Refractive Error Research Articles

Spectacle Lenses With Highly Aspherical Lenslets for Slowing Axial Elongation and Refractive Change in Low-Hyperopic Chinese Children: A Randomized Controlled Trial

Purpose: Spectacle lenses with highly aspherical lenslets (HAL) have been shown to effectively retard myopia progression in myopic children. This study aimed to investigate the impact of spectacle lenses with HAL on refractive and axial length (AL) changes in Chinese children with low amount of hyperopia. Design: Randomized controlled trial Methods: A total of 108 Chinese children aged 6.0 to 9.9 years and spherical equivalent refractive error (SERE) from 0.00 to +2.00 D were randomly allocated into two groups: the HAL group and the single vision spectacle lens (SVL) group. Cycloplegic refraction, AL, and uncorrected visual acuity (UCVA) was measured at baseline, three months, six months, and 12 months after lens dispensing. The duration of spectacle lens wear was monitored using a wearable device attached to the spectacle frame and by questionnaire logs provided by participants at each follow up visit. Results: The one-year SERE change was -0.19 [-0.32, 0.03] D and −0.23 [-0.36, 0.05] D in the SVL and HAL groups (P=0.883). The one-year AL elongation was 0.24 [0.18, 0.34] mm and 0.19 [0.12, 0.27] mm in the SVL and HAL groups (P=0.057). In the HAL group, changes in AL and SERE were significantly correlated to lens wearing time (P<0.001 and P=0.024, respectively). Participants in the HAL group who wore their lenses for more than 30 hours per week had significantly slower AL elongation (0.11 [0.05, 0.17] mm) compared to their SVL counterparts (0.27 [0.21, 0.33] mm) (P<0.001). Conclusion: Spectacle lenses with HAL significantly reduced AL elongation in low hyperopic children who wore lenses for over 30 hours per week. A dose-response relationship was evident with longer lens wearing time associated with less AL change.

Contact lenses as a preferred choice for vision correction in various clinical scenarios with regard to work environment

Amendment to the Regulation of Minister of Labour and Social Policy of 1 December 1998 on safety and occupational hygiene at positions equipped with display monitors, adopted on October 18th, 2023, entered the long-awaited by employees possibility of reimbursement for corrective contact lenses, adjusting the Polish legislation to European directive regulating working conditions with display screen equipment. Contact lenses in many cases of refractive errors can be an alternative to prescription glasses method of correcting the visual impairment. There are however many clinical conditions, in which contact lenses can provide a better corrective effect on visual acuity. The information contained in medical databases of articles and scientific journals (PubMed, Biblioteka Nauki), online publications (Lippincott Journals), books, applicable legal regulations (available in Internetowy System Aktów Prawnych) and guidelines published by organizations and associations (Nofer Institute of Occupational Medicine in Łódź, Occupational Safety and Health Administration, Tear Film & Ocular Surface Society) were analyzed, covering the discussed issues over the years 2000-2023. Non-correction or suboptimal correction of a refractive error can cause a wide variety of troublesome symptoms, such as eye pain, headache, double vision, balance disorders, nausea, disturbances in the perception of the surroundings, contributing to poorer work efficiency, faster fatigue or an increased risk of error. This article, which is a narrative review, aims to present these conditions, as well as provide a brief overview of the types of contact lenses used, complications that may result from their use and contraindications to the use of this type of correction. Med Pr Work Health Saf. 2024;75(4):383-390.

Vessel density, macula thickness and foveal avascular zone measurements in young African adults with moderate myopia: A pilot study.

The aim of this study was to investigate the association between macula thickness and vessel density in African myopic and emmetropic eyes through the use of Spectral Domain Optical Coherence Tomography (OCT). The study population comprised African adults aged 18-35 years old. The study was conducted at a University eye clinic located in Durban, South Africa. Purposive sampling was utilised to obtain 59 participants of whom 24 were myopes and 35 were emmetropes. Vessel density (VD), foveal avascular zone (FAZ) and retinal thickness (RT) were obtained using the Heidelberg Spectralis OCT with angiography. Thereafter, a multivariate linear regression was used to investigate associations between the spherical equivalent myopic refractive error and VD, FAZ and RT for the myopic group only. Myopic participants had a mean spherical equivalent (MSE) and standard deviation (SD) of -4.79 D (1.27) while the emmetropic group had an MSE (SD) of -0.32 D (0.46). Both superficial and deep VD were significantly decreased at the central fovea (radius (r) = 0.4 mm), peri-foveal (r = 1.10-1.45 mm) and para-foveal (r = 0.75-1.10 mm) sectors in myopes when compared with emmetropes. Myopes showed a significant reduction in RT in the inner retinal layer across the inferior and temporal zones of the peri-foveal region as well as the inferior and temporal zones of the para-foveal region when compared with emmetropes. A significantly smaller FAZ was found at both the superficial and deep vascular plexuses (p < 0.001). In African myopes, significant associations were not found between MSE and VD or FAZ and macula retinal thickness. Retinal vascular and thickness reduction may occur in young African adults with moderate myopia. A broad-based study targeting VD and IRT in African myopes is proposed to confirm preclinical myopic macula disruptions in adults of African ethnicity. OCT angiography should be considered when monitoring progressive myopia.

