (HC-PD, ß = 2.57), deformation amplitude ratio max (DA Rmax, ß = -0.36), Ambrósio's relational thickness to the horizontal profile (ARTh, ß = 0.002). For axial length / corneal radius ratio, only A1v (ß = -2.01), A1 deflection amplitude (A1DeflA, ß = 2.30), HC-DeflA (ß = 1.49), HC-PD (ß = -0.21), DA Rmax (ß = 0.07), stress-strain index (SSI, ß = -0.29), ARTh (ß < 0.001) were significant associates. A1v (ß = 23.18), HC-DeflA (ß = -15.36), HC-PD (ß = 1.27), DA Rmax (ß = -0.66), SSI (ß = 3.53), ARTh (ß = -0.02) were significantly associated with spherical equivalent. CONCLUSION: Myopic eyes were more likely to have more deformable corneas and corneas in high myopia were easier to deform and were even softer compared with those in the mild/moderate myopia.

Clinical characteristics of acute acquired concomitant esotropia among different age groups / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To analyze the clinical characteristics of acute acquired concomitant esotropia(AACE)in patients among different age groups.METHODS: Retrospective analysis of clinical data. A total of 112 non-Swan type AACE patients who underwent surgery at Peking University People's Hospital from January 2015 to December 2022 were retrospectively analyzed. Clinical data were collected and the characteristics were compared, including gender, age, diopter, duration of disease, daily time spent on near work, angles of deviation before and after surgery, stereopsis, etc. According to age, patients were divided into three groups: &#x003C;18 years old group(22 cases), 18-45 years old group(67 cases), and &#x003E;45 years old group(23 cases). The clinical characteristics of patients were compared in each group.RESULTS: A total of 112 patients were included in the study, comprising 56 males and 56 females, with a median age of 29.50(19.25, 41.75)years old. Among them, 97 patients had myopia(86.6%). There were 93 patients(83.0%)who spent more than 8 h on near work. The age group &#x003C;18 years old had the shortest duration before surgery, with a median time of 1.00(0.50, 1.00)a, the minimum negative diopter, with a median diopter of -0.75(-3.19, -0.56)D in the right eye and the diopter of -1.25(-2.81, -0.75)D in the left eye, and the maximum preoperative near angle of deviation, with a median angle of 30.00(18.50, 80.00)PD, and the maximum preoperative distant angle of deviation, with a median angle of 35.00(23.75, 80.00)PD. All these differences were statistically significant compared with other two groups(both P&#x003C;0.05). For the age group from 18 to 45 years old, the median near angle of deviation was 20.00(14.00, 30.00)PD, and the median distant angle of deviation was 25.00(20.00, 35.00)PD, both of which were higher than those in the age group &#x003E;45 years old(both P&#x003C;0.05). For the age group &#x003E;45 years old, the median near angle of deviation after surgery was -4.50(-7.50, 0)PD, and the median distant angle of deviation after surgery was 4.50(0, 9.50)PD, which were smaller than those in other two groups(all P&#x003C;0.05). The age group &#x003E;45 years old had the hiughest surgical success rate(100%). The preoperative stereopsis was better in age group &#x003E;45 years old than the group &#x003C;18 years old(P&#x003C;0.05). The postoperative stereopsis of the age group of 18 to 45 years old and the age group &#x003E;45 years old was better than age group &#x003C;18 years old(both P&#x003C;0.05).CONCLUSION: Surgical patients with AACE are mainly in the age group from 18 to 45 years old. The characteristic of angle of deviation is that distant angle of deviation is greater than near angle of deviation. The patients &#x003C;18 years old have larger preoperative angles of deviation than adults, while their stereoacuity is worse than adults in the early postoperative period. It is recommended that augmented-dose surgery should be performed in AACE patients who are in the age group of 18 to 45 years old(5-10 PD). A conservative surgery should be designed for hyperopia young children without established binocular vision.

Impact of Dry Eye Disease on the Uncorrected Distance Visual Acuity after Small Incision Lenticule Extraction.

