Cause Of Amblyopia Research Articles

Pattern of Refractive Error among Amblyopic Children at tertiary referral hospital of Ahmedabad, Gujarat.

Introduction: Amblyopia is one of the common causes of preventable uniocular or binocular vision loss in children. Timely diagnosis and management of amblyopia is crucial. If corrective measures are not taken in time it becomes permanent. Aim: To study the various types of refractive errors in amblyopic children aged 5-18 years in tertiary eye hospital. Materials and Methods: Retrospective cross –sectional study was carried out in the tertiary eye care hospital. All the children attending the ophthalmology OPD during January2021 to January 2023 were enrolled. All underwent detailed ophthalmic evaluation. After post mydriatic test, children with difference of two lines or more in visual acuity on Snellen chart were taken and detailed ophthalmic evaluation done. Results: The prevalence of amblyopia was 6.2% (n=48) with male dominant of 62.5% (n=30), while female was 37.5% (n=18). In types of Amblyopia, most common was simple Hypermetropic of 42% (n=20) followed by simple myopic and hypertropic Astigmatism 19% (n=9) in each. The Anisometropia Amblyopia was in 12% (n=6), while myopic astigmatism in 8%(n=4). The 69%(n=33) was binocular while 31% (n=15) was uniocular amblyopia. Conclusion: The Refractive errors are treatable and preventable cause of amblyopia. Timely diagnosis and proper treatments like spectacles, contact lenses, patching and active vision exercises, we can treat Amblyopia and prevent the psychosocial, economical loss in adult life. Keywords: Myopia, Hypermetropia, Anisometropia, Astigmatism

Epiblepharon Induced Anisometropic Amblyopia : Should We Treat or Observe?

Introduction : Previous study reported that epiblepharon strongly associated with astigmatism. Uncorrected refractive errors are considered the most common cause of amblyopia. Amblyopia by pure anisometropia is the one with the best prognosis recovery of visual acuity.
 Case Illustration : A children, 9 years old complained of eye discomfort, watery eyes and difficulties in recognizing distant object. After clinical examination and investigations, the patient had visual acuity 5/60 for right eye and 6/18 for left eye was identified as epiblepharon in both eyes with corneal erosion in right eye. The patient underwent repair epiblepharon surgery for right eye and topical antibiotics for corneal erosion. At 2 months after surgery, corneal erosion completely resolved. Best corrected visual acuity 6/21 with spectacle lens S - 1.00 C - 3.00 X 180o positive crowding phenomenon, and 6/6 for left eye with S – 1.00 C - 1.00 X 180o. Topography examination show with-the-rule astigmatism. At 2 month follow up after correction, visual acuity reached 6/6 for both eyes.
 Discussion : Epiblepharon induced astigmatism by mechanical force of the eyelid that influences corneal contour. Long term epithelial erosion also contribute to triggers corneal curvature remodelling and induced with-the-rules astigmatism. Diopter differences for astigmatism more than 2.00 D leads to anisometropic amblyopia.
 Conclusion : Adequate correction after surgery is proven to recover visual acuity in amblyopia patient caused by epiblepharon

The prevalence of functional amblyopia and its related risk factors in preschool children in North-Eastern Iran.

Purpose was to determine the prevalence of amblyopia and its related risk factors in children aged 3-6 years in Bojnurd, north-eastern Iran. In this cross-sectional study, from 12,331 children aged 3-6 in Bojnurd, 6600 children participated in annual amblyopic screening program and among them, around 1100 suspected cases were referred for full ophthalmic examinations. Measurement of visual acuity, cycloplegic refraction, subjective refraction, and cover test were performed for all participants. Amblyopia was defined as CDVA of 0.2 LogMar or less in each eye or 2-line difference or more in best-corrected visual acuity between two eyes. The prevalence of amblyopia was estimated 0.95% (95% confidence interval [CI]: 0.73%-1.2%). There was no relationship between amblyopia with age and genders. Most amblyopic children were hyperopic (61.9%; 95% CI: 48.7-73.8). Strabismus was found in 17.4% of amblyopic patients (95% CI: 9.05%-29.09%). Approximately half of the amblyopic children were anisometropic (55.5%; 95% CI: 42.40%-68.08%). The most common type of amblyopia was anisohyperopic (55.56%; 95% CI: 42.5%-67.5%). The prevalence of bilateral amblyopia was more than unilateral amblyopia. The assessment of data showed that hyperopia, astigmatism, and anisometropia were the most common causes of amblyopia in this study. The prevalence of amblyopia was estimated about 1% in north-eastern Iran. Our study indicated a valuable information around the effect of refractive error and anisometropia on amblyopia which could be helpful in designing a comprehensive vision screening program for preschool children.