Comparative Effect of Cylindrical Lenses Versus Spherical Equivalent on Contrast Sensitivity

Background: Astigmatism is a common refractive error that affects visual acuity and contrast sensitivity. Cylindrical lenses and spherical equivalents are commonly prescribed to correct these errors, but their comparative effects on contrast sensitivity are not well-documented.Objective: To compare the effects of cylindrical lenses versus spherical equivalents on contrast sensitivity in individuals with astigmatism.Methods: A randomized controlled trial was conducted involving 68 participants with astigmatism, aged 15 to 30 years. Participants were randomly assigned to receive either cylindrical lens correction or spherical equivalent correction. Contrast sensitivity was measured using the Pelli-Robson chart at baseline and during two follow-ups over three months. Data were analyzed using Friedman's Two-Way Analysis of Variance and the Wilcoxon Signed Ranks Test, with p ≤ 0.05 considered statistically significant.Results: The mean contrast sensitivity decreased from 1.95 ± 0.07 to 1.93 ± 0.09 over three months. Cylindrical lenses resulted in higher contrast sensitivity scores (2.00 in 67.6% of cases at final visit) compared to spherical equivalents (44.1%, p &lt; 0.001).Conclusion: Cylindrical lenses significantly improve contrast sensitivity compared to spherical equivalents, particularly in moderate to high astigmatism.

Distribution and associated factors of keratometry and corneal astigmatism in an elderly population

To determine the distribution of keratometry and corneal astigmatism (CA) and their association with demographic factors, systemic parameters, anthropometric measures, ocular biometric indices, and refractive errors in people aged 60 years and above. In this cross-sectional study, 160 clusters were randomly selected from Tehran city (Iran) using the multi-stage cluster sampling method. All participants underwent optometric examinations including testing uncorrected and best-corrected distance visual acuity, non-cycloplegic autorefraction, and subjective refraction. Pentacam imaging for all participants was carried out using Pentacam AXL. Keratometry and CA were reported based on Pentacam’s data. The average, standard deviation (SD) and 95% confidence interval (CI) of flat keratometry (Kf), steep keratometry (Ks), mean keratometry (mean K), and CA were 44.02 ± 1.58 D (95% CI 43.94–44.1), 44.86 ± 1.67 D (95% CI 44.78–44.94), 44.44 ± 1.58 D (95% CI 44.36–44.52), and 0.84 ± 0.74 D (95% CI 0.81–0.87), respectively. The 95% and 99% percentiles of mean K were 47.1 and 48.6 D, respectively. According to the multiple generalized estimating equation model, the mean K was significantly higher in males, in myopes, and in those with higher systolic blood pressure. Moreover, the mean K was inversely related to the axial length, height, anterior chamber depth (ACD), corneal diameter, and central corneal thickness (CCT). The prevalence of various types of CA based on a cut-off > 0.50 D was as follows; with-the-rule: 32.5% (95% CI 30.6–34.4), against-the-rule: 18.2% (95% CI 16.7–19.7), and oblique: 10.0% (95% CI 9.1–11.0). The present study investigated the normal distribution of keratometry and CA in individuals ≥ 60 years, and results can be used in clinical matters, especially in intraocular lens power calculation. Sex, systolic blood pressure, height, and some biometric components such as ACD, corneal diameter, and CCT were significantly related to keratometry and should be considered.

Distance stereopsis in patients with accommodative esotropia.

