Treatment rate of strabismus and amblyopia is associated with the location of pediatric ophthalmologists in the United States.

PURPOSE: To determine whether the geographic density of pediatric ophthalmologists is associated with the rate of children treated for strabismus and amblyopia. METHODS: This cross-sectional study included children treated for strabismus and amblyopia 0-17 years of age with commercial insurance who were included in the Vision and Eye Health Surveillance System. Additionally, pediatric ophthalmologists by state were determined using the American Association for Pediatric Ophthalmology and Strabismus website. Unadjusted linear regression was used to compare the geographic density of pediatric ophthalmologists and the rate of children treated for strabismus and amblyopia by state in 2016. This was repeated using multivariable linear regression, controlling for race, poverty, non-English-speaking children, and insurance coverage for children by state. RESULTS: New York and Mississippi had the highest and lowest rates of treatment of strabismus and amblyopia, with 3.97 and 0.83 children treated per 100 children, respectively. The geographic density of pediatric ophthalmologists was associated with the rate of children treated for strabismus and amblyopia in unadjusted analyses (ß = 0.62, P < 0.001). Further, the geographic density of pediatric ophthalmologists was associated with the rate of children treated for strabismus and amblyopia in adjusted analyses (ß = 0.61, P < 0.001). CONCLUSIONS: The geographic density of pediatric ophthalmologists by state was positively associated with the rate of children treated for strabismus and amblyopia.

Clinical and genetic risk factors underlying severe consequence identified in 75 families with unilateral high myopia.

BACKGROUNDS: Unilateral high myopia (uHM), commonly observed in patients with retinal diseases or only with high myopia, is frequently associated with amblyopia with poor prognosis. This study aims to reveal the clinical and genetic spectrum of uHM in a large Chinese cohort. METHODS: A total of 75 probands with simplex uHM were included in our Pediatric and Genetic Eye Clinic. Patients with significant posterior anomalies other than myopic fundus changes were excluded. Variants were detected by exome sequencing and then analyzed through multiple-step bioinformatic and co-segregation analysis and finally confirmed by Sanger sequencing. Genetic findings were correlated with associated clinical data for analysis. RESULTS: Among the 75 probands with a mean age of 6.21 ± 4.70 years at the presentation, myopic fundus of C1 and C2 was observed in 73 (97.3%) probands. Surprisingly, specific peripheral changes were identified in 63 eyes involving 36 (48.0%) probands after extensive examination, including peripheral retinal avascular zone (74.6%, 47/63 eyes), neovascularization (54.0%), fluorescein leakage (31.7%), peripheral pigmentary changes (31.7%), and others. Exome sequencing identified 21 potential pathogenic variants of 13 genes in 20 of 75 (26.7%) probands, including genes for Stickler syndrome (COL11A1 and COL2A1; 6/20), FEVR (FZD4, LRP5, and TSPAN12; 5/20), and others (FBN1, GPR179, ZEB2, PAX6, GPR143, OPN1LW, FRMD7, and CACNA1F; 9/20). For the peripheral retinal changes in the 20 probands, variants in Stickler syndrome-related genes were predominantly associated with retinal pigmentary changes, lattice degeneration, and retinal avascular region, while variants in genes related to FEVR were mainly associated with the avascular zone, neovascularization, and fluorescein leakage. CONCLUSIONS: Genetic defects were identified in about one-fourth of simplex uHM patients in which significant consequences may be hidden under a classic myopic fundus in up to half. To our knowledge, this is the first systematic genetic study on simplex uHM to date. In addition to routine care of strabismus and amblyopia, careful examination of the peripheral retina and genetic screening is warranted for patients with uHM in order to identify signs of risk for retinal detachment and other complications and provide meaningful genetic counseling.

