Ocular Refractive Error Research Articles

Regional/ethnic differences in ocular axial elongation and refractive error progression in myopic and non-myopic children.

To determine the regional and ethnic differences in ocular axial elongation and refractive error progression in myopic and non-myopic children. A retrospective analysis of 15 longitudinal clinical and population-based studies was conducted in the UK, Sweden, Australia (classified as European), China, and Vietnam (classified as East Asian) between 2005 and 2021. A total of 14,593 data points from 6208 participants aged 6-16 years with spherical equivalent from +6 to -6 D were analysed. Progression was annualised from longitudinal axial length and cycloplegic spherical equivalent (SE) refraction. Generalised estimating equation models including main effects and interactions were used for model building. Age and region-specific estimates for myopes and non-myopes and confidence intervals are reported. Factors affecting axial elongation and SE progression in children included being myopic, followed by age, region/ethnicity and sex. The magnitude of regional/ethnic differences was dependent on myopia and age. Axial elongation and SE progression were lower in European compared with East Asian children, but differences were reduced with increasing age and differences in axial elongation were larger in myopes than non-myopes. Age-specific regional/ethnic differences indicated that axial elongation for a 6-year-old East Asian myopic child was greater than a European child by 0.15 mm/year (0.58 vs. 0.43 mm/year) and by 0.09 mm/year (0.35 vs. 0.26 mm/year) for a 10-year-old myope. SE progression was lower in a 6-year-old European myope by 0.48 D/year and at 10 years of age by 0.34 D/year compared with an East Asian myope. There are regional/ethnic differences in age-specific refractive and axial growth patterns in both myopic and non-myopic eyes, with more marked differences in younger East Asian children who demonstrated a higher axial growth and greater negative SE shift than their non-Asian peers. Regional/ethnic differences in progression reflect environmental and ethnic variations. Age and region/ethnicity-specific estimates could contribute as a reference for future comparisons.

Refraction and ocular biometric parameters in 3-to 6-year-old preschool children : a large-scale population-based study in Chengdu, China

PurposeTo understand the ocular biometric parameters characteristics and refractive errors in 3-to 6-year-old preschool children in Chengdu, China, and to investigate the prevalence of refractive errors.MethodA school-based cross-sectional study was conducted in Chengdu from 2020 to2022 with a total of 666 kindergartens. All children were measured by non-cycloplegic autorefraction and uncorrected visual acuity (UCVA) and ocular biometric parameters. Finally, univariate linear regression models were used to analyze the relationship between ocular biometric parameters and refraction.ResultsA total of 108,578 preschool children aged 3–6 underwent examinations, revealing a myopia prevalence of 6.1%. The mean axial length (AL), keratometry (K), corneal radius (CR), axial length/corneal radius (AL/CR) Ratio, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD) were 22.35 ± 0.69 mm, 43.35 ± 1.58 D, 7.80 ± 0.28 mm, 2.87 ± 0.08, 533.31 ± 32.51 μm, 2.70 ± 0.28 mm, 3.91 ± 0.27 mm, and 15.20 ± 0.68 mm, respectively. With increasing age, AL, CR, AL/CR ratio, CCT, ACD, LT, and VCD also increased. Regardless of age, males consistently exhibited longer AL, flatter corneal curvature, shallower ACD, thicker CCT, thinner LT, and longer VCD compared to females. AL, K, CR, LT, and VCD all showed significant linear relationships with SE (all P < 0.001) in univariate linear regression analysis after adjusting for gender and age.ConclusionThe prevalence of myopia among preschool children aged 3–6 in Chengdu is relatively low. Ocular biometric parameters affecting refractive errors include AL, K, CR, LT, and VCD. The preschool period serves as a critical phase for myopia prevention and control.

Associations between Ocular Biometry, Refractive Error, and Body Characteristics

Myopia is a refractive error widely spread throughout the world, usually related to excessive axial length (AL) of the eye. This elongation could have severe consequences, even leading to blindness. However, AL varies among subjects, and it may be correlated with other anthropometric parameters. The aim of this study was to evaluate the relationships between AL, body height, refractive error, and sex. A total of 72 eyes of 36 myopic participants with a mean age of 11.1 ± 1.42 years (ranging from 8 to 14 years) were included in the study. Participants underwent objective refraction by NVision-K5001, AL measurement by Topcon MYAH biometer, and body height measurement. Significant correlations were observed between AL, body height, and spherical equivalent (SE) (Spearman’s correlation, all p ≤ 0.016). When participants were grouped by AL, significant differences were observed for body height and SE, and when grouped by height percentile, significant differences were observed for AL and SE (Kruskal–Wallis test, all p ≤ 0.006). There was a significant difference in SE, AL, and body height between genders (Mann–Whitney U test, all p ≤ 0.038). AL relates to the refractive state of the eye and is also influenced by individual anatomical characteristics.