We aimed to evaluate distance stereoacuity (DS) in patients with successfully treated accommodative esotropia (AET) and its association with other clinical factors. The medical records of 176 children with refractive AET with a follow-up period ≥ 1year were reviewed to identify a cohort of patients who achieved a stable alignment within 4 prism diopters (PD) of orthotropia at both distance and near fixation. Age of onset, duration of misalignment, uncorrected near and distance deviation, accommodative convergence/accommodation ratio, refractive error, presence of anisometropia and amblyopia, near stereopsis were evaluated as predictors of outcome. DS was measured using the Distance Randot Stereo test and near stereoacuity by Randot Stereotest. The patient group was compared with 50 age-matched normal controls for DS. Fifty-six patients were included, and 38 patients had DS at the final visit. All patients with DS attained uncontoured near stereopsis (UCNS). UCNS was present only in 11 patients without DS (p = 0.001). Anisometropia (p = 0.997), uncorrected near deviation (p = 0.224), distance deviation with correction (p = 0.255), and high hypermetropia (p = 0.998) were not associated with DS. The multivariable regression model showed a significant positive correlation between UCNS and DS (OR = 31.14 (95% CI 2.25-430.48); p = 0.01). Contoured near stereopsis outcome was significantly different between the patients with and without DS (p = 0.001 for animals and p = 0.003 for circles). Compared with the control group, the patient group yielded lower DS scores (p = 0.001). Distance Randot Stereotest can be useful in measuring binocular vision recovery after successful realignment in refractive AET patients. Patients attaining normal scores for near stereopsis tests after optical correction revealed subnormal thresholds for DS.

Effect of capsular tension ring implantation on intraocular lens calculation formula selection for long axial myopia

PurposeThe study investigated the effect of capsular tension ring (CTR) implantation on postoperative refractive stability and accuracy of intraocular lens (IOL) formulas for axial length (AL) ≥ 27.0 mm patients.MethodsProspective case series. The eyes of patients underwent phacoemulsification extraction combined with IOL implantation were classified as CTR implantation (A-CTR) and without CTR implantation (B-CON) groups. Refractive outcome and anterior chamber depth (ACD) were recorded at 1 week, 1 month, and 3 months post-operation. Prediction refractive error (PE) and absolute refractive error (AE) of each formula were calculated.ResultsA total of 89 eyes (63 patients) were included and randomized into the CTR (A-CTR) and control groups (B-CON). Comparison of refraction at different postoperative times of the CTR group showed no statistical difference (all P > 0.05). The ACD in the A-CTR group gradually deepened, and that in the B-CON group gradually shallowed (all P > 0.05). The formulas’ AE showed statistically significant differences in CTR and CON groups (P < 0.001). The PE of Hill-RBF 2.0 and EVO formulas in the A-CTR group were more hyperopic than that in the B-CON group (all P > 0.05), the other five formulas were more myopic in A-CTR group than that in the B-CON group (all P > 0.05).ConclusionPatients with 13 mm diameter CTR implantation tended to have stable refraction at 1 week post-surgery and 1 month for those without it. CTR of the 13 mm diameter had no effect on the selection of formulas. Additionally, it is found that Kane and EVO formulas were more accurate for patients with AL ≥ 27.0 mm.

Regional Summed Corneal Refractive Power Changes in Myopic Orthokeratology and Their Relationships With Axial Elongation.

To determine the relationship between regional summed corneal refractive power changes (CRPCs) in myopic orthokeratology and axial elongation. This retrospective study included 70 eyes of 70 patients aged 8 years to 13 years who underwent orthokeratology lens (OK lens) treatment, and all patients underwent regular follow-ups at 1 week, 1 month, 6 months, and 12 months at Zhongshan Ophthalmic Center between January 2019 and May 2021. Axial length (AL) was measured at baseline and 12 months by an IOLmaster 5.0. Refractive error power was measured using cycloplegia. Regional summed CRPCs were calculated by MATLAB software using difference tangential power maps at the sixth month acquired by corneal topography measurements (Medmont E300 Corneal Topographer; Medmont Pty, Victoria, Australia) and defined as changes in corneal refractive power at the sixth month from baseline. The regional summed CRPCs were then subdivided into 4-mm diameter circles, 4- to 5-mm diameter chords, and 5- to 6-mm diameter chords according to the distance from the central of the pupil and into negative, positive, and total according to the values. Pearson correlation, multiple linear regression analysis, and stepwise multiple linear regression analysis were performed to analyze the relationships among these parameters. Axial elongation had a negative relationship with positive regional summed corneal refractive power in the central 4-mm diameter circle and age (r=-0.282, P =0.018; r=-0.473, P <0.001, respectively) and a positive relationship with negative regional summed corneal refractive power in the 5- to 6-mm diameter chord (r=0.361, P =0.002). Stepwise multiple linear regression analysis identified age (standardized β =-0.434, P <0.001) and negative regional summed corneal refractive power in the 5- to 6-mm diameter chord (standardized β =0.305, P =0.004) as factors influencing AL elongation. Negative regional summed corneal refractive power in a 5- to 6-mm diameter chord after OK lens treatment may be an important index for evaluating the control effects of axial elongation.

