Evaluation of nutritional status in children with amblyopia / Avaliação do estado nutricional de crianças com ambliopia

ABSTRACT Purpose: We aimed to compare the body mass index and vitamin and mineral status of children with and without amblyopia. Methods: Amblyopic children aged between 5 and 18 years (n=46) and age-matched control children (n=32) were evaluated in terms of anthropometric parameters, including height, weight, body mass index and demographic features. Serum vitamin B12 and folate were measured using an Advia Centaur XP (Siemens, Ireland) biochemistry analyzer. We evaluated the inorganic mineral elements from hair samples with inductively coupled plasma-mass spectrometry using a Thermo XSeries 2 analyzer (Thermo Fisher Scientific, Bremen, Germany). Results: No significant difference was found between the two groups in terms of height, weight, and body mass index or serum B12 and folate concentrations (p>0.05). Children with severe amblyopia had lower vitamin B12 and folate and higher body mass index. The levels of phosphorus (p=0.012), selenium (p=0.002), molybdenum (p<0.001), iodine (p=0.002), chromium (p=0.022), boron (p<0.001), and beryllium (p=0.005) were all significantly lower in the amblyopia group compared to the control group. All of these minerals, except phosphorus, were also significantly lower in those with severe amblyopia compared to those with milder amblyopia and controls (p<0.05). Conclusion: Amblyopic children are significantly deficient in some inorganic elements. Inorganic elements, vitamin B12, and folate may play an important role in the visual development of amblyopic children.

RESUMO Objetivo: Nosso objetivo foi comparar o índice de massa corporal e o nível de vitaminas e minerais de crianças com e sem ambliopia. Métodos: Crianças amblióticas com idades entre 5 e 18 anos (n=46) e crianças controle pareadas por idade (n=32) foram avaliadas quanto a parâmetros antropométricos, incluindo altura, peso, índice de massa corporal e características demográficas. A vitamina B12 e o folato séricos foram medidos utilizando um analisador bioquímico Advia Centaur XP (Siemens, Irlanda). Avaliamos os elementos minerais inorgânicos de amostras de cabelo com espectrometria de massa de plasma indutivamente acoplado usando um analisador Thermo XSeries 2 (Thermo Fisher Scientific, Bremen, Alemanha). Resultados: Não houve diferença significativa entre os dois grupos em relação à altura, peso e índice de massa corporal ou concentrações séricas de B12 e folato (p>0,05). Crianças com ambliopia severa tinham menor vitamina B12 e folato e maior índice de massa corporal. Os níveis de fósforo (p=0,012), selênio (p=0,002), molibdênio (p<0,001), iodo (p=0,002), cromo (p=0,022), boro (p<0,001) e berílio (p=0,005) foram todos significativamente menores no grupo com ambliopia em comparação com o grupo controle. Todos esses minerais, exceto o fósforo, também foram significativamente menores naqueles com ambliopia em comparação com aqueles com ambliopia leve e grupo controle (p<0,05). Conclusão: As crianças amblíopes são significativamente deficientes em alguns elementos inorgânicos. Elementos inorgânicos, vitamina B12 e folato podem desempenhar um papel importante no desenvolvimento visual de crianças com ambliopia.

Amblyopia: neural basis and therapeutic approaches / Ambliopia: bases neurais e intervenções terapêuticas

ABSTRACT Abnormalities in visual processing caused by visual deprivation or abnormal binocular interaction may induce amblyopia, which is characterized by reduced visual acuity. Occlusion therapy, the conventional treatment, requires special attention as occlusion of the fellow normal eye may reduce its visual acuity and impair binocular vision. Besides recovering visual acuity, some researchers have recommended restoration of stereoacuity and motor fusion and reverse suppression in order to prevent diplopia. Recent studies have documented that the amblyopic visual cortex has a normal complement of cells but reduced spatial resolution and a disordered topographical map. Changes occurring in the late sensitive period selectively impact the parvocellular pathway. Distinct morphophysiologic and psychophysical deficits may demand individualization of therapy, which might provide greater and longer-lasting residual plasticity in some children.