Amblyopie-Prävalenz in Europa

Purpose. The aim of the present study is to estimate the prev- alence of amblyopia in Europe. Amblyopia is one of the most common causes of visual impairment, especially in children. It is defined as any unilateral or bilateral decrease in the visual acuity in the absence of structural and pathologic disorders of the eye. Amblyopia is due to insufficient development of the visual system in early childhood. If amblyopia is not detected and treated in time, the visual acuity reduction will persist for life. Material and Methods. An extensive literature review was conducted using the PubMed database using search combi- nations of “amblyopia”, “amblyopia prevalence”, “amblyopia screening” and “amblyopia therapy”. European studies on amblyopia prevalence and meta-analyses were included. The results on amblyopia prevalence are summarized. The German vision screening program is presented in detail and compared with other European programs. Results. Studies on amblyopia prevalence showed high het- erogeneity. Meta-analyses revealed pool prevalences of 2.7 to 3.7 percent. Anisometropia was the most common cause of amblyopia. For Germany, the prevalence in adults was estimated at 5.6 percent, which is a high rate compared with other European countries. Data from a German child cohort showed a prevalence of 1.5 percent. This estimate is consistent with prevalence rates in other European countries. Conclusion. Amblyopia prevalence in Germany appears to be lower in children than in adults. However, studies on amblyo- pia prevalence are difficult to compare with each other. This is partly due to the use of different amblyopia definitions. In addition, there are still no uniform European standards for amblyopia screening. Keywords amblyopia, prevalence, children, anisometropia, strabismus, screening

Anisometropic amblyopia: A review of functional and structural changes and treatment.

Amblyopia is the decreased best-corrected visual acuity (BCVA) in one or both eyes caused by the abnormal processing of visual input during development. One common cause of amblyopia is anisometropia, which has attracted widespread attention. Many structural changes occur in the primary and extrastriate visual areas of the cerebral cortex, as well as in the eyes, in patients with anisometropic amblyopia. Understanding these mechanisms has provided a favorable theoretical basis for treating anisometropic amblyopia. This article reviews the functional and anatomical changes and progress toward the treatment of anisometropic amblyopia.

Macular pigment optical density of hyperopic anisometropic amblyopic patients measured by fundus reflectometry.

PurposeHyperopic anisometropia is a major cause of amblyopia and may be associated with macular pigment optical density (MPOD) reduction. To explore whether the MPOD changes in hyperopic anisometropic amblyopia, we measured the MPOD using fundus reflectometry in eyes with hyperopic anisometropic amblyopia and normal vision.MethodsThis was a cross-sectional study conducted from January 2017 to June 2017. Forty subjects (25 males and 15 females) between the ages of 6 and 10 years were recruited. The subjects' eyes were divided into two groups: amblyopic eyes (best-corrected visual acuity (BCVA) not more than 20/25 or BCVA of two eyes differing by two or more lines) and fellow eyes. All enrolled subjects underwent a comprehensive ophthalmic examination, including extraocular motility assessment, cover-uncover testing, and refractive error (noncycloplegic), BCVA, axial length (AL), macular foveal thickness (MFT) and MPOD (Visucam® 200, Carl Zeiss Meditec AG, Germany).ResultsThe MPOD of amblyopic and fellow eyes was 0.12 ± 0.03 log units and 0.13 ± 0.04 log units, respectively, with a significant difference (P = 0.026). The MFT of amblyopic and fellow eyes was 241.28 ± 13.95 and 237.13 ± 16.02 μm, respectively, revealing that the MFT was significantly higher in amblyopic eyes than in fellow eyes (P = 0.028). Conversely, there was no correlation between the MPOD and MFT in the two groups.ConclusionsThis study is the first to report that the MPOD is decreased in hyperopic anisometropic amblyopia. In this study, no correlation between the MPOD and MFT was found. In the future, factors that induce a decrease in the MPOD in eyes with hyperopic anisometropic amblyopia should be explored in a large-sample study with follow-up observation.

