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BACKGROUND: To investigate the improvement of fixation stability of severe amblyopia with traditional patching treatment by the MP-1 microperimeter. METHODS: Eighteen patients with severe unilateral amblyopia were enrolled and received prescribed 6 h per day of patching of the fellow eye with optical correction if needed. Fixation test was performed on eighteen severe unilateral amblyopia patients by the MP-1 microperimeter in baseline, 3-month and 6-month after treatment. The bivariate contour ellipse area (BCEA, deg2) was used to quantify fixation stability. RESULTS: The RMANOVA showed that significant differences were found in best-corrected visual acuity (BCVA) between amblyopia eyes/fellow eyes (AE/FE) group (F = 113.52, p < 0.001) and among follow-up time (F = 74.684, p < 0.001). Moreover, a significant interaction could be found between AE/FE group and follow-up time (baseline/3-month/6-month, F = 60.189, p < 0.001). Post hoc analysis by Bonferroni showed significant improvement of BCVA in AE at 3-month (p < 0.001) and 6-month (p < 0.001), compared to baseline, and also significant between 3-month and 6-month (p = 0.002). The RMANOVA showed that significant differences were found in BCEA between AE/FE group (F = 8.432, p = 0.006) and among follow-up time (F = 10.431, p = 0.003). Moreover, a significant interaction could be found between AE/FE group and follow-up time (F = 9.099, p = 0.005). The mean BCEA of AE changed from 13.14 ± 17.97 deg2 at baseline to 6.03 ± 7.27 deg2 at 3-month (p = 0.084) and 3.38 ± 6.40 deg2 at 6-month (p = 0.018). No significant difference of BCEA in fellow eyes was found during the follow-up period (between baseline and 3-month: p = 0.230; between baseline and 6-month: p = 0.692. 0.89 ± 1.02, 0.58 ± 0.40, and 0.03 ± 0.04 deg2 for baseline, 3-month and 6-month, respectively). No significant correlation could be found between BCEA and BCVA of AE, both in enrollment and follow-up (p > 0.05). CONCLUSIONS: The fixation stability in the amblyopic eyes is significantly worse than that of the fellow eyes in patients with unilateral severe amblyopia. The fixation stability became better after 6-month occlusion treatment, but the change of fixation stability was not correlated with visual acuity improvement. These quantitative results highlight the importance of fixation in the mechanism of amblyopia.
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Ambliopía , Ambliopía/terapia , Fijación Ocular , Humanos , Retina , Agudeza VisualRESUMEN
BACKGROUND: To investigate prognostic factors in patients with augmented superior rectus transposition (SRT) for sixth nerve palsy. METHODS: Thirteen patients who were diagnosed with sixth nerve palsy and underwent augmented SRT between January 2015 and February 2017 in EENT Hospital of Fudan University were reviewed retrospectively. Data including age, sex, etiology of the abducens nerve palsy, degree of pre- and postoperative deviation in the primary position, pre- and postoperative abduction deficit, any induced vertical or torsional deviations, reoperations, and other complications was collected. Patients with undercorrection of SRT surgeries received additional inferior rectus transposition (IRT) surgery. RESULTS: Mean esodeviation in primary position improved from 81.92â³ to 30.54â³ (p < 0.001) with a 1.54-unit improvement in abduction (p = 0.001). Six patients achieved alignment defined as esodeviation in primary position within 10â³ of orthotropia and seven patients were undercorrected after the first SRT surgery. Multivariable linear regression analysis showed that among factors (disease duration, preoperative esodeviation, preoperative abduction deficit), only the degree of preoperative abduction deficit (ß = - 13.68) was the prognostic factor for success of SRT surgery. After IRT procedures, the mean esodeviation in primary position improved from 40â³ to 8â³ (p < 0.01). CONCLUSION: The degree of preoperative abduction deficit is the prognostic factor for augmented SRT for sixth nerve palsy. Patients with worse abduction deficit have a greater likelihood of needing a secondary operation, and IRT could be a good choice for reoperation after SRT.
