Refractive Status Research Articles

Profil Anisometropia pada Orang Dewasa di Rumah Sakit Ibnu Sina Makassar

Anisometropia is an interocular asymmetric refractive condition and is caused by a significant difference in diopters between the right and left eyes. Anisometropia occurs when there is a difference in the refractive power of the two eyes. Classification of several levels of difference, namely 1) difference in refraction between the two eyes less than 1.5 D, where both eyes can still be used together with good fusion and stereoscopic, 2) difference in refraction between the two eyes 1.5 D to 3.0 D (the presence of cylindrical differences is more significant than spherical), and 3) the difference in refraction is more than 3.0 D. The high incidence of Anisometropia can be caused by a lack of community initiative in seeking health assistance to treat Anisometropia, or even prevent Anisometropia from getting worse. The aim of this study was to determine the characteristics of Anisometropia in adults at Ibnu Sina Hospital Makassar. This research is descriptive in nature. The population of this study was all Anisometropia patients registered at Ibnu Sina Hospital Makassar so that the research sample was obtained by total sampling, namely the entire study population of 20 patients. Sample acquisition was adjusted to the inclusion criteria, namely Anisometropia patients with complete medical record data. The data was processed using the univariate method so that the research results showed that the majority of Anisometropia patients at the eye clinic at Ibnu Sina Hospital Makassar were on average 18-25 years old (45%) and mostly occurred in women (60%) and most were students (40%). %) The incidence of Anisometropia is probably caused by excessive use of cellphone or laptop gadgets and at very close range.

An assessment of the thickness of the retinal nerve fiber layer around the optic disc using spectral domain optical coherence tomography in myopia patients at an industrial hospital in India

Myopia is rising as a silent epidemic across the globe with marked ocular morbidity and pathological changes. The retinal nerve fiber layer (RNFL) thinning is indicative of glaucomatous damage; it remains uncertain whether RNFL thickness would vary with the refractive status of the eye. It is therefore important to investigate whether any correlation exists between RNFL measurements and axial length/refractive error in myopia. Purpose. To assess the peripapillary RNFL thickness by spectral domain optical coherence tomography (SD-OCT) and to determine the correlation between axial length and peripapillary RNFL thickness in myopia patients. Material and methods. A total of 100 patients (200 eyes) with low, moderate and high myopia (ave -3.58 ± 2.45 D) aged 15 to 40 years were examined to assess the peripapillary RNFL thickness by SD-OCT and to determine the correlation between axial length (AL) and peripapillary RNFL thickness myopia patients. Results. Average 360-degree RNFL thickness (mean ± SD) was 92.25 ± 10.04 μm. In the low myopic group this parameter was 98.82 ± 6.67 μm, in the moderate myopic group — 89.28±5.23 μm, and in the high myopic group — 78.54 ± 7.32 μm. The average 360-degree mean RNFL thickness in patients with AL < 24 mm was 100.06 ± 5.92 μm, in patients with AL between 24–26 mm — 89.48 ± 4.59 μm, and in patients with AL > 26 mm — 78.2 ± 6.77 μm. There was significant association between thinning of the average 360-degree RNFL thickness with increasing degree of myopia and AL (p < 0.0001). Conclusion. The study shows RNFL thickness decreases with increase in refractive error and increase in axial length of myopic eyes. The degree of myopia may affect the RNFL thickness differently.

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

BackgroundThe 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.MethodsThis 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.ResultsOf 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).ConclusionIn 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.

Anterior chamber and angle characteristics in Chinese children (6–11 years old) with different refractive status using swept-source optical coherence tomography