Clinical Practice and the Attitude of Ophthalmologists Regarding Amblyopia in the Population of Jordan: A Cross-Sectional Study

Aim The study was aimed at finding out the knowledge and attitude among ophthalmologists regarding amblyopia in the population of Jordan. Methodology This was an observational cross-sectional study conducted in 2021 among ophthalmologists who live and work in the local society of Jordan and were aged between 30 and 50 years. The survey was conducted using an online questionnaire administered through email and various social media platforms. The level of knowledge and awareness of amblyopia, its causes, methods of treatment, and the best age for treating amblyopia was assessed. Results Out of 200 participants, the majority were in the age group of 30-34 years (47.5%). The male:female ratio was 1:1. The average better age for examination and treatment of amblyopia was three to five years (46%). The most common cause of amblyopia was strabismic amblyopia (50%). Children's and parents' cooperation most significantly influenced the treatment's success (49%). The preferred assessment was cycloplegic refraction (56%), and the preferred patching treatment was a direct cover placed over the eye (77%). The average time to treat amblyopia was less than three years in the majority (53.5%). The most critical factor determining the success of treatment was when the treatment began (57.5%). Conclusions Our study found that although the majority of the participants were less experienced overall, they had a good knowledge of the amblyopia age group and the method of examination. Still, there was a mixed response regarding the treatment. Hence there is a need to increase awareness regarding amblyopia by Jordanian ophthalmologists, social organizations, and educational institutes.

Comparative Analysis of Vision Screening Guidelines in the United States

Aims: To assess current school vision screening guidelines of states spread across different regions of the United States to inform quality guideline parameters and help combat preventable pediatric vision loss.
 Study Design: Cross-sectional comparative analysis.
 Methodology: States were first ordered alphabetically and then selected using an online random number generator (Alphabet Inc., Mountain View, California). States were selected until 13 available screening guidelines were identified. Each guideline was assessed using a 10-point multi-factorial scoring criteria detailed in Table 1. Descriptive statistics (mean and standard deviation) were calculated for each scoring criteria using Microsoft® Excel (version 16.63.1, Redmond, WA).
 Results: Most state guidelines included what ages to screen (84.62%, 11/13), how to screen (84.62%, 11/13), and how to follow-up with students to arrange (92.31%, 12/13) and confirm eye care delivery (76.92%, 10/13). Sadly, only the minority of state guidelines described at least two main causes of amblyopia (46.15%, 6/13), and a less than one-third of school nurse vision screening guidelines discussed the window of time to save vision in amblyopia (30.77%, 4/12). Worse yet, very few nurse vision screening guidelines explained that subjectively a child can’t tell you if they are at risk of developing amblyopia (15.38%, 2/13), or included two treatments for amblyopia (7.69%, 1/13) in the vision screening educational program.
 Conclusion: This study found that most of the assessed vision screening guidelines outlined the process of screening and follow-up but failed to emphasize why screening is important, causes, and treatment options for amblyopia. Gaps in these training guidelines may contribute to delayed recognition and treatment for amblyopia¾the leading cause of irreversible pediatric vision loss. Further improvements to vision screening guidelines are needed for school nurses and paraprofessional staff in the majority of the states evaluated.

The Clinical Characteristics of Amblyopia in Children Under 17 Years of Age in Qassim Region, Saudi Arabia.

PurposeTo provide the clinical characteristics of amblyopia in children under 17 years of age in Qassim Region, Saudi Arabia.Patients and MethodsThe study was a cross-sectional hospital-based, included 121 children with amblyopia aged between 3 and 17 years, referred from 6 hospitals in Qassim region to the paediatric optometry clinic at Qassim University medical city. Demographics and comprehensive ocular examination including visual acuity (VA), assessment of anterior and posterior segment, cycloplegic refraction (RE), angle of deviation, and cause of amblyopia were collected.ResultsThe mean age at diagnosis of amblyopia was 8.93 ± 3.67 years. The leading cause of amblyopia was strabismus and anisometropia shared the same percentage at 29.75%, and the combined-mechanism at 18.18%. Amblyopia was more common in males 57.85%, particularly strabismic amblyopia in 66.67% and anisometropic amblyopia in 61.11%, p = 0.408. Amblyopia was more predominant in the age group 6- to 9-year-old, particularly, strabismic amblyopia 44.44%, and amblyopia due to a combined mechanism of 36.36%, p = 0.066. The degree of hyperopia was not varied by the cause of amblyopia (P = 0.401), with slightly high hyperopia found in ametropic and strabismic amblyopia. Conversely, hyperopic astigmatism was significantly associated with amblyopia P = 0.020, with a high degree of hyperopic astigmatism found in meridional amblyopia and ametropic amblyopia.ConclusionThe commonest types of amblyopia in children were attributed to strabismus and anisometropia. Causes of amblyopia differed by age group with strabismus, anisometropia, and combined mechanism accounting for most children aged 6- to 9-years and strabismus for children aged less than 6 years. Hyperopic and myopic astigmatism were significantly associated with anisometropia and meridional amblyopia. Therefore, efforts should be made for early diagnosis and management of childhood amblyopia and uncorrected refractive errors to avoid their impact on quality of life.