A Study of Ocular Manifestations in Children with Developmental Delay

Background and Objective: The study was conducted to determine the occurrence and types of ophthalmologic abnormalities in children with developmental delay. Methods: children with developmental delay between age group of 6 months to 16 years visiting Himalayan hospital were studied for presence and types of ocular manifestations over a period of 1year. Results: Among 54 children, ocular manifestation was noted in 48 (88.89%) children. Among various ocular manifestations refractive error was commonest seen in 29 out of 54(53.70%) cases of which hypermetropia was most common. Second most common manifestations was esotropia 11 out of 54 (20.37%) followed by exotropia 7 out of (12.96%). In 12 out of 54 (22.22%) subjects temporal disc pallor was present. Conclusion: In developmentally delayed children, visual handicap plays an important role in overall morbidity. early assessment and correction of visual problems will provide such children greater chances of achieving their true potential and will prevent unnecessary visual impairment

Accuracy and Precision of New Optical Biometer Designed for Myopia Management in Measurement of Ocular Biometry.

This study provides information about the repeatability of Myopia Master and its agreement with Lenstar LS900, which might be useful for the practitioners involved in myopia management. Myopia Master is a new optical biometer that measures ocular biometry and refractive error. The purpose of this study is to assess its repeatability (intra-session and short-term inter-session) and its agreement with Lenstar LS900 for the measurement of axial length and corneal curvature. A total of 304 participants including 254 children (Mean age: 13.7 ± 1.6 years) and 50 adults (24 ± 2.9 years) underwent measurements on Myopia Master and Lenstar LS900 to obtain axial length (AL), flat K (K1), and steep K (K2). On a subset of 30 participants, measurements were obtained with Myopia Master in two sessions that were spread over 10 minutes to assess the short-term inter-session repeatability. The mean standard deviation of Myopia Master in the measurement of axial length in the total sample was 0.01 mm for intra-session, when the best three measurements were considered. The short-term inter-session mean standard deviation for AL, K1, and K2 was 0.06 mm, 0.15 D, and 0.21 D respectively. There were statistically significant differences in mean values of AL (-0.04 ± 0.06 mm), K1 (-0.07 ± 0.15 D), and K2 (-0.24 ± 0.29 D) between Lenstar LS900 and Myopia Master with the Lenstar providing slightly longer axial length and steeper K values. Adults showed better repeatability with Myopia Master and better agreement between the biometers for AL measurement than children. Neither axial length nor refractive error influenced the repeatability or agreement. Myopia Master is repeatable for the measurement of axial length and corneal curvature. Considering the differences in axial length between the Myopia Master and Lenstar LS900, caution must be applied when these biometers are used interchangeably.

Estimating the Genetic Contribution to Astigmatism and Myopia in the Mexican Population.

Astigmatism and myopia are two common ocular refractive errors that can impact daily life, including learning and productivity. Current knowledge suggests that the etiology of these conditions is the result of a complex interplay between genetic and environmental factors. Studies in populations of European ancestry have demonstrated a higher concordance of refractive errors in monozygotic (MZ) twins compared to dizygotic (DZ) twins. However, there is a lack of studies on genetically informative samples of multi-ethnic ancestry. This study aimed to estimate the genetic contribution to astigmatism and myopia in the Mexican population. A sample of 1399 families, including 243 twin pairs and 1156 single twins, completed a medical questionnaire about their own and their co-twin's diagnosis of astigmatism and myopia. Concordance rates for astigmatism and myopia were estimated, and heritability and genetic correlations were determined using a bivariate ACE Cholesky decomposition method, decomposed into A (additive genetic), C (shared environmental) and E (unique environmental) components. The results showed a higher concordance rate for astigmatism and myopia for MZ twins (.74 and .74, respectively) than for DZ twins (.50 and .55). The AE model, instead of the ACE model, best fitted the data. Based on this, heritability estimates were .81 for astigmatism and .81 for myopia, with a cross-trait genetic correlation of rA = .80, nonshared environmental correlation rE = .89, and a phenotypic correlation of rP = .80. These results are consistent with previous findings in other populations, providing evidence for a similar genetic architecture of these conditions in the multi-ethnic Mexican population.

