Refractive Error Research Articles

Lens Factor Choice in IOL Power Calculation after Laser Refractive Surgery: The Right Constant for Advanced Lens Measurement Approach (ALMA).

Background/Objectives: To evaluate the advanced lens measurement approach (ALMA) formula accuracy using different lens constants available on the user group for laser interference biometry (ULIB) and IOL Con platforms. Methods: In this retrospective, comparative, case-series study, 150 eyes of 160 patients with previous myopic Photorefractive Keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK), who underwent uneventful cataract surgery and IOL implantation, were examined. The ALMA formula was evaluated to calculate the refractive prediction error (PE), analysing four different categories of lens constants: both nominal and optimized A-Constant for SRKT, which are available on the ULIB and IOL Con platforms. An additional analysis was carried out in this study, evaluating if a decreased ULIB optimized constant (DUOC) with different fixed factors (-1.2 -1.3 -1.4 -1.5) could improve refractive outcomes. Median absolute error (MedAE) and percentage of eyes within ±0.50 and ±1.00 diopters (D) of prediction error were measured as the main outcomes. Results: Comparing the lens factors available on ULIB and IOL Con platforms, the ALMA formula reported a lower MedAE and higher percentages of eyes with a refractive PE within 1.0 D using ULIB nominal constants (all p < 0.05). Using DUOC (-1.3), and there was a statistically significant improvement of both MedAE and of the percentages of eyes with PE within ±0.50 D with the ALMA method compared to nominal ULIB constants (all p < 0.05). Conclusions: The impact of different lens factors in the IOL power calculation after myopic LRS should be carefully evaluated. The ALMA formula, in the absence of optimized constants by zeroing the mean error, should be used by subtracting 1.3 from the optimized ULIB constants available on the IOL Con website. This finding suggests further studies to test which of these constants could work better with the other post-refractive surgery formulas.

Preventable vision loss in children with Coats disease

PurposeTo describe the prevalence and risk factors associated with amblyogenic refractive error in children with Coats disease. MethodsThe medical records of children (<18 years of age) with unilateral Coats disease treated at a single tertiary care center were retrospectively reviewed. Data collected included patient demographics, ocular examinations, and treatments. Outcomes included the prevalence and factors associated with amblyogenic refractive error. ResultsA total of 50 children (82% male) were included; of these, 37 (74%) had refractive data to review. The median age at presentation was 5 years (IQR, 2-10). The Coats disease classification was stage 1 in 1 (2%), stage 2 in 29 (58%), and stage 3 or greater in 20 (40%). Most children (76%) had at least one visit with a pediatric specialist; the rest were only seen by a retina specialist. Among patients with refractive data, amblyogenic refractive error was identified in 46%. Glasses were prescribed to 50% of children. Children diagnosed at an earlier age had increased odds of amblyogenic refractive error (OR = 0.72; 95% CI, 0.57-0.91; P = 0.006) than those diagnosed at an older age. ConclusionsOur results suggest that amblyogenic refractive error is prevalent among children with Coats disease, and refractions are not always performed. There is a need to coordinate care between pediatric and retina specialists caring for children with Coats disease to ensure timely diagnosis of amblyogenic refractive error to optimize visual outcomes in this population.

Stereopsis Following Implantation of Presbyopia-Correcting Intraocular Lenses: A Narrative Review.