The aim of this study was to explore the impact of dry eye disease (DED) on the uncorrected distance visual acuity (UDVA) and refractive status after small incision lenticule extraction (SMILE). This prospective cohort study enrolled 29 patients (DED group, 11 eyes; non-DED group, 18 eyes) who underwent SMILE in our center from July to September 2022. The examinations on DED, refractive status and UDVA were performed before surgery, and on day 7 and 20 after surgery. The results showed that on day 20 after SMILE, subjects in the non-DED group reported greater changes of ocular surface disease index value increase and tear-film breakup time reduction compared to baseline than those in the DED group (p < 0.001 and p = 0.048, respectively). Compared to preoperative status, DED patients had greater improvements of UDVA and better optometric outcomes on day 20 after surgery than non-DED subjects (p = 0.008 and 0.026, respectively). Multiple linear regression analysis showed age, contact lens daily wearing time, and tear meniscus height before surgery were of the highest value to predict UDVA on day 20 after SMILE in contact lens wearers (p = 0.006, 0.010 and 0.043, respectively). In conclusion, preoperative tear function could affect UDVA after SMILE. The impact of DED on UDVA and refraction should be taken into consideration before surgery.

Relatively anterior lens position in primary angle-closure glaucoma eyes with long axial length.

Purpose: To evaluate the refractive status and ocular biometric parameters in primary angle-closure glaucoma (PACG) eyes with different axial lengths (ALs). Methods: In total, 742 Chinese PACG subjects with complete ophthalmic examinations were enrolled. The refractive status was categorized as myopia (spherical equivalent [SE] ≤-0.5 D), emmetropia (-0.5 D < SE < +0.5 D), and hyperopia (SE ≥+0.5 D), whereas the AL was divided into short (AL <22.5 mm), regular (22.5 ≤ AL <23.5 mm), and long (AL ≥23.5 mm). The refractive status and ocular biometric parameters were compared among different AL groups. Results: The mean AL of the PACG eyes was 22.53 ± 0.84 mm (range: 19.68-25.57 mm). The refractive status was significantly different among different AL groups (P < 0.001). Also, 92.6% of hyperopic PACG eyes showed AL <23.5 mm, and 19.0% of myopic PACG eyes showed AL ≥23.5 mm. The SE showed significant differences among different AL groups only in the hyperopic subjects (P = 0.012). The AL was significantly longer in myopic eyes (P < 0.001). The PACG eyes with longer AL exhibited lower keratometry, longer central anterior chamber depth and corneal diameter, and lens position and relative lens position closer to the anterior (P < 0.001). Conclusion: Axial hyperopia was common in PACG eyes, and axial myopia was not uncommon. Relatively anterior lens position could explain the occurrence of PACG in the eyes with long AL.

Refractive status and retinal morphology in children with a history of intravitreal ranibizumab for retinopathy of prematurity.

This study investigated the characteristics of refractive status, visual acuity, and retinal morphology in children with a history of receiving intravitreal ranibizumab for retinopathy of prematurity (ROP). Children 4-6 years of age were enrolled and divided into the following four groups: group 1, children with a history of ROP who had been treated with intravitreal ranibizumab; group 2, children with a history of ROP who had not received any treatment; group 3, premature children without ROP; and group 4, full-term children. Refractive status, peripapillary retinal nerve fiber layer (RNFL), and macular thickness were measured. A total of 204 children were enrolled. In group 1, myopic shift was not noted, but poorer best corrected visual acuity (BCVA) and shorter axial length were observed. Significantly lower peripapillary RNFL thickness in the average total and superior quadrant, higher central subfield thickness, lower parafoveal retinal thickness in average total, superior, and nasal and temporal quadrants were observed in group 1 than in the other groups. The poor BCVA in patients with ROP was correlated with the lower RNFL thickness in the superior quadrant.   Conclusion: Children with a history of type 1 ROP treated with ranibizumab did not show a myopic shift but did show abnormal retinal morphology and the poorest BCVA among all groups. We suggest that pediatric ophthalmologists should always pay attention to visual development in patients with ROP with a history of intravitreal ranibizumab. What is Known: • Anti-VEGF is efficiently and widely used in the treatment of type 1 retinopathy of prematurity (ROP), and different anti-VEGF agents are associated with different prevalence of myopia. • Patients with ROP who receive treatment such as laser therapy or cryotherapy have abnormal macular development and retinal nerve fiber layer (RNFL) thickness. What is New: • Children with a history of ROP treated with intravitreal ranibizumab did not show a myopic shift but did show poor BCVA at 4-6 years of age. • Abnormal macular morphology and lower peripapillary RNFL thickness were found in these children.

