Myopic Refraction Research Articles

Associations of prenatal arsenic exposure with myopia in primary school children: modifying effects of vitamin D levels.

The increasing role of environmental pollutants and nutrients in the development of myopia. Further longitudinal evidence is needed to elucidate the effects of early-life environmental pollutants on myopia and nutrients to protect against pollutant-induced myopia. We used mother-child dyads from the Ma'anshan Birth Cohort (n = 2028) to explore the modifying effects of maternal vitamin D status of prenatal and childhood arsenic exposure with refractive parameters and myopia. We measured serum or plasma arsenic concentrations during three trimesters, in cord blood, in childhood (5-year-old), and performed cycloplegic refraction in children aged 7 to 9 years (n = 1616). Primary outcomes were myopia and refractive parameters including axial length (AL), corneal radius of curvature, and spherical equivalent refraction error. Linear regression, logistic regression, and multiple informant models were performed for the association of prenatal and childhood arsenic exposure with vision health. Sex- and vitamin D status stratification analyses were also conducted. Cord serum arsenic was positively associated with AL (β = 0.15, 95%CI: 0.01, 0.29) and the risk of developing myopia (OR = 1.72, 95%CI: 1.07, 2.75). Among boys, a 1 ng/L increase in cord serum log10-transformed arsenic resulted in larger AL and a higher risk of myopia. In the vitamin D deficient group (<20 ng/mL), cord serum arsenic showed positive associations with AL (0.26 [0.06, 0.46]) and the risk of myopia (1.99 [1.01, 3.90]). Late pregnancy arsenic exposure likely affects offspring development of myopia, especially in boys. Maternal sufficient vitamin D may confer protective effects against the development of myopia.

Myopic shift in female mice after ovariectomy

Myopia is a global public health concern, with a higher prevalence in women than that in male. As the relationship between sex hormone and myopia remains unclear, we aimed to reveal the relationship between sex hormone and myopia by removing the ovaries of mice and measuring changes in ocular parameters related to myopia. Lens-induced myopia (LIM) surgeries were performed on 3-week-old male mice and age-matched female mice to evaluate the effects of sex on myopia development, which indicated a high degree of myopia and rapid progression of axial elongation in male mice. Bilateral ovariectomy (OVX) performed on 4-week-old female mice induced myopic refraction status in ovariectomized mice. Although axial length elongation was larger in ovariectomized mice than that in sham control mice, the result was insignificant. To further reveal the relationship between female sex hormones and myopia, LIM combined with OVX was performed, which revealed a magnified myopic refraction status in ovariectomized mice. Nevertheless, elongation of the anterior chamber depth in the − 30 D lens-treated eyes significantly increased in LIM + OVX mice compared with the frame-treated eyes in LIM + OVX mice and − 30 D lens-treated eyes in LIM + Sham surgery mice. Sex hormones play a role in regulating myopia development in female mice.

Efficacy of weekly dose of 1% atropine for myopia control in Chinese children

PurposeTo assess the effect of weekly 1% atropine use on children’s myopia progression and whether the effect is sustainable.MethodsMedical records of myopic children aged 3–15 years receiving weekly 1% atropine...

Machine Learning Models for Predicting Cycloplegic Refractive Error and Myopia Status Based on Non-Cycloplegic Data in Chinese Students.

To develop and validate machine learning (ML) models for predicting cycloplegic refractive error and myopia status using noncycloplegic refractive error and biometric data. Cross-sectional study of children aged five to 18years who underwent biometry and autorefraction before and after cycloplegia. Myopia was defined as cycloplegic spherical equivalent refraction (SER) ≤-0.5 Diopter (D). Models were evaluated for predicting SER using R2 and mean absolute error (MAE) and myopia status using area under the receiver operating characteristic (ROC) curve (AUC). Best-performing models were further evaluated using sensitivity/specificity and comparison of observed versus predicted myopia prevalence rate overall and in each age group. Independent data sets were used for training (n = 1938) and validation (n = 1476). In the validation dataset, ML models predicted cycloplegic SER with high R2 (0.913-0.935) and low MAE (0.393-0.480 D). The AUC for predicting myopia was high (0.984-0.987). The best-performing model for SER (XGBoost) had high sensitivity and specificity (91.1% and 97.2%). Random forest (RF), the best-performing model for myopia, had high sensitivity and specificity (92.2% and 96.9%). Within each age group, difference between predicted and actual myopia prevalence was within 4%. Using noncycloplegic refractive error and ocular biometric data, ML models performed well for predicting cycloplegic SER and myopia status. When measuring cycloplegic SER is not feasible, ML may provide a useful tool for estimating cycloplegic SER and myopia prevalence rate in epidemiological studies. Using ML to predict cycloplegic refraction based on noncycloplegic data is a powerful tool for large, population-based studies of refractive error.