Investigation of the efficacy and safety of retinal inactivation as a treatment for amblyopia in cats.

Deprivation of normal vision early in postnatal development elicits modifications of neural circuitry within the primary visual pathway that can cause a severe and intractable vision impairment (amblyopia). In cats, amblyopia is often modeled with monocular deprivation (MD), a procedure that involves temporarily closing the lids of one eye. Following long-term MD, brief inactivation of the dominant eye's retina can promote recovery from the anatomical and physiological effects of MD. In consideration of retinal inactivation as a viable treatment for amblyopia it is imperative to compare its efficacy against conventional therapy, as well as assess the safety of its administration. In the current study we compared the respective efficacies of retinal inactivation and occlusion of the dominant eye (reverse occlusion) to elicit physiological recovery from a prior long-term MD in cats. Because deprivation of form vision has been associated with development of myopia, we also examined whether ocular axial length or refractive error were altered by a period of retinal inactivation. The results of this study demonstrate that after a period of MD, inactivation of the dominant eye for up to 10 days elicited significant recovery of visually-evoked potentials that was superior to the recovery measured after a comparable duration of reverse occlusion. After monocular retinal inactivation, measurements of ocular axial length and refractive error were not significantly altered from their pre-inactivation values. The rate of body weight gain also was not changed during the period of inactivation, indicating that general well-being was not affected. These results provide evidence that inactivation of the dominant eye after a period of amblyogenic rearing promotes better recovery than eye occlusion, and this recovery was achieved without development of form-deprivation myopia.

Results of the School Children Ocular Biometry and Refractive Error Study in South India.

Axial length (AL) is an important contributor to refraction, and growth curves are gaining importance in the prediction of myopia. This study aimed to profile the distribution of ocular biometry parameters and to identify correlates of spherical equivalent refraction (SE) among school children in South India. The School Children Ocular Biometry and Refractive Error study was conducted as part of a school screening program in southern India. The enrolled children underwent tests that included vison check, refraction, binocular vision assessment, and biometry measurements. The study included 1382 children whose mean (standard deviation [SD]) age was 10.18 (2.88) years (range: 5-16 years). The sample was divided into 4 groups (grades 1-2, grades 3-5, grades 6-9, and grade 10) based on significant differences in right AL (p<0.001). The mean (SD) AL (range: 20.33-27.27 mm) among the four groups was 22.50 (0.64) mm, 22.88 (0.69) mm, 23.30 (0.82) mm, and 23.58 (0.87) mm, respectively. The mean SE (range: +1.86 to -6.56 D) was 0.08 (0.65 D) in class 1 and decreased with increasing grade to -0.39 (1.20 D) in grade 10. There was a significant difference in all biometry parameters between boys and girls (p<0.001). Age, AL, and mean corneal curvature were the main predictors of SE. This study provides a profile of ocular biometry parameters among school children in South India for comparison against profiles from other regions across the country. The study data will form a reference for future studies assessing myopia in this ethnicity.

Sex differences in ocular biometric measurements: A twin study.

Gender differences in ocular biometric measurements of opposite-sex and same-sex twin pairs are still unclear. We aimed to investigate the difference between ocular biometric measurements in adolescent twin pairs. This retrospective study included a total of 64 eyes of 64 adolescents from 32 twins. The ocular biometric measurements and refractive prediction error (RE) were acquired from four groups of dizygotic (DZ) twins: boys from same-sex twin-pairs (SSM, n = 20), boys from opposite-sex twin-pairs (OSM, n = 8), girls from opposite-sex twin-pairs (OSF, n = 8), and girls from same-sex twin-pairs (SSF, n = 29). The mean age of the patient was 9.92 ± 2.84 (range: 6-18) years. Overall, boys had higher height, AL, WTW, but lower Ks, and Kf than girls (p < 0.05). Specifically, SSF was found to have the lowest lens thickness (LT), anterior chamber depth (ACD), central corneal thickness (CCT), white to white (WTW), and axial length (AL) levels, while the highest keratometry readings in the flat (Kf) and steep (Ks) levels compared with OSM, OSF, and SSM adolescents (p < 0.05). Compared with the OSF adolescents, ACD levels of the SSF adolescents were significantly lower [(2.99 ± 0.35) and (3.26 ± 0.15) mm, p = 0.033)], but Kf indicator was significantly larger [(43.93 ± 1.64) and (42.91 ± 1.75), p = 0.016)]. Our study indicates that there was a significant difference in ocular biometric measurements between twin pairs, and sharing the uterus with a DZ twin SSF has smaller ocular indicator measurements. Our findings provide information on the eyeball and refractive development in adolescents.