COMPARISON OF VISUAL ACUITY RESULTS AFTER FEMTOSECOND LASER-ASSISTED IN SITU KERATOMILEUSIS (FS-LASIK) AND SMALL INCISION LENTICULE EXTRACTION (SMILE)

Introduction: Two of the most popular refractive surgery methods currently used are Femtosecond Laser-Assisted In Situ Keratomileusis (FS-LASIK) which creates a flap using femtosecond laser and stromal ablation using excimer laser, and Small Incision Lenticule Extraction (SMILE), a flapless procedure in which a lenticule is extracted through a small incision. The aim of this study is to compare the visual acuity results of FS-LASIK and SMILE. Methods: This is a descriptive cross-sectional study. Data were collected from the medical record of patients who underwent FS-LASIK or SMILE procedure at Cicendo Eye Hospital, the national eye centre, in 2022. Patients were followed up at 1 day, 1 week, and 1 month postoperatively and visual acuity outcomes between the two procedures were compared. Results: A slightly higher percentage of eyes in FS-LASIK (46.6%) achieved a UCVA of 1.0 at 1 day postoperatively compared to SMILE (45.5%). At 1 week and 1 month, SMILE showed superior results with 83% and 94.6% of eyes achieving a UCVA of 1.0, meanwhile FS-LASIK had 72.2% and 86.2%. Residual refractive error at 1 month had a median of -0.6146 and -0.3125 in the FS-LASIK and SMILE groups. Conclusion: This study found better UCVA results in the FS-LASIK group compared to the SMILE group at 1 day postoperatively. Meanwhile, UCVA at 1 week and 1 month postoperatively, showed superior results in the SMILE group. Residual refractive error at 1 month postoperatively also showed better results in SMILE than FS-LASIK.

Outcomes of Photorefractive Keratectomy in Patients Who Underwent Keratoplasty

&amp;lt;i&amp;gt;Purpose&amp;lt;/i&amp;gt;: To assess the efficacy of photorefractive keratectomy (PRK) in patients who underwent corneal transplantation, and to determine the influencing factors. &amp;lt;i&amp;gt;Methods&amp;lt;/i&amp;gt;: The present study was a retrospective chart review research that was conducted at Dhahran Eye Specialist Hospital between 2014 and 2017. &amp;lt;i&amp;gt;Results&amp;lt;/i&amp;gt;: Seventy-nine eyes were included in the study. The mean BCVA showed an improvement of two lines post-PRK as compared to that before PRK (0.73 ± 0.1 and 0.54 ± 0.2, respectively). There was a statistically significant decrease in the cylindrical value postoperatively as compared to that preoperatively (−2.15 ± 1.4 and−3.25 ± 1.8, respectively; p &amp;lt; 0.001). However, there was no statistically significant difference in spherical equivalent and sphere. Three eyes (4%) developed postoperative complications. There was a medium positive correlation between residual stroma and achieved spherical equivalent (SE) (r = 0.305, p = 0.006), as well as between optical zone and postoperative uncorrected visual acuity (r = 0.350, p = 0.001), in addition to post SE (r = 0.307, p = 0.006). However, the depth of ablation showed a medium negative correlation with achieved SE (r = −0.375, p = 0.001). &amp;lt;i&amp;gt;Conclusion&amp;lt;/i&amp;gt;: PRK may be an option for correcting refractive errors in patients who underwent keratoplasty. The optical zone and residual stromal thickness have a positive correlation with the effects of the outcomes, whereas the depth of ablation has a negative correlation with the outcomes.

Refractive Error Impact on Video Head Impulse Test Outcomes.

The objective of this study is to investigate the potential influence of refractive error on Video Head Impulse Test outcomes. Eighty-two patients were included in the study, and all patients underwent video head impulse testing. Patients were divided into four groups according to their refractive error: myopia, myopia-astigmatism, astigmatism, and emmetropia as control. Patients with myopia are younger than patients with astigmatism and controls; similarly, patients with myopia-astigmatism are younger than patients with astigmatism. The right and left lateral, anterior, and posterior gain values were statistically significantly lower in the control group compared with myopia and myopia-astigmatism patients (p < 0.05). There was a statistically significant relationship between the right and left lateral, anterior, and posterior gain values and the degree of myopia in the patients (p < 0.05). The results of the Video Head Impulse Test gain in myopia patients are higher than that in patients without refractive error. In addition, age may have an effect on gain values. It is important to consider this factor when evaluating the results of the Video Head Impulse Test in patients, and corrections should be made if necessary. Level 3 Laryngoscope, 2024.