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Enfermedades del Nervio Abducens/complicaciones , Esotropía/cirugía , Movimientos Oculares/fisiología , Músculos Oculomotores/cirugía , Procedimientos Quirúrgicos Oftalmológicos/métodos , Visión Binocular/fisiología , Enfermedades del Nervio Abducens/fisiopatología , Adulto , Anciano , Esotropía/etiología , Esotropía/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Músculos Oculomotores/fisiopatología , Pronóstico , Estudios Retrospectivos , Factores de Tiempo , Adulto JovenRESUMEN
IMPORTANCE: This study introduces a modified loop myopexy technique for severe high myopic strabismus fixus. BACKGROUND: This study aims to evaluate the surgical results of loop myopexy with or without medial rectus recession for the treatment of patients with myopic strabismus fixus. DESIGN: This is a retrospective study in a Chinese teaching hospital. PARTICIPANTS: Data was collected from 25 myopic strabismus fixus patients (33 eyes) with restriction in both abduction and sursumduction. METHODS: First, the loop myopexy technique was performed. Following the loop myopexy technique, a medial rectus recession was performed if esotropia remained. If esotropia and/or hypotropia still persisted, second-stage surgery of the contralateral eye was performed. MAIN OUTCOME MEASURES: The main outcome measures were ocular deviations, eye movements and the angles of dislocation of the globe. RESULTS: At the last follow-up, mean deviation of esotropia was significantly improved (10 vs. 92 PD; p = 0.000), while mean deviation of hypotropia was improved (6 vs. 32 PD; p = 0.008). Mean abduction limitation was improved (-2.7 vs. -5.0; p = 0.000); mean elevation limitation improved (-3.2 vs. -5.0; p = 0.000). The angle of dislocation of the globe was significantly decreased (103.0 vs. 235.3 D; p = 0.002). CONCLUSIONS AND RELEVANCE: Modified Yokoyama's surgery effectively corrected the restrictive esotropia and hypotropia, restored the dislocated globe back into the muscle cone and improved the eye movement in severe myopic strabismus fixus.
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Movimientos Oculares/fisiología , Músculos Oculomotores/cirugía , Procedimientos Quirúrgicos Oftalmológicos/métodos , Estrabismo/cirugía , Adulto , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Miopía Degenerativa , Músculos Oculomotores/diagnóstico por imagen , Músculos Oculomotores/fisiopatología , Estudios Retrospectivos , Estrabismo/diagnóstico , Estrabismo/etiología , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Low vision, along with cataract, trachoma, onchocerciasis, childhood blindness and refractive error, is one of the priorities in the global initiative, VISION 2020-The Right to Sight. The purpose of this study was to characterize the traits of patients presenting at a low vision clinic in China. METHODS: A retrospective study was conducted of the records of 299 patients who visited the Low Vision Clinic of Eye and ENT Hospital Affiliated to Fudan University from January 2009 to May 2014. Reviewed parameters included age, gender, education, occupation, cause of visual impairment and types of low vision aids (LVAs) dispensed. RESULTS: Of all the patients (193 male; aged from 3 to 96 years, with a mean of 29.74 ± 25.23 years), 43.48% experienced moderate visual impairment, 25.42% had severe visual impairment and 21.07% were blind. The four major causes of visual impairment were congenital cataract (14.38%), degenerative myopia (13.71%), juvenile macular degeneration (9.36%) and retinitis pigmentosa (9.36%). The most common causes of visual impairment were congenital cataract (22.67%) in 0-19-year-olds, retinitis pigmentosa (20.62%) in 20-59-year-olds, and age-related macular degeneration (36.54%) in the 60+ group. With the help of LVAs, a significant improvement of distance and/or near vision or visual field was observed in 243 patients, of whom 185 accepted LVAs and 58 patients refused due to high price, inconvenience, young age (≤ 6 y), clumsy appearance and ignorance. The most commonly dispensed LVAs were stand magnifiers (21.57%) followed by spectacle-type LVAs (19.21%). CONCLUSIONS: The majority of the patients in our low vision clinic were young, the main causes of visual impairment were congenital and hereditary diseases. Stand magnifiers were the most commonly dispensed LVAs. High price was the major reason for refusing LVAs.
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Baja Visión/epidemiología , Personas con Daño Visual/estadística & datos numéricos , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Instituciones de Atención Ambulatoria , Niño , Preescolar , China/epidemiología , Escolaridad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Auxiliares Sensoriales/estadística & datos numéricos , Distribución por Sexo , Baja Visión/diagnósticoRESUMEN
Blue light, with the wavelength between 400 nm and 500 nm, has caused public concern because of the injury to the retinal cells. Meanwhile, it is important in circadian rhythm regulation, scotopic vision and ocular growth. Is the blue light safe? Should it be eliminated from the daily life? Here we review the effect and safety of the blue light.