Recent advancements in cataract surgery have broadened its scope from mere vision restoration to include correction of refractive errors and presbyopia. This evolution has introduced multifocal and extended depth-of-focus (EDOF) intraocular lenses (IOLs), allowing enhanced vision across multiple distances. However, the influence of these advanced IOLs on stereopsis remains controversial. Factors influencing stereopsis after surgery include visual acuity, interocular differences, residual astigmatism, and the type of IOL, etc. Binocular vision integration and neuroadaptation further affect stereopsis, especially in cases of presbyopia-correcting IOLs. It is widely acknowledged that bilateral implantation of presbyopia-correcting IOLs yield superior stereopsis compared to unilateral implantation. However, there remains no consensus on whether binocular implantation of multifocal or monofocal IOLs provides superior stereopsis. Most studies suggest no significant difference in stereopsis between these two types of implants. Among different types of multifocal IOLs, refractive multifocal IOLs may offer better stereopsis than diffractive multifocal IOLs when implanted bilaterally. Emerging EDOF and hybrid multifocal-EDOF IOLs also demonstrate promising postoperative stereopsis. Additionally, a mix-and-match strategy with different types of IOLs implanted in each eye may result in interocular differences in visual acuity at certain distances, potentially affecting stereopsis. Nevertheless, with appropriate selection, most patients can achieve satisfactory postoperative stereopsis. This review synthesizes current literature on the effects of presbyopia-correcting IOLs on postoperative stereopsis recovery following cataract surgery. Studies on stereopsis outcomes with different IOLs have yielded mixed results, urging further investigation for optimized surgical strategies and patient outcomes.

The effect of individualized ocular refraction customized spectacle lenses on myopia control in schoolchildren: A 1-year randomised clinical trial.

The aim of this study was to investigate the effect of individualized ocular refraction customized (IORC) spectacle lenses with different actual amounts of peripheral myopic defocus (MD) on myopia control over 1 year. These lenses compensate for the original peripheral refraction via the free-form surface on the back of the lens. This 1-year, double-masked randomised clinical trial included 184 myopic schoolchildren aged 8-12 years. Participants were randomised to receive IORC lenses with high (IORC-H group, +4.50 D), medium (IORC-M group, +3.50 D) or low (IORC-L group, +2.50 D) MD or single-vision (SV) lenses. The spherical equivalent refractive error (SER) and axial length (AL) were measured at baseline and 6-monthly intervals. After 1 year, the mean (SD) changes in SER were -0.18 (0.37), -0.36 (0.37), -0.52 (0.39) and -0.60 (0.42) D for the IORC-H, IORC-M, IORC-L and SV groups, respectively. Compared with the SV group, the effects of slowing myopia progression were 70%, 40% and 13% for the IORC-H (difference of 0.47 D, p < 0.001), IORC-M (difference of 0.32 D, p = 0.001) and IORC-L (difference of 0.15 D, p > 0.05) groups, respectively. The mean (SD) changes in AL were 0.12 (0.16), 0.23 (0.17), 0.29 (0.17) and 0.36 (0.17) mm for the IORC-H, IORC-M, IORC-L and SV groups, respectively. The axial elongation was 67%, 36% and 19% lower in the IORC-H (difference of 0.25 mm, p < 0.001), IORC-M (difference of 0.15 mm, p < 0.001) and IORC-L (difference of 0.10 mm, p = 0.04) groups, respectively, compared with the SV group. The IORC-H group exhibited significantly less axial elongation than the IORC-M and IORC-L groups (p = 0.01 and p < 0.001, respectively). Compared with the IORC-M and IORC-L lenses, the IORC-H lens was found to have superior efficacy in inhibiting myopic progression and slowing eye growth in schoolchildren, with better myopia control efficacy in younger children.

Chromatic cues for the sign of defocus in the peripheral retina.

Detecting optical defocus at the retina is crucial for accurate accommodation and emmetropization. However, the optical characteristics of ocular defocus are not fully understood. To bridge this knowledge gap, we simulated polychromatic retinal image quality by considering both the monochromatic wavefront aberrations and chromatic aberrations of the eye, both in the fovea and the periphery (nasal visual field). Our study revealed two main findings: (1) chromatic and monochromatic aberrations interact to provide a signal to the retina (chromatic optical anisotropy) to discern positive from negative defocus and (2) that chromatic optical anisotropy exhibited notable differences among refractive error groups (myopes, emmetropes and hyperopes). These findings could enhance our understanding of the underlying mechanisms of defocus detection and their subsequent implications for myopia control therapies. Further research is needed to explore the retinal architecture's ability to utilize the optical signals identified in this study.