Actualización clínica en nanoftalmos: características, enfermedades y complicaciones asociadas / Clinical update in nanophthalmos: Features, diseases and complications associated

El nanoftalmos es una condición congénita infrecuente del globo ocular que se caracteriza por un menor tamaño de los segmentos anterior y posterior en ausencia de una malformación ocular definida. Tradicionalmente se han descrito alteraciones anatómicas asociadas como una longitud axial corta, esclera engrosada, córnea con menor diámetro, cámara anterior estrecha y aumento de la relación entre el volumen del cristalino y el globo ocular. La causa se desconoce, aunque se han descrito múltiples mutaciones que podrían estar asociadas. En la actualidad, falta todavía una definición y una clasificación consensuada. Su relevancia clínica deriva de la asociación con múltiples afecciones oculares que pueden limitar la función visual como son hipermetropía elevada, ambliopía, glaucoma de ángulo cerrado, desprendimiento de retina y catarata. Asimismo, tanto la cirugía de catarata como la de glaucoma siguen constituyendo un desafío en estos ojos en los que el riesgo de numerosas complicaciones tanto intraoperatorias como postoperatorias es significativamente más elevado. El tratamiento del nanoftalmos tiene una doble orientación. Es preciso tratar las enfermedades asociadas y, además, reducir y controlar las complicaciones quirúrgicas. Esta revisión pretende realizar una actualización de lo publicado en los últimos años en relación con esta enfermedad. (AU)

Nanophthalmos is a rare congenital condition of the eyeball that is characterized by a smaller size of the anterior and posterior segments without associated ocular malformations. Typical features that have traditionally been described in these eyes are short axial length, thickened sclera, cornea with a smaller diameter, narrow anterior chamber, and an increased lens to globe volume ratio. However, at present, there is still a lack of recognized diagnostic criteria for nanophthalmos and a classification of its severity. Its clinical relevance stems from the increased risk of multiple ocular conditions, such as high hyperopia, amblyopia, angle-closure glaucoma, retinal detachment, and cataracts. Likewise, in relation to surgery in these eyes, there are particularities in cataract and glaucoma surgery and with a greater risk of associated intra- and postoperative complications. In this way, the treatment of nanophthalmos focuses on controlling the associated eye conditions and reducing and controlling surgical complications. This review aims to update what has been published in recent years regarding nanophthalmos. (AU)

Factors affecting the total occlusion time in eyes with hyperopic anisometropic amblyopia.

BACKGROUND: Amblyopia treatment by occluding the healthy eye is known to be effective during a sensitive critical period. This study aims to clarify the factors for the total occlusion time (TOT) required for the amblyopic eye to achieve a normal visual acuity (VA) level of 1.0 (0.0 logMAR equivalent). This could contribute to an efficient treatment plan for eyes with hyperopic anisometropic amblyopia. METHODS: Subjects were 58 patients (26 boys and 32 girls; age range, 3.6-9.2, average, 5.8 ± 1.3 years) with hyperopic anisometropic amblyopia. All the subjects had initially visited and completed occlusion therapy with improved VA of 1.0 or better in the amblyopic eye at Kindai University Hospital between January 2007 and March 2017. Using the subjects' medical records, we retrospectively investigated five factors for the TOT: the age at treatment, the initial VA of the amblyopic eye, refraction of the amblyopic eye, anisometropic disparity, and the presence of microstrabismus. Patient's VA improvement at one month after treatment was also evaluated to confirm the effect of the occlusion therapy. RESULTS: The initial VA of the amblyopic eye ranged from 0.1 to 0.9 (median, 0.4). The TOT ranged from 140 to 1795 (median, 598) hours with an average daily occlusion time of 7 hours. The initial VA of the amblyopic eye and presence of microstrabismus were the significant factors for the TOT (p < 0.01). To achieve VA of 1.0 or better, patients with an initial VA of ≤ 0.3 in the amblyopic eye required a longer TOT. Moreover, patients with concomitant microstrabismus required a 1.7-fold longer TOT compared to those without microstrabismus. CONCLUSION: Longer daily occlusion hours and early start of the treatment will be necessary for patients with poor initial VA or microstrabismus to complete occlusion therapy within the sensitive critical period.