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Ritmo Circadiano , Color , Luz/efectos adversos , Retina/efectos de la radiación , Humanos , Visión OcularRESUMEN
PURPOSE: Scleral remodeling is an important mechanism underlying the development of myopia. Atropine, an antagonist of G protein-coupled muscarinic receptors, is currently used as an off-label treatment for myopia. Regulator of G-protein signaling 2 (RGS2) functions as an intracellular selective inhibitor of muscarinic receptors. In this study we measured scleral RGS2 expression and scleral remodeling in an animal model of myopia in the presence or absence of atropine treatment. METHODS: GUINEA PIGS WERE ASSIGNED TO FOUR GROUPS: normal (free of form deprivation), form deprivation myopia (FDM) for 4 weeks, FDM treated with saline, and FDM treated with atropine. Biometric measurements were then performed. RGS2 expression levels and scleral remodeling, including scleral thickness and collagen type I expression, were compared among the four groups. RESULTS: Compared with normal eyes and contralateral control eyes, the FDM eyes had the most prominent changes in refraction, axial length, and scleral remodeling, indicating myopia. There was no significant difference between control and normal eyes. Hematoxylin and eosin staining showed that the scleral thickness was significantly thinner in the posterior pole region of FDM eyes compared to normal eyes. Real-time PCR and western blot analysis showed a significant decrease in posterior scleral collagen type I mRNA and protein expression in the FDM eyes compared to the normal eyes. The FDM eyes also had increased levels of RGS2 mRNA and protein expression in the sclera. Atropine treatment attenuated the FDM-induced changes in refraction, axial length, and scleral remodeling. Interestingly, atropine treatment significantly increased collagen type I mRNA expression but decreased RGS2 mRNA and protein expression in the sclera of the FDM eyes. CONCLUSIONS: We identified a significant RGS2 upregulation and collagen type I downregulation in the sclera of FDM eyes, which could be partially attenuated by atropine treatment. Our data suggest that targeting dysregulated RGS2 may provide a novel strategy for development of therapeutic agents to suppress myopia progression.
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Miopía/genética , Miopía/patología , Proteínas RGS/genética , Esclerótica/metabolismo , Privación Sensorial , Regulación hacia Arriba/genética , Animales , Atropina/farmacología , Atropina/uso terapéutico , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Cobayas , Miopía/tratamiento farmacológico , Fenotipo , Proteínas RGS/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Esclerótica/efectos de los fármacos , Esclerótica/patología , Regulación hacia Arriba/efectos de los fármacosRESUMEN
OBJECTIVE: To investigate surgical approach for paralytic strabismus with lateral rectus muscles paralysis and evaluate its clinical effects. METHODS: Design retrospective, observational case series. 28 patients (31 eyes) who underwent augmented partial rectus muscle transposition (APRMT) in the treatment of paralytic strabismus with lateral rectus muscles paralysis from May 2009 to May 2011 at Eye & ENT Hospital of Fudan University were included in this study. The following data were analyzed: (1) The procedure that was performed, (2) The angle of deviation of primary position, (3) The presence of compensatory head posture, (4) The presence of diploma in the primary position, (5) The binocular single visual fields, (6) The motility of the affected eye. RESULTS: According to the results of rectus muscle forced traction test and examination before and after operation, among 31 eyes in 28 patients, 8 eyes were treated with APRMT, 10 eyes were treated with recession of antagonistic muscle of paralytic rectus muscle combined with APRMT, 7 eyes were treated with APRMT and recession of yoke muscle, 6 eyes were treated with APRMT and recession of yoke muscle combined with recession of antagonistic muscle. 17 among 28 patients were orthotopic in the primary position while others were in mild under correction with deviation no more than 10 prism degrees during 5 months (range: 3-8 months) follow-up in average. The diploma and abnormal head posture were eliminated in 26 patients except one patient who was appeared with 10 prism degrees under correction postoperatively and was resolved by wearing prisms thereafter. Binocular single visual fields were extended from 27.0° ± 6.4 ° preoperatively to 40.5° ± 4.8 ° postoperatively (t = -34.692, P < 0.001). Ocular movement was improved from -4.9 ± 0.4 to -2.9 ± 0.9 postoperatively (t = -13.418, P < 0.001). CONCLUSIONS: APRMT can safely and effectively correct the primary position in paralytic strabismus with lateral rectus muscles paralysis, eliminate the presence of diploma in primary position and abnormal head posture, and improve the ability of the ocular movement, furthermore, significantly expand the scope of binocular single visual fields. The results also demonstrate that rectus muscle forced traction test is a key measurement to determine the surgical procedure.