Electroacupuncture improves retinal function in myopia Guinea pigs probably via inhibition of the RhoA/ROCK2 signaling pathway

ObjectiveTo investigate the effect of electroacupuncture (EA) on retinal function in guinea pigs with negative lens-induced myopia (LIM) by inhibiting the RhoA/ROCK2 signaling pathway. MethodsGuinea pigs were randomly divided into normal control (NC) group, LIM group, EA group, SHAM acupoint (SHAM) group, and electro-acupuncture + ROCK pathway inhibitor Y27632 (EA + Y27632) group. The refraction, axial length, retinal blood flow density, choroidal vascular index, retinal physiological function, the contents of total antioxidant capacity (T-AOC), catalase (CAT), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) of each group were determined. The changes in retinal tissue structure were observed by hematoxylin and eosin (H&E) staining, and the expression of the RhoA/ROCK2 signaling pathway-related molecules in the retina was measured by real-time quantitative polymerase chain reaction (qPCR) and Western blot. ResultsMyopic refraction, AL, and MDA content in the LIM and SHAM groups were significantly increased, retinal blood flow density and CVI, SOD, GSH, CAT, T-AOC content were decreased. After EA intervention, myopic refraction, AL, and MDA content decreased, retinal blood flow density and CVI, SOD, GSH, CAT, T-AOC content were increased. H&E staining showed that the thickness of the guinea pig retina, the thickness of the inner and outer layers of the nucleus, and the number of cells were significantly increased after EA intervention. qPCR and western blot analyses showed that the expression of RhoA、ROCK2、MLC、CollagenⅠ、MMP-2、TIMP-2 and α-SMA were elevated in the LIM and SHAM group than those in the NC group. Compared with the LIM group, the expression of EA group was significantly decreased. ConclusionsElectroacupuncture can improve retinal function by improving retinal blood flow, reducing retinal oxidative damage, inhibiting RhoA/ROCK2 signaling pathway and controlling extracellular matrix remodeling, thus delaying the occurrence and development of myopia.

Inner Retinal Microvasculature With Refraction in Juvenile Rhesus Monkeys.

To characterize inner retinal microvasculature of rhesus monkeys with a range of refractive errors using optical coherence tomography angiography. Refractive error was induced in right eyes of 18 rhesus monkeys. At 327 to 347days of age, axial length and spherical equivalent refraction (SER) were measured, and optical coherence tomography and optical coherence tomography angiography scans (Spectralis, Heidelberg) were collected. Magnification-corrected metrics included foveal avascular zone area and perfusion density, fractal dimension, and lacunarity of the superficial vascular complex (SVC) and deep vascular complex (DVC) in the central 1-mm diameter and 1.0- to 1.5-mm, 1.5- to 2.0-mm, and 2.0- to 2.5-mm annuli. Pearson correlations were used to explore relationships. The mean SER and axial length were 0.78 ± 4.02 D (-7.12 to +7.13 D) and 17.96 ± 1.08mm (16.41 to 19.93mm), respectively. The foveal avascular zone area and SVC perfusion density were correlated with retinal thickness for the central 1mm (P < 0.05). SVC perfusion density of 2.0- to 2.5-mm annulus decreased with increasing axial length (P < 0.001). SVC and DVC fractal dimensions of 2.0- to 2.5-mm were correlated with axial length and SER, and DVC lacunarity of 1.5- to 2.0-mm annulus was correlated with axial length (P < 0.05). Several inner retinal microvasculature parameters were associated with increasing axial length and SER in juvenile rhesus monkeys. These findings suggest that changes in retinal microvasculature could be indicators of refractive error development. In juvenile rhesus monkeys, increasing myopic refraction and axial length are associated with alterations in the inner retinal microvasculature, which may have implications in myopia-related changes in humans.