Factors affecting the benefit of glasses alone in treating childhood amblyopia: an analysis of PEDIG data.

BACKGROUND: To evaluate factors associated with better outcomes from optical treatment alone in amblyopic children from 3 up to 7 years. METHODS: Data extracted from two studies with similar protocols, Amblyopic Treatment Studies 5 (n = 152) and 13 (n = 128) from the Pediatric Eye Disease Investigator Group database, were used to determine by regression analysis the factors associated with improvements in visual acuity in the amblyopic eye, inter-ocular visual acuity difference and stereoacuity. Input variables were aetiology of amblyopia (anisometropic, strabismic and combined-mechanism amblyopia), treatment compliance, visual acuity, interocular visual acuity difference, stereoacuity, tropia size at distance and near, age and refractive error at baseline. RESULTS: Despite the range of clinical factors considered, our models explain only a modest proportion of the variance in optical treatment outcomes. The better predictors of the degree of optical treatment success in amblyopic children are visual acuity of the amblyopic eye, interocular visual acuity difference, stereoacuity, treatment compliance and the amblyopic eye spherical-equivalent refractive error. While the aetiology of the amblyopia does not exert a major influence upon treatment outcome, combined-mechanism amblyopes experience the smallest improvement in visual acuity, tropia and stereoacuity and may need longer optical treatment periods. CONCLUSIONS: While results identify the factors influencing optical treatment outcome in amblyopic children, clinicians will be unable to predict accurately the benefits of optical treatment in individual patients. Whether this is because relevant clinical or non-clinical factors (e.g. nature and volume of daily activities undertaken) influences the outcomes from optical treatment has not yet been identified and remains to be discovered.

Systematic review and meta-analysis of childhood visual impairment in the Eastern Mediterranean Region.

Background: Childhood visual impairment has a significant effect on social life, educational performance, and professional choices, and can lead to poverty. Aims: To review the prevalence and causes of visual impairment among children aged 5-17 years in the Eastern Mediterranean Region (EMR). Methods: This study was conducted in 2021 using the Preferred Reporting Items for Systematic reviews and Meta- Analyses (PRISMA) method. We searched Google Scholar, PubMed, Web of Science, Scopus, Index Medicus for the Eastern Mediterranean Region, and Medline for studies published between January 2000 and April 2020. The articles included were epidemiological studies of prevalence and causes of childhood visual impairment published in peer-reviewed journals. Results: Of the 12 705 articles screened, 23 from 9 countries met the inclusion criteria. The pooled prevalence of uncorrected, presenting, and best-corrected childhood visual impairment was 11.57%, 8.34% and 1.21%, respectively. The most common causes of childhood visual impairment were refractive error (51.89%), amblyopia (11.15%), retinal disorders (3.90%), corneal opacity (3.0%), and cataract (1.88%). There was a highly significant heterogeneity between the studies (P < 0.0001). Conclusion: The prevalence of visual impairment among children in the EMR was high, and the leading causes were uncorrected refractive error and amblyopia, which were avoidable. Access to eyecare services may help improve early diagnosis and treatment of preventable causes of childhood visual impairment.

[Corneal disease in childhood-Hereditary, degenerative or infectious?] / Hornhauterkrankungen im Kindesalter ­ Hereditär, degenerativ oder infektiös?

BACKGROUND: Adequate visual acuity significantly contributes to the age-appropriate development of children's neurobehavior. Infantile corneal opacities are rare but implicate a high potential for amblyopia. OBJECTIVE: This review aims to provide an overview of the most common causes of infantile corneal opacities and highlights ophthalmopathological correlations. METHODS: The following review is based on an extensive literature search. RESULTS: If metabolic diseases, traumatic or infectious events can be excluded as a cause for an infantile corneal opacity, it is important to focus on the 3Ds, corneal dysgenesis, corneal dystrophy or corneal degeneration. DISCUSSION: If corneal opacities occur in childhood, early recognition, diagnosis, and initiation of treatment, including prophylaxis of amblyopia, are of utmost importance. In unexplained corneal opacities the histopathological work-up of the explanted cornea can contribute to the final diagnosis.