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Músculos Oculomotores/cirugía , Procedimientos Quirúrgicos Oftalmológicos/métodos , Oftalmoplejía/cirugía , Estrabismo/cirugía , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Patients with highly myopic strabismus generally develop esotropia and hypotropia. We report the case of a 54-year-old woman with a combination of esotropia-hypertropia complex in the right eye and esotropia-hypotropia complex in the left eye, with unilateral congenital severe ptosis. The patient had inferotemporal prolapse of the globe in the right eye. Inferotemporal prolapse in this case could have been due to extraocular muscle pulley dehiscence in this area, causing the inferior oblique muscle to slip around the globe along the path of least resistance. Subsequently, the inferotemporal staphyloma would have prevented the typical esotropia and hypotropia of the globe.
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Esotropía , Miopía , Estrabismo , Femenino , Humanos , Persona de Mediana Edad , Esotropía/etiología , Esotropía/cirugía , Procedimientos Quirúrgicos Oftalmológicos/efectos adversos , Imagen por Resonancia Magnética , Estrabismo/cirugía , Estrabismo/complicaciones , Miopía/complicaciones , Músculos Oculomotores/cirugía , ProlapsoRESUMEN
Molecular engineering of carbon nitride (CN) was considered as a suitable and compelling strategy to overcome the intrinsic imperfections and enhance photocatalytic H2O2 production. However, the photocatalytic H2O2 production of conventional single molecular engineering is still unsatisfactory, and the comprehension of photogenerated carrier migration and separation is still indistinct. Herein, dual molecules were engineered on CN molecular skeleton for achieving an outstanding photocatalytic rate of H2O2 production. The photocatalytic H2O2 production rate of the dual molecules engineered CN was up to 3320 µmol g-1 h-1, which was approximately 25 times than that of the pristine CN. After the dual-molecular engineering, pyrimidine and cyano group were co-grafted. Synchronously, K ion and Na ion were co-embedded near the interlamination of CN layers. The synergistic effect of the dual molecules in CN not only restrained photogenerated carrier recombination and broadened visible light response by modulating the intrinsic energy band structure, but also enhanced the capture of the photogenerated electrons and accelerated the migration of proton. Hence, the photocatalytic 2e- oxygen reduction reaction, the rate-determining step, was significantly strengthened. Additionally, caused by the positive valence band potential, the H2O oxidation reaction became an indispensable role in photocatalytic H2O2 production. This work provided a viable route to modulate the molecular skeleton of organic semiconductors and presented a promising strategy to obtain high-efficient photocatalytic H2O2 production.
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OBJECTIVES: To assess the effectiveness of an eye-tracking-based test (ETBT) to measure eye deviation angle vs. a manual prism alternating cover test (PACT) in children with strabismus. DESIGN: The prospective, masked, cross-sectional study included 95 children aged 1.8 years and older. Eye deviation was tested twice by each of ETBT and PACT. Each subject underwent four strabismus measurements, two by the ETBT and two by PACT. In each test, subjects were fixated on accommodative targets at 50 cm, with habitual optical correction allowed. Masked examiners compared the manual PACT results with those of the ETBT. RESULTS: There was a high correlation (about 90%) between the ETBT and PACT. Repeatability of ETBT was higher than that of PACT (correlation coefficients of 0.99 and 0.91 respectively, p < .002). Age, strabismus type, and eye deviation measurement did not affect repeatability of ETBT. However, in PACT, results could not be correlated between the two examiners when the deviation was larger than 40 prism diopters. CONCLUSIONS: The ETBT was effective in measuring eye deviation in children as young as 1.8 years. The ETBT showed higher repeatability compared to PACT.
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Tecnología de Seguimiento Ocular , Estrabismo , Niño , Estudios Transversales , Humanos , Estudios Prospectivos , Estrabismo/diagnósticoRESUMEN
Purpose: Wavelength and temporal frequency have been found to influence refractive development. This study investigated whether retinal dopamine (DA) plays a role in these processes. Methods: Guinea pigs were randomly divided into nine groups that received different lighting conditions for 4 weeks, as follows: white, green, or blue light at 0, 0.5, or 20.0 Hz. Refractions and axial lengths were measured using streak retinoscopy and A-scan ultrasound imaging. DA and its metabolites were measured by high-pressure liquid chromatography-electrochemical detection. Results: At 0 Hz, green and blue light produced myopic and hyperopic shifts compared with that of white light. At 0.5 Hz, no significant changes were observed compared with those of green or blue light at 0 Hz, whereas white light at 0.5 Hz induced a myopic shift compared with white light at 0 or 20 Hz. At 20 Hz, green and blue light acted like white light. Among all levels of DA and its metabolites, only vitreous 3, 4-dihydroxyphenylacetic acid (DOPAC) levels and retinal DOPAC/DA ratios were dependent on wavelength, frequency, and their interaction. Specifically, retinal DOPAC/DA ratios were positively correlated with refractions in white and green light conditions. However, blue light (0, 0.5, and 20.0 Hz) produced hyperopic shifts but decreased vitreous DOPAC levels and retinal DOPAC/DA ratios. Conclusions: The retinal DOPAC/DA ratio, indicating the metabolic efficiency of DA, is correlated with ocular growth. It may underlie myopic shifts from light exposure with a long wavelength and low temporal frequency. However, different biochemical pathways may contribute to the hyperopic shifts from short wavelength light.