Mathematical Model for Enhancement of Visual Acuity through Electronic System Biofeedback

The majority of people across the world have issues with their vision caused by human ocular refractive errors. Myopia affects 51% of adults, hyperopia affects 38% of adults, and astigmatism affects 27% of adults in the United States. This frequency is much higher in the adult population. 42 percent of global causes of visual impairment are attributable to failure to take prophylactic action against these disorders. This percentage includes presbyopia in adulthood. Visual strain brought on by an excessive use of electronic devices has led to the creation of new techniques and the development of various solutions, including corrective lenses, contact lenses, laser and non-laser refractive surgical operations, and so on. Using a signal electromyography feedback, we describe a technique that may be used to increase a person’s visual acuity. An electronic controlled lens with a power range of -10 to +10 diopters was used in its implementation, along with a LabVIEW interface-connected electromyographic signal gathering equipment. Five separate persons were given the Snellen test to evaluate the proposed system, giving each of them twenty opportunities to complete the exam. Consequently, it is feasible to enhance visual acuity up to 20/20 with an accuracy of 90 percent utilising a biofeedback system, together with other spherical ocular refraction errors such presbyopia, farsightedness, and myopia.

Variations in Ocular Biometrics Related to Refractive Errors Among Adult Patients Attending the University Teaching Hospitals-Eye Hospital in Lusaka, Zambia

Coordination among anatomical components (Ocular biometrics) of the eye [corneal and lens power (CP/LP), anterior chamber depth (ACD), lens thickness (LT), and axial length (AL)] determine the refractive state of the eye. Ocular biometric measurements are crucial for the selection of the correct IOL and prescription of power to achieve the desired refractive outcome after cataract surgery and refractive errors respectively. This was a cross-sectional study conducted at University Teaching Hospitals Eye Hospital in Lusaka– Zambia; from April to June 2021, to assess the relationship between ocular biometrics and refractive errors. The study involved the measurement of refractive errors and ocular biometrics (Axial length, Lens power, Lens thickness, anterior chamber depth, corneal dioptric power, corneal radius, and Pupil size) in 205 study participants aged between 16 and 60 years of which 64 (31.2%) were males and 141 (68.8%) were females. Refractive errors were measured with a KR-9600 auto keratore fractometer whilst Ocular biometric parameters were done using an Optilex 780 marvels 11 A/B Scan Dell ultrasonography machine and autokeratometry. Out of 205 recruited study participants, 135 (65.9%) had refractive errors. The proportion of types of refractive errors were 66 (48.9%), 39 (28.9%), 19 (14.1%), and 11 (8.1%) for myopia, presbyopia, astigmatism, and hyperopia respectively. Variations of ocular biometrics among participants showed that mean values of anterior chamber depth, axial length and pupil size were greater in myopic study participants (2.7 mm, 23. 9 mm, and 4.39 mm respectively). Mean Lens thickness was much thicker in Presbyopia (3.95+/-0.65) while Lens power varied across all types of REs. Ocular biometrics related to refractive errors were axial length, anterior chamber depth, and lens thickness. Axial length and anterior chamber depth associated strongly with Myopia while lens thickness was more linked to Presbyopia. Age (16 and 47) years, inheritance, and childhood-onset associated strongly with Myopia while Presbyopia increased with increase in age.

Ocular Dimensions, Refractive Error, and Body Stature in Young Chinese Children with Myopia in Kuala Lumpur, Malaysia.

PurposeEyeball shape varies with refraction and body stature. Nevertheless, there are few reports on three-dimensional measurements of eyeball shape in children. The aim of this cross-sectional observational study was to investigate the associations between three-dimensional measurements of ocular dimensions, refractive error, and body stature in young Chinese children with myopia in Kuala Lumpur.Materials and MethodsThirty-five female and 35 male school children aged 8–9 years old were recruited in this study. Cycloplegic spherical equivalent (SE) and visual acuity (VA) were determined using a logarithm of the minimum angle of resolution (logMAR) chart. Body mass index (BMI), body height, and head circumference were ascertained. Three ocular dimensions, that is, longitudinal axial length (LAL), horizontal width (HW), and vertical height (VH), were determined using magnetic resonance imaging (MRI).ResultsThere were significant differences among the ocular dimensions in the myopic children. Bonferroni-corrected pairwise t-tests showed that LAL was significantly longer (mean difference, 0.318 mm) than VH, which was in turn significantly longer (mean difference, 0.245 mm) than HW. Body height was significantly correlated with LAL (p < 0.001) and SE (p < 0.001), and multivariate linear regression confirmed that longer LAL and more myopic SE were associated with increased body height (p < 0.001 for both) but not BMI (p = 0.894 and p = 0.413) or head circumference (p = 0.305 and p = 0.226).ConclusionThis study confirms previous reports that changes in ocular dimensions are associated with body height in young children. Axial elongation (forming a prolate profile) occurs in myopic children of both genders at a young age.

Awareness and Predominance of Blue Light Related Visual Problems Among Undergraduate Medical Students

Background:As students spend more time for online class sessions by using computer, they get more prone toblue light exposure.Visual problems among the university students can have an adverse impact on their educational and employment opportunities.The aim of this study is to investigate the blue light exposure and visual problems among the undergraduate university students. Methods:A cross-sectional study was carried out in a private medical school in the Kedah state, Malaysia. Total of 200 students from pre-clinical years were taken as sample by convenient sampling method.A self-administered structured questionnaire was used, and the data were computerized and analysed by using IBM SPSS Statistics Version 22. Results: The prevalence of refractive error was 66.6% and the highest problem was short sightedness with astigmatism. Sufficient awareness towards eye problems was noticed among the respondents. More than 90% of the students showed satisfactory knowledge related to the harmful effects of blue light.Dry eyes and recent headache were associated to fluorescent light. Recent visual complaints were depending on computer exposure whilerecent headache was related to mobile use. Worsening of eye problems and computer or projector exposure were found to be associated. Conclusion: Our study highlights the constrained awareness among novice medical students regarding ocular health. We carefully discerned the pattern of blue light exposure and the prevalence of ocular symptoms and refractive errors in the studied population. Recommendations for further research that can help improve eye health were suggested.

A Comparison of Visual Quality and Contrast Sensitivity between Patients with Scleral-Fixated and In-Bag Intraocular Lenses.

Purpose: To analyze visual quality and contrast sensitivity in patients after intraocular lens (IOL) implantation with sutured scleral fixation. Setting: Chang Gung Memorial Hospital, Taoyuan, Taiwan. Design: Retrospective observational study. Methods: Data on the refractive outcome, visual acuity, and subjective visual symptoms in patients with scleral-fixated or in-bag IOL implantation were collected from September 2019 to March 2020. We also investigated patients’ postoperative higher-order aberrations (HOAs) and dysphotopsia using a wavefront aberrometer and glaretester, respectively. The following values were compared: corrected distance visual acuity, spherical equivalent, root mean square values for aberrations, and contrast sensitivity. Results: A total of 23 eyes implanted with scleral-fixated IOL and 74 eyes with in-bag IOL were studied. The mean postoperative spherical equivalent and logarithm of the minimum angle of resolution after scleral fixation were −1.09 ± 3.32 D and 0.20 ± 0.17, respectively. The ocular HOAs were higher in the scleral-fixation group than in the in-bag group (p = 0.001). Contrast sensitivity was negatively associated with age, and it was similar between the two groups after controlling for the age effect. Conclusions: Ocular HOAs and refractive errors were higher in the scleral-fixation group than in the in-bag group. However, no significant difference was noted in contrast sensitivity between advanced scleral fixation and in-bag IOL implantation.

Recovery From Form-Deprivation Myopia in Chicks Is Dependent Upon the Fullness and Correlated Color Temperature of the Light Spectrum.

PurposeThe purpose of this study was to evaluate the impact of full-spectrum light-emitting diodes mimicking sunlight (Sunlike LEDs) on ocular growth and refractive error development in a chicken model of myopia.MethodsOne-day old chicks (n = 39) were distributed into 3 groups and raised for 28 days in isoluminant (approximately 285 lux) fluorescent (n = 18, [FL-4000], correlated color temperature [CCT] = 4000 K) or Sunlike LED (n = 12, [SL-4000], CCT = 4000 K; n = 9, [SL-6500], CCT = 6500 K) white lighting environments. Form-deprivation myopia was induced monocularly from day 1 post-hatching (D1) until D14. On D14, form deprivation was halted and the recovery of form-deprived (FD) eyes was monitored until D28. Axial length (AL), refraction, choroidal thickness, and anterior chamber depth were measured in vivo on D1, D7, D14, D22, and D28. Differences in outcome measures between eyes and groups were compared using 2-way repeated-measures ANOVA.ResultsAL and myopic refraction of FD eyes increased similarly among groups during form-deprivation. FD eyes of animals raised under SL-4000 (D22: P < 0.001 and D28: P < 0.001) and SL-6500 (D22: P = 0.006 and D28: P < 0.001) recovered faster from axial elongation compared with animals raised under FL-4000. The refractive status of FD eyes reared under SL-6500, not under FL-4000 or SL-4000, was similar to control eyes on D28 (P > 0.05). However, SL-4000 and SL-6500 exhibited similar refraction on D28 than FL-4000 (P > 0.05). Choroidal thickness was significantly greater in FD eyes of chickens raised under SL-6500 than in animals raised under FL-4000 (P = 0.03).ConclusionsCompared to fluorescent light, moderate intensities of full-spectrum Sunlike LEDs can accelerate recovery from form-deprivation myopia in chickens, potentially through a change in the choroid-mediated pathway.

Early choroidal structure and choroidal vascularity index change after carotid stenting

PurposesWe aimed to evaluate changes in subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) in the first postoperative day and month in patients with severe internal carotid artery (ICA) stenosis after ICA stenting. MethodThe patients who diagnosed with severe ICA stenosis and was performed ICA stenting were included in the study. Patients with any ocular disease and refractive error more than 3 diopters were not included in the study. The imaging of the choroid was performed using enhanced depth imaging (EDI) techniques by spectral domain optical coherence tomography (SD-OCT) (OptovueRTVue XR, Optovue Inc., Fremont, CA).The choroidal vascularity index (CVI), total choroidal area (TA), luminal area (LA), and stromal area (SA) were measured in the subfoveal 2 mm area. These measurements before ICA stenting was compared with the first day and first month after ICA stenting. ResultsThe study included 41 eyes from 41 patients (11 women [26.83%]; 30 men [73.17%]). The mean age of patients was 62.25 ± 4.85 (57–71) years. The differences in subfoveal CT, TA, LA, SA between before ICA stenting and 1 day after ICA stenting, before ICA stenting and 1 month after ICA stenting was statically significant(p<0.05 for each). ConclusionWe have observed ıncreases in SFCT, CVI, LA, SA, and TA on the 1st day and 1st month after ICA stenting in patients with severe carotid stenosis. İmprovement in choroidal thickness and choroidal vascular flow is seen even in the early period of ICA stenting.

Clinical and molecular features of 66 patients with musculocontractural Ehlers−Danlos syndrome caused by pathogenic variants in CHST14 (mcEDS-CHST14)

BackgroundMusculocontractural Ehlers−Danlos syndrome is caused by biallelic loss-of-function variants in CHST14 (mcEDS-CHST14) or DSE (mcEDS-DSE). Although 48 patients in 33 families with mcEDS-CHST14 have been reported, the spectrum of pathogenic...

How do the amblyopic and fellow eyes differ in adults?