RESUMO Anormalidades nos processamentos visuais causadas por privação visual ou interação binocular anormal podem gerar ambliopia, caracterizada por redução da acuidade visual. A terapia de oclusão (tratamento convencional) necessita de cuidados especiais, pois a oclusão do olho normal (não-amblíope) pode reduzir a acuidade visual do mesmo e prejudicar a visão binocular. Além de recuperar a acuidade visual, alguns pesquisadores alertam para a necessidade em potencial de se restaurar a estereoacuidade e a fusão motora, bem como reverter a supressão a fim de impedir diplopia. Estudos recentes revelam que nos córtices visuais de amblíopes há uma quantidade normal de células, mas com resolução espacial reduzida e mapa topográfico desorganizado. Alterações ocorridas durante o período crítico tardio do desenvolvimento visual humano impactam seletivamente a via parvocelular. Déficits morfofisiológicos e psicofísicos distintos podem exigir programas de tratamento potencialmente seletivos e poderiam explicar a plasticidade residual maior e mais duradoura em algumas crianças.

Dysfunction in the fellow eyes of strabismic and anisometropic amblyopic children assessed by visually evoked potentials / Alterações dos potenciais visuais evocados nos olhos contralaterais de crianças com ambliopia estrabísmica e anisometrópica

ABSTRACT Purpose: To evaluate visual acuity and transient pattern reversal (PR) visual evoked potentials (VEPs) in the fellow eyes of children with strabismic and/or anisometropic amblyopia. Methods: Children diagnosed with strabismic and/or anisometropic amblyopia were recruited for electrophysiological assessment by VEPs. Monocular grating and optotype acuity were measured using sweep-VEPs and an Early Treatment Diabetic Retinopathy Study chart, respectively. During the same visit, transient PR-VEPs of each eye were recorded using stimuli subtending with a visual angle of 60', 15', and 7.5'. Parameters of amplitude (in μV) and latency (in ms) were determined from VEP recordings. Results: A group of 40 strabismic and/or anisometropic amblyopic children (22 females: 55%, mean age= 8.7 ± 2.2 years, median= 8 years) was examined. A control group of 19 healthy children (13 females: 68.4%, mean age= 8.2 ± 2.6 years, median= 8 years) was also included. The fellow eyes of all amblyopes had significantly worse optotype acuity (p=0.021) than the control group, regardless of whether they were strabismic (p=0.040) or anisometropic (p=0.048). Overall, grating acuity was significantly worse in the fellow eyes of amblyopes (p=0.016) than in healthy controls. Statistically prolonged latency for visual angles of 15' and 7.5' (p=0.018 and 0.002, respectively) was found in the strabismic group when compared with the control group. For the smaller visual stimulus (7.5'), statistically prolonged latency was found among all fellow eyes of amblyopic children (p<0.001). Conclusions: The fellow eyes of amblyopic children showed worse optotype and grating acuity, with subtle abnormalities in the PR-VEP detected as prolonged latencies for smaller size stimuli when compared with eyes of healthy children. These findings show the deleterious effects of amblyopia in several distinct visual functions, mainly those related to spatial vision.

RESUMO Objetivo: Avaliar a acuidade visual e os potenciais visuais evocados transientes por reversão de padrões no olho contralateral de crianças com ambliopia estrabísmica e/ou anisometrópica. Métodos: Foram avaliados os potenciais visuais evocados de crianças com ambliopia estrabísmica e/ou anisometrópica. As acuidades visuais monoculares de grades e de optotipos foram mensuradas utilizando o PVE de varredura e a tabela EDTRS, respectivamente. Na mesma visita, foram registrados os PVERP transients de cada olho usando estímulos de ângulo visual de 60'; 15' e 7,5'. Parâmetros de amplitude (em microvolts) e latência (em milissegundos) foram determinados para os registros dos potenciais visuais evocados. Resultados: Um grupo de 40 crianças amblíopes estrábicas e/ou anisometrópicas (22 meninas - 55%, media idade= 8,7 ± 2,2, mediana= 8) foi examinado. Um grupo de 19 crianças saudáveis (13 meninas 68,4%, media idade= 8,2 ± 2,6, mediana= 8) de controle também foi incluído. A acuidade visual por optotipos foi significativamente pior (p=0,021) nos olhos contralaterais de todos os amblíopes, quando comparado com o grupo controle, independentemente se estrábico (p=0,040) ou anisometrópico (p=0,048). No geral, a acuidade visual por grades foi significativamente pior nos olhos contralaterais dos amblíopes (p=0,016), quando comparados com o grupo controle. Foi encontrada latência estatisticamente prolongada para ângulos visuais de 15' (p=0,018) e 7,5' (p=0,002) no grupo estrábico, quando comparado com o grupo controle. Para o menor estímulo visual (7,5') foi encontrada latência estatisticamente prolongada nos olhos contralaterais de todas crianças amblíopes (p<0,001). Conclusões: Os olhos contralaterais de crianças amblíopes mostraram pior acuidade visual de optotipo e de resolução de grades, com alterações sutis nos PVERP, detectadas pelas latências prolongadas para estímulos de menor tamanho, quando comparados com os olhos de crianças saudáveis. Estes resultados mostram os efeitos deletérios da ambliopia em várias funções visuais distintas, principalmente relacionadas à visão espacial.

Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia

PURPOSE: To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. METHODS: In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. RESULTS: A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). CONCLUSIONS: HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia.

Higher order aberrations in amblyopic children and their role in refractory amblyopia / Aberrações de alta ordem em crianças com ambliopia e seu papel na ambliopia refratária

Objective: Some studies have hypothesized that an unfavourable higher order aberrometric profile could act as an amblyogenic mechanism and may be responsible for some amblyopic cases that are refractory to conventional treatment or cases of “idiopathic” amblyopia. This study compared the aberrometric profile in amblyopic children to that of children with normal visual development and compared the aberrometric profile in corrected amblyopic eyes and refractory amblyopic eyes with that of healthy eyes. Methods: Cross-sectional study with three groups of children – the CA group (22 eyes of 11 children with unilateral corrected amblyopia), the RA group (24 eyes of 13 children with unilateral refractory amblyopia) and the C group (28 eyes of 14 children with normal visual development). Higher order aberrations were evaluated using an OPD-Scan III (NIDEK). Comparisons of the aberrometric profile were made between these groups as well as between the amblyopic and healthy eyes within the CA and RA groups. Results: Higher order aberrations with greater impact in visual quality were not significantly higher in the CA and RA groups when compared with the C group. Moreover, there were no statistically significant differences in the higher order aberrometric profile between the amblyopic and healthy eyes within the CA and RA groups. Conclusions: Contrary to lower order aberrations (e.g., myopia, hyperopia, primary astigmatism), higher order aberrations do not seem to be involved in the etiopathogenesis of amblyopia. Therefore, these are likely not the cause of most cases of refractory amblyopia. .

Objetivo: Alguns estudos levantaram a hipótese de que um perfil aberrométrico de alta ordem desfavorável poderia ser um fator ambliogênico, responsável por certos casos de ambliopia “idiopática” ou refratária ao tratamento convencional. Este trabalho tem como objetivos: 1) comparar o perfil aberrométrico de crianças amblíopes com o de crianças com desenvolvimento visual normal; 2) comparar a aberrometria de olhos amblíopes tratados com sucesso/curados e olhos amblíopes refratários ao tratamento convencional com a aberrometria de olhos saudáveis. Métodos: Estudo transversal com três grupos de crianças: grupo CA (22 olhos de 11 crianças com ambliopia unilateral curada), grupo RA (24 olhos de 13 crianças com ambliopia unilateral refratária) e grupo C (28 olhos de 14 crianças com desenvolvimento visual normal). Avaliou-se a aberrometria ocular total utilizando o OPD Scan-III (NIDEK). Comparou-se o perfil aberrométrico dos três grupos de estudo bem como dentro dos grupos CA e RA, o olho amblíope com o saudável. Resultados: As aberrações de alta ordem com maior impacto na qualidade visual não foram significativamente superiores nos grupos CA e RA, comparativamente ao grupo C. Por outro lado, não se encontraram diferenças estatisticamente significativas entre o perfil aberrométrico de alta ordem dos olhos amblíopes e dos olhos sãos dentro dos grupos CA e RA. Conclusão: Contrariamente às aberrações de baixa ordem (miopia, hipermetropia, astigmatismo primário), as de alta ordem não parecem relacionar-se com a etiopatogênese da ambliopia. É também pouco provável que estas sejam a causa da maioria dos casos de ambliopