Major Cause Of Visual Impairment Research Articles

Rapid survey for assessing effective cataract surgical coverage (eCSC) and effective refractive error coverage (eREC)-Novel indicators of universal eye health.

As per the recent World Health Organization estimates, approximately 2.2 billion people have near and distance vision impairment (VI) globally, and out of this almost 50% is avoidable. The Rapid Assessment of Avoidable Visual Impairment survey was a cross-sectional study conducted in September 2021, using cluster random sampling in 42 clusters with a cluster size of 140, giving a total of 6000 participants. Two teams comprising of trained optometrists and social workers conducted the ocular examination which included unaided, pinhole, and aided visual acuity assessments followed by examination of the anterior segment and lens. Distance visual acuity was measured using simplified tumbling "E" charts of different sizes for VA of 6/12, 6/18, and 6/60. The lens assessment was done in an un-dilated pupil with torch light by the optometrist. Overall, 6520 individuals aged 6 years and above were enumerated, of whom 5440 (83.4%) were examined. The response rate for examination was better among females (93.1%) than males (73.9%), and it decreased from 93.8% in the age group 6-15 years to 77.1% in the 45+ age group. The prevalence of blindness and VI were 0.18% (95% CI: 0.06-0.29) and 4.19% (95%CI: 3.65-4.72), respectively. The major causes of VI in all age groups were uncorrected refractive error (65.4%), cataract (23.7%), cataract surgical complications (2.6%), corneal opacity (0.4%), and other posterior segment diseases (7.5%). The effective cataract surgical coverage (eCSC) was 61.8%, effective refractive error coverage (eREC) for distance vision was 59.8%, and eREC for near vision was 47.0%. The RAAVI methodology is suitable to measure effective coverage in the general population, both for baseline measurement and periodic monitoring. The 2030 targets for the surveyed district are 90% eCSC and 100% eREC. Such exercises need to be conducted in each district of the country to determine the baseline and target values of effective coverage.

Associated factors of diabetic retinopathy in type 1 and 2 diabetes in Limpopo province in South Africa.

Diabetic retinopathy (DR) is the major cause of vision impairment or blindness in individuals who have diabetes. It has accounted for 2.6% of all cases of blindness, and 1.9% of all cases of vision impairments globally. There is a lack of data on the prevalence of diabetic retinopathy and its associated factors amongst diabetic rural populations. Hence, the current study aimed to determine factors associated with diabetic retinopathy (DR) among diabetes mellitus (DM) patients undergoing diabetic therapy. The study was cross-sectional in design and the participants were selected using convenient sampling. STATA version 15 software was used for data analysis. Chi-square was used to compare proportions. Logistic regression was used to determine the relationship between DR and associated risk factors. The prevalence of DR was 35.3%, of which 32% were mild and 3.4% were moderate non-proliferative DR (NPDR). Females were more unemployed than males (32.1% versus 16.8%, p=0.0058). Males were found to drink alcohol (21.8% versus 1.9%, p<0.001) and smoke cigarettes (4% versus 0.3%, p=0.0034) more than females. Being aged ≥ 55 years (OR: 2.7, 95% CI: 1.6-4.4), with matric qualification (OR: 0.6; 95% CI: 0.4-1.0); employed (OR: 1.4, 95% CI: 1.2-1.6); having high systolic blood pressure (OR=1.4, 95%CI=1.1-1.7) were the independent determinants of DR. The prevalence of diabetic retinopathy was 34%. DR was determined by high systolic blood pressure, old age, and employment. Although not statistically significant, gender, hyperglycemic state, poor glycemic control, smoking, and increased body mass index (BMI) were associated with increased risk of developing DR.