To investigate the differences between the amblyopic eye and the fellow eye in adults with anisometropic amblyopia. Measurements of the central macular thickness [CMT], subfoveal choroidal thickness [SFCT], and retinal nerve fiber layer [RNFL] in patients with anisometropic amblyopia were obtained using optical coherence tomography [OCT]. Axial length [AL], anterior chamber depth [ACD], and central corneal thickness [CCT] were measured with optical biometry. All 12parameters were compared between the amblyopic eye [Group 1] and the fellow eye [Group 2]. A total of 110 eyes of 55 patients [9 myopic, 46 hypermetropic] were analyzed retrospectively. The ages of the patients ranged from 17 to 55 years, with a mean of 30.8±10.7 years. 56.4% [n=31] of the patients were female, and 43.6% [n=24] were male. The mean spherical equivalent [SE] was 1.96±3.79 in Group 1 and 1.28±2.45 in Group 2. SFCT was 312.00±53.03 in Group 1 and 283.47±51.91 in Group 2. AL was 22.53±1.40 in Group 1 and 22.79±1.18 in Group 2. SE, SFCT, and AL were statistically significantly different between the two groups. There was no difference between the two groups in terms of CMT, RNFL, ACD and CCT values. In adults with anisometric amblyopia, the SFCT of the amblyopic eye is greater than that of the fellow eye. The choroid plays an important role in the nutrition of the retinal layers, the development of ocular function and refractive error, and its development may be affected by the refractive error. Since the majority of our patients were hyperopic, the AL was found to be shorter in the amblyopic eye. CMT, RNFL, ACD and CCT values were the similar in both groups. There was no clinically significant relationship between biometric parameters and OCT parameters.

Comparison of Ocular Characteristic Between Major Thalassemia and Healthy Group

To determine and compare ocular characteristics and refractive errors between major thalassemia patients and normal subjects. In this study, 71 thalassemia major patients and 79 age and sex-matched healthy subjects that were selected in an ongoing manner underwent complete optometric and ophthalmic examinations, including autorefraction, subjective refraction, fluorescein tear break-up time, and pachymetry after anthropometric measurements. The results showed that the mean UCVA was better in the control group versus the thalassemia group (P&lt;0.001), while there was no difference in BCVA between the two groups (P=0.416). Moreover, the mean spherical equivalent was 0.38±0.13 D less in the thalassemia group compared to the control group (P=0.007), while corneal power (P&lt;0.001) and cylinder power (P=0.001) were larger in thalassemia patients. The most common type of astigmatism was against the rule pattern in thalassemia patients and with the rule pattern in the control group (P&lt;0.001). The mean tear break-up time was 11.35±6.43 in the thalassemia group and 14.63±5.79 in the control group (P=0.001), and the mean near the point of accommodation (NPA) (P=0.009) and near the point of convergence (NPC). (P=0.003) were significantly smaller in the thalassemia group compared to the control group. These patients suffer from a myopic shift due to exaggerated responses to changes in ocular growth, dry eye secondary to goblet cell loss, and a higher prevalence of vertical astigmatism due to eyelid laxity and pressure on the cornea. Therefore, regular ophthalmological evaluations are highly recommended in these patients.

Pediatric patients at a high risk of headache of ocular origin: the HAMS Score (Hyperopia, Astigmatism, Myopia, and Strabismus)

AbstractPediatric patients identified at increased risk for headache due to ocular refractive errors were evaluated to produce a diagnostic tool called the HAMS score that will help establish the likelihood of headache due to refractive errors.Methods Data on the ocular diagnosis and headache complaints of 726 pediatric patients of both sexes were obtained from the medical records of an ophthalmological service in Brazil (Hospital de Olhos Santa Luzia). Age, use of glasses, and ocular diagnosis were also considered to create an index based on the number of ocular diagnoses in a given individual (HAMS score) to verify their association with the incidence of headache. Once the database was finalized, it was then analyzed to identify the variables capable of predicting the occurrence of headaches, following which a profile of those at the highest risk was produced by comparison.Results Only the ocular diagnosis was significantly associated with headache as a function of sex, age, use of glasses, farsightedness, astigmatism, myopia, and strabismus, indicating the relative impact of each ocular diagnosis on the probability of headache. According to the HAMS score, strabismus is more likely to have headache (5.21), followed by hyperopia (3.10), myopia (2.67), and, finally, astigmatism (1.86). The findings showed that the presence or absence of refraction errors and strabismus is predictive of the occurrence of headache, particularly in a small group of patients (6.2%) where the probability of headache was 57.8%. Such patients were characterized by being younger, having a combination of strabismus, hyperopia, and astigmatism, and already be using corrective lenses.Conclusion The index based on the most common ocular diagnoses (HAMS score) is effective, and it has practical application in identifying children and adolescent patients with a greater or lesser propensity for headaches of ophthalmic origin.