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Dopamina/fisiología , Emetropía/fisiología , Hiperopía/metabolismo , Miopía/metabolismo , Retina/efectos de la radiación , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Longitud Axial del Ojo/metabolismo , Cromatografía Líquida de Alta Presión , Cobayas , Hiperopía/diagnóstico , Hiperopía/fisiopatología , Luz , Miopía/diagnóstico , Miopía/fisiopatología , Refracción Ocular/fisiología , Retina/metabolismo , Retinoscopía , Ultrasonografía , Cuerpo Vítreo/metabolismoRESUMEN
OBJECTIVES: To investigate the fixation patterns in severe amblyopia with eccentric or central fixation by the MP-1 microperimeter. DESIGN: Fixation test was performed on 38 patients with severe amblyopia using the MP-1 microperimeter, 20 patients with eccentric fixation (EF group), and 18 patients with central fixation (CF group). Fixation location and fixation stability were quantified by preferred fixation eccentricity and bivariate contour ellipse area (BCEA, deg2) respectively. Comparisons of BCEA between amblyopic and fellow eyes (FE) in both groups and between amblyopic eyes (AE) in both groups were analyzed. Linear regression analysis was used to investigate the risk factors for fixation instability in patients with eccentric fixation. RESULTS: In EF group, the BCEA of AE was 14.68 ± 19.21 deg2, which was significantly larger than that of FE (1.294 ± 1.840, F = 9.243, p = .007). Linear regression analysis showed that only preferred fixation eccentricity (ß = 6.536, 95% CI: 2.665 ~ 10.406, p < .005) was correlated with BCEA of AE. The BCEA of AE in the EF group was significantly larger than that of AE in the CF group (4.95 ± 3.44 deg2, t = 2.227,p < .05), although the BCVA was not significantly different between two groups (t = 0.129, p = .898). CONCLUSIONS: The fixation ability in amblyopia with eccentric fixation was found to be significantly worse than those with central fixation and preferred fixation eccentricity was the only predictor for the instability. MP-1 is an effective tool to quantify fixation features for diagnosis and follow-up of eccentric amblyopia patients.
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Ambliopía , Fijación Ocular , Humanos , Retina , Factores de Riesgo , Agudeza VisualRESUMEN
IMPORTANCE: Patching is often less effective for severe amblyopia because of poor adherence. For the treatment of severe amblyopia, although combined atropine and patching therapy (CAPT) has been found to be efficacious, it is currently unknown whether CAPT is more efficacious than patching alone. OBJECTIVE: To compare the efficacy of CAPT vs patching alone in children aged 3 to 12 years with severe amblyopia. DESIGN, SETTING, AND PARTICIPANTS: This single-center randomized clinical trial was conducted from November 2018 to May 2020. The visual acuity (VA) examiner was masked to the treatment groups. The follow-up visits were at 3 months and 6 months. Participants aged 3 to 12 years with severe amblyopia (20/100 to 20/500) resulting from strabismus, anisometropia, or both were randomly assigned to CAPT or patching therapy. INTERVENTIONS: CAPT or patching alone for 6 months. MAIN OUTCOMES AND MEASURES: Change of the amblyopic eye VA from baseline to 6 months. RESULTS: Among 108 participants, the mean (SD) age was 5.2 (1.8) years, and 54 (50%) were female. Overall, 53 participants (49%) were randomized to CAPT and 55 (51%) were randomized to patching therapy. At baseline, the mean (SD) amblyopic eye VA was 0.95 (0.22) logMAR (approximately 20/200 [2.2 lines]). At 6 months, the CAPT group's mean improvement in amblyopic eye VA was 0.72 logMAR (7.2 lines) compared with 0.58 logMAR (5.8 lines) in the patching alone group (difference, 0.14 logMAR [1.4 lines] greater in the CAPT group; 95% CI, 0.05-0.22 logMAR [0.5-2.2 lines]; P = .002). The amblyopic eye VA improvement in the CAPT group also was greater than that in the patching alone group at 3 months (difference in the means, 0.13 logMAR [1.3 lines]; 95% CI, 0.04-0.22 logMAR [0.4-2.2 lines]; P = .004). No participants were withdrawn because of adverse effects. CONCLUSIONS AND RELEVANCE: CAPT resulted in more mean improvement of amblyopic eye VA than patching alone among participants enrolled in this trial, although the clinical relevance of this relatively small VA difference cannot be determined from this trial. TRIAL REGISTRATION: Chinese Clinical Trial Registry Identifier: ChiCTR1800018663.