Characteristics of facial nerve palsy in 112 children and risk factors for ocular complications.

PURPOSE: To report the ophthalmic findings and ocular complications in a large cohort of pediatric patients with facial nerve palsy (FNP). METHODS: Ocular data of children (≤16 years of age) diagnosed with FNP presenting to an eye care network from 2012 to 2021 were analyzed. Study parameters were etiology of FNP, ocular and imaging findings, degree of lagophthalmos, and degree of vision loss. Clinical characteristics were compared between those with and without moderate-to-severe vision impairment (best-corrected visual acuity <20/50) and those with and without exposure keratopathy at presentation. RESULTS: A total of 112 patients were included. Mean age at presentation was 8.3 ± 5.0 years. The most common etiology was idiopathic (57%) followed by congenital (22.3%) and traumatic (13.4%). There was bilateral involvement in 8% of children, multiple cranial nerve involvement in 15.2%, and exposure keratopathy at presentation in 38.4%. One-fifth (20.5%) of children (29.6% of affected eyes with known visual acuity) had moderate-to-severe visual impairment. Multiple cranial nerve involvement was present in 31% of eyes with visual impairment compared with 14% of those without. Corneal scarring and strabismic amblyopia were both frequent causes of visual impairment. Most children with exposure keratopathy had lagophthalmos (76.6%), whereas it was less common in those without keratopathy (49.2%). CONCLUSIONS: Pediatric FNP was most commonly idiopathic, secondarily congenital. Strabismic amblyopia and corneal scarring were the most common causes of visual impairment in our cohort.

Ocular and visual perceptive factors associated with treatment outcomes in patients with anisometropic amblyopia.

BACKGROUND: The aim of this observational study was to identify ocular and visual perceptive risk factors related to treatment results following refractive correction and patching in children with anisometropic amblyopia, who were between the ages of 4 to 14 years old. METHODS: One-hundred and two children with newly diagnosed anisometropic amblyopia were recruited. Successful treatment of amblyopia was defined as the final best corrected visual acuity (BCVA) better than or equal to 0.1 logMAR and amblyopic eye BCVA within 1 line of the sound eye BCVA by the end of the treatment period. BCVA, cycloplegic refraction, stereoacuity, perceptual eye position (PEP) and interocular suppression were measured. RESULTS: Of these patients, 45.10% achieved successful treatment of amblyopia after refractive correction and patching for 10.5 months. The mean age was not significantly different between patients who were successfully and unsuccessfully treated (5.50 ± 1.59 years vs 6.14 ± 2.19 years, respectively). Patients who failed treatment had significantly larger interocular difference of BCVA at the time of initial treatment (successful group: 0.33 ± 0.29 logMAR, unsuccessful group: 0.65 ± 0.35 logMAR) and after refractive adaptation (successful group: 0.15 ± 0.13 logMAR, unsuccessful group: 0.42 ± 0.35 logMAR). They also had higher spherical equivalent (SE) of amblyopic eyes (successful group: 3.08 ± 3.61 D, unsuccessful group: 5.27 ± 3.38 D), bigger interocular difference of SE (successful group: 0.94 ± 2.71 D, unsuccessful group: 3.09 ± 3.05 D), worse stereoacuity (successful group: 2.32 ± 0.37 log seconds of arc, unsuccessful group: 2.75 ± 0.32 log seconds of arc), larger vertical PEP deviation (successful group: 6.41 ± 6.08 pixel, unsuccessful group: 19.07 ± 24.96 pixel) and deeper interocular suppression (successful group: 21.7 ± 19.7%, unsuccessful group: 37.8 ± 27.1%) than those of successfully treated patients. The most influential treatment failure risk factors were larger vertical PEP deviation [adjusted odds ratio (OR) (95% confidence interval) 1.12 (1.02-1.22)] and worse stereoacuity [adjusted odds ratio (OR) (95% confidence interval) 7.72 (1.50-39.85)] in multiple logistic regression analysis. CONCLUSIONS: Larger vertical PEP deviation and worse stereoacuity were the most influential treatment failure risk factors in children with anisometropic amblyopia. The vertical PEP deviation and stereoacuity, which can reflect interocular interaction, may be useful in predicting the response to therapy.