BackgroundThe anatomic structure of the anterior chamber (AC) helps to explain differences in refractive status in school-aged children and is closely associated with primary angle closure (PAC). The aim of this study was to quantify and analyze the anterior chamber and angle (ACA) characteristics in Chinese children with different refractive status by swept-source optical coherence tomography (SS-OCT).MethodsIn a cross-sectional observational study, 383 children from two primary schools in Shandong Province, China, underwent a complete ophthalmic examination. First, the anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) were evaluated automatically using a CASIA2 imaging device. AOD and TISA were measured at 500, 750 μm nasal (N1 and N2, respectively), and temporal (T1 and T2, respectively) to the scleral spur (SS). Cycloplegic refraction and axial length (AL) were then measured. According to spherical equivalent refraction (SER), the children were assigned to hyperopic (SER > 0.50D), emmetropic (-0.50D < SER ≤ 0.50D), and myopic groups (SER ≤ -0.50D).ResultsOut of the 383 children, 349 healthy children (160 girls) with a mean age of 8.23 ± 1.06 years (range: 6–11 years) were included. The mean SER and AL were − 0.10 ± 1.57D and 23.44 ± 0.95 mm, respectively. The mean ACD and ACW were 3.17 ± 0.24 mm and 11.69 ± 0.43 mm. The mean AOD were 0.72 ± 0.25, 0.63 ± 0.22 mm at N1, T1, and 0.98 ± 0.30, 0.84 ± 0.27 mm at N2, T2. The mean TISA were 0.24 ± 0.09, 0.22 ± 0.09mm2 at N1, T1, and 0.46 ± 0.16, 0.40 ± 0.14mm2 at N2, T2. The myopic group had the deepest AC and the widest angle. Compared with boys, girls had shorter AL, shallower ACD, narrower ACW, and ACA (all p < 0.05). By Pearson’s correlation analysis, SER was negatively associated with ACD, AOD, and TISA. AL was positively associated with ACD, ACW, AOD, and TISA. In the multiple regression analysis, AOD and TISA were associated with deeper ACD, narrower ACW, and longer AL.ConclusionIn primary school students, the myopic eyes have deeper AC and wider angle. ACD, ACW, AOD, and TISA all increase with axial elongation. ACA is highly correlated with deeper ACD.

Topographic and Surgical Risk Factors for Early Myopic Regression between Small Incision Lenticule Extraction and Laser In Situ Keratomileusis.

Our objective was to evaluate the topographic and surgical factors of early myopic regression between laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE). A retrospective case-control study was conducted, and 368 and 92 eyes were enrolled in the LASIK and SMILE groups via propensity score matching (PSM). Visual acuity, refractive status, axial length, and topographic/surgical parameters were collected. Multiple linear regression was applied to the yield coefficient and the 95% confidence interval (CI) of the parameters. The cumulative incidence of early myopic regression was higher in the LASIK group (p < 0.001). In the SMILE group, a lower central corneal thickness (CCT) thinnest value and a higher corneal cylinder associated with early myopic regression were observed; meanwhile, in the LASIK group, a lower CCT thinnest value, a higher steep corneal curvature, a larger optic zone, and a lower flap thickness related to early myopic regression were observed (all p < 0.05). In the SMILE group, a higher CCT difference correlated with early myopic regression was observed compared to the LASIK group (p = 0.030), and higher steep corneal curvature and lower cap/flap thickness (both p < 0.05) correlated with early myopic regression were observed in the LASIK group compared to the SMILE group. In conclusion, CCT differences significantly influence early myopic regression in the SMILE group; meanwhile, corneal curvature and flap thickness affect early myopic regression principally in the LASIK group.

Rare micropupil secondary to congenital cataract surgery favoring the development of the affected eye: a case report