Changes in anterior segment after short-term scleral lens wear in healthy Chinese population

PurposeTo evaluate the impact of short-term scleral lens (SL) wear on anterior chamber (AC) dimension and central corneal thickness (CCT) in healthy Chinese people. MethodsThis is a prospective, daily wear study. Eligible participants were dispensed SLs to correct refractive errors. Anterior segment (AS) parameters were measured by AS optical coherence tomography (AS-OCT) before, during, and after 2 and 4 hours of lens wear. Repeated-measures analysis of variance (ANOVA) was used to analyze the changes in AS parameters over time. ResultsTwelve subjects (10 females and 2 males) with a mean age of 25.3 ± 3.8 years (ranging from 21 to 34 years) were recruited. The AC parameters, including anterior chamber depth (ACD) from the endothelium (endo-ACD), angle opening distance at 500 μm (AOD500), and trabecular-iris space area at 500 μm (TISA500), significantly decreased after wearing SLs for 4 hours (P<0.05). CCT increased by 12 μm (2.29 %) after wearing SLs for 4 hours (P=0.013). ConclusionThis study suggests that SL wear has a significant impact on AS dimensions in patients with healthy corneas in the short term with SL in situ, but tend to recover quickly after SL removal. Further research is needed to determine whether the change in AS dimensions during SL wear affects aqueous humor (AH) outflow and causes changes in intraocular pressure (IOP).

Astigmatism among schoolchildren in Mumbai, India: a large, population-based study

Background: Astigmatism is a common refractive error. If left untreated, it may result in blurred or distorted vision. We determined the prevalence of astigmatism in schoolchildren aged 6–16 years in Mumbai, India. Methods: A cross-sectional study was conducted using a stratified cluster random sampling method. We included primary and secondary schoolchildren aged 6–16 years. All children underwent a comprehensive eye examination. Astigmatism was characterized as having a diopter cylinder (DC) power of 0.50 or more in at least one eye, and for prevalence estimation, we reported the number of children with astigmatism. Astigmatism severity was defined as mild (less than or equal to - 1.50 DC), moderate (- 1.50 DC to - 2.50 DC), and severe (&gt; - 2.50 DC). Based on the axis orientation, astigmatism was categorized as with-the-rule, against-the-rule, and oblique. Results: A total of 3151 schoolchildren with a mean (standard deviation) age of 12.1 (2.9) years were screened; boys and girls accounted for 49.22% and 50.78%, respectively. Age groups of 6–9, 10–13, and 14–16 years accounted for 51.35%, 28.53%, and 20.12%, respectively. The overall prevalence of astigmatism was 11.46%, with no significant difference between sexes (P &gt; 0.05). The prevalences of astigmatism in the groups aged 6–9-, 10–13-, and 14–16 years were 5.24%, 3.49%, and 2.73%, respectively. Prevalence differed significantly among age groups (P &lt; 0.05), with a trend of decreasing prevalence with increasing age. No significant association was found between age and severity of astigmatism (P &gt; 0.05). The prevalences of mild, moderate, and severe astigmatism were 6.51%, 3.11%, and 1.84%, respectively. Mild astigmatism was significantly more prevalent than moderate (P &lt; 0.05) or severe astigmatism (P &lt; 0.05). The prevalence of astigmatism differed significantly among the three orientations of axis (P &lt; 0.001). The prevalences were 9.20%, 1.68%, and 0.57% for with-the-rule, against-the-rule, and oblique astigmatism, respectively. We found a statistically significant difference in the prevalences of astigmatism based on the axis orientation between boys and girls (P &lt; 0.05) and between age groups (P &lt; 0.001), with a decreasing trend observed with increasing age. Conclusions: We found a prevalence of 11.46% for astigmatism among schoolchildren aged 6–16 years in Mumbai, India. There was a decreasing trend in prevalence with increasing age, with no difference between sexes. The prevalence was the highest for mild astigmatism, followed by moderate and severe astigmatism. Prevalence differed significantly based on the axis orientation among the three subtypes, age groups, and between the two sexes, with a decreasing trend with increasing age. With-the-rule astigmatism was the most common, followed by against-the-rule astigmatism; oblique astigmatism was the least common.