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Ambliopía , Ambliopía/terapia , Atropina/uso terapéutico , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Privación Sensorial , Resultado del TratamientoRESUMEN
Purpose: Environmental light plays an important role in the process of emmetropization. This study investigated how the retina integrates wavelength and temporal signals to regulate eye emmetropization. Methods: Guinea pigs (n = 220) were randomly divided into 11 groups (n = 20/group) that received different environmental lighting (12:12 light cycle) for 8 weeks: white, green, or blue light at steady, 0.5 or 20 Hz. White-steady group was repeated for each wavelength. Refraction, axial length, and corneal curvature were measured using streak retinoscopy, A-scan ultrasonography, and keratometry, respectively, every 2 weeks. Results: (1) In white light, the white-0.5 Hz group was more myopic than the white-steady group or the white-20 Hz group (both P < 0.0001), with a longer axial length (both P < 0.0001). White-20 Hz did not significantly differ from white-steady. (2) At low temporal frequencies (0 and 0.5 Hz), green-steady (P = 0.0008) and green-0.5 Hz (P < 0.0001), were more myopic than the white-steady group, with longer axial lengths (both P < 0.0001). No significant difference was found between green-0.5 Hz and green-steady. Blue-steady and blue-0.5 Hz were more hyperopic than white-steady (both P < 0.0001), with shorter axial lengths (both P < 0.0001). Blue-0.5 Hz showed no significant difference from blue-steady. (3) At high temporal frequencies (20 Hz), green-20 Hz, was more hyperopic than green-steady or green-0.5 Hz (both P < 0.0001) and had a shorter axial length (both P < 0.0001). Green-20 Hz showed a 1.10 D hyperopic shift compared to green-steady. Blue-20 Hz was less hyperopic than blue-steady (P < 0.0001) or blue-0.5 Hz (P = 0.0012), with a longer axial length (both P < 0.0001). Blue-20 Hz showed a 1.18 D myopic shift compared to blue-steady. Conclusions: Eyes use both wavelength and temporal frequency of light to regulate emmetropization. Their interactions provide different cues to control eye growth. At low temporal frequencies, the eye can use wavelength defocus to guide eye growth. This signal is weakened at high temporal frequencies.
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Adaptación Ocular/fisiología , Emetropía/fisiología , Luz , Refracción Ocular/fisiología , Errores de Refracción/fisiopatología , Animales , Animales Recién Nacidos , Longitud Axial del Ojo/fisiología , Modelos Animales de Enfermedad , Cobayas , Retina/fisiopatologíaRESUMEN
PURPOSE: Radiation therapy is a standard treatment for nasopharyngeal carcinoma. Diplopia due to radiation damage to the sixth nerve significantly erodes the patient's quality of life. This study investigated the effectiveness of extraocular surgery in the treatment of delayed diplopia caused by radiation therapy. METHODS: A retrospective case series of 16 patients (7 men and 9 women) with delayed diplopia after radiation therapy for nasopharyngeal carcinoma was enrolled in the study. Unilateral lateral rectus resection was performed under topical anesthesia. Follow-up time was more than 12 months. Outcome measures were prism diopter and self-reported symptoms. RESULTS: All patients diagnosed with sixth nerve palsy reported elimination of symptoms on postoperative day 1 without complications. One patient required a second procedure due to recurrence of symptoms. At 12-month follow-up, no patient reported recurrence of symptoms. The absolute horizontal deviation significantly decreased from a preoperative value of 16 prism diopter to a value of 1.5 prism diopter postoperatively (p < 0.001). CONCLUSION: These results suggest that unilateral lateral rectus resection under topical anesthesia is an effective treatment for delayed diplopia after radiation therapy for nasopharyngeal carcinoma. A large randomized prospective study to confirm these findings is warranted.