BackgroundCongenital microcoria has been extensively reported and usually leads to visual dysfunction or blindness. However, micropupil development secondary to cataract surgery has never been reported. Here, we describe a rare case of micropupil development in infancy that occurred secondary to combined cataract extraction and intraocular lens implantation for treatment of congenital cataract. When the patient reached adulthood, the affected eye not only gained good vision but also showed better ocular development and refractive status than the fellow eye.Case presentationA 17-year-old boy presented to our outpatient clinic with decreased vision in his left eye related to congenital cataract surgery at 6 months of age. The affected eye had exhibited a pinhole pupil since the third month postoperatively. The condition had been managed with observation and regular monocular occlusion treatment. Upon presentation to our clinic, the best-corrected visual acuity (BCVA) in his fellow eye was 0.0 logMAR(20/20) with a refraction of − 5.75 diopters cylinder/−2.25 diopters sphere, and the BCVA in his affected eye was 0.5 logMAR(20/40) with a refraction of 0.00 diopters. Ophthalmic examination of the affected eye revealed a pinhole pupil (approximately 0.5 mm) with high light reflex sensitivity but no response to pupil-dilating drugs. The patient underwent pupilloplasty of the affected eye under corneal surface anesthesia. Postoperative examination revealed better ocular development in the affected eye than in the fellow eye (axial length: 24.21 vs. 27.02 mm, respectively) as well as better refractive status in the affected eye (BCVA of 0.0 logMAR(20/20) with a refraction of − 2.23 diopters cylinder/−3.00 diopters sphere vs. 0logMAR(20/20) with a refraction of -5.75 diopters cylinder/-2.25 diopters sphere).ConclusionsWe have reported a rare case of micropupil development secondary to congenital cataract surgery, which is an uncommon complication, especially in children. However, unlike congenital microcoria, the secondary pinhole pupil may have reduced imaging haze and halos, possibly favoring the development of the affected eye. This case provides further insight into the treatment of congenital cataract.

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

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. 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. 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). 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.

Corneal Endothelial Morphology and Ocular Biometric Indexes in Premature Children With and Without Retinopathy of Prematurity.

The purpose of this study was to analyze human corneal endothelial cells (HCECs) morphology and ocular biometrics in premature (PM) children with or without retinopathy of prematurity (ROP). Retrospective data on patient demographics, HCECs status, and ocular biometrics with at least 2 visits between 2016 and 2021 were reviewed. The main outcomes were endothelial cell density (ECD), coefficient of variation (CV), hexagonal cell ratio (HEX), central corneal thickness (CCT), axial length, anterior chamber depth, keratometry, corneal diameter, pupil diameter, and refraction status. Generalized estimating equation was used to evaluate the differences between PM no-ROP and ROP groups. We also analyzed the trend of ECD, CV, HEX, and CCT change with age between groups. The study included 173 PM patients without ROP and 139 patients with ROP. A total of 666 and 544 measurements were recorded in the PM no-ROP and ROP groups, respectively. The ROP group had higher spherical power, myopic spherical equivalent (SE), and steeper steep keratometry (K; P < 0.05). The ROP group had higher CV (P = 0.0144), lower HEX (P = 0.0012) and thicker CCT (P = 0.0035). In the HCECs parameters, the ROP group had slower ECD decrement (P < 0.0001), faster CV decrement (P = 0.0060), and faster HEX increment (P = 0.0001). A difference in corneal morphology changes between the ROP and PM no-ROP groups were prominent in patients with lower gestational age (GA) in the subgroup analysis. Worse HCECs morphology and higher myopic status were initially observed in patients with prior ROP but not in PM patients with no-ROP. ECD and HCECs morphology improved with age, especially in patients with low GA.

Comparison of Safety and Efficacy of Four-Point Scleral Intraocular Lens Fixation and the Yamane Technique.

The purpose of our study was to compare the safety and efficacy of two scleral fixation intraocular lens (IOL) methods of four-point scleral fixation (Akreos AO60) and the Yamane technique (AcrySof MA60AC). This prospective, randomized study was conducted at the Military Institute of Medicine-National Research Institute in Warsaw between 2021 and 2023. We compared both groups for cause of aphakia, ocular history, refractive status, and complication. Our study included 50 eyes from 47 patients. Four-point fixation was performed in 25 eyes (group1), and the Yamane technique was used in 25 eyes (group2). Surgical time was 24.1min ± 8.9 in group1 and 25.1min ± 9.9 in group2 (p > 0.05). The postoperative BCVA (best-corrected visual acuity) for group1 and group2 at 1year's observation was 0.10 ± 0.15 and 0.09 ± 0.17 logMAR, respectively (p > 0.05). Postoperative total refractive error (RE) was - 0.06 ± 0.71 diopters (D) for four-point scleral fixation and 0.83 ± 0.70D for Yamane technique (p < 0.05). Endothelial cell density (ECD) loss was 0.9% in group1 and 3.5% in group2 (p > 0.05). Bleeding into the anterior chamber and vitreous body was more frequent in the group of patients operated on with the use of the Yamane technique (10 cases, 20%, p = 0.01). IOL displacement was found in one case (2%) in group2. Both analyzed techniques are well tolerated and ensure good refractive results (extremely predictable in four-point scleral fixation) and have a similar safety profile. Four-point scleral fixation of IOL would appear to be safe, effective and beneficial for young, active patients, especially after trauma or recurrent subluxation. ClinicalTrials.gov identifier NCT06389643.