Impact of blur on clinical and occupational colour vision test results.

To evaluate whether colour vision normal (CVN) adults pass two Fletcher-Evans (CAM) lantern tests and to investigate the impact of imposed blur on Ishihara, CAM lantern and computerised colour discrimination test (colour assessment and diagnosis test [CAD] and Cambridge colour test [CCT]) results. In a pilot experiment, 20 (16 CVN and 4 colour vision deficient [CVD]) participants with normal VA were tested with the CAM lantern. In the main experiment, the impact of imposed dioptric blur (up to +8.00 D) on visual acuity and the Ishihara test, CAM lantern, CAD and CCT was assessed for 15 CVN participants. CVN participants can fail the CAM lantern, with specificity of 81.25% (aviation mode) and 75% (clinical mode), despite following the test requirements of participants having at least 0.18 logMAR (6/9) in the better eye. With blur, test accuracy was affected. As expected, significant detrimental effects of blur on test results were found for logMAR VA and CAM lantern (aviation) with +1.00 D or higher. Ishihara, CAD and CCT results were not detrimentally affected until +8.00 D. Yellow-blue discrimination was more affected by blur for the CAD than the CCT, which was not explained by the different colour spaces used or vectors tested. False-positive findings on lantern colour vision tests with small apertures are likely to be increased in patients with blur due to uncorrected refractive error or ocular and visual pathway disease. Other colour vision tests with larger stimuli are more robust to blur.

Treating hyperglycaemia in a patient with maternally inherited diabetes and deafness with an inhibitor of dipeptidyl peptidase-4: a case report and two-year follow-up.

Maternally inherited diabetes and deafness (MIDD) is a mitochondrial disorder with diverse characteristics, which make early diagnosis difficult. We report a case of 32-year-old woman with diabetes who was admitted due to weight loss and poor glycemic control. She had a history of gestational diabetes at age 26. Pancreatic function was evaluated by oral glucose tolerance. An ophthalmologic examination detected conjunctivitis and refractive errors and hearing tests were normal. The patient had a family of diabetes. Then we tested the patient and her first-degree relatives with a confirmed genetic mutation at position 3243 in the tRNA. After two years of treatment with linagliptin, both glycated hemoglobin and pancreatic function have shown improvement to some extent. Although MIDD is a rare form of diabetes, due to distinctive management and associated comorbidities it is important to diagnose.

Medial rectus insertion site in cases of acute acquired comitant esotropia associated with excessive digital device usage.

To compare the distance of the medial rectus muscle insertion to the limbus (DMIL) between patients with acute acquired comitant esotropia (AACE) associated with excessive digital device usage (EDDU) and exotropic patients. Retrospective study. The medical records of 72 eyes of 44 patients with EDDU were retrospectively analyzed. The DMIL was measured from the anterior part at the midpoint of the medial rectus muscle insertion into the anterior limbus using a caliper after dissecting the medial rectus muscle with two control sutures at 12 o'clock and 6 o'clock. The DMIL in the non-fixation eye was compared between 44 patients with AACE and 23 patients with exotropia. The mean daily EDDU was 6.5 ± 3.1h. The mean cycloplegic refractive errors (spherical equivalent: SE) were - 3.18 ± 2.52 diopters (D) OD and - 3.03 ± 2.42 D OS. The mean DMIL in the 72 eyes of 44 patients with AACE associated with EDDU was 4.30 ± 0.66mm. The difference in DMIL of non-fixation eyes between 44 AACE patients and 23 exotropic patients was significant (4.28 ± 0.65mm vs. 5.28 ± 0.50mm, p < 0.0001). However, the SE in 44 non-dominant eyes of AACE was - 3.08 ± 2.56 D, significantly stronger than - 1.22 ± 1.93 D in the 23 exotropic eyes (p = 0.008). DMIL in patients with AACE associated with EDDU was significantly shorter. This anatomical anomaly may be an etiology of AACE associated with EDDU.