Changes in Choroidal Thickness and Structure Induced by 1% Atropine Instillation in Children With Hyperopic Anisometropic Amblyopia.

PURPOSE: To investigate the effects of 1% atropine eye drops on the choroidal thickness and structure of amblyopic and fellow eyes in children with hyperopic anisometropic amblyopia. METHODS: This study included 16 children with hypermetropic anisometropic amblyopia. All patients received 1% atropine eye drops in both eyes twice a day for 7 days. In the subfoveal choroidal region, choroidal thickness, total choroidal area, luminal area, and stromal area were measured quantitatively using swept-source optical coherence tomography. The choroidal parameters of the amblyopic and fellow eyes were compared between the baseline and atropine conditions. RESULTS: There were no significant differences in all choroidal parameters of the amblyopic eye between baseline and atropine conditions. However, the subfoveal choroidal thickness in the fellow eye was significantly higher for the atropine condition than the baseline condition. This change was accompanied by a significant increase in both the luminal and stromal areas of the choroid. The median differences of subfoveal choroidal thickness between the conditions were larger for the fellow eye (6.46%) than the amblyopic eye (0.26%). CONCLUSIONS: The choroidal structural change induced by 1% atropine instillation was smaller for the amblyopic eye than the fellow eye in children with hyperopic anisometropic amblyopia. Mechanisms of choroidal thickness changes could be inhibited in amblyopic eyes. [J Pediatr Ophthalmol Strabismus. 2023;60(1):39-45.].

Unusual case of double anterior segment with two lenses and double cataract in a 6-month child.

INTRODUCTION: Anterior segment duplicity with two lenses is a rare event which pathogenesis is still unknown. Different ocular and systemic abnormalities might be associated with such event. CASE OBSERVATIONS: Hereby we describe a case of a 6-months female child referred to our service due to signs of ocular malformation in the left eye. The ocular exam showed a double anterior segment with twin lenses in one single eye, associated with double lamellar opacity and persistence of the two hyaloid arteries. The patient underwent surgical treatment with lensectomy and vitrectomy aiming visual stimulation and prevention of definitive visual loss secondary to amblyopia. CONCLUSION: In any case of ocular malformation, efforts to provide adequate visual stimulus are necessary to avoid amblyopia. In our case, the opacified lenses were removed, the patient adapted contact lenses and will be followed-up for visual stimulation at the ophthalmic pediatric division aiming the best visual prognosis possible.

What the Canadian public (mis)understands about eyes and eye care.

CLINICAL RELEVANCE: Inadequate public knowledge about eyes and eye care poses avoidable risks to vision-related quality of life. BACKGROUND: This study of eye care knowledge among Canadians extends earlier findings from focus groups. METHODS: Perceptions about eyes and eye care were sought using a 21-item online survey and snowball sampling. Inclusion criteria were living in Canada and being at least 18-years old; eye care professionals and staff were excluded. Response frequencies were converted to percentages, with eye condition items analysed according to 'expected' or 'unexpected' eye impacts. Proportions selecting these impacts or 'unsure' were determined. RESULTS: There were 424 respondents: 83.0% aged 20-65 years and 69.6% female. Mismatches existed between perceived recommendations and behaviours for booking eye exams: within two years (86.7% vs. 68.4%) and symptom-driven (3.3% vs. 13.0%). First eye exams after age one year were deemed appropriate by 43.6%. Few respondents associated glaucoma with no symptoms (6.0%) or amblyopia with blurred vision (13.5%). A notable proportion incorrectly related tunnel vision with age-related macular degeneration (AMD, 36.8%) and cataract (21.9%). Identifying all 'expected' responses was unlikely for glaucoma (1.9%), amblyopia (6.7%), and cataract (12.0%). Most respondents identified no 'expected' effects for glaucoma (63.8%) and AMD (46.2%) and some 'expected' effects for cataract (59.5%) and amblyopia (72.6%). Selecting 'unsure' was 9-10 times more common among respondents choosing no 'expected' impacts than those choosing some. Awareness of thyroid-associated eye disease was lowest (32.4%) of seven conditions. Respondents were most likely to consult optometrists for routine eye exams, eye disease, diabetes eye checks and blurred vision but family physicians for red eyes and sore eyes. Respondents typically paid for their eye exams and eyewear but wanted government to pay. CONCLUSION: Vision-threatening knowledge gaps and misinformation about eyes and eye care among Canadian respondents highlight the need for accessible, targeted public education.