Vertical implantable collamer lens as a novel method to increase rotational stability.

We investigated the vertical implantation of a toric implantable collamer lens (ICL) and compared the rotational stability with that of horizontal implantation. This matched comparative study retrospectively reviewed and analyzed data from patients who underwent ICL implantation from 2003-2022 by 1:1 matching vertical and horizontal (V and H toric groups, respectively) implantation patients according to preoperative astigmatism, spherical equivalent, sulcus-to-sulcus, anterior chamber depth, and ICL size. Visual acuity, manifest refraction, vaulting, and rotation were measured 3 months postoperatively. We included 646 eyes (323 each in the V and H toric groups). No statistically significant difference was observed between groups in postoperative visual acuity, refractive error, and astigmatism. Vaulting was lower in the V toric group. (P < 0.001). The mean lens rotation in the V toric group was less than that in the H toric group (1.11 ± 2.84° versus 3.02 ± 10.34°, P = 0.001). The proportion of eyes in the V and H toric groups showing ≥10° of rotation was 2.5% (8 eyes) and 6.5% (21 eyes), respectively (P = 0.014). Despite repositioning from rotation, three (0.9%) and eight (2.5%) eyes required removal owing to lens re-rotation in the V and H toric groups, respectively. Toric ICL vertical implantation showed good rotational stability, and appropriate visual acuity correction results with relatively low vaulting. This procedure therefore presents an effective novel method that could replace horizontal toric ICL implantation.

Interventional human ocular safety experiments for 222-nm far-ultraviolet-C lamp irradiation.

The study aimed to directly assess the ocular safety of 222-nm far-ultraviolet-C (UVC) irradiation in humans, given the limited clinical trials in this area. This wavelength offers the potential for safe and effective microbial inactivation in occupied spaces, but its safety profile for human eyes requires thorough investigation. This prospective, interventional study involved five subjects aged 29-47 years, who were exposed to 222-nm UVC at doses of 22, 50, and 75 mJ/cm2. The subjects were monitored using custom-made glasses with a UV-cut filter on one eye to serve as a control. UVC irradiation was conducted using a KrCl excimer lamp, and ocular examinations were performed prior to exposure, 24 h post-exposure, and at 1, 3, and 6 months. Parameters assessed included visual acuity, refractive error, corneal endothelial density, corneal erosion scores, and conjunctival hyperemia scores. The study found no clinically significant photokeratitis or long-term eye damage across the five subjects, even at the highest dose of 75 mJ/cm2. Temporary ocular discomfort, including sensations of dryness and epiphora, was reported, but these symptoms subsided within hours after irradiation. The findings indicate that 222-nm far-UVC irradiation up to 75 mJ/cm2 does not cause "clinically significant photokeratitis" or long-term ocular damage, though it may induce temporary discomfort. This supports the safe use of 222-nm UVC for germicidal applications in occupied environments, providing a basis for revised safety guidelines.

Relative peripheral refraction in school children with different refractive errors using a novel multispectral refraction topographer.

To compare relative peripheral refraction (RPR) in Chinese school children with different refractive errors using multispectral refraction topography (MRT). A total of 713 eyes of primary school children [172 emmetropia (E), 429 low myopia (LM), 80 moderate myopia (MM), and 32 low hypermetropia (LH)] aged 10 to 13y were analyzed. RPRs were measured using MRT without mydriasis. MRT results showed RPR at 0-15° (RPR 0-15), 15°-30° (RPR 15-30), and 30°-45° (RPR 30-45) annular in the inferior (RPR-I), superior (RPR-S), nasal (RPR-N), and temporal (RPR-T) quadrants. Spherical equivalent (SE) was detected and calculated using an autorefractor. There were significant differences of RPR 15-30 between groups MM [0.02 (-0.12; 0.18)] and LH [-0.13 (-0.36; 0.12)] (P<0.05), MM and E [-0.06 (-0.20; 0.10)] (P<0.05), and LM [-0.02 (-0.15; 0.15)] and E (P<0.05). There were also significant differences of RPR 30-45 between groups MM [0.45 (0.18; 0.74)] and E [0.29 (-0.09; 0.67)] (P<0.05), and LM [0.44 (0.14; 0.76)] and E (P<0.001). RPR values increased from the hyperopic to medium myopic group in each annular. There were significant differences of RPR-S between groups MM [-0.02 (-0.60; 0.30)] and E [-0.44 (-0.89; -0.04)] (P<0.001), and LM [-0.28 (-0.71; 0.12)] and E (P<0.05). There were also significant differences of RPR-T between groups MM [0.37 (0.21; 0.78)] and LH [0.14 (-0.52; 0.50)] (P<0.05), LM [0.41 (0.06; 0.84)] and LH (P<0.05), and LM and E [0.29 (-0.10; 0.68), P<0.05]. A Spearman's correlation analysis showed a negative correlation between RPR and SE in the 15°-30° (P=0.005), 30°-45° (P<0.05) annular (P=0.002), superior (P<0.001), and temporal (P=0.001) quadrants. Without pupil dilation, values for RPR 15-30, 30-45, RPR-S, and T shows significant differences between myopic eyes and emmetropia, and the differences are negatively correlated with SE.