Effect of refractive status on retinal nerve fiber layer thickness in Chinese Population.

PURPOSE: To evaluate the relationship between retinal nerve fiber layer (RNFL) thickness and other related parameters measured by spectral-domain optical coherence tomography and the refractive error of eyes. METHODS: A total of 5394 subjects were enrolled in this population-based cohort study, who were divided into three groups by refractive state after they underwent a standardized ophthalmic examination: emmetropia (the absolute value should range from 0 to 0.5 D), low-moderate myopia (the absolute value of myopic error should range from 0.5 to 6 D), and high myopia (the absolute value of myopic error should be over than 6 D). R 3.6.1 software was adopted for statistical analysis. RESULTS: Two thousand five hundred fifty-two subjects (4548 eyes) were collected in this study, with an average age of 53.14 ± 10.64 years. There were significant differences among groups in average central corneal curvature, spherical equivalent, and axial length (P < 0.001). The measurements of average retinal nerve fiber layer (RNFL) were 113.95 ± 10.62 µm, 112.97 ± 11.59 µm, and 101.88 ± 15.67 µm, respectively, in the emmetropia, low-moderate, and high myopia groups (P < 0.001). Meanwhile, there was a decreasing trend of cup area, cup volume, disc area, and rim area in the high myopia group compared with the emmetropia group (P < 0.001). CONCLUSION: The measurements of RNFL thickness vary greatly with refractive error, and this study indicated that it is of great significance for the accurate diagnosis of glaucoma to establish an individualized RNFL thickness database.

Clinical characteristics and treatment of patients with acute acquired concomitant esotropia in different refractive status / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To analyze the clinical characteristics and treatment of patients with acute acquired concomitant esotropia(AACE)in different refractive status.METHODS: A retrospective analysis was conducted on 110 patients with non-type I AACE treated from January 2020 to January 2022. The non-myopic group(30 cases, spherical equivalent&#x003E;-0.5D)and the myopic group(80 cases, spherical equivalent≤-0.5D)were divided according to the refractive status. The degree of deviation, accommodative convergence and accommodation ratio(AC/A), visual function, and surgical methods were observed. RESULTS: The non-myopic group had no difference in the degree of near deviation [(47.13±23.54)△] and the degree of distant deviation [(48.90±22.59)△](P&#x003E;0.05); near deviation [(40.49±26.09)△] of myopic group was less than distant deviation [(50.09±25.41)△](P&#x003C;0.001); and there was no difference in the same distance between the two groups(P&#x003E;0.05). AC/A in the non-myopic group(5.40±2.23)was higher than that in the myopic group(3.14±3.10; P&#x003C;0.05). Patients in the myopic group had better near stereopsis than the non-myopic group(P&#x003C;0.05). The non-myopic group had a variety of surgical methods, while the myopic group mostly used lateral rectus resection or/and medial rectus recession.CONCLUSION: AACE can occur in different refractive status. Non-myopic patients have the same degree of distant and near strabismus, high AC/A, and varied surgical methods. However, myopic patients have less degree of near deviation than distant deviation and have normal AC/A and better near stereopsis, and lateral rectus resection or/and medial rectus recession are commonly used.

Influence of the duration of orthokeratology lens cessation on patients' refractive status and corneal endothelial cells / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the influence of the duration of orthokeratology lens cessation on patients' refractive status and corneal endothelial cells.METHODS: Adolescent myopia patients who wore orthokeratology lens from July 2019 to July 2020 and recently planned to stop wearing the lens were divided into mild group and severe group according to spherical equivalent. Refractive status, corneal morphology, corneal endothelial cells, and visual quality were measured at cessation and 1, 2 and 3mo after cessation.RESULTS: The corneal flat K values, steep K values and mean K values in the two groups were lower at cessation than those before wearing lenses. These values returned to the level before wearing lenses at 2mo after cessation(P&#x0026;#x003E;0.05). The corneal astigmatism, surface regularity index and surface asymmetry index in each group showed no statistically significant difference before wearing lenses and at 1, 2 and 3mo after cessation(P&#x0026;#x003E;0.05). There was no significant change in corneal endothelial cell density of the two groups at 1, 2 and 3mo after cessation compared with those before wearing lenses(P&#x0026;#x003E;0.05). The proportion of hexagonal cells in the two groups was lower at cessation than that before wearing lenses, and it returned to the level before wearing lenses at 1mo after cessation(P&#x0026;#x003E;0.05).CONCLUSION: Corneal morphology and corneal endothelial cells can be restored to the level before wearing orthokeratology lens at 3mo after cessation.