Profile of Amblyopia Among Children Aged from 5 to 15 Years at Hawassa University Comprehensive Specialized Hospital Pediatric Eye Clinic, South Ethiopia, 2020/21.

PurposeFunctional visual impairment in children is mostly caused by amblyopia. Permanent visual impairment is caused by belated treatment of amblyopia and underlying causes, mostly due to the lack of awareness. Amblyopia affects children’s school performance, social interaction and motor skills. This study was aimed to assess the profile of amblyopia among children aged from 5 to 15 years.Methods and MaterialsA hospital-based, cross-sectional study was done from November to April 2020/21. Data were collected from all children who came to Hawassa university comprehensive specialized hospital pediatric eye out patient department in the data collection period. Visual acuity measurement, slit lamp examination, cycloplegic refraction, cover test and dilated fundus examination were conducted. Data was entered in Epi-info version 7 and analyzed by Statistical Package for Social Science version 20. Descriptive statistics were conducted to estimate the proportion of amblyopia and its causes.ResultsThe proportion of amblyopia was 23.8% (18.3–29.7). Most of the participants were within the age range of 5–9 years (55.4%) and males (51.5%). Anisometropia was the commonest cause of amblyopia (31.25%), followed by meridional (20.83), mixed (16.67%), isometropia (12.50%), sensory deprivation (10.42%) and strabismus (8.33%).ConclusionThe proportion of amblyopia was 23.8%. Anisometropia, meridional, sensory deprivation, isometropia, mixed type and strabismus were the identified causes of amblyopia.

Visual Perceptual Learning Induces Long-Lasting Recovery of Visual Acuity, Visual Depth Perception Abilities and Binocular Matching in Adult Amblyopic Rats.

An abnormal visual experience early in life, caused by strabismus, unequal refractive power of the eyes, or eye occlusion, is a major cause of amblyopia (lazy eye), a highly diffused neurodevelopmental disorder severely affecting visual acuity and stereopsis abilities. Current treatments for amblyopia, based on a penalization of the fellow eye, are only effective when applied during the juvenile critical period of primary visual cortex plasticity, resulting mostly ineffective at older ages. Here, we developed a new paradigm of operant visual perceptual learning performed under conditions of conventional (binocular) vision in adult amblyopic rats. We report that visual perceptual learning induced a marked and long-lasting recovery of visual acuity, visual depth perception abilities and binocular matching of orientation preference, and we provide a link between the last two parameters.

Amblyopia screening for first and second-grade children in Jordan.

To share the results of a national screening program for amblyopia in school children in the north of Jordan. This is a prospective national screening study for amblyopia. The program rolls first and second-grade children (6 to 7 years old) in the north of Jordan. The eye examination included: best-corrected visual acuity, cover-uncover test, and cycloplegic retinoscopy. Monocular visual acuity was tested using an ETDRS visual acuity chart without correction. Moreover, children were tested with full cycloplegic refraction when the test criteria were met. Unilateral amblyopia was defined as a best-corrected visual acuity difference of 2 or more lines. In comparison, bilateral amblyopia was defined as a best-corrected visual acuity of 20/40 or worse in the best eye. The prevalence of amblyopia for the total sample tested (n=17 203) was 2.78% (n=479). The most common cause of amblyopia was hypermetropia (64.45%), followed by previous ocular surgeries (15.1%), myopia (10.43%), strabismus (9.39%), and congenital cataract (0.63%). This is the first and only study, identifing modifiable risk factors in Jordanian children with amblyopia. In their first couple of years of elementary education, many Jordanian children are affected by amblyopia and pass unnoticed. A more governmental effort is needed into screening programs to improve vision in the Jordanian population.