Myopia and Environmental Risk Factors: A Comprehensive Study

Background: The global rise in the prevalence of myopia calls for evidence-based strategies to be devised to reduce the incidence and delay the progression of Myopia. The aim is to determine the relationship between myopia incidence and some environmental factors. Methods: A cross-section observational study was conducted at Alzahraa Teaching Hospital from May 2023 to December 2023. Primary school students of both genders. All students were enrolled in the study after an agreement with their parents/guards. Data was collected using a pre-constructed data collection sheet (questionnaire) including three sections, the first section was sent to the families to fill and sign the consent for participation and provide the required data including the demographic variables, family history and medical history of the students, time outdoors, prolonged near work/increased study hours, high BMI, use of LED lamps for homework, less sleeping hours, low Vitamin D levels, less participation in sports and low socioeconomic status. The second part included the general examination of the students, school grades and education performance (assessed according to the student school Cards). The third section involved the ophthalmological examination, visual acuity and ophthalmoscopic examination. Results: A total of 100 students were enrolled in this study, they were equally distributed according to gender, 50 boys and 50 girls. The age of students ranged between 6 and 12 years. Only 12 students had positive past medical and surgical history. A family history of myopia was reported in 20% of the studied group, 20 children were wearing spectacles and a history of past eye complaints was reported in 9 (9%) of children. The refractive errors were 45% hypermetropia, 39% myopia and 16% astigmatism. Abnormal visual acuity was detected in 35%. Myopia was significantly higher in children with family history (p=0.007). A statistically significant relationship was found between large time outdoors and myopia (OR=4.52, p=0.02). A statistically significant relationship was found between prolonged near-work/increased study hours and myopia (OR=4.52, p=0.02). A statistically significant relationship was found between using LED lamps for homework and myopia (OR=10.33, p&lt;0.0001). A statistically significant relationship was found between fewer sleeping hours and myopia (OR=7.5, p&lt;0.0001). Conclusion: Prevention of the onset of myopia and delay in the progression of myopia can be altered by modifying the contributing environmental risk factors. Raise outdoor time with adequate sunlight exposure, rural environment, less duration of near work, use of incandescent lamp and normal sleeping rhythms with adequate regular sleeping hours can prevent the onset and progression of myopia. Myopia is associated with high BMI, watching television and playing digital devices. High socioeconomic status associated with more indoor activity, increased academic pressure, sedentary lifestyle contribute to the prevalence of myopia.

Objective Refraction Status before and after Cycloplegia: From Childhood to Young Adulthood.

This study aimed to evaluate the clinical information revealed after cycloplegia and assess how age and non-cycloplegic refractive status influence the classification of types of refractive error, as well as the relationship between age and cycloplegia-induced changes in the power of refractive errors. We analysed the records of 472 non-population-based ophthalmology practice patients aged 3-28 years (mean ± SD: 9.1 ± 4.6). Cycloplegia was induced with one drop of cyclopentolate 1% in each eye, and eye refraction was measured 30 ± 5 min later using an objective autorefractometer. Cycloplegia induced a clinically significant (≥0.50 D) hyperopic shift in the spherical equivalent of 60.2% of participants and a myopic shift in 1%, resulting in a 34.1% increase in the frequency of participants with hyperopia, while the frequency of those with myopia and emmetropia decreased by 5.5% and 23.3%, respectively. The average spherical equivalent difference (mean ± SD) induced by cycloplegia was 0.72 ± 0.73 D, with the highest difference observed in the 3-5 years age group (1.18 ± 0.85 D). The differences in astigmatism power (p = 0.84) and astigmatism axis (p = 0.97) between non-cycloplegic and cycloplegic conditions were not statistically significant.