Solid-state laser (266 nm) as an alternative to ArF excimer laser (193 nm) for corneal reshaping: Comparative numerical study of the thermal effect.

Laser corneal reshaping is a safe and effective technique utilized to treat common vision disorders. An advanced laser delivery system equipped with a pulsed UV laser with specific parameters is used to ablate parts of the cornea surface to correct the existing refractive error. The argon fluoride (ArF) excimer pulsed gas laser at 193 nm is the most employed type in the commercial devices for such treatments. This laser is generated using a mixture of Argon, Fluorine, and a significant amount of Neon gases. However, due to the ongoing Russian-Ukraine war, the availability of Neon gas is currently very limited, as this region is considered the primary supplier of pure Neon gas. Consequently we suggest replacing the common ArF laser source in the commercial devices with a solid-state (forth harmonic neodymium-doped yttrium aluminum garnet laser at 266 nm). This replacement uses the same operation parameters, optics, and scanning algorithm. Parameters from five commercial devices (Zeiss MEL 90, Technolas TENEO 317, Alcon Wave Light EX 500, Schwind Amaris 750 s, OptoSystems MICROSCAN VISUM) were compared with those of the i-ablation device, a research device that uses a 266 nm laser source. Our goal is to reduce production costs through a simple modification that has a significant impact. Consequently, the present study aims to find an alternative laser source for the current ArF laser without exchanging the complete system's design. This recommendation is based on a numerical simulation study. The thermal effect on a human cornea model was numerically evaluated using finite-element solutions of Pennes' bioheat equation on the COMSOL platform by applying two laser wavelengths. The results demonstrated that changing the laser source significantly impacts the thermal effect, even with the same laser settings. All studied devices showed a reduction in the thermal effect to below 40°C, compared with nearly 100°C under ordinary conditions.

Myopia dominance in preterm infants without and with retinopathy of prematurity: Indian Twin Cities ROP study (ITCROPS) report number 15.

To investigate the refractive error profile and progression in infants with different stages of ROP, without ROP, and those who received laser treatment for ROP. This retrospective study included the data from 838 infants (baseline mean age 3.7 ± 5.4 months) who had premature birth. Among these, 433 infants had one of the stages of ROP and 405 had no ROP. Infants with ROP were sub-divided into stage 1 (n = 76), stage 2 (n = 142), and stage 3 (n = 136) and aggressive posterior ROP, (APROP, n = 79). They were further categorized into those who received treatment (n = 213) and with no treatment for ROP (n = 220). Data from a subset of 117 infants was used to assess the 1-year change in the refractive error. Myopia was defined as spherical equivalent refraction (SER) <-0.50 diopters (D). Eyes with retinal detachment were excluded. Higher percentage of myopia was found in infants with ROP (39.7%) than no-ROP (19.8%), and it increased with severity of ROP: stage 1: 19.7%, stage 2: 33.8%, stage 3: 45.6%, and 59.5% in APROP. Percentage of myopia doubled in those who underwent treatment for ROP (54.5%) compared to no-treatment group (25.5%). Mean (± SEM) change in SER after 1 year was significantly greater in infants with APROP -4.55 ± 1.38 D and stage 3 ROP -2.28 ± 0.57 D compared to other stages and no-ROP. Myopia was found to be more prevalent in preterm infants in general, and more in the presence of ROP. Preterm infants without or with any form of ROP, particularly those with severe form of ROP and those who received treatment require meticulous periodic refractive error assessment.