Refraction dynamics in schoolchildren with congenital partial atrophy of the optic nerve over a ten-year observation period

Introduction. Optic nerve atrophy is a degenerative condition and a prevalent cause of visual impairment, including in children. Data on refractogenesis in schoolchildren with partial atrophy of the optic nerve (PAON) are scarce, with existing literature focusing primarily on the correction of low vision associated with this disorder. Purpose: to assess the refraction dynamics in schoolchildren with congenital PAON over a ten-year observation period.Materials and methods. We conducted a retrospective analysis of refraction changes over a decade among three groups: 1) 47 schoolchildren with PAON, 2) 49 schoolchildren with ametropia without PAON, and 3) 49 schoolchildren without any ophthalmopathology.Results. All groups exhibited a trend towards myopization (р &lt; 0.001). In groups with myopic and emmetropic refractions (without ophthalmopathology at the start), either the emergence or an increase in myopic refraction was noted. In hypermetropic children, a gradual decrease towards emmetropic refraction or a shift to myopic refraction was observed. For myopic schoolchildren using contact lenses and perifocal glasses from the ages of 11–13, myopia progression stabilized, particularly with perifocal optical correction (р &lt; 0.01). Despite refractive changes during the school years, regular courses of functional treatment and accommodation training led to a slight improvement in visual acuity in PAON patients (by an average of 0.05 ± 0.01 (p = 0.001) in myopes and 0.06 ± 0.01 (р &lt; 0.001) in hypermetropes) and a significant increase in visual acuity in children with normal fundus ametropia (by an average of 0.14 ± 0.02 (р &lt; 0.001) in myopes and 0.18 ± 0.02 (р &lt; 0.001) in hypermetropes).Conclusion. The ten-year observation demonstrates a myopization trend in all groups of schoolchildren, which holds particular relevance for those with PAON due to their inherently lower visual acuity. An optimal optical correction strategy, employing modern myopia control measures in tandem with regular functional treatment and accommodation training, is essential for a health-preserving educational approach in schoolchildren with PAON.

Analysis of Refractive Error Changes in Elementary School Children under 13 Years of Age before and after COVID-19 Pandemic: A Hospital-Based Study

Purpose: To analyze changes in refractive error among elementary school children under the age of 13 who visited an outpatient clinic for eye examinations before and after the onset of the COVID-19 pandemic.Methods: A retrospective analysis of medical records was conducted to calculate the spherical equivalent refractive error of the right eye for 3,854 children aged 6 to 12 who attended our ophthalmology department from 2016 to 2023. We analyzed the average refractive error and myopia prevalence by year and subsequently performed a subgroup analysis by dividing the children into two age groups: 6-9 years old and 10-12 years old. To provide insight into long-term trends, data from 4,351 subjects aged 6-12 years from the 4th, 5th (2008-2012), and 7th (2016) Korea National Health and Nutrition Examination Surveys were also analyzed for reference.Results: The mean refractive error for subjects visiting our clinic throughout the study period was -1.51 ± 2.12 D. A trend of increasing myopic values in refractive error was observed from 2017 to 2021, with a more substantial change noted in 2020 compared to other years, though not reaching statistical significance. In the subgroup analysis, the change in refractive error for the 6-9-year-old group was more pronounced in 2020 but did not reach statistical significance, and no specific trend was identified in the 10-12-year-old group. Myopia prevalence exhibited a consistent increase since 2019 in the 6-9 age group, with a higher proportion of moderate myopia in 2020 compared to previous years. Conversely, no distinct trend was observed in the 10-12-year-old group.Conclusions: Although statistical significance was not reached, it appears that the increase in indoor activities due to COVID-19 had an impact on the changes in refractive values for elementary school children, especially in the lower grades of elementary school in 2020.

Распространенность кератоконуса и пограничных состояний по данным эпидемиологических исследований

Purpose. To study the prevalence of keratoconus and borderline conditions, as well as their association with ophthalmological parameters among the population of the Southern Urals in population-based studies. Material and methods. On the basis of the Ufa Eye Research Institute, population-based studies were conducted in three age groups: among children and adolescents of school age (6–17 years old) – 4,890 people, respondents 40+ years old and over 85 years old – 5,314 and 651, respectively. Standard and additional ophthalmological examinations were performed, as well as a retrospective analysis of keratotopograms of both eyes of the respondents. For statistical processing of the obtained results, the SPSS application software package was used, the significance criteria were applied: χ², Student’s t-test and Fisher’s criterion (F-test) of variance analysis. Results. The results of the analysis of population studies data showed that the incidence of keratoconus in different age groups of the population is 0.02%, among children and adolescents of school age, 0.07% – in respondents 40+, 0.15% – over 85 years old. Borderline conditions (steep cornea) are more common at the age of 85+ (6.45%), much less common in 40+ (2.11%) and even more rare in children and adolescents (0.09%). At the same time, the frequency of occurrence of borderline conditions correlated in children with a shorter axial length of the eye, and in adults with a shorter axial length, a higher index of myopic and cylindrical refraction, a smaller thickness and a larger volume of the cornea, and a larger thickness of the lens. Conclusion.In the group of children and adolescents, the prevalence of keratoconus was 0.02%, in respondents 40+ – 0.07%, over 85 years of age – 0.15%. The prevalence of borderline conditions (steep cornea) increased with age – from 0.09% to 2.11% and 6.45%, respectively. Key words:keratoconus, prevalence, borderline conditions, population-based studies

Myopia Management Need in Germany

Purpose: The increasing prevalence of myopia, particularly in Southeast Asia, and the predicted increase of the prevalence of myopia in Western countries mean that more children will benefit from myopia management. The current study evaluated by retrospectively analyzing electronic health records from eye health care practices in Germany how many children receiving single vision correction showed an annual myopia progression that indicates the need of myopia management (MM). Material and Methods: The Euronet database with a total data set of &gt; 1 million orders from the years 2000 to 2020 served as the basis for the present analysis. The dataset was filtered by age (6 - 14 years), refractive errors and the presence of longitudinal order data (baseline and second visit after 11 - 24 months, n = 64,825). First, the database was filtered to only include children with a myopic refraction of the right eye (in terms of the SE) of −0.5 D or below (n = 52,936). Next, the database was divided into children with an annual progression of the SE of ≤ −0.5 D (as a criterion for the need of MM, n = 25,432) and children with an annual progression of &gt; −0.50 D (n = 27,504), respectively. The number of children that require MM per shop per year was evaluated and the groups were further characterized with regards to the distribution of baseline SE and SE progression. Results: The analysis revealed that there are children of all ages who require myopia management, while their number increases with age, reaching a maximum at 10 to 11 years and declining afterwards (60 % of all children at age 7 and 30 % of all children at age 14, respectively). Children who have an early onset and high progression have baseline SE of around −1.50 D to −1.75 D and a second prescription SE of around −3.00 D. In contrast, children with later onset and lower progression have a similar baseline SE (average −1.62 D) but develop a second prescription SE of only around −2.00 D. Conclusion: Awareness of myopia, its progression and its potential impact on eye health needs to be raised in Germany. Even though the absolute number of children requiring myopia management is still rather low compared to other regions, the baseline refraction of myopic children is already very high. It is important to note that children who require myopia management benefit from efficient treatment options.

Longitudinal Study on Myopia Progression Considering Axial Length and Refraction in Caucasian Students

Purpose: Students are a risk group for myopia progression because of their intensive levels of near work. This study aimed to evaluate the progression of myopia in Caucasian students over a period of two years. Material and Methods: In a prospective multivariate longitudinal design over a period of two years, data from both eyes of 84 subjects (mean age = 23.7 ± 3.7 years; mean spherical equivalent = −2.01 ± 2.52 D) were randomized for statistical analysis. Axial length, non-cycloplegic refraction and corneal refractive power were measured using the Myopia Master (Oculus Optikgeräte GmbH, Germany). Additionally, data on near phoria, accommodation, outdoor activity, daily time with near work, and refractive influences were collected. Results: The subjects showed a statistically significant increase in axial length from baseline mean 23.98 ± 1.19 mm by 0.067 ± 0.025 mm ( = 0.010). The objective spherical equivalent (baseline mean = −2.01 ± 2.52 D) showed no statistically significant shift towards myopia (p = 0.113). In the moderate myopic subgroup, 40.0 %, 50.0 %, and 10.0 % showed axial myopia and refractive myopia of the crystalline lens or cornea, respectively. The main reasons for myopia progression were an increase in axial length (51.3 %), a change in refractive power of the lens (41.0 %), and a change in refractive power of the cornea (7.7 %). Near phoria and progression of myopia were correlated (p = 0.033). All other parameters were within the normal range and did not show a correlation with the progression of myopia. Conclusion: The risk group of Caucasian students showed neither a clinically relevant increase in axial length of the eye nor a change in objective spherical equivalent towards myopia over a period of two years. Nevertheless, the change in the refractive power of the crystalline lens is supposed to be an important factor for myopia progression, in addition to the change in axial length.

Анализ кератотопографических и биомеханических показателей роговицы c оценкой влияния результатов диагностики на тактику ведения пациента с миопической рефракцией

Abstract Analysis of keratopographic and biomechanical corneal indicators with evaluation of the impact of diagnostic results on myopic refraction patient management tactics D.D. Sibakin, V.A. Breev, E.G. Solodkova S. Fyodorov Eye Microsurgery Federal State Institution, Volgograd Branch, Volgograd, Russian Federation Purpose. To analyse keratopographic and biomechanical corneal indicators with the diagnostic results assessment of the influence on the treatment tactics of myopic refraction patient. Material and methods. Keratotopographic and biomechanical parameters of the cornea in a patient with mild myopia were evaluated. Results. The Belin/Ambrosio (Enchanced Ectasia Display) – BAD keratoconus screening program was used on Pentacam AXL, which did not reveal corneal pathology. According to the results of CBI (Corvis biomechanical index) on Corvis ST (Oculus, Germany) (OD – 0.61, OS – 0.48), that was indicating poor corneal biomechanical properties and a high risk of keratectasia development. Conclusion. Ophthalmic examination, using The Corvis ST biomechanical measurements, makes possible to reveal with greater sensitivity subclinical signs of a keratectatic process at the pre-clinical stage of development. Key words: keratotopography, corneal biomechanics, keratoconus

Brimonidine as a possible treatment for myopia

BackgroundMyopia is becoming a huge burden on the world’s public health systems. The purpose of this study was to explore the effect of brimonidine in the treatment of form-deprivation myopia (FDM) and the relationship between intraocular pressure (IOP) and myopia development.MethodsMonocular form deprivation myopia (FDM) was induced in three-week-old pigmented male guinea pigs. They were treated with 3 different methods of brimonidine administration (eye drops, and subconjunctival or intravitreal injections). Four different concentrations of brimonidine were tested for each method (2µg/µL, 4µg/µL, 20µg/µL, and 40µg/µL). All treatments continued for a period of 21 days. Tonometry, retinoscopy, and A-scan ultrasonography were used to monitor intraocular pressure, refractive error and axial length (AL), respectively.ResultsTreatment with subconjunctival brimonidine at 40µg/µL, and intravitreal brimonidine at 2µg/µL and 4µg/µL, inhibited the development of FDM. The myopic refraction, excessive axial length, and elevation of IOP were significantly decreased. Brimonidine in eye drops was ineffective.ConclusionBrimonidine at appropriate doses significantly reduced the development of FD myopia in guinea pigs. The IOP may change with FD myopia.

Factors Associated with the Myopia Degree in Students

Purpose: to identify the most significant factors associated with myopic refraction in medical university students, which can be used for early prediction and prevention of myopia.Materials and methods. The survey data of students of 1–6 courses of Kazan State Medical University and the data on refraction of patients’ eyes obtained from the “Medical record of a patient receiving medical care on an outpatient basis” (registration form No. 025/y) were used. The refraction of the eye in each of the participants was calculated as the average value of the spherical equivalent of the right and left eyes.Results. According to the ophthalmologist’s examination, myopia was detected in 219 (69 %) of the surveyed students. 134 (42 %) students had mild myopia, 66 (21 %) had moderate myopia, 19 (6 %) were highly myopic. Among myopes, 73 % of students wear glasses (160/219), contact lenses — 41 % of respondents (90/219). The median age of onset of spectacle wear was 13 years (Q1–Q3 = 10–26). The median refraction of the right eye (D) was -2.50 D (Q1–Q3 = -1.5…-4.0), the left eye -2.75 D (Q1–Q3 = -1.6…-4.0). The early age of onset of spectacle wear is the factor most significantly associated with myopic refraction (+0.23 D/year, p = 1.30×10-11), and an important prognostic sign of the development of high myopia. Factors associated with stronger myopic refraction are high height and low weight, as well as less physical activity.Conclusion. It is necessary to take into account the anthropometric and behavioral features of the patient when developing an individual plan for the prevention and treatment of myopia, in order to avoid the development of complications leading to vision loss.