Lutein protects senescent ciliary muscle against oxidative stress through the Keap1/Nrf2/ARE pathway

BackgroundAging-induced decline in ciliary muscle function is an important factor in visual accommodative deficits in elderly adults. With this study, we provide an innovative investigation of the interaction between ciliary muscle aging and oxidative stress. MethodsTricolor guinea pigs were used for the experiments in vivo and primary guinea pig ciliary smooth muscle cells were used for the experiments in vitro. ResultsWe enriched for genes associated with muscle-aging-lutein relationship using bioinformatics, including Nuclear factor-erythroid 2-related factor-2 (Nrf2), Glutathione Peroxidase (GPx) gene family, Superoxide Dismutase (SOD) gene family, NAD(P)H: Quinone Oxidoreductase 1 (NQO1) and Heme Oxygenase-1 (HO-1). After gavage to aged guinea pigs, lutein reduced Reactive Oxygen Species (ROS) and P21 levels in senescent ciliary muscle; lutein decreased refractive error and restored accommodation of the eye. In addition, lutein increased GPx, SOD, and Catalase (CAT) levels in serum; lutein increased GPx and CAT levels in ciliary bodies. Lutein regulated the expression of proteins such as Nrf2, Kelch-like ECH-associated protein 1 (Keap1), and downstream proteins in senescent ciliary bodies. Similarly, guinea pig ciliary muscle cell senescence was associated with oxidative stress. In vitro, 100 μM lutein reversed the damage caused by 800 μM H2O2; it reduced Senescence-Associated β-galactosidase (SA-β-Gal) and ROS activites, cell apoptosis and cell migration. Also, lutein increased the expression of smooth muscle contractile proteins. Lutein also increased the expression of Nrf2, GPx2, NQO1 and HO-1, decreased the expression of Keap1. A reduction in Nrf2 activity led to a reduction in the ability of lutein to activate antioxidant enzymes in the cells, thus reducing its inhibitory effect on cell senescence. Conclusionlutein improved resistance to oxidative stress in senescent ciliary muscle in vivo and in vitro by regulating the Keap1/Nrf2/Antioxidant Response Element pathway. We have innovatively demonstrated the molecular pharmacological mechanism by which lutein reverse age-related ciliary muscle systolic and diastolic deficits.

Long-term follow-up results and visual outcomes of childhood glaucoma in the black sea region of turkey.

To investigate long-term visual outcomes and factors associated with low vision in patients with childhood glaucoma. A retrospective review was conducted on the medical records of pediatric glaucoma patients at the Ondokuz Mayıs University Ophthalmology Clinic from 2005 to 2023. The patients were categorized into three groups: primary congenital glaucoma (PCG), secondary childhood glaucoma, and glaucoma following cataract surgery (GFCS). Groups were analyzed regarding visual acuity (VA), ocular conditions and comorbidities, and the cause of visual impairment. The study also investigated the potential risk factors associated with visual impairment. A total of 105 eyes of 60 patients with a mean age of 9.7 ± 5.5years were included in the study. The mean VA in logMAR was 0.59 ± 0.52. At the final follow-up, 34.1% had good VA (≥ 20/50), 29.5% had moderate VA (20/50-20/200), and 36.4% had poor VA (< 20/200). The final mean intraocular pressure (IOP) was 16.2 ± 6.2mmHg. Amblyopia was the leading cause of vision loss (38.2%), followed by glaucomatous damage (36.4%). Patients with GFCS had a higher rate of visual impairment (42.4%) and refractive error. The results of the regression analysis showed that low vision was associated with undergoing more than two surgeries, high IOP at baseline, high initial and final cup-to-disc (C/D) ratio, and high initial central corneal thickness (CCT) (CI 95%, p = 0.018, p= 0.017, p = 0.013, p = 0.003, p = 0.001, respectively). Good VA can be achieved in 34.1% of childhood glaucoma cases. However, the VA prognosis may be worse in patients with GFCS. Achieving good visual outcomes in childhood glaucoma requires timely and effective treatment, consideration of risk factors, and management of amblyopia and ocular comorbidities.