Refractive status and optical components in premature infants with and without retinopathy of prematurity: A 4- to 5-year cohort study.

This study was aimed to investigate the characteristics of refractive parameters in premature infants and children aged 3-8 years with mild retinopathy of prematurity (ROP) and to explore the effects of premature delivery and mild ROP on the development of refractive status and ocular optical components. Premature infants who underwent ocular fundus oculi screening in our hospital between January 2009 and February 2011 were included and divided into the ROP group and the non-ROP group. Full-term infants were the controls. The results of the annual ocular examination conducted between 2014 and 2018 were analysed, and the refractive status, optical components, and developmental trends were compared among the three groups. The total follow-up time was 4-5 years. The prevalence of myopia and astigmatism was high in the ROP group (P < 0.05). In the non-ROP group, the prevalence of myopia was also higher than that in the control group. The prevalence of myopia increased with age in the ROP and non-ROP groups, while the prevalence of astigmatism remained unchanged. In the ROP group, the corneal refractive power was the largest, the lens was the thickest and the ocular axis was the shortest; in the control group, the corneal refractive power was the smallest, the lens was the thinnest, and the ocular axis was the longest. These parameters in the non-ROP group were between those in the two groups mentioned above (P < 0.05). The corneal refractive power was relatively stable at 3-8 years old in the three groups. The change in lens thickness was small in both the ROP group and the non-ROP group (P = 0.75, P = 0.06), and the lens became thinner in the control group (P < 0.001). The length of the ocular axis increased in the three groups. Preterm infants are more likely to develop myopia than full-term infants, and children with ROP are more likely to develop both myopia and astigmatism. Thicker lenses were the main cause of the high prevalence of myopia in premature infants with or without ROP.

Association between serum vitamin D and refractive status in United States adolescents: A cross-sectional study.

Purpose: We performed this study to determine the relationship between serum vitamin D levels and refractive status in adolescents aged 12-19 years. Methods: Cross-sectional study using the National Health and Nutrition Examination Survey (NHANES) database from 2001 to 2006. We used weighted multivariate linear regression models to assess the association between serum vitamin levels and adolescent refractive status and then built a smooth curve fitting to investigate their internal non-linear relationships. Finally, subgroup analysis was performed according to gender, and the threshold effect of serum vitamin D levels on spherical equivalent degree was analyzed using a two-piecewise linear regression model. Result: A total of 5,901 adolescents aged 12 to 19 years were included in this study. After adjusting for all confounding factors, the multiple linear regression model showed no significant correlation between adolescent spherical equivalent degree and serum vitamin D [0.0019 (-0.0018, 0.0046)]. However, smooth curve fitting analysis showed an inverted U-shaped curve relationship between spherical equivalent degree and serum vitamin D levels in adolescents (turning point: 58.1 nmol/L). In analyses by gender subgroup, this inverted U-shaped relationship was found to be more pronounced in female adolescents (turning point: 61.6 nmol/L). Conclusion: Our results suggest that the correlation between refractive status and serum vitamin D in adolescents differs by gender. When serum vitamin D concentrations were <61.6 nmol/L in female adolescents and <53.2 nmol/L in male adolescents, the spherical equivalent degree showed a positive correlation with serum vitamin D levels. However, there was no significant correlation when adolescent vitamin levels exceeded this threshold.