Retinopathy of prematurity in multiple births versus single births preterm, extremely preterm infants

The purpose of the study was to compare the retinopathy of prematurity in preterm, extremely preterm infants between multiple and single births.It was a hospital – based cross sectional comparative study conducted among preterm 28 - ≤37 weeks of gestational age, extremely preterm ≤ 28 weeks of gestational age at delivery of multiple and single births. Data on Gestational age, birth weight, birth order (single/multiple), Risk factors, Refractive status, and Treatment type were noted. Ophthalmological findings were performed routinely at 4 weeks and repeated later depending upon the severity. 49 infants were involved in this study; 22 were born as singletons and 27 as multiples. Our results show 2.0% of subject in stage 1, 18.4% in stage 2, 8.2% in stage 3, 2.0% in stage 4 substantially corresponds with the severity of retinopathy of prematurity due to lower gestational week and lower birth weight. Multiple birth infants statistically had 6.1% in stage 1, 18.4% in stage 2, 8.2% in stage 3, 2.0% in stage 4 retinopathy of prematurity than single birth infants. Risk factor results indicates necrotizing enterocolitis (33.3% in stage 2), oxygen (35.5% in stage 2 and 16.1% in stage 3), sepsis (37.9%, and 20.7% in stage 3), and continuous positive airway pressure (44.4% in stage 2 and 11.1% in stage 3) Compound hyperopic astigmatism was the most typical refractive error in both births. Laser treatment accounts for 18.1% in both groups. This study showed a significant correlation with ROP development in multiple births.

Evaluation of Keratoconus Patients Refractive Status Before and after Corneal Collagen Cross-linking

Background: Corneal Collagen Cross Linking (CXL) incorporated with riboflavin solution activated by UV (Ultraviolet) irradiation is a modern promising treatment protocol for keratoconus. Evaluation of the clinical effect of CXL treatment on keratoconus patients was the aim of this study. Methods: This Quasi Experimental (before-and-after) study was comprised with 50 patients, having progressive keratoconus (progression was documented by Corneal Topography), reported to Cornea Clinic, CMH Dhaka, from February 2022 to January 2023. Before and after the CXL procedure; un-corrected and best-corrected visual acuity of study population was documented using Snellen visual acuity chart. Auto-refractometry readings were also noted. Results: Among the 50 study subjects; 26 (52%) were men and 24 (48%) were female, age was 24.14 ± 5.07 (mean+SD) years and age range was 18-35 years. Mean preoperative spherical power was −1.84 ± 0.82 Diopter (D) and mean cylindrical power was −3.66 ± 0.97 D. Postoperatively, mean spherical power was found −1.15 ± 0.55 D and mean cylindrical power was −2.87 ± 0.99 D. After CXL treatment; significant vision improvement found in 15 (30%) patients (p&lt;0.05). Conclusion: Despite strengthening the corneal stromal collagen bond and halting the keratoconus progression, CXL treatment stabilize the refractive status of keratoconus patient and also in some extent, it improves vision. Bangladesh Armed Forces Med J Vol 56 No (2) December 2023, pp 45-50

Quantitative comparison of binocular suppression of patients with anisometropic amblyopia and ametropic amblyopia