Prevalence of Visual Disorders among Urban Palestinian Preschool Children

Background: Childhood blindness is a major public health concern since 40% of visual disorders that can cause blindness among children are preventable. Vision screening programs among preschool children have been implemented in several countries as a tool for early detection and intervention of visual disorders. In Palestine, there is a lack of scientific data on the prevalence of visual disorders among children. In addition, vision-screening programs that are currently implemented are neither validated nor effective. Objective: Using validated vision screening protocols, a cross-sectional study is conducted to determine the prevalence of visual disorders among urban Palestinian preschool children between the ages of 3 to 5 years in Nablus city. Methods: All children attending eight preschools selected using single-stage cluster sampling technique, underwent a validated vision screening administered by trained eye care professionals. The screening protocol was based on a combination of clinical assessment adopted from the Modified Clinical Technique and the Vision in Preschoolers studies, including assessment of visual acuity, ocular alignment, depth perception, color vision, non-cycloplegic retinoscopy, and ocular health. A pass-fail criterion was used to refer all children who did not attend the vision screening for comprehensive eye examination, including cycloplegic retinoscopy and a dilated fundus exam. A chi-squared test was used to determine any association between visual disorders and their independent risk factors. Results: A total number of 764 children underwent vision screening. Out of the 290 children who did not attend the vision screening, 127 children responded to the referral call for comprehensive eye examinations. Refractive error was the most prevalent visual disorder with a prevalence of (29.37%), followed by amblyopia (4.10%), color vision deficiency (1.24%), strabismus (1.24%), and ocular health abnormalities (0.70%). There was no age (p=0.35) and gender (p=0.32) variation in children having refractive errors. Anisometropia was the leading cause for amblyopia (1.32%, n=7), followed by significant refractive error (1.13%, n=6) and strabismus (0.37%, n=2). Conclusion: Refractive error was the most prevalent visual disorder affecting Palestinian preschoolers in Nablus. Anisometropia and significant refractive errors were found to be the major causes of amblyopia. Effective nationwide preschool vision screening programs should be implemented in Palestine to screen amblyogenic risk factors.

Measurement Of Retinal Nerve Fiber Layer Thickness In Patients Of Unilateral Amblyopia Using Optical Coherence Tomography.

The retinal changes that develop in the eyes during amblyopia are still unclear. It has been proven that thickness of the nerve fiber layer of the retina is positively correlated with refractive error. The objective of the present study was to measure the Retinal Nerve Fiber Layer Thickness (RNFLT) using Ocular Coherence Tomography (OCT) in patients of amblyopia.. A descriptive study was conducted in the Department of LRBT Free Eye Hospital, Lahore for 6 months. After meeting the inclusion criteria, 80 patients (40 amblyopic and 40 normal) were taken and grouped as A and B. Socio-demographic details of all the patients were recorded. They then underwent a complete ophthalmologic evaluation that included BCVA, slit lamp biomicroscopy, OCT examination was carried by TOPCON OCT. Each examination was done using the "fast retinal thickness" protocol for each test eye. Mean RNFLT was calculated for each eye. The mean age of patients was 12.58±4.44 years. There were 20 (50%) males and 20 (50%) females. In amblyopic eyes, the mean RNFLT was 125.82±13.06mm while in normal eyes, the mean RNFLT was 94.82±1.11mm. The overall mean RNFLT was significantly higher in amblyopic eyes as compared to normal eyes (p<0.01), as well as significant when data was stratified for age and gender. There was significant difference observed in RNFLT in amblyopic eyes as compared to normal eyes. So, these results can help us to enhance our knowledge and understand the causes of amblyopia hence improving diagnosis and management of disease.

Impact of Covid 19 pandemic on pattern of paediatric inpatient referral for ophthalmic consultation in a teaching institute hospital