Prevalence of myopia in schoolchildren of a highly urbanized city in Eastern Siberia

Myopia is one of the most urgent problems of modern ophthalmology. Statistics show that the number of children and adolescents suffering from myopia is steadily increasing worldwide. But it also noted that in different regions of the Russian Federation, the proportion of children who are diagnosed with myopia may differ markedly. Purpose: to determine the prevalence and structure of myopia in schoolchildren of the city of Krasnoyarsk, depending on age and gender. Materials and methods. A survey of 3005 students of secondary schools in the city of Krasnoyarsk aged from 6 to 18 years, including 1,421 schoolboys and 1,584 schoolgirls, was conducted. Refraction was determined after cycloplegia using the autorefractometry method. Results. The predominant type of refraction in primary school students of both fi elds is emmetropia, myopia is in second place and other refractive errors are in third place. The prevalence of myopia in schoolchildren increases as they grow up. At the same time, in the schools of the city of Krasnoyarsk, already in the primary grades in the group of subjects of both sexes, the proportion of students with myopia was 17.9 %, in the middle – 36.8 %, and by the high classes it reached 49.7 %. When considering the data obtained, depending on gender, approximately the same proportions of myopia were found in primary grades in both schoolgirls (19.2 %) and schoolchildren (16.7 %), in middle grades, a statistically significant predominance of myopic refraction in girls, compared with boys (42.8 and 29.5 %, respectively, p &lt; 0.05). In high school, the proportion of myopia increases both in girls to 52.1 % and in boys to 47.2 %. The proportion of subjects with emmetropic refraction decreases as individuals of both sexes grow up. The percentage of other refractive errors remains without significant gender-age changes. Low myopia was the most common in all groups, but its percentage significantly decreased as they moved to higher grades, simultaneously with an increase in the proportion of moderate and high myopia. Conclusions. There is an increase in the prevalence of myopia in schoolchildren as they move to higher grades. A threefold increase in the proportion of myopia in high school compared with primary school was revealed. It is necessary to further study the prevalence of myopia in all Russian regions and develop preventive programs to control myopia in children.

Predicting myopic changes in children wearing glasses using the Plusoptix photoscreener

IntroductionWith high increase in myopia prevalence, we aimed to assess whether Plusoptix_A09 can be used in myopic children over spectacles to predict visual acuity (VA) and myopic refraction changes.MethodsMyopic children underwent a complete ophthalmological examination. Plusoptix_A09 was performed over spectacles. VA changes, refraction changes and time since previous glasses prescription, were determined. Age, current or past history of amblyopia, presence of strabismus and self-perception of VA changes were registered.ResultsIn total, 199 patients were included. Spherical power (SP) and spherical equivalent (SE) measured by Plusoptix_A09 over spectacles predicted both VA changes (p < 0.001) and refraction changes (p < 0.001). Values of SP < − 0.06D or SE < − 0.22D indicated a VA decrease (AUC > 0.9, p < 0.01) for sensitivity and specificity of 85.1%, 82.1% and 82.6%, 83.3%, respectively. Age and ophthalmological comorbidities did not influence Plusoptix_A09 measurements (p > 0.05). Plusoptix_A09 over spectacles was a stronger predictor of VA changes when compared to children's self-perception, either in 4–9-year-old patients (p < 0.001 versus p = 0.628) and in 10–18-year-old children (OR < = 0.066 versus OR = 0.190). A decrease in SP and SE of − 0.10D in Plusoptix_A09 predicted a myopia progression of − 0.04D and − 0.05D, respectively.Conclusion/RelevanceThis study unveiled new features for the Plusoptix, a worldwide available photoscreener used inamblyopia screening. When Plusoptix is performed in children with their glasses on, it can rapidly predict myopia progression.For each decrease of − 0.10D in Plusoptix, a myopia progression of -0.05D is expected. Moreover, Plusoptix is more reliablethan children's self-perception of visual acuity changes, making it a useful tool either in primary care or ophthalmologypractice