Objective: To explore the differences in clinical characteristics and interocular interactions between patients with anisometropic amblyopia and ametropic amblyopia. Methods: Cross-sectional study. The newly diagnosed anisometropic (the binocular difference in spherical equivalent≥1.00 D) amblyopia patients and ametropic amblyopia patients (aged 4 to 6 years) in Beijing Tongren Hospital from January 2020 to December 2022 were involved. Patients were further categorized by the refractive status after cycloplegia, including hyperopia, myopia, astigmatism, hyperopia with astigmatism, myopia with astigmatism, mild anisometropia and severe anisometropia. Quantitative measurements of best-corrected visual acuity (logMAR), stereoacuity (transformed to log units), perceptual eye position and interocular suppression were performed, and the differences between groups were analyzed. The rank sum test was used for statistical evaluation. Results: The average age of 45 ametropic amblyopia patients (21 males and 24 females) and 84 anisometropic amblyopia patients (48 males and 36 females) was 5.0 (4.0, 5.0) years and 5.0 (4.0, 6.0) years, respectively. The interocular differences in spherical equivalent [2.56 (1.50, 4.19) D vs. 0.25 (0.13, 0.56) D] and best-corrected visual acuity [0.40 (0.18, 0.70) logMAR vs. 0.07 (0.00, 0.12) logMAR] were larger in patients with anisometropic amblyopia than those with ametropic amblyopia. The anisometropic amblyopia patients had worse stereoacuity [2.60 (2.00, 2.90) log arcsec vs. 2.00 (2.00, 2.30) log arcsec] and deeper suppression [20.0% (13.3%, 40.0%) vs. 10.0% (0, 23.3%)], compared with the ametropic amblyopia patients. The differences were all statistically significant (P<0.05). The suppression and stereoacuity between patients with hyperopic anisometropic amblyopia [suppression, 30.0% (17.5%, 50.0%); stereoacuity, 2.90 (2.30, 2.90) log arcsec] and astigmatic anisometropic amblyopia [suppression, 10.0% (0, 20.0%); stereoacuity, 2.00 (2.00, 2.30) log arcsec] were significantly different (P<0.05). The differences of suppression and stereoacuity between patients with severe (binocular difference in spherical equivalent>2.50 D) [suppression, 30.0% (20.0%, 53.3%); stereoacuity, 2.90 (2.57, 2.90) log arcsec] and mild anisometropia [suppression, 20.0% (0, 30.0%); stereoacuity, 2.00 (2.00, 2.90) log arcsec] were also statistically significant (P<0.05). Conclusions: Patients with anisometropic amblyopia have deeper binocular suppression, worse stereoacuity and more severe binocular interaction abnormality than those with ametropic amblyopia. The severity of anisometropia affects the degree of the interaction abnormality.

Dependence of Body Stability on Optical Conditions during VR Viewing

The dependence of body stability on the distance between the optical centers of VR-device lenses and the refractive error status of users during VR viewing was investigated. Participants included 31 adults, and their postural-control ability was measured using a BTrackS device. The optical conditions were (1) COCD (comfortable optical center distance), (2) COCD+2D (comfortable optical center distance with 2D myopia), (3) COCD-2D (comfortable optical center distance with 2D hyperopia), (4) DOCD (uncomfortable optical center distance), (5) DOCD+2D (uncomfortable optical center distance with 2D myopia), and (6) DOCD-2D (uncomfortable optical center distance with 2D hyperopia). Posture was assessed under these six optical conditions while the participants were wearing a VR device and watching a 3D roller-coaster video. The sway-path length was significantly increased under the COCD-2D, DOCD, DOCD+2D, and DOCD-2D conditions compared to the COCD condition (p &lt; 0.05). In the case of maximum sway velocity, the results showed significant increases under the DOCD, DOCD+2D, and DOCD-2D conditions compared to the COCD condition (p &lt; 0.05). The analysis revealed that when users are viewing VR displays, optimization of the distance to the optical center of the VR-device lenses and correction of the refractive errors for individual users was a significant factor in minimizing body instability.