Subconjunctival injection of rapamycin-loaded polymeric microparticles for effective suppression of noninfectious uveitis in rats

Noninfective uveitis is a major cause of vision impairment, and corticosteroid medication is a mainstay clinical strategy that causes severe side effects. Rapamycin (RAPA), a potent immunomodulator, is a promising treatment for noninfective uveitis. However, because high and frequent dosages are required, it is a great challenge to implement its clinical translation for noninfective uveitis therapy owing to its serious toxicity. In the present study, we engineered an injectable microparticulate drug delivery system based on biodegradable block polymers (i.e., polycaprolactone-poly (ethylene glycol)-polycaprolactone, PCEC) for efficient ocular delivery of RAPA via a subconjunctival injection route and investigated its therapeutic efficacy in an experimental autoimmune uveitis (EAU) rat model. RAPA-PCEC microparticles were fabricated using the emulsion-evaporation method and thoroughly characterized using scanning electron microscopy, fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry. The formed microparticles exhibited slow in vitro degradation over 28 days, and provided both in vitro and in vivo sustained release of RAPA over 4 weeks. Additionally, a single subconjunctival injection of PCEC microparticles resulted in high ocular tolerance. More importantly, subconjunctival injection of RAPA-PCEC microparticles significantly attenuated the clinical signs of EAU in a dose-dependent manner by reducing inflammatory cell infiltration (i.e., CD45+ cells and Th17 cells) and inhibiting microglial activation. Overall, this injectable microparticulate system may be promising vehicle for intraocular delivery of RAPA for the treatment of noninfective uveitis.

Age–period–cohort analysis of the global burden of visual impairment according to major causes: an analysis of the Global Burden of Disease Study 2019

BackgroundCataract, glaucoma and age-related macular degeneration (AMD) are major causes of visual impairment. As these are age-related conditions, the prevalence of associated visual impairment is anticipated to increase as the...

Non-surgical treatment of stage 4A retinopathy of prematurity

BackgroundRetinopathy of prematurity (ROP) is a major cause of visual impairment in premature infants, often requiring surgical interventions in advanced stages. This retrospective case series study investigates non-surgical management for Stage 4A ROP, specifically the use of combined laser therapy and intravitreal anti-vascular endothelial growth factor (VEGF) injections.MethodsTen eyes from five infants with Stage 4A ROP were treated with a combined laser and anti-VEGF approach. Comprehensive follow-up examinations were conducted to evaluate the treatment outcomes.ResultsThe study demonstrated successful retinal attachment without complications, showcasing the efficacy and safety of this non-surgical method. A comparison with surgical interventions highlighted the potential benefits in terms of reduced adverse effects.DiscussionThis combined treatment emerges as a promising first-choice option for Stage 4A ROP, offering rapid regression without surgical intervention, particularly in early stages. However, larger randomized clinical trials are necessary to validate these findings and establish definitive guidelines for managing this complex condition.ConclusionCombined laser and anti-VEGF therapy proved to be an effective and safe non-surgical approach for Stage 4A ROP, with the potential to reduce the need for surgery, especially in its early presentation. Further research is required to confirm these findings and provide comprehensive recommendations for clinical practice.

Diabetic Macular Edema Management: A Review of Anti-Vascular Endothelial Growth Factor (VEGF) Therapies.

Diabetic macular edema (DME) is a major cause of vision impairment in diabetic individuals, characterized by fluid accumulation in the macula due to a breakdown of the blood-retinal barrier (BRB). This review article explores the role of anti-vascular endothelial growth factor (anti-VEGF) therapies in the management of DME. Anti-VEGF treatments, including ranibizumab, bevacizumab, and aflibercept, have revolutionized DME management by targeting VEGF, a key mediator in DME pathogenesis. We critically examined the efficacy of these therapies in reducing macular edema and improving visual acuity, assessed their safety and tolerability, and explored the variability in treatment response. The review highlights the latest advancements and future directions in anti-VEGF therapy, including novel drug delivery systems and emerging treatment paradigms. By providing a comprehensive overview of current anti-VEGF therapies, this review seeks to inform clinical practice, guide future research, and contribute to improved patient outcomes in DME management.