Visual factors associated with physical activity in schoolchildren.

CLINICAL RELEVANCE: Physical activity is an essential part of childhood physical and mental development. Recent research identified visual problems associated with a sedentary lifestyle in children in Ireland. BACKGROUND: This study explored the association between visual function in children and their engagement with physical activities outside school. METHODS: Participants were 1,626 schoolchildren (728 aged 6-7-years, 898 aged 12-13-years) in randomly selected schools in Ireland. Before data collection, parents/legal guardians of participants completed a standardised questionnaire reporting physical activity as no activity (mostly on screens), light activity (occasional walking/cycling), moderate activity (<3 hrs/week engaged in sports), or regular activity (>3hrs/week engaged in sports). Measurements included logMAR monocular visual acuities (with spectacles and pinhole), in the distance (3 m) and near (40 cm), stereoacuity (TNO stereo-test), cover test, and cycloplegic autorefraction (1% cyclopentolate). RESULTS: Controlling for confounders (socioeconomic disadvantage and non-White ethnicity), linear regression analysis revealed presenting distance visual acuity, near visual acuity, and stereoacuity were significantly better amongst participants who reported regular physical activity rather than moderate, light or no activity in both 6-7-year-old and 12-13-year-old participants. Absence of clinically-significant refractive error (>-0.50D < 2.00D) was associated with regular physical activity. Participants presenting with visual impairment (better-eye vision <6/12) (odds ratio = 5.78 (2.72-12.29)), amblyopia (pinhole acuity ≤6/12 plus an amblyogenic factor) (odds ratio = 5.66 (2.33-13.76)), and participants at school without their spectacles (odds ratio = 2.20 (1.33-3.63)), were more likely to report no activity. CONCLUSIONS: Children regularly engaged in physical activities, including sports; had better visual and stereoacuity; and were less likely to need spectacles. Visual impairment, amblyopia, and refractive error were associated with no physical activity. Spectacle wear compliance was associated with regular physical activity. Regular physical activity is an essential factor in childhood vision and addressing visual impairment in children is vital to increasing participation in sports and exercise. Socioeconomically disadvantaged and non-White communities would benefit most from these measures.

Distribution and Clinical Characteristics of Periorbital Infantile Hemangiomas.

Background: Periorbital infantile hemangiomas (POIHs) are associated with a high incidence of visual complications. Objective(s): To analyze the sites of predilection of POIHs and to determine whether certain sites require earlier intervention due to their higher rate of visual complications. Methods: A retrospective case series study was conducted on patients from two tertiary care centers for 25 years. The location of POIHs was determined from clinical photographs, medical records, and radiological studies. The presence or absence of anisometropic astigmatism (anisoastigmatism) and amblyopia was recorded. Data were analyzed using a chi-square test. Results: There were 486 patients, of which 302 patients had ophthalmology evaluations and 245 patients had refractive error data. At presentation, 10% of patients already had amblyopia and 44% had anisoastigmatism. Medial eyelid lesions had the highest risk of developing anisoastigmatism (anisoastigmatism correlates with eyelid position, p = 0.0001). Segmental and upper medial lesions had the highest risk of amblyopia at initial evaluation. Conclusion: The site of POIH is an important indicator for developing clinically significant anisoastigmatism and amblyopia, underlining the need for early ophthalmologic assessment and management.