Scope of Ayurveda treatment in Myopia: A systematic review of current trends

Abstract BACKGROUND: Though myopia is an ophthalmic refractive error disease that is commonly managed with refractive glasses and advanced surgeries, it still remains a refractive condition of great concern. Patients often resort to alternate methods to rectify or manage myopia and prevention of its progression. Ayurveda refers to myopia as Timira (errors of refraction), characterized by disturbances in vision; hence, it is considered to be a part of Drishtigata Rogas (eyesight disorders). According to the Ayurvedic perspective, myopia is primarily a result of vitiated Doshas, particularly the imbalance of the Vata Dosha, which impairs the eye muscles and lens, resulting in the inability to focus on distant objects. MATERIALS AND METHODS: This review adhered to the 2020 PRISMA guidelines and involved a comprehensive search of PubMed, Scopus, and UGC-CARE-listed Ayurveda journals from January 2000 to September 2023. The focus was on randomized controlled trials examining Ayurvedic interventions, including topical and oral therapies, for managing myopia or Timira. The search aimed to identify all relevant studies published within the specified timeframe. The Cochrane risk-of-bias tool for randomized trials (RoB 2) was utilized to evaluate the risk of bias. RESULTS: A total of six publications in credible journals were found and analyzed, which revealed that practices such as Netra Tarpana (retaining of medicated ghee over the eye), Nasya (medication through the nasal route), Anjana (collyrium), use of Triphala, Ayurvedic formulations, yoga, and specific eye exercises can enhance the strength of ocular muscles, promote better nourishment of ocular tissues, and foster overall eye health. CONCLUSION: By implementing prophylactic measures, followed by therapeutic and systemic therapies, myopia can be controlled with a multidimensional approach, but due to limited sources of evidence, the certainty can only be proven after extensive clinical trials.

INVESTIGATION OF TROPOSPHERIC RADIO REFRACTIVITY AND OTHER RELEVANT PARAMETERS USING METEOROLOGICAL VARIABLES OVER BAUCHI, NIGERIA

The National Aeronautics and Space Administration (NASA) archives were used in this work to obtain the measured monthly average daily temperature, relative humidity, and atmospheric pressure over a 41-years period (1981–2021) for Bauchi (latitude , longitude ) to calculate the monthly tropospheric radio refractivity. The site is located in Nigeria's midland climate zone. We also looked into the variation with other factors, the refractivity gradient, and the percentage contribution of the dry term (Ndry) and wet term (Nwet) radio refractivity. The results showed that during the rainy and dry seasons, respectively, the months of August and February had the highest and lowest average values of radio refractivity, measuring 355.032 (N-units) and 273.255 (N-units), respectively. This suggests that radio refractivity is higher during the rainy season than it is during the dry season. The wet term contributes to the significant fluctuation in radio refractivity values, while the dry term makes up 77.60 % of the total value. The average refractivity gradient estimate was found to be – 40.854 N – units/km suggesting super-refraction propagation for Bauchi indicating that electromagnetic waves are often bent downward towards the earth when the super refraction condition occurs.

Glutathione and a Pool of Metabolites Partly Related to Oxidative Stress Are Associated with Low and High Myopia in an Altered Bioenergetic Environment.

Oxidative stress forms part of the molecular basis contributing to the development and manifestation of myopia, a refractive error with associated pathology that is increasingly prevalent worldwide and that subsequently leads to an upsurge in degenerative visual impairment due to conditions that are especially associated with high myopia. The purpose of our study was to examine the interrelation of potential oxidative-stress-related metabolites found in the aqueous humor of high-myopic, low-myopic, and non-myopic patients within a clinical study. We conducted a cross-sectional study, selecting two sets of patients undergoing cataract surgery. The first set, which was used to analyze metabolites through an NMR assay, comprised 116 patients. A total of 59 metabolites were assigned and quantified. The PLS-DA score plot clearly showed a separation with minimal overlap between the HM and control samples. The PLS-DA model allowed us to determine 31 major metabolite differences in the aqueous humor of the study groups. Complementary statistical analysis of the data allowed us to determine six metabolites that presented significant differences among the experimental groups (p < 005). A significant number of these metabolites were discovered to have a direct or indirect connection to oxidative stress linked with conditions of myopic eyes. Notably, we identified metabolites associated with bioenergetic pathways and metabolites that have undergone methylation, along with choline and its derivatives. The second set consisted of 73 patients who underwent a glutathione assay. Here, we showed significant variations in both reduced and oxidized glutathione in aqueous humor among all patient groups (p < 0.01) for the first time. Axial length, refractive status, and complete ophthalmologic examination were also recorded, and interrelations among metabolic and clinical parameters were evaluated.