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Carcinoma/radioterapia , Diplopía/cirugía , Neoplasias Nasofaríngeas/radioterapia , Procedimientos Quirúrgicos Oftalmológicos , Traumatismos por Radiación/cirugía , Enfermedades del Nervio Abducens/etiología , Adulto , Anestesia Local , Diplopía/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Músculos Oculomotores/cirugía , Periodo Posoperatorio , Calidad de Vida , Traumatismos por Radiación/etiología , Recurrencia , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Purpose: To develop a novel dichoptic optokinetic nystagmus (OKN) paradigm and investigate its effectiveness in objectively quantifying the interocular suppression in subjects with monocular amblyopia. Methods: Centripetal moving gratings with different contrast ratios and constant velocity were dichoptically presented to eight monocular anisometropic amblyopes and eight normal subjects. We analyzed the OKN records with an eye tracker (EyeLink; SR-Research, Ontario, Canada) to obtain the relationship between ocular-dominance of OKN and the interocular contrast ratio by fitting power curves, and examined the correlation between the effective contrast ratio for a balanced OKN and the visual acuity of the amblyopic eye in amblyopes. Results: In normal subjects, the OKN pursuit times were roughly balanced for opposite directions when stimulated with centripetal gratings of same contrast; however, in amblyopes, the OKN pursuit times of the dominant eye exceeded that of the amblyopic eye. Increasing the contrast of one eye's grating led to an increase in its OKN dominance. The OKN directional ratio (y) could be well fitted by a power function of the interocular contrast ratio (x): y = axb. Moreover, in amblyopes, the effective contrast ratio (xb) for a balanced OKN correlated significantly positively with the visual acuity of the amblyopic eye (Spearman's correlation coefficient, 0.9698). Conclusions: The OKN induced by dichoptic gratings moving centripetally could be used as a reliable measure to objectively quantify the interocular suppression. This paradigm, avoiding the need for subjective report from patients, offers a promising alternative index for research on the mechanisms of amblyopia and in clinical practice.
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Ambliopía/fisiopatología , Anisometropía/fisiopatología , Nistagmo Optoquinético/fisiología , Visión Binocular/fisiología , Adolescente , Adulto , Sensibilidad de Contraste/fisiología , Femenino , Humanos , Masculino , Agudeza Visual/fisiología , Adulto JovenRESUMEN
PURPOSE: To analyze the changes of refraction and metabolism of the retinal cones under monochromatic lights in guinea pigs. METHODS: Sixty guinea pigs were randomly divided into a short-wavelength light (SL) group, a middle-wavelength light (ML) group, and a white light (WL) group. Refraction and axial length were measured before and after 10-week illumination. The densities of S-cones and M-cones were determined by retinal cone immunocytochemistry, and the expressions of S-opsins and M-opsins were determined by real-time PCR and Western blot. RESULTS: After 10-week illumination, the guinea pigs developed relative hyperopia in the SL group and relative myopia in the ML group. Compared with the WL group, the density of S-cones and S-opsins increased while M-cones and M-opsins decreased in the SL group (all, p < 0.05); conversely, the density of S-cones and S-opsins decreased while M-cones and M-opsins increased in the ML group (all, p < 0.05). Increased S-cones/opsins and decreased M-cones/opsins were induced by short-wavelength lights. Decreased S-cones/opsins and increased M-cones/opsins were induced by middle-wavelength lights. CONCLUSIONS: Altered retinal cones/opsins induced by monochromatic lights might be involved in the refractive development in guinea pigs.
RESUMEN
PURPOSE: To compare the 1-year outcome of visual quality after laser-assisted subepithelial keratomileusis (LASEK) and femtosecond laser-assisted small incision lenticule extraction (SMILE) for high myopia correction. MATERIALS AND METHODS: This prospective, comparative study included 24 eyes of 24 patients in the LASEK group, with a mean spherical equivalent (SE) of -7.59 ± 1.32 diopters, and 26 eyes of 26 patients in the SMILE group, with a mean SE of -7.91 ± 1.08 diopters. Visual acuity, corneal topography, contrast sensitivity (CS), and wavefront aberrations were recorded preoperatively and compared with postoperative measurements. Objective scatter index (OSI) and modulation transfer function (MTF) cut-off frequency were measured 1 year postoperatively. RESULTS: One year postoperatively, the two groups demonstrated no significant difference in the CS at all spatial frequencies. The increments of higher-order aberrations (HOAs) (HOA = 0.583 ± 0.210 µm), including spherical aberration (SA) (SA = 0.546 ± 0.249 µm), were higher (P < 0.05) in the LASEK group than those in the SMILE group (HOA = 0.451 ± 0.143 µm; SA = 0.450 ± 0.340 µm) after surgery. There were no significant differences in the increments of coma and trefoil aberrations between the two groups. The OSI and MTF cut-off frequency exhibited no significant differences between the two groups postoperatively. No vision-threatening complications were noted at any stage in either group. CONCLUSIONS: Both LASEK and SMILE are safe and effective surgical options for the correction of high myopia. SMILE has a lower HOAs and SA induction rate 1 year postoperatively.