RESTORE VISION: Novel advanced and repurposed therapeutics for vision restoration in a group of severe rare ocular diseases – Short introductory talk

Rare Eye Diseases (REDs) collectively represent a major cause of visual impairment and blindness for children and young adults in Europe. But importantly, REDs also affect adults and the aging population. Defective wound healing at the cornea and ocular surface, excessive inflammation, nerve degeneration, stem cell dysfunction, and aberrant vessel ingrowth are the common denominators in many REDs, representing a critical medical problem and an area of unmet medical need. The onset and progression of many REDs are characterized by common pathophysiologic mechanisms. The goal of many research groups is to disrupt these aberrant mechanisms with the aim of making therapy more effective. Current management is often prohibitively expensive, has low efficacy and leads to debilitating side effects, pointing to a critical medical problem and area of unmet medical need.Here, we will briefly introduce the RESTORE VISION project, which has been recently funded by the European Commission and brings together actors from across the full value chain: 6 leading research institutions, 3 SMEs and a European patient organization. The project will take a ground‐breaking approach to improve eye health by verifying disease pathomechanisms, using cutting‐edge models for each rare disease to test novel and repurposed compounds and determine drug mechanisms of action, formulating compounds as safe eye drop suspensions or subconjunctival drugs, and performing several first‐in‐human trials of novel therapies.

On the structure of eye diseases in children leading to blindness or low vision in various countries of the world

The review presents differences in the nosological structure of ophthalmic pathology leading to childhood blindness and low vision in different countries. Worldwide, 1.4 million children are blind, about three quarters of whom live in the poorest regions of Africa or Asia. In lowincome countries, the congenital cataract is one of the leading causes of visual impairment in children, while retinopathy of prematurity is more common in middle-income countries. Uncorrected refractive errors both in children and adults, remain a major cause of visual impairment in all countries. The development of new technologies and quality medical care impacts the structure of blindness and low vision causes, as well as their geographical specificities. The analysis showed that much effort is required from large-scale state programs of prevention, early diagnosis, treatment and rehabilitation of children with socially significant eye diseases.

The m6A reader YTHDC2 maintains visual function and retinal photoreceptor survival through modulating translation of PPEF2 and PDE6B

Inherited retinal dystrophies (IRDs) are major causes of visual impairment and irreversible blindness worldwide, while the precise molecular and genetic mechanisms are still elusive. N6-methyladenosine (m6A) modification is the most prevalent internal modification in eukaryotic mRNA. YTH domain containing 2 (YTHDC2), an m6A reader protein, has recently been identified as a key player in germline development and human cancer. However, its contribution to retinal function remains unknown. Here, we explore the role of YTHDC2 in the visual function of retinal rod photoreceptors by generating rod-specific Ythdc2 knockout mice. Results show that Ythdc2 deficiency in rods causes diminished scotopic ERG responses and progressive retinal degeneration. Multi-omics analysis further identifies Ppef2 and Pde6b as the potential targets of YTHDC2 in the retina. Specifically, via its YTH domain, YTHDC2 recognizes and binds m6A-modified Ppef2 mRNA at the coding sequence and Pde6b mRNA at the 5′-UTR, resulting in enhanced translation efficiency without affecting mRNA levels. Compromised translation efficiency of Ppef2 and Pde6b after YTHDC2 depletion ultimately leads to decreased protein levels in the retina, impaired retinal function, and progressive rod death. Collectively, our finding highlights the importance of YTHDC2 in visual function and photoreceptor survival, which provides an unreported elucidation of IRD pathogenesis via epitranscriptomics.

Requirement of Site-Specific Tyrosine Phosphorylation of Cortactin in Retinal Neovascularization and Vascular Leakage.

Retinal neovascularization is a major cause of vision impairment. Therefore, the purpose of this study is to investigate the mechanisms by which hypoxia triggers the development of abnormal and leaky blood vessels. A variety of cellular and molecular approaches as well as tissue-specific knockout mice were used to investigate the role of Cttn (cortactin) in retinal neovascularization and vascular leakage. We found that VEGFA (vascular endothelial growth factor A) stimulates Cttn phosphorylation at Y421, Y453, and Y470 residues in human retinal microvascular endothelial cells. In addition, we observed that while blockade of Cttn phosphorylation at Y470 inhibited VEGFA-induced human retinal microvascular endothelial cell angiogenic events, suppression of Y421 phosphorylation protected endothelial barrier integrity from disruption by VEGFA. In line with these observations, while blockade of Cttn phosphorylation at Y470 negated oxygen-induced retinopathy-induced retinal neovascularization, interference with Y421 phosphorylation prevented VEGFA/oxygen-induced retinopathy-induced vascular leakage. Mechanistically, while phosphorylation at Y470 was required for its interaction with Arp2/3 and CDC6 facilitating actin polymerization and DNA synthesis, respectively, Cttn phosphorylation at Y421 leads to its dissociation from VE-cadherin, resulting in adherens junction disruption. Furthermore, whereas Cttn phosphorylation at Y470 residue was dependent on Lyn, its phosphorylation at Y421 residue required Syk activation. Accordingly, lentivirus-mediated expression of shRNA targeting Lyn or Syk levels inhibited oxygen-induced retinopathy-induced retinal neovascularization and vascular leakage, respectively. The above observations show for the first time that phosphorylation of Cttn is involved in a site-specific manner in the regulation of retinal neovascularization and vascular leakage. In view of these findings, Cttn could be a novel target for the development of therapeutics against vascular diseases such as retinal neovascularization and vascular leakage.

MiR-423-5p promotes Müller cell activation via targeting NGF signaling in diabetic retinopathy

AimsDiabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus and one of the major causes of visual impairment and blindness in industrialized countries. The early neuro-glial perturbations, especially retinal Müller cells (rMC) activation, intimately associated with the vascular alterations. MicroRNAs (miRNAs) have been reported to play critical roles in the progression of DR. Here, we aimed to further explore the role and underlying mechanism of miR-423-5p in Müller cell activation in streptozotocin (STZ)-induced diabetic mice and oxygen-induced retinopathy (OIR) model. Materials and methodsRetinal histology, optical coherence tomography (OCT) and biochemical markers were assessed. Key findingsOur data revealed that the expression of miR-423-5p was significantly increased under high-glucose environment. We also demonstrated that miR-423-5p overexpression markedly accelerated retinal vascular leakage, leukocytosis, and rMC activation. This response was ameliorated in animals pre-treated with the inhibition of miR-423-5p. Specifically, miR-423-5p bound to the nerve growth factor (NGF) 3′ UTR region to induce its silencing. NGF inhibition significantly promoted retinal microvascular dysfunction. SignificanceThese findings demonstrate that miR-423-5p is a critical miRNA that promotes microvascular dysfunction in DR.

Prevalence and Risk Factors of Retinopathy in Type 1 Diabetes: A Cross-Sectional Study.

Introduction Diabetic retinopathy (DR) is a severe complication of diabetes. It remains a major cause of visual impairment and blindness, especially in young people. It is a silent affection that only becomes symptomatic at the onset of complications. Our study aimed to estimate the prevalence of retinopathy in patients with type 1 diabetes mellitus (T1DM) and evaluate the associated risk factors in our population. Materials and methods A descriptive and analytical study, with a cross-sectional study involving 359 patients with type 1 diabetes, was followed up in the Department of Endocrinology, Diabetology, and Nutrition of the University Hospital Center Mohammed VI Oujda, Morocco. Data were collected from medical records and analyzed by binary logistic regression using IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp. Results The average age of our patients was 24.2 ± 11.4 years. The mean duration of diabetes was 11.8±4.4 years. The average glycated hemoglobin (HbA1c) at admission was 10.1 ± 2.4%. DR was found in 30% of patients, including 28.6% with minimal non-proliferative diabetic retinopathy (NPDR), 19.1% with moderate NPDR, 19.1% with severe NPDR, and 33.3% with proliferative DR. Patients with diabetic retinopathy appear to have a longer duration of diabetes (13.05±9.05 vs. 10.6±8.07 years). The longer duration of diabetes, neuropathy, and nephropathy was significantly associated with diabetic retinopathy (p=0.02, p=0.002, and p=0.0001, respectively). Conclusion The frequency of diabetic retinopathy increases with age, poor glycemic control, and the duration of diabetes. Therefore, cooperation between diabetologists and ophthalmologists is essential for making an early diagnosis and providing early treatment.

Managing Pediatric Cataract Patients – The Whole Story: Aphakic Contact Lenses in Children – Techniques and Challenges

ABSTRACT Infantile cataract is one of the major causes of visual impairment in children. This article will discuss some of the techniques, challenges, complications, and compliance issues with aphakic contact lenses.

Protective effect of ethyl ferulate against hypoxic injury in retinal cells and retinal neovascularization in an oxygen-induced retinopathy model

BackgroundPathological neovascularization is a major cause of visual impairment in hypoxia-induced retinopathy. Ethyl ferulate (EF), the natural ester derivative of ferulic acid commonly found in Ferula and Angelica Sinensis, has been shown to exert antioxidant, neuroprotective, and anti-inflammatory properties. However, whether EF exerts a protective effect on retinal neovascularization and the underlying mechanisms are not well known. PurposeThe aim of the study was to investigate the effect of EF on retinal neovascularization and explore its underlying molecular mechanisms. Study-design/methodsWe constructed hypoxia models induced by cobalt chloride (CoCl2) in ARPE-19 cells and Rhesus choroid-retinal vascular endothelial (RF/6A) cells in vitro, as well as a retinal neovascularization model in oxygen-induced retinopathy (OIR) mice in vivo. ResultsIn this work, we demonstrated that EF treatment inhibited hypoxia-induced vascular endothelial growth factor A (VEGFA) expression in ARPE-19 cells and abrogated hypoxia-induced tube formation in RF/6A cells. As expected, intravitreal injection of EF significantly suppressed retinal neovascularization in a dose-dependent manner in OIR retinas. We also found that hypoxia increased VEGFA expression by blocking autophagic flux, whereas EF treatment enhanced autophagic flux, thereby reducing VEGFA expression. Furthermore, EF activated the sequestosome 1 (p62) / nuclear factor E2-related factor 2 (Nrf-2) pathway via upregulating oxidative stress-induced growth inhibitor 1 (OSGIN1) expression, thus alleviating oxidative stress and reducing VEGFA expression. ConclusionAs a result of our findings, EF has an inhibitory effect on retinal neovascularization, implying a potential therapeutic strategy for hypoxia-induced retinopathy.

DME-DeepLabV3+: a lightweight model for diabetic macular edema extraction based on DeepLabV3+ architecture.

Diabetic macular edema (DME) is a major cause of vision impairment in the patients with diabetes. Optical Coherence Tomography (OCT) is an important ophthalmic imaging method, which can enable early detection of DME. However, it is difficult to achieve high-efficiency and high-precision extraction of DME in OCT images because the sources of OCT images are diverse and the quality of OCT images is not stable. Thus, it is still required to design a model to improve the accuracy of DME extraction in OCT images. A lightweight model (DME-DeepLabV3+) was proposed for DME extraction using a DeepLabV3+ architecture. In this model, MobileNetV2 model was used as the backbone for extracting low-level features of DME. The improved ASPP with sawtooth wave-like dilation rate was used for extracting high-level features of DME. Then, the decoder was used to fuse and refine low-level and high-level features of DME. Finally, 1711 OCT images were collected from the Kermany dataset and the Affiliated Eye Hospital. 1369, 171, and 171 OCT images were randomly selected for training, validation, and testing, respectively. In ablation experiment, the proposed DME-DeepLabV3+ model was compared against DeepLabV3+ model with different setting to evaluate the effects of MobileNetV2 and improved ASPP on DME extraction. DME-DeepLabV3+ had better extraction performance, especially in small-scale macular edema regions. The extraction results of DME-DeepLabV3+ were close to ground truth. In comparative experiment, the proposed DME-DeepLabV3+ model was compared against other models, including FCN, UNet, PSPNet, ICNet, and DANet, to evaluate DME extraction performance. DME-DeepLabV3+ model had better DME extraction performance than other models as shown by greater pixel accuracy (PA), mean pixel accuracy (MPA), precision (Pre), recall (Re), F1-score (F1), and mean Intersection over Union (MIoU), which were 98.71%, 95.23%, 91.19%, 91.12%, 91.15%, and 91.18%, respectively. DME-DeepLabV3+ model is suitable for DME extraction in OCT images and can assist the ophthalmologists in the management of ocular diseases.

The 18th amino acid glycine plays an essential role in maintaining the structural stabilities of γS-crystallin linking with congenital cataract

γS-crystallin is particularly rich in the embryonic nuclear region and is crucial to the maintenance of lens transparency and optical properties. Gene mutations in crystallin are the main factors leading to congenital hereditary cataracts, which are a major cause of visual impairment in children. Some mutations located in the 18th amino acid glycine of γS-crystallin were reported to be linking with congenital cataracts. However, the pathogenic mechanism has not been elucidated. Interestingly, we previously identified a novel variant of γS-crystallin (c.53G > A; p. G18D) with progressive cortical and sutural congenital cataracts in one Chinese family. In this study, we purified the γS-crystallin wildtype and mutant proteins to investigate the effects of the G18D mutation on the structural stability of γS-crystallin. The results showed that there were tertiary structural differences between the wild-type γS-crystallin and the G18D variant. The mutation significantly impaired the stability of γS-crystallin under environmental stress and promoted aggregation. Furthermore, molecular dynamics (MD) simulations showed that the mutation altered H-bonding and surface electrostatic potential. Significantly decreased stability along with an increased tendency to aggregate under environmental stress may be the major pathogenic factors for cataracts induced by the G18D mutation.

Automatic diagnosis of diabetic retinopathy using vision transformer based on wide-field optical coherence tomography angiography

Diabetic retinopathy (DR) is one of the major causes of visual impairment in adults with diabetes. Optical coherence tomography angiography (OCTA) is nowadays widely used as the golden criterion for diagnosing DR. Recently, wide-field OCTA (WF-OCTA) provided more abundant information including that of the peripheral retinal degenerative changes and it can contribute in accurately diagnosing DR. The need for an automatic DR diagnostic system based on WF-OCTA pictures attracts more and more attention due to the large diabetic population and the prevalence of retinopathy cases. In this study, automatic diagnosis of DR using vision transformer was performed using WF-OCTA images (12[Formula: see text]mm × 12[Formula: see text]mm single-scan) centered on the fovea as the dataset. WF-OCTA images were automatically classified into four classes: No DR, mild nonproliferative diabetic retinopathy (NPDR), moderate to severe NPDR, and proliferative diabetic retinopathy (PDR). The proposed method for detecting DR on the test set achieves accuracy of 99.55%, sensitivity of 99.49%, and specificity of 99.57%. The accuracy of the method for DR staging reaches up to 99.20%, which has been proven to be higher than that attained by classical convolutional neural network models. Results show that the automatic diagnosis of DR based on vision transformer and WF-OCTA pictures is more effective for detecting and staging DR.

A comparative study of visual outcome in patients with optic neuritis treated with five or seven days of intravenous corticosteroid treatment.

Optic neuritis (ON), a major cause of visual impairment in young adults, is generally associated with rapid visual recovery when treated with intravenous methylprednisolone treatment (IVMPT). However, the optimal duration of such treatment is unknown, ranging from three to seven days in clinical practice. We aimed to compare the visual recovery in patients treated with 5-day or 7-day duration IVMPT. We performed a retrospective cohort study of consecutive patients with ON in São Paulo, Brazil, from 2016 to 2021. We compared the proportion of participants with visual impairment in 5-day and 7-day treatment schedules at discharge, at 1 month and between 6 and 12 months after the diagnosis of ON. The findings were adjusted to age, severity of the visual impairment, co-intervention with plasma exchange, time from symptom onset to IVMPT and the etiology of the ON to mitigate indication bias. We included 73 patients with ON treated with 5 or 7-day duration of 1g/d intravenous methylprednisolone therapy. Visual impairment at 6-12 months in the 5-day or the 7-day treatment groups was similar (57% x 59%, p > 0.9, Odds Ratio 1.03 [95% CI 0.59-1.84]). The results were similar after adjusting for prognostic variables and when observed at different time points. Visual recovery is similar in patients treated with 5-day and 7-day duration treatments of 1g/day intravenous methylprednisolone, suggesting a ceiling effect. Limiting the duration of the treatment can reduce hospital stay and costs, without interfering with clinical benefit.

Long-term Outcomes Following Endoscopic Transnasal Surgery for Optic Neuropathy Due to Craniofacial Fibrous Dysplasia.

To investigate the feasibility of endoscopic transnasal optic canal decompression (ETOCD) guided by a navigation surgical system (NSS) for vision recovery in patients with compressive optic neuropathy (CON) caused by craniofacial fibrous dysplasia (CFD), and to explore the underlying cause of visual impairment. All patients underwent unilateral NSS-guided ETOCD and were followed up periodically for at least six months. Paired sample t-test and Pearson correlation analyses were used to compare continuous variables of the visual outcomes at the final review. A histopathological test of abnormal bone specimens was performed postoperatively. Thirty-four patients were finally included, and all surgeries were uneventful. The best corrected visual acuity (BCVA) (logMAR units) decreased from 1.29 ± 0.80 preoperatively to 0.97 ± 0.78 at the last follow-up (p = 0.0012), improving in 28 patients (82.35%). The absolute value of mean defect (MD) significantly decreased (p < 0.001). Color vision was impaired in 17 patients preoperatively and improved in 6 patients. BCVA at the last follow-up was significantly correlated with preoperative BCVA, onset time, preoperative retinal nerve fibril layer thickness, and MD (all p < 0.05). Among 34 patients, 26 had a blunt bony process near the anterior foot of the optic chiasm. Of the total patients, 73.53% patients experienced bony fiber recurrence 6 months or earlier after surgery without visual loss. NSS-guided ETOCD appeared to be safe and effective for visual recovery in patients with CON due to CFD, and early surgical intervention was critical for long-term recovery. Unbalanced compression of the optic canal by the blunt bony process may be a major cause of visual impairment. 4 Laryngoscope, 133:1857-1866, 2023.

Prevalence and causes of visual impairment and use of low-vision devices at a tertiary eye hospital in western Uttar Pradesh, India

Objectives: The objective of this study was to determine the hospital-based prevalence and major causes of visual impairment in patients attending the low-vision clinic of a tertiary eye institute. Materials and Methods: This study was a retrospective non-intervention hospital-based study. Clinical records of visually impaired patients presented to the department of low vision from February 2017 to December 2021 were retrieved. Blindness has been defined as the best-corrected distance visual acuity of &lt;3/60 and/or &lt;10° visual field in the better eye. Low vision was defined as a best-corrected distance visual acuity of &lt;6/18 but equal to or better than 3/60 in the better eye. The presenting visual acuity, causes of low vision and blindness, and prescribed low-vision devices were recorded and analyzed to determine the prevalence and major causes of visual impairment. Results: Among 414 visually impaired patients, the prevalence of low vision and blindness was 52.9% (n = 219) and 47.1% (n = 195), respectively. Retinitis pigmentosa (n = 57, 13.8%) and glaucoma (n = 43, 10.4%) were the major causes of low vision; however, glaucoma (n = 55, 13.3%) and cortical visual impairment (CVI) (n = 37, 8.9%) were the major causes of blindness. A total of 229 low-vision devices were dispensed, of them 166 (40.1%) were distance and 63 (15.1%) were near devices. Conclusion: The hospital-based prevalence of low-vision patients was more as compared to blindness. The major causes of visual impairment were retinitis pigmentosa, glaucoma, and CVI. A comprehensive approach to the causes of low vision and low-vision services is needed to reduce the burden of visual impairment in the country.