Investigation of structural, electrical, magnetic, and optical properties of Cu (111) and the impact of Ag adatoms adsorption: A density functional theory study

Our study conducts a comprehensive investigation on the structural, electrical, magnetic and optical properties of pure Cu with a (111) crystallographic orientation, as well as the impact of the adsorption of Ag adatoms on a Cu (111) surface. To perform this analysis, we utilized the full potential linearized augmented plane-wave (FP-LAPW) approach in conjunction with Generalized Gradient Approximations (GGA + U) and the Wien2k simulation software. Specifically, we calculated electrical and optical properties including the band structure, density of states (DOS) for the Cu (111) surface with and without the presence of adsorbed Ag atoms. Based on the observed results, the overlapping of the electronic bands for simple Cu (111) is comparatively less than that of adsorbed Ag/Cu (111) slab, indicating higher conductivity. Moreover, the evolutions are also observed which are mainly due to d orbitals of Cu and Ag for Cu (111) and Cu/Ag (111) respectively. The calculated magnetic optimization and weak diamagnetic magnetic moments shows weak diamagnetism in these materials. The optical properties like Dielectric Function(ε), Refractive index(n), Extinction co-efficient(k), Reflectivity(R), Energy Loss (L), Absorption (α) and Optical conduction (σ) are calculated. Our research examines the importance of band structure calculation in relation to optical properties. We discuss how plasmon-energy plays a crucial role in producing peaks in the energy loss function, with a crystallographic axis of 13.7 eV and 13.6 eV for both Cu (111) and Ag/Cu (111) slab. In addition, we calculated the static dielectric function, absorption coefficient, and refraction values for these materials. Reflectivity spectra for both Cu (111) and Ag/Cu (111) exhibits Infra-red region, indicating good coating materials to reduce heating, for the application of electrical appliances and for optical application like anti-reflecting coating, optical fibers and solar cells.

Distribution and correlation of refractive parameters in children with different corneal curvatures in southeast China.

To analyze the distribution of refractive status in school-age children with different corneal curvatures (CC) and the correlation between CC and refractive status. A total of 2214 school-aged children of grade 4 in Hangzhou who were screened for school myopia were included. Uncorrected distance visual acuity (UCDVA), non-cycloplegic refraction, axial length (AL), horizontal and vertical corneal curvature (K1, K2) were measured and spherical equivalent (SE), corneal curvature radius (CCR) and axial length/corneal radius of curvature ratio (AL/CR) were calculated. UCDVA<5.0 and SE≤-0.50 D were classified as school-screening myopia. According to the different CCRs, the patients were divided into the lower corneal curvature (LCC) group (CCR≥7.92) and the higher corneal curvature (HCC) group (CCR<7.92). Each group was further divided into the normal AL subgroup and the long AL subgroup. The refractive parameters were compared to identify any differences between the two groups. Both SE and AL were greater in the LCC group (P=0.013, P<0.001). The prevalence of myopia was 38% in the LCC group and 44% in the HCC group (P<0.001). The proportion of children without screening myopia was higher in the LCC group (62%) than in the HCC group (56%). Among these children without screening myopia, the proportion of long AL in the LCC group (24%) was significantly higher than that in the HCC group (0.012%; P<0.001). The change of SE in the LCC group was less affected by the increase of AL than that in the HCC group. School-aged children in the LCC group have a lower incidence of screening myopia and longer AL. Low CC can mask SE reduction and AL growth to some extent, and the change of AL growth change more in children with low CC than high CC. Before the onset of myopia, its growth rate is even faster than that after the onset of myopia.