FREQUENCY OF AMBLYOPIA AMONG SCHOOL GOING CHILDREN

Background: To determine the frequency of amblyopia among school going children.&#x0D; Objective(s): To find out the frequency of amblyopia gender-wise, age-wise in children with respect to the most frequent type of amblyopia.&#x0D; Methodology: It was a descriptive cross-sectional study which comprises of 264 individuals. It was conducted at Elementary school Muridke. A self-designed Performa was used to gather the data which mainly included individual’s biodata, ocular history and visual acuity. Individual’s eyes were examined using Auto refractometer, Retinoscope, Ophthalmoscope, trail box with, occlude, Snellen chart used and all the findings were then recorded on the Performa. When it comes to entering and analyzing the data, we used the IBM Spss version.&#x0D; Results: A total of 264 subjects participated out of which 104(39.3%) were females and 160(60.6%) were males. The mean age of the subjects was 9.45±2. 871.All students are belonging to Muridke. Total of 264 subjects in which 16 (6.1%) individuals have VA 6/12, 5 (1.9%) individuals have 6/18, 234(88.6%) individuals have 6/6 VA, 3 (1.1%) individuals have 6/60 VA and 6 (2.3%) individuals have 6/9 visual acuity in right eye and 14 (5.3%) subjects have VA 6/12, 6 (2.3%) subjects have VA 6/18, 236 (89.4%) subjects have VA 6/6 and 8 (3.0%) subjects have VA 6/9 in left eye. In this study1 (0.4%) subjects have corrected visual acuity in right eye is 6/18, 260(98.5%) individuals have corrected VA 6/6, 2 (0.8%) subjects have corrected VA 6/60 and 1 (0.4%) have corrected VA 6/9 in right eye. And 262 (99.2%) individuals have corrected VA 6/6 and 2 (0.8%) individuals have corrected VA 6/9 in left eye. which 21 (8.0%) individuals have refractive error myopia, 5 (1.9%) have astigmatism, 3(1.1%) have hypermetropia and 235 (89.0%) individuals are Emmetropia. All the study participants were orthophoric with full extra ocular motility and clear ocular media.&#x0D; &#x0D; Conclusion(s): Our study concludes that 1.5% individuals are amblyopic and have refractive type amblyopia and 98.5% individuals are non-amblyopic.

Analysis of the effect of keratotopographic parameters on tonometric intraocular pressure

BACKGROUND: Applanation tonometers remain popular in most countries of the world; in Russia, the Maklakov tonometer is one of them. When using a Maklakov tonometer, intraocular pressure values are obtained indirectly through the cornea, which has individual characteristics, which certainly introduces its own errors into the accuracy of the measurement results.&#x0D; AIM: The aim of this study was to investigate the influence of keratotopographic parameters on tonometric intraocular pressure.&#x0D; MATERIALS AND METHODS: A study of 16 keratotopographic indices (using ALLEGRO Oculyzer Wavelight Oculyzer II) and of tonometric intraocular pressure values obtained using Maklakov tonometer (NGm2-“OFT-P”) was carried out in 500 patients (1000 eyes). Among the study population there were patients with both emmetropic refraction — 8 eyes (0.8%), and patients with refractive errors 992 eyes (99.2%), among them: 978 eyes (97.8%) had myopic refraction 14 (1.4%) eyes had isolated refraction with myopic astigmatism. 889 eyes (88.9%) combined myopic refraction with myopic astigmatism.&#x0D; RESULTS: Based on the analysis of 16 keratotopographic parameters and tonometric intraocular pressure values, 500 patients (1000 eyes), the greatest influence of 13 studied parameters of the cornea was determined, such as: K1 (keratometry of flatter meridian); K2 (keratometry of steeper meridian); Km (mean keratometry); Rf (radius of the flatter meridian); Rs (radius of the steeper meridian); Rm (mean radius of curvature); Rmin (minimal radius of curvature); Rper (average radius of curvature between the 6 mm and 9 mm zone center); IVA (index of vertical asymmetry); ISV (index of surface variance); CKI (central keratoconus index); Thickness (thickness); IHD (index of height decentration) — on intraocular pressure values.&#x0D; CONCLUSIONS: Based on the results obtained, we determined the effect of topographic parameters of the cornea on tonometric intraocular pressure, and created a formula for correcting intraocular pressure values based on the original formula we developed: Pt keratotopographic corrected = Pt + (±ISVp) + (±IVAp) + (±Rmp) + (±Kmp) + (±CKIp) + (±Thicknessp), where Pt keratotopographic corrected is the corrected tonometric intraocular pressure and Pt is the tonometric intraocular pressure.