Importance:Pediatric inpatient referral for Ophthalmology consultations are often requested to evaluate a variety of conditions at a teaching institute hospital. The on-going coronavirus disease (COVID-19) pandemic has affected every aspect of health care in general, including inpatient referrals that could result in long term adverse effect due to the delay in screening, management and providing of required care. Objective: To know the change in paediatric inpatient referral pattern for ophthalmic consultation from pre COVID to COVID times and the effect of the same on visual morbidity. Design, Setting, and Participants: This retrospective record review study included paediatric inpatient references for ophthalmology consultation in a teaching institute hospital from Dec 2019 to May 2020. Result: Of the total 67 inpatient referrals requested, 45 were during preCOVID-19 times (group 1) and 22 during COVID-19 pandemic (group 2). Mean age was 4.85 ±4.47 and 4.55 ± 4.35 years in group 1 and 2 respectively. Refractive error was the cause for referral in 10 patients in group 1 and none in group 2(P=0.019). Referral for optic disc oedema assessment was seen in 6 and 15 in group 1 and 2 respectively (P=0.000). 2 and 4 patients were referred in group 1 and 2 respectively to screen for cataract (P=0.069) of which a group 1 patient was diagnosed and treated for the same. While 10 and 2 patients were referred for ophthalmic screening (P=0.193), it was 3 and 1 for strabismus (P=0.732) respectively in group 1 and 2. Conclusion: COVID times adversely affected the inpatient refractive error screening, a cause of amblyopia in older patients. In patient referral for papilledema screening increased despite the pandemic as the condition is considered an emergency.

Refractive amblyopia among children aged 4-12 years in a hospital-based setting in Gaza Strip, Palestine.

Refractive amblyopia is the most common cause of amblyopia in the Gaza Strip. However, the pattern of this condition has not yet been studied in this region. This study aimed to determine the pattern of refractive amblyopia in Gazan children aged 4‒12 years. This was a hospital-based cross-sectional study using a purposive sampling method. Children aged 4‒12 years who attended the Children's Unit at Gaza Ophthalmic Hospital, Gaza Strip, Palestine from September 2019 to July 2020, were examined. A comprehensive eye test was conducted for all participants. Those who failed the eye examinations and were diagnosed with refractive amblyopia were included in the study. Demographic data and amblyopic refractive error patterns were analyzed accordingly. Of the 107 children, 72.9% were newly diagnosed with refractive amblyopia. The mean (standard deviation [SD]) of age of the children who participated was 7.85 (1.55) years. Approimately two-thirds of the patients were female (57.9%). Unilateral amblyopia was predominant in 60.7% of the cases. Moderate amblyopia was common (81.9%). A total of 149 amblyopic eyes were examined in total, with a mean (SD) (range) of best-corrected distance visual acuity and spherical equivalent of 0.45 (0.19) (0.2 to 1.3) logarithm of the minimum angle of resolution and + 0.76 (4.51) diopters (- 10.25 to + 11.50). Astigmatism was the most common amblyogenic factor (53.7%) among children with amblyopia. The frequency of refractive amblyopia was 72.9%, and meridional amblyopia accounted for the highest percentage. Girls were more commonly affected than boys. The majority were in the 7-year-old age group. Most cases were unilateral with moderate refractive amblyopia. Our study yields insights into the patterns of refractive amblyopia among children in the Gaza Strip.

Cause of amblyopia in adult patients: a cross-sectional study

Background: Amblyopia has been defined as a decrease of visual acuity for which no causes can be detected by the physical examination of the eye, caused by vision deprivation or abnormal binocular interaction. This study aims to determine the cause of amblyopia in adult patients at HAHC hospital South Delhi.Methods: This is a cross-sectional study conducted over a period from January 2018 till March 2018 among the patients in HAHC hospital. A comprehensive eye examination was used to analyse the visual condition.Results: Amblyopia was diagnosed in 42 participants, with age-and gender-adjusted prevalence of 3.2%. Of these, 1.9% were unilateral cases, and 1.3% were bilateral cases. A major cause of amblyopia in this population was a refractive error, hence using spectacle correction and vision therapy for its initial management.Conclusions: This study has provided causes of amblyopia in an adult population. Amblyopia is a frequent cause of lifelong unilateral visual impairment.

Profile of Amblyopia and Outcome of Occlusion Therapy in Amblyopic Patients Attending Tertiary Care Hospital of Kathmandu