Willingness to pay for cataract surgery and its associated factors in selected medical centers in Urmia, Iran

IntroductionCataracts represent a significant public health issue and are the most prevalent vision disorder following refractive errors. They can restrict the economic, social, and psychological activities of those affected, thereby diminishing their quality of life. This study was undertaken to examine the willingness to pay for cataract surgery and the factors influencing this decision in selected medical centers in Urmia. The two-stage Heckman model was utilized to aid decision-making in financing this service.MethodsThis research was a descriptive-analytical study evaluating the economic aspects of health interventions, conducted from the patient’s perspective. In this cross-sectional study, a sample size of 217 patients with cataract issues was selected using Michel Carson’s table. These patients were from Imam Khomeini Hospital and Aftab Urmia Surgery Center in 2023. Data was collected using a conditional valuation approach to determine the maximum amount patients were willing to pay, as gathered through a questionnaire. The factors influencing the willingness to pay for cataract surgery were estimated using the two-stage Heckman regression model. The final effect value of each variable was calculated using Stata version 14 software.ResultsIn this study, 81.11% of participants (176 individuals) expressed a willingness to pay for cataract surgery, with the average amount they were willing to pay being $206.3. However, out of the 217 respondents, 41 rejected the proposed amounts and were not willing to pay anything. The results of the Hemken model indicated that the income of patients and the size of their households significantly influenced their willingness to pay for cataract surgery. However, other variables investigated did not have a significant impact.ConclusionThe study results revealed a significant influence of both income and household size on the likelihood of willingness to pay, as well as the extent of willingness to pay for cataract surgery. Consequently, it is crucial to formulate policies and provisions that guarantee access to cataract services, particularly for individuals from large households with low income and high costs.

Does blepharospasm effect biometric parameters and intraocular lens power calculations?

To investigate the effect of botulinum toxin-A (BTX-A) treatment on corneal topography, ocular biometry and keratometry in patients with benign essential blepharospasm (BEB) and hemifacial spasm (HFS). This study comprised 66 eyes of 33 patients with BEB and 5 eyes of 5 patients with HFS who underwent BTX-A injections consecutively. Refractive error values, tear break-up time (TBUT), corneal topography [corneal power of flat axis (K1) and steep axis (K2), mean corneal power (Km), corneal astigmatism (K2-K1)] and ocular optical biometry [axial length (AL), anterior chamber depth (ACD)] were recorded before BTX-A treatment and 1 month after BTX-A treatment. The researchers calculated the expected emmetropic intraocular lens power (emm-IOL) using the SRK-T, Holladay, Hoffer-Q and Haigis formulas at each examination. K1 (43.48 ± 2.02 vs. 43.57 ± 2.08, p = 0.036), Km (43.91 ± 1.99 vs. 43.99 ± 2.06, p = 0.024) and ACD (3.22 (2.77-3.76) vs. 3.41 (2.99-4.02), p < 0.001) values were found to be significantly higher. The expected emm-IOL according to the SRK-T (21.04 ± 1.6 vs. 20.93 ± 1.6, p = 0.048), Holladay (21.05 ± 1.6 vs. 20.91 ± 1.62, p = 0.037) and Hoffer-Q (21.08 ± 1.65 vs. 20.94 ± 1.68, p = 0.038) decreased significantly. The expected emm-IOL according to the Haigis formula slightly decreased, but it was not significant (p = 0.386). Additionally, TBUT was found to be significantly lower (p < 0.001) after BTX-A injection. Other parameters were not statistically significant (p > 0.05). Our study is the first in the literature to compare optic biometry data and intraocular lens power calculation formulas before and after BTX-A injection in eyes with BEB and HFS. BTX-A injection could play an important role in changing the keratometric and ACD values. It should be considered that IOL power calculations that might be unpredictable due to blepharospasm, so repeated measurements and especially measurements after releasing the spasm with BTX-A injections, are necessary in BEB and HFS.