Subthreshold Amblyopia: Characterization of a New Cohort.

PURPOSE: Published studies of amblyopia include only patients with visual acuity (VA) worse than 20/40 in one or both eyes. The purpose of this study is to evaluate patients diagnosed and treated as amblyopic despite not meeting traditional VA criteria for amblyopia. DESIGN: Retrospective clinical cohort study. METHODS: Setting: Institutional practice. PATIENT POPULATION: All patients diagnosed with amblyopia at Boston Children's Hospital between 2010 and 2014. INCLUSION CRITERIA: VA better than 20/40 but not correctable to 20/20 in one or both eyes; age 2 to 12 years. OBSERVATIONS: Demographics, VA, baseline characteristics. OUTCOME MEASURES: Resolution, defined as VA 20/20 in both eyes; stereopsis at the last follow-up. RESULTS: Of 2311 patients reviewed, 464 (20.1%) had subthreshold amblyopia. A majority (61.7%) had an amblyogenic factor, most commonly anisometropia (32.8%). Patients were followed for a median of 3.1 years; nearly all (97.5%) were treated. Of 318 patients who returned for follow-up, 47.8% achieved resolution, including 55.7% of treatment-naïve patients, and 62.5% (5 of 8 patients) offered observation alone. Median stereopsis improved by 0.4 log units in those who achieved resolution, with no change in those with persistent amblyopia. In the multivariate analysis, a longer length of follow-up was significantly associated with resolution of subthreshold amblyopia (odds ratio: 1.38; 95% confidence interval: 1.22-1.57, P < .001). CONCLUSIONS: Patients with subthreshold amblyopia represent a sizeable cohort in real-world amblyopia practice. When offered treatment, half achieved 20/20 vision in both eyes with improved stereopsis as well. Further studies are needed to assess whether observation alone would result in similar outcomes.

Disconjugacy of Eye Movements during Attempted Fixation: A Sufficient Marker for Amblyopia?

BACKGROUND: To investigate whether detection of disconjugacy of eye movements during attempted fixation, or interocular position instability, may serve as a single sensitive test for amblyopia. PATIENTS/METHODS AND MATERIAL: Binocular eye movements were recorded at 500 Hz using the EyeLink 1000 eye tracker (SR Research Ltd., Kanata, Ontario, Canada) and analyzed using EyeLink software and Matlab (MathWorks, Natick, MA, USA). Eight subjects (four amblyopes, one successfully treated amblyope, and three non-amblyopes: 7 - 44 years) were asked to fixate on a stationary cross subtending 0.5° at 57 cm. Interocular position instability was quantified by calculating the minimum area bivariate contour ellipse (BCEA) encompassing 68% of the difference between right and left eye position points during 20-second viewing epochs. For statistical analysis, BCEA values, as well as visual acuity and stereoacuity, were normalized by base-10 logarithm transformation. RESULTS: The amblyopic subjects with persistent vision loss (one anisometropic, two strabismic, one deprivation; uncorrected visual acuity range 20/60 - 20/300, corrected stereoacuity range nil-400 arcsec) showed significantly higher interocular position instability (larger 68% BCEAs) than the non-amblyopic subjects (uncorrected visual acuity range 20/20 - 20/800, corrected stereoacuities of 20 arcsec) and the successfully treated strabismic amblyope (to the 20/20 level of visual acuity and 70 arcsec of stereoacuity) during binocular viewing trials; p < 0.01. Interocular position stability was strongly correlated with stereoacuity (in that better stereoacuity was associated with lower 68% BCEAs; r = 0.95), but not with visual acuity (r = 0.20). CONCLUSION: Interocular position instability appears to differentiate amblyopic from non-amblyopic subjects and appears to improve after successful treatment. Interocular position instability may therefore prove to be a single sensitive test for the presence of amblyopia. As a difference measure, it is inherently less susceptible to head motion and calibration error, as well as to conjugate eye motion, and as such is expected to be somewhat immune to latent nystagmus. Interocular position instability may also be useful to guide treatment, especially in preverbal children, and to assess the efficacy of novel treatments. Further research is required to establish optimal interocular position instability thresholds and to determine how specific this measure is to amblyopia.