Amblyopia is a common cause of visual impairment in children. The aim of this study was to assess the profile of amblyopia and the outcome of occlusion therapy in amblyopic children attending the eye department of a tertiary care hospital. This was a hospital based prospective interventional study. Sixty-five eyes of 47 patients fulfilling the inclusion criteria were included in the study. Occlusion therapy was started for the diagnosed amblyopic cases after refractive adaptation of 4 weeks. The mean age of presentation was 8.8 ±3.2 years. 29(61.7%) cases had unilateral amblyopia, 18(38.3%) cases had bilateral amblyopia. Ametropic amblyopia (52.3%) was the most common type of amblyopia followed by Anisometropia (23.1%). Refractive error was the most common cause of amblyopia with compound myopic astigmatism seen among 30.8% and hypermetropia among 29.2% of patients. There was no significant association between initial visual acuity with age of presentation and types of amblyopia respectively (P=0.1, P=0.5). The final visual outcome after therapy was better among patients with Ametropic amblyopia than other types (P=0.02). There was significant association between final visual outcome with age, initial visual acuity, type and severity of amblyopia respectively (P&lt;0.001, P&lt;0.001, P=0.02, P=0.02). In conclusion, Ametropia was the most common type of amblyopia. The mean age of presentation was 8.8 years, which was beyond the critical period affecting the outcome of treatment. Uncorrected refractive error was the most common amblyogenic factor. Age of presentation, types and severity of amblyopia are the important contributing factors for the outcome of occlusion therapy. Therefore, early detection and management of amblyopia is important to reduce visual impairment among children.

Clinical Meaning of Half Success Duration in Successful Occlusion Treatment of Amblyopia

Purpose To evaluate the factors affecting total occlusion duration and to determine whether half success duration (the time to reach an intermediate visual acuity between the initial visual acuity and 1.0) affects the total duration of treatment in amblyopia patients when the best-corrected visual acuity (BCVA) improves to that of the fellow eye after occlusion. Methods Fifty-three pediatric patients with amblyopia who achieved the same BCVA as that of the fellow eye after occlusion were selected. The total duration and half success duration were compared according to sex, initial visual acuity, age, spherical equivalent, cause of amblyopia (anisometropia, strabismus, or combined), as well as other factors. Results The mean age of the initial amblyopic patients was 4.6 years, and the mean duration of total occlusion treatment was 23.15 months. The mean half success duration was 9.98 months. The duration of total occlusion treatment was longer in children whose spherical equivalent of the amblyopic eye was over +3.0 diopters. The half success duration was longer in amblyopic patients with esotropia whose angle of deviation exceeded 20 prism diopters. However, there were no significant differences according to other factors. The total occlusion duration was shorter in patients whose half success duration was less than 12 months. Conclusions The treatment duration that was needed to achieve a BCVA close to that of the fellow eye was shortened when the spherical equivalent of the amblyopic eye was below +3.0 diopters. The half success duration was shortened when the angle of deviation was well below 20 prism diopters in patients with esotropia. Additionally, patients with a short half success duration had a shorter total occlusion duration. These factors can be used to predict the duration of occlusion treatment. Keywords: Amblyopia; Half success duration; Occlusion; Total occlusion duration

Prevalence and pattern of amblyopia in a rural hospital in Ghana

ABSTRACT Amblyopia is a developmental ocular disease of childhood-onset which may lead to persistent sequelae into adulthood. Early detection and management of amblyopia usually result in an improved visual outcome. The purpose of this study was to determine the prevalence and pattern of amblyopia in a rural hospital in Ghana. Clinical records of patients seen (from January 2014 to December 2018) at Westphalian Medical Center, Oyoko, Ashanti Region, Ghana, were reviewed retrospectively. Unilateral amblyopia was defined as a two-line interocular difference or more in visual acuity. Bilateral amblyopia was defined as best-corrected visual acuity (BCVA) of Snellen 6/12 or worse in both eyes, with evidence of bilateral ametropia or obstruction of the visual pathway. Following a review of 12,602 patient records, 258 cases of amblyopia were identified. The mean (±SD) presenting age of amblyopic patients was 24.3 ± 16.1 years, with a male-to-female ratio of 1:1.1. The period prevalence of amblyopia was 2.04%. The period prevalence of unilateral and bilateral amblyopia was 1.38% and 0.66%, respectively. The most prevalent form of amblyopia was refractive with a cumulative prevalence of 1.42%. Strabismic and stimulus deprivation amblyopia accounted for 0.36% and 0.21% of all amblyopic cases, respectively. A major cause of amblyopia in this population was refractive error, hence the use of spectacle correction for its initial management. Repeated assessment after an appropriate period of refractive adaptation would elucidate the proportion of amblyopias needing additional treatment modalities. Vision screening for early detection of amblyopia in childhood with accessible and effective management of amblyopia (including refractive correction and occlusion treatment) is necessary to reduce the impact of amblyopia in Ghana.