An infant who cannot open her eyes and does not smile: a case report

Noonan syndrome (NS) is a genetically heterogeneous disorder, with distinctive facial features, short stature, chest deformity, and congenital heart diseases. Germline mutations in the RAS-MAPK (mitogen-activated protein kinase) signal transduction pathway result in Noonan syndrome. It shares clinical features with other RASopathies like Costello syndrome, and cardio-facio-cutaneous syndrome. Ocular findings like hypertelorism, ptosis, refractive errors, strabismus, amblyopia, and external eye abnormalities. It is often difficult to differentiate from other syndromes. Molecular genetic testing can confirm the diagnosis in 70% of cases and plays an important role in genetic counselling and management.

A Field Research on the Problems Experienced by Opticians and Optical Stores

The optician profession forms an important bridge between ophthalmologists and patients in the treatment of eye diseases and refractive errors. Optical glasses, frames, contact lenses and other devices are provided and applied by opticians in accordance with prescriptions written by ophthalmologists. However, the optician profession and institutions in Turkey face various problems. This research aims to identify and analyze issues such as education and qualification problems, regulatory difficulties, economic difficulties and adaptation to technological innovations experienced by the optician profession and institutions in Turkey. By evaluating the opinions and expectations of different stakeholders, solution suggestions and strategies will be developed to make the profession more efficient and effective. Thus, it is aimed that the results of the study will contribute to the future development of the optician profession and its institutions.

Clinical Efficacy of MiSight 1 day Soft Contact Lenses in Korean Myopic Children.

This study aimed to investigate the clinical efficacy of MiSight 1 day soft contact lenses (MiSight CL) in Korean children with mild-to-moderate myopia. In addition, the study compared the effects of MiSight CL in children who had or had not previously used orthokeratology contact lenses (Ortho-K). A total of 66 children aged 5 to 16 years, who were prescribed MiSight CL, were included in the study. Based on a myopia degree of -4 diopters (D), children were divided into mild and severe myopia groups to compare the effectiveness of myopia suppression. In addition, 55 eyes previously using Ortho-K were compared with 76 eyes using MiSight CL for the first time. The average follow-up period was 6.58±3.74 months. The average refractive value before using MiSight CL was 3.64±1.56 D, and there was no significant change in the final visit. Comparing myopia suppression between different degrees of myopia and previous use of Ortho-K lenses, there was no significant change in refractive error before and after using MiSight CL (unpaired t test, P >0.05). The main reason for Ortho-K failure was low visual acuity after correction. Regardless of Ortho-K history, children showed good visual acuity after wearing MiSight CL, and no other side effects were observed. MiSight CL effectively inhibited the progression of myopia in Korean children with mild-to-moderate myopia. MiSight CL offer the advantage of easy application, making them a viable alternative when Ortho-K are not suitable.

Factors Related to Raised Intraocular Pressure: In a Tertiary Hospital in Bangladesh

Glaucoma, a leading cause of irreversible blindness globally, accounts for 8% of such cases. The probability of developing glaucoma appears to be elevated in individuals with systemic hypertension or diabetes mellitus. Elevated intraocular pressure (IOP) is the only modifiable risk factor associated with the development and progression of glaucoma, and both medical and surgical interventions are available for its management. This study, conducted in the Ophthalmology department of BSMMU from July 2021 to June 2022, was a hospital-based cross-sectional investigation with a sample size of 153. The majority of participants fell into the 41-50 age group, with a mean age of 37.15±17.14. 41.8% of the responders were men and 58.2% were women. Refractive errors were identified in 7.2% of cases, with primary open-angle glaucoma (POAG) diagnosed in 60% of cases, normal-tension glaucoma (NTG) in 11.1%, and angle-closure glaucoma (PACG) in 10.5%, among other types. The study also observed associations between age groups and IOP levels, with 42% of individuals aged 30-50 having IOP in the 18-22 mmHg range. Additionally, 50% of established glaucoma cases had diabetes mellitus, 30% had hypertension, and 10% had a history of steroid therapy. Together with other variables including steroid usage, diabetes, and hypertension, high IOP continues to be a substantial risk factor for the start and progression of glaucoma. J. of Sci. and Tech. Res. 5(1): 157-162, 2023