Reading difficulties in amblyopia: Consequence of visual sensory and oculomotor dysfunction.

INTRODUCTION: Reading is a vision-reliant task, requiring sequential eye movements. Binocularly discordant input results in visual sensory and oculomotor dysfunction in amblyopia, which may contribute to reading difficulties. This study aims to determine the contributions of fixation eye movement (FEM) abnormalities, clinical type and severity of amblyopia to reading performance under binocular and monocular viewing conditions. METHODS: Twenty-three amblyopic patients and nine healthy controls were recruited. Eye movements elicited during fixation and reading of preselected passages were collected for each subject using infrared video-oculography. Subjects were classified as having no nystagmus (n = 9), fusion maldevelopment nystagmus (FMN, n = 5), or nystagmus without structural anomalies that does not meet criteria for FMN or infantile nystagmus (n = 9). Reading rate (words/min), the number of forward and regressive saccades (per 100 words) and fixation duration (s) were computed. RESULTS: Amblyopic patients with and without nystagmus exhibited greater vergence and fixation instability. In patients without nystagmus, the instability arises from increased amplitude and velocity of fast and slow FEMs respectively. Amblyopic patients with and without nystagmus exhibited lower reading speeds with increased fixation duration, regressive and progressive saccades than controls in all viewing conditions. Mixed etiology, greater amblyopic eye visual acuity and stereopsis deficits were associated with greater reading difficulties under binocular viewing. CONCLUSIONS: The presence of oculomotor dysfunction and the extent of visual acuity and stereoacuity deficits contribute to reading difficulties in patients with amblyopia, with and without nystagmus. The understanding of reading difficulties is essential to devise accommodations to limit long-term academic and vocational consequences of amblyopia.

Upper eyelid taping to stimulate visual development in amblyogenic congenital ptosis.

Amblyogenic congenital ptosis in a young child generally requires amblyopia therapy and, if that proves ineffective, prompt surgical intervention. However, early surgery for severe congenital ptosis is often associated with poor cosmesis and a higher reoperation rate than surgery performed near school age. We report the case of a child with amblyogenic congenital ptosis successfully managed with upper eyelid taping through 5 years of age.

A rare case of congenital pupillary abnormality: a case report.

BACKGROUND: Congenital anomalies of the pupil are quite varied, including abnormal size, shape, color, response to stimulus, and function. We are here reporting an unusual case presented with the absence of pupillary opening with folds of iris tissue at the center. Only an extremely small pupil (diameter < 0.5 mm) could be observed during the operation. CASE PRESENTATION: A 15-year-old male patient visited our outpatient clinic due to vision difficulty in his right eye for more than ten years. The best-corrected visual acuity was 2.0 logMAR and 0 logMAR for the right and left eye, respectively. There were amblyopia, astigmatism and constant exotropia in his right eye. Ophthalmic examination of the right eye showed flat iris root, minimal iris pigmentation, and the pupil area was entirely covered by iris tissue. Lens status and fundus evaluation could not be commented. The left eye was found to be within normal limit. Based on ophthalmic examination, the admission diagnosis was given as acorea. Pupilloplasty was performed on the right eye due to the situation that the iris tissue blocked the visual axis, which led to visual impairment and stimulus deprivation amblyopia. However, an extremely small pupil at the center of his pupillary area was observed during the operation. The postoperative course was favorable, and a normal pupil was secured. Hospital discharge diagnosis was given as microcoria, and amblyopia treatment was followed. CONCLUSIONS: We report a rare case of congenital pupillary abnormality. The further diagnosis was given as microcoria, which should be differentiated from acorea. For this kind of pupil disorder which blocks the visual axis, early diagnosis and treatment can help prevent the development of stimulus deprivation amblyopia.