A study on the distribution characteristics of peripheral retinal defocus in children and adolescents

Objective: To explore the distribution characteristics of peripheral retinal defocus in children and adolescents. Methods: This cross-sectional study included 500 individuals aged 3 to 18 years, who visited the People's Hospital of Lincang, the First Affiliated Hospital of Dali University and Dali Ophthalmology Hospital between January and December 2021. Data of the right eye of each participant was analyzed. There were 226 males (45.20%) and 274 females (54.80%), with an average age of (10.79±3.79) years. All participants underwent post-cycloplegic refraction, optical biometry, and intraocular pressure measurement to obtain spherical equivalent, average corneal curvature, axial length, and intraocular pressure. Multispectral refraction topography was performed to obtain topographic maps and values at various field angles and orientations of peripheral retinal defocus. Based on multispectral refraction topography, peripheral retinal defocus values were categorized as crater type, hemilateral upturn type, saddle type, and relatively flat type. The distribution of different refractive states was analyzed. Results: The spherical equivalent of the 500 participants was(-1.51±2.61) D, axial length was (24.10±1.28) mm, and average corneal curvature was (43.20±1.22) D. Among the 500 eyes, 382 exhibited hyperopic peripheral retinal defocus values, with 316 eyes (82.72%) being myopic. Myopic peripheral retinal defocus values were observed in 118 eyes, with 15 eyes (12.72%) being myopic. Among different types of peripheral retinal defocus values, 112 eyes (22.4%) exhibited a crater type, 153 eyes (30.6%) exhibited a hemilateral upturn type, 107 eyes (21.4%) exhibited a saddle type, and 128 eyes (25.6%) exhibited a flat type. The proportion of myopia was 82.14% (92 eyes), 69.28% (106 eyes), 60.75% (65 eyes), and 3.90% (5 eyes), respectively. The peripheral retinal defocus values at 15°, 30°, and 45° were (0.01±0.08) D, (0.06±0.21) D, and (0.20±0.37) D, respectively. The peripheral retinal defocus values at temporal, inferior, nasal, and superior locations were (0.58±0.69) D, (0.52±0.63) D, (0.21±0.64) D, and (-0.26±0.67) D, respectively. Notably, the superior primarily manifested as myopic, while the others were predominantly hyperopic. Conclusions: Approximately three-fourths of children and adolescents exhibit hyperopic peripheral retinal defocus values, with a higher prevalence of myopia in this subgroup. The hyperopia peripheral retinal defocus value increases with the distance from the retina to the macula. The peripheral retinal defocus values between superior and inferior, nasal and temporal locations are asymmetrical, with the temporal hyperopic peripheral retinal defocus value being most prominent and the superior myopic peripheral retinal defocus value being most evident.

Early Alterations in Inner-Retina Neural and Glial Saturated Responses in Lens-Induced Myopia.

Myopic marmosets are known to exhibit significant inner retinal thinning compared to age-matched controls. The purpose of this study was to assess inner retinal activity in marmosets with lens-induced myopia compared to age-matched controls and evaluate its relationship with induced changes in refractive state and eye growth. Cycloplegic refractive error (Rx), vitreous chamber depth (VCD), and photopic full-field electroretinogram were measured in 14 marmosets treated binocularly with negative contact lenses compared to 9 untreated controls at different stages throughout the experimental period (from 74 to 369days of age). The implicit times of the a-, b-, d-, and photopic negative response (PhNR) waves, as well as the saturated amplitude (Vmax), semi-saturation constant (K), and slope (n) estimated from intensity-response functions fitted with Naka-Rushton equations were analyzed. Compared to controls, treated marmosets exhibited attenuated b-, d-, and PhNR waves Vmax amplitudes 7 to 14days into treatment before compensatory changes in refraction and eye growth occurred. At later time points, when treated marmosets had developed axial myopia, the amplitudes and implicit times of the b-, d-, and PhNR waves were similar between groups. In controls, the PhNR wave saturated amplitude increased as the b + d-wave Vmax increased. This trend was absent in treated marmosets. Marmosets induced with negative defocus exhibit early alterations in inner retinal saturated amplitudes compared to controls, prior to the development of compensatory myopia. These early ERG changes are independent of refraction and eye size and may reflect early changes in bipolar, ganglion, amacrine, or glial cell physiology prior to myopia development. The early changes in retinal function identified in the negative lens-treated marmosets may serve as clinical biomarkers to help identify children at risk of developing myopia.