The prevalence of refractive errors and corneal topographic changes in unilateral congenital ptosis versus the fellow eye- A cross-sectional study

The drooping upper eyelid in ptosis induces pressure on the eyelid and the same has been implicated to induce refractive errors. Very limited literature is available on the actual prevalence of corneal topographic changes and refractive errors seen in ptosis.Aim of this study was done to examine the effect of pressure of the upper eyelid on refractive errors and corneal topography in ptotic eyes and its comparison with fellow normal eyes. This was a cross-sectional observational study and included 83 patients with unilateral congenital ptosis. The study was conducted at NavJyoti Eye Hospital, Gorakhpur, Uttar Pradesh from Jul 2021- Feb 2023. Only unilateral cases of simple congenital ptosis were included in the study. Ptosis was evaluated to classify it into mild, moderate and severe. Retinoscopic refraction and corneal mapping for topography were done to get keratometric data, refractive errors, astigmatism and topographic patterns. The observations in ptotic eyes were compared with those in fellow normal eyes. Data was analyzed using the Statistical Package for Social Sciences (SPSS) version 20. P- value of &amp;#60; 0.05 was considered significant. Around 18 (21.69%) patients were found to have mild ptosis, 30 (36.14%) showed moderate and 35 (42.17) participants had severe ptosis. 16 (19.28%) ptotic eyes had myopia as compared to 10 (12.05%) non-ptotic eyes. 14 (16.86%) ptotic eyes were hyperopic as compared to 2 (2.41%) non-ptotic eyes. 38 (45.78%) ptotic eyes showed significant astigmatism (refractive) as compared to 5 (6.02%) non-ptotic eyes. 48 (57.83%) of ptotic eyes had significant Sim K (topographic) astigmatism as compared to 24 (28.92%) non-ptotic eyes. The prevalence of refractive errors was found to increase with the severity of ptosis. The majority of ptotic eyes 44 (53.01%) showed symmetrical bow tie pattern on corneal imaging (topography) whereas the most common pattern seen in non-ptotic eyes was round 33 (39.76%). Pressure from the upper eyelid in congenital ptosis induces significant corneal topographic changes and errors of refraction. Meticulous refraction and corneal topography should be done in all cases of congenital ptosis to timely detect astigmatism and suitable corrective measures should be instituted to prevent the development of amblyopia.

Prevalence and risk factors for refractive error in older adults in eight ethnicities in China: The China national health survey

PurposeThis study aimed to investigate the prevalence of refractive error (RE) and risk factors for myopia among older adults in the Han and various minority ethnic groups across seven provinces in China. MethodsThis cross-sectional study forms a part of the ophthalmic dataset of the China National Health Survey (CNHS). Face-to-face interviews and ophthalmic examinations were conducted in seven provinces located in western and northern China. The age- and sex-adjusted prevalence of RE among Han and seven other ethnic groups aged 50–80 years were compared. A mixed-effects model was used to identify the risk factors associated with RE. ResultsA total of 12,902 participants, including 8800 Han and 4102 from ethnic minorities, were included in the study. The age- and sex-adjusted prevalence of myopia, high myopia, hyperopia, and astigmatism ranged from 15.3 % (Manchu) to 22.9 % (Han), 0.2 % (Yugur) to 2.8 % (Han), 21.6 % (Tibetan) to 48.9 % (Uyghur), and 38.7 % (Yi) to 57.5 % (Manchu) across different ethnicities, respectively. Compared to the Han population, the Mongolian (odds ratios (OR) 0.62, 95 % confidence interval (CI) 0.46–0.84, p = 0.002), Tibetan (OR 0.66, 95 % CI 0.52–0.85, p = 0.001), Uyghur (OR 0.63, 95 % CI 0.49–0.80, p < 0.001), Yi (OR 0.65, 95 % CI 0.46–0.92, p = 0.014), and Yugur (OR 0.65, 95 % CI 0.50–0.85, p = 0.001) ethnicities were less likely to have myopia. There was no significant difference in the prevalence of myopia between the Manchu, Korean, and Han ethnic groups. Factors associated with a lower prevalence of myopia included rural residence (p < 0.001), a body mass index (BMI) > 18.5 kg/m2 (all p < 0.001), residence in higher latitude areas (p = 0.020), and a history of smoking (p = 0.002 in the past smoking group, p = 0.031 in the current smoking group). The Mongolian (p = 0.006) and Yugur (p = 0.007) populations, participants living in rural areas (p = 0.012), and those with a BMI >24 kg/m2 (p = 0.038 in the >24.0 ≤ 27.0 kg/m2 group or p = 0.041 in the >27.0 kg/m2 group) were less likely to have high myopia. Factors associated with a higher prevalence of hyperopia included older age (all p < 0.001), rural residence (p = 0.039), higher latitude areas (p = 0.031), smoking history (p = 0.040), and Mongolian (p = 0.001), Uyghur (p < 0.001), Yi (p < 0.001), and Yugur (p = 0.002) ethnicities. Conversely, the Manchu population (p = 0.004) and individuals with higher education levels than illiteracy (p = 0.024 or p < 0.001) were less likely to have hyperopia. ConclusionsMyopia affected more than one-fifth of the older adults in the Han population in this survey. Significant differences in the prevalence of RE were observed between minority ethnicities and Han individuals, except for the Manchu and Korean groups.