Influence of eye movement on precision of corneal ablation and refraction status in SMILE / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the influence of slight eye movement during laser scanning on femtosecond laser precision of corneal ablation and postoperative refractive status in small incision lenticule extraction(SMILE). METHODS: Totally 32 patients(62 eyes)who underwent SMILE surgery in our hospital from January 2019 to March 2021 were included and divided into the movement group and the fixation group according to whether the eyeballs were slightly moved during the operation, and select patients with slightly moved monocular eyeballs for binocular pairing. The actual difference of absolute value of corneal absolute cutting error(ACE), astigmatism error(AE), absolute refractive error(ARE)and absolute visual error(AVE)was compared between the movement group and the fixation group and the two eyes of the patients with slight ocular movement in one eye at 1mo after surgery, and the surgical images were quantified to analyze the correlation between the amplitude of ocular movement and AE, and to compare the effects of the area, layer and direction of slight eye movement on ACE.RESULTS: There were no differences in all observed results between movement group and fixation group(P&#x003E;0.05). Patients with slight movement of one eye had a difference in binocular AE(0.57±0.31D vs 0.33±0.27D, P&#x003C;0.05), and the amplitude of movement was positively correlated with AE at 1mo after surgery(r=0.564, P&#x003C;0.05). There was no statistical differences in ACE at 1mo after surgery in patients with slight ocular movement in different regions(central/peripheral), layers(upper/lower lens)and direction(nasal/temporal)(all P&#x003E;0.05).CONCLUSION:The slight eye movement during laser scanning in SMILE has no significant influence on precision of corneal ablation. It mainly causes decentered ablation and the changes of corneal astigmatism, which has little effect on the spherical equivalent and visual acuity.

Normal Ocular Protrusion Values in South Indian Population and Effect of Age, Gender and Refractive Status on Ocular Protrusion.

AIM: To determine the absolute and relative ocular protrusion values in normal south Indian population, and its relation to age, gender and type of refractive error. METHODS: A total of 387 subjects aged 7-70 years were included in this study. Both right and left absolute ocular protrusion values were measured by a single physician using Luedde exophthalmometer in primary gaze. Right eye ocular protrusion data were used for reporting the absolute ocular protrusion values, and difference between right and left eye absolute ocular protrusion values of the same individual was used to report the relative ocular protrusion values. Subject age was grouped as decades. Measurement values were evaluated by descriptive and inferential statistics. RESULTS: The mean absolute ocular protrusion of right eye was 14.67 ± 1.70 mm and left eye was 14.32 ± 1.75 mm. The mean right absolute ocular protrusion values from 1st to 7th decade were 12.73 ± 1.21 mm, 14.8 ± 1.25 mm, 15.79 ± 1.31 mm, 15.77 ± 1.36 mm, 15.87 ± 1.28 mm, 15 ± 1.03 mm and 14.36 ± 0.88 mm respectively. One-way analysis of variance showed that there was a significant difference in the ocular protrusion among the age groups (p < 0.005). The mean relative ocular protrusion was 0.35 ± 0.64 mm. The type of refractive error (up to ±6.00D) has no significant effect on the absolute ocular protrusion values and showed a weak correlation between magnitude of myopia and hyperopia on absolute ocular protrusion. There was a statistically significant difference in absolute ocular protrusion among the female and male subjects. CONCLUSION: Age and gender seems to significantly influence the absolute ocular protrusion and need to be considered for clinical evaluation of bilateral proptosis. The refractive error up to ±6.00D seems to have no significant effect on the absolute ocular protrusion.

Difference of refractive status before and after cycloplegic refraction: the Lhasa Childhood Eye Study.