Asunto(s)
Queratectomía Subepitelial Asistida por Láser/métodos , Miopía/cirugía , Agudeza Visual/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miopía/fisiopatología , Periodo Posoperatorio , Estudios Prospectivos , Adulto JovenRESUMEN
PURPOSE: The aim was to describe the characteristics of the paediatric population attending the low vision clinic of the Eye and ENT Hospital, located in Shanghai, China. METHODS: The clinical records of all the children attending the low vision clinic of Eye and ENT Hospital affiliated to Fudan University between January 1, 2009 and May 31, 2014 were retrospectively reviewed. The main data analysed were age, gender, education, visual demand, diagnosis, visual acuity and prescription of low vision aids. RESULTS: Of the 162 patients, 104 (64.20 per cent) were male. The age range of the study population was three to 20 years, with a mean of 10.73 ± 5.08 years. There were 43.21 per cent with moderate visual impairment, 26.54 per cent had severe visual impairment and 19.75 per cent were blind. The leading causes of visual impairment were congenital cataract (21.61 per cent), optic atrophy (14.20 per cent), macular dystrophy (11.73 per cent), nystagmus (9.88 per cent) and congenital glaucoma (9.26 per cent). The most frequently prescribed low vision devices for distant and near vision were binocular telescopes (23.57 per cent) and stand magnifiers (22.93 per cent), respectively. Young age (up to six years, 37.93 per cent), high cost (24.14 per cent), cosmetic reasons (17.24 per cent) and inconvenience (13.79 per cent) were the main reasons that children or parents refused to accept useful low vision aids. CONCLUSIONS: Congenital and hereditary diseases constituted the major causes of low vision in the study population. Strategies that make good-quality rehabilitation services available, affordable and accessible, especially in developing countries, will have the greatest impact on visual impairment. In China, both urban and rural, the coverage of low vision services should be strengthened.
Asunto(s)
Baja Visión/epidemiología , Adolescente , Adulto , Recursos Audiovisuales , Catarata/congénito , Niño , Preescolar , China/epidemiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Telescopios , Trastornos de la Visión/etiología , Baja Visión/terapiaRESUMEN
PURPOSE: To compare the objective and subjective quality of vision after femtosecond laser-assisted small incision lenticule extraction (SMILE) and laser-assisted subepithelial keratomileusis (LASEK) for mild to moderate myopia. METHODS: This prospective, comparative study included 65 eyes of 33 patients in the SMILE group, with a mean spherical equivalent (SE) of -4.16 ± 0.82 diopters, and 50 eyes of 25 patients in the LASEK group, with a mean SE of -3.81 ± 0.97 diopters. Visual acuity, corneal topography, contrast sensitivity, and wavefront aberrations were recorded preoperatively and compared with postoperative measurements. A quality of vision questionnaire was scored and analyzed 3 months postoperatively. RESULTS: Three months postoperatively, the SMILE group had fewer (P < .05) higher-order aberrations (HOAs) (0.390 ± 0.175 µm), including spherical aberration (SA) (0.262 ± 0.242 µm), than the LASEK group (HOAs = 0.479 ± 0.148 µm, SA = 0.576 ± 0.287 µm, trefoil = 0.465 ± 0.248 µm). There was no significant difference in the amount of coma and trefoil between the two groups after surgery. Analysis of the scores of glare and halos in the quality of vision questionnaire revealed that SMILE (night glare = 1.25 ± 1.22, halos = 0.97 ± 1.12) provided a better quality of vision (P < .05) than LASEK (night glare = 2.32 ± 1.99, halos = 1.96 ± 1.77). The two groups demonstrated no significant difference in contrast sensitivity 3 months postoperatively. No vision-threatening complications were noted at any stage in either group. CONCLUSIONS: Both SMILE and LASEK are safe and effective surgical procedures in the correction of myopia. SMILE has a lower induction rate of HOAs and a higher degree of patient satisfaction than LASEK at 3 months postoperatively.