Epidemiology of eye diseases in Bangladesh

Bangladesh is densely populated country in South Asia, faces significant challenges in eye health due to various socioeconomic, environmental, and healthcare access factors. Limited access to quality eye care services, poor hygiene practices, prevalence of infectious diseases, and a high burden of non-communicable diseases contribute to the prevalence of eye disorders in the region. This study aims to comprehensively analyze the prevalence, distribution, and risk factors associated with various eye diseases among the population of Bangladesh. A systematic review and meta-analysis were conducted to gather data on the epidemiology of eye diseases in Bangladesh. Published studies, national surveys, and reports from relevant health organizations were reviewed to compile data on the prevalence, distribution, and risk factors of common eye conditions, including cataracts, refractive errors, conjunctivitis, glaucoma, diabetic retinopathy, and age-related macular degeneration. The prevalence of eye diseases in Bangladesh is relatively high, with conditions such as refractive errors, cataracts, glaucoma, and corneal diseases being major concerns. Refractive errors, including myopia, hyperopia, and astigmatism, affect a substantial portion of the population, particularly among children and young adults. Cataracts, a leading cause of blindness worldwide, also pose a significant burden in Bangladesh, with prevalence increasing with age. While the prevalence of glaucoma in Bangladesh is lower compared to some other countries, the condition remains a cause of concern due to its impact on quality of life and the healthcare system. Diabetic retinopathy, a complication of diabetes mellitus, affects the retina and is a leading cause of vision loss and blindness globally in the elderly. In Bangladesh, the rising prevalence of diabetes, fueled by changing lifestyles and an aging population, has contributed to an increasing burden of diabetic retinopathy. Conjunctivitis is prevalent, particularly in densely populated urban areas and rural communities with limited access to clean water and sanitation facilities.Collaborative efforts involving government agencies, healthcare providers, non-governmental organizations, and the community are essential to effectively address the burden of eye diseases in Bangladesh. By implementing preventive measures and improving access to quality eye care services, it is possible to mitigate the impact of these eye diseases and improve visual health outcomes for the population.

Practice patterns in pediatric myopia management: Insights from a 2023 survey among Indian ophthalmologists.

This study investigates the practice patterns related to paediatric myopia among Paediatric Ophthalmologists in India, based on a 2023 survey conducted via Google Forms. The survey aimed to gather insights into physicians' perceptions and experiences concerning the clinical and treatment aspects of myopia in children. The survey reveals several key insights into current practice patterns among Paediatric Ophthalmologists in India regarding paediatric myopia management. The recommended mean age for a child's first eye checkup is 3 years, underscoring the importance of early detection. Refractive error thresholds for prescribing spectacles are set at 3.0 D for infants, 2.0 D for preschool children, and 1.0 D for school-going children older than 3 years. There is a growing trend in using 0.01% Atropine eye drops for myopia management, with a mean prescription age of 4.83 years. Notably, 80.11% of respondents prioritize documenting myopia progression regardless of the child's age. Orthokeratology and Peripheral Defocus spectacle lenses are gaining recognition, and lifestyle modifications such as increasing outdoor activities and reducing near activities are widely acknowledged as effective. While most respondents do not use progressive lenses for myopia, there is significant emphasis on axial length measurements and considering the lag of accommodation. Additionally, under-correction of myopia is favored by a notable proportion of practitioners. These findings indicate a shift towards early intervention and evidence-based strategies in myopia control. The survey highlights a shift towards early intervention and evidence-based myopia control strategies among practitioners. There is, however, room for improvement in standardizing approaches and considering additional factors like axial length and lag of accommodation. Collaborative efforts among policymakers, health regulatory bodies, and industry stakeholders are essential to enhance the accessibility and affordability of myopia control treatments and address the growing health burden associated with paediatric myopia.