PURPOSE: To compare the differences between cycloplegic and noncycloplegic refraction as well as associated factors in grade one students of primary schools, and explore the effectiveness of noncycloplegic refraction for refractive error screening. STUDY DESIGN: Cross-sectional study. METHODS: A school-based study of 1856 students was conducted in Lhasa, Tibetan Plateau, China. Cycloplegia was achieved with two drops of 1% cyclopentolate and 1 drop of Mydrin P at a 5-min interval. Autorefraction was performed under both cycloplegic and noncycloplegic conditions. Bland-Altman analysis, receiver operating characteristic curve analysis, univariate and multiple linear regression models were used for analysis. RESULTS: Of the 1856 children enrolled, 1830 (98.60%) completed all procedures. The average age was 6.83 ± 0.46 years. 965 (52.73%) children were boys and 1737 (94.92%) were Tibetan. Overall, there was a significant difference between cycloplegic and noncycloplegic SE of 0.90 ± 0.76D (P < 0.001). However, the intra-class coefficient correlation (ICC) for cylinder between these two methods was high (ICC = 0.941, 95% CI, 0.935-0.946). Larger differences between cycloplegic and noncycloplegic SE were associated with hyperopic RE and higher cylindrical value (P < 0.001). The prevalence of myopia, emmetropia and hyperopia with and without cycloplegia was (3.93% vs 14.59%), (9.95% vs 45.8%) and (86.21% vs 39.56%), respectively. Myopia, emmetropia and hyperopia based on noncycloplegic refraction was defined as SE ≤ - 0.625D, - 0.625 < SE ≤ 0D, and SE > 0D, respectively. CONCLUSIONS: Lack of cycloplegia leads to underestimation of hyperopia, with overestimation of myopia and emmetropia. Larger hyperopic refraction exhibited greater difference between cycloplegic and noncycloplegic refraction.

Influence of refractive status and age on corneal higher-order aberration.

This study aimed to investigate the influence of refractive status and age of patients on corneal higher-order aberrations (HOAs). Four hundred and twenty-six right eyes of 426 patients were enrolled in this study. The mean and standard deviation of patient age was 47.7 ± 22.1 years. Total HOAs, spherical-like aberration, coma-like aberration, Z-13, Z13, Z-33, Z-33 and spherical aberration (Z04) for 6-mm pupil were measured using anterior segment optical coherence tomography (AS-OCT). Subjects were classified into three groups according to the amount of spherical equivalent refractive error (SE): myopia (<-0.5 D), emmetropia (-0.5 to 0.5 D), and hyperopia (>0.5 D). The amount of corneal astigmatism was recorded. Relationship between corneal aberrations, refractive status, astigmatism, and age was analyzed. In total, total HOAs, spherical-like aberration and amount of Z-33 and Z04 were significantly larger in the hyperopia group than in the myopia group. After adjustment for age, however, aberration components did not differ among the three refractive groups. In multiple regression analysis, age and corneal astigmatism showed significant correlation with aberrations, whereas amount of SE and refractive status did not. The current study indicated that age and amount of corneal astigmatism have significant influence on corneal HOAs, but refractive status (myopia, emmetropia, or hyperopia) is not associated with corneal HOAs.

Evaluation of Refractive Status and Ocular Biometric Parameters in Primary Angle Closure Disease.

INTRODUCTION: The aim of the study was to evaluate the refractive status and ocular biometric parameters in subjects with angle closure in Malaysia. METHODS: This cross-sectional study was conducted on 171 primary angle closure patients (268 eyes). Visual acuity, refraction, and ocular biometry (central anterior chamber depth [ACD], axial length [AL], and lens thickness) were recorded. Vitreous cavity length (VL) and relative lens position (RLP) were calculated. RESULTS: A total of 92 Primary Angle Closure Suspect (PACS), 30 Primary Angle Closure (PAC), and 146 Primary Angle Closure Glaucoma (PACG) eyes were included. Chinese ethnicity formed the majority (n = 197, 73.5%), followed by Malay (n = 57, 21.3%) and Indian (n = 14, 5.2%). There was a significant female preponderance with a female to male ratio of 1.85. Mean age was 65.7 ± 7.7 years. Mean spherical equivalent was +0.33 ± 1.29 D. Approximately half (n = 137, 51%) of the eyes were hyperopic (spherical power ≥+0.5), with PACG having the highest percentage of hyperopia (n = 69, 50.4%). Myopia and emmetropia were present in 48 (17.9) and 83 (31%) eyes, respectively. Although AL and VL in myopia patients were significantly longer than emmetropic and hyperopic eyes (p < 0.001), the ACD was not significantly different (p = 0.427). While the RLP is smaller in myopic eyes, lens thickness was increased in hyperopic eyes. PACG was significantly higher in elderly patients compared to PACS and PAC (p = 0.005). A total of 37 (13.8%) eyes were blind (vision worse than 3/60) and 19 of them (51.3%) were female patients. CONCLUSION: A decrease in RLP is predictive of angle closure disease in myopic eyes, whereas increased lens thickness contributes to angle closure disease in hyperopic eyes.