Рефракционная замена хрусталика при рефракционной амблиопии: «лечение» или диагностика?

Relevance. Refractive amblyopia is one of conditions that reduce best corrected visual acuity (BCVA) in patients. With the advent of new methods of refractive surgery, we note new features of the course of refractive amblyopia in adult patients after refractive surgery. Purpose. Determination of changes in uncorrected visual acuity and BCVA as well as changes in the degree of amblyopia in patients with high-grade refractive errors after implantation of toricIOLs during refractive lens replacement (RLL). Materials and methods. Retrospective evaluation of functional outcomes in 20 patients over 18 years (28 eyes) who received surgical treatment in the form of refractive lens replacement for myopic and hypermetropic astigmatism in the presence of high-grade ametropia with amblyopia. Results. In 35.3% of patients with myopic refraction, the diagnosis of amblyopia was removed. In 41.2%, we saw reducing the degree of amblyopia, 23.5% added 1 line of BCVA without changing the degree of amblyopia. When comparing the BCVA of patients with myopic refraction before and after surgical treatment, significant differences were obtained. In all eyes with hypermetropic refraction, there was no change in the degree of amblyopia after surgery, 22% of operated ones received an increase in BCVA by 1 line. There were no significant differences of BCVA a week after surgery in patients with hyperopic refraction. Conclusion. The revealed change in the degree of amblyopia in patients in early stages after RLL makes us clarify diagnosis and doubt sufficiency of standard methods for diagnosing amblyopia and determining its degree. In amblyopic patients with high myopia, in comparison with patients with hyperopia, refractive replacement of the transparent lens in most cases leads to an increase in BCVA in a short time after. Refractive lensectomy, is a amblyopia treatment, and is an important tool to exclude the diagnosis of amblyopia or reduce its degree. Key words: amblyopia, lens, refractive surgery, myopia, hypermetropia

The method for determining intraocular pressure according to keratotopographic indicators

Relevance. In most countries of the world, applanation tonometers remain popular, such as the Maklakov tonometer and the Goldman tonometer. When measuring ophthalmotonus, such tonometers receive IOP values indirectly through the cornea, which certainly introduces its own errors into the measurement results. The creation of methods for measuring IOP different from the currently existing ones is relevant. Purpose: to create a new method for determining intraocular pressure without tonometry, based on the indicators of the individual profi le of the cornea with its parameters, indices and autorefractometry data. Materials and methods. Statistical analysis of 16 parameters of a keratotopograph (ALLEGRO Oculyzer, WaveLight Oculyzer II), data of an autorefractometer (TONOREF Nidek device) and data of tonometric intraocular pressure was carried out using a Maklakov tonometer (НГм2-«ОФТ-П») in 500 patients (1000 eyes). Among the sample population there were patients with both emmetropic refraction – 8 eyes (0.8%), and patients with refractive errors 992 eyes (99.2%), among them: 978 eyes (97.8%) had myopic refraction, 14 (1.4%) eyes had isolated refraction with myopic astigmatism. 889 eyes (88.9%) combined myopic refraction with myopic astigmatism. Results. Based on the analysis of keratotopographic parameters, autorefractometry values and tonometric IOP of 500 patients (1000 eyes), we have created a new method for determining intraocular pressure without tonometry, presented in the form of a mathematical model: Pt keratotopographic = 61.9 – 0.06 × SPH – 2.39 × Rf + 0.64 × Rmin – 0.15 × log2 (IVA) – 31.9 × CKI – 0.006 × Thickness. Conclusions. Based on the results obtained for determining IOP without physical interaction with the eye, the mathematical model created by us can be used in cases where the use of any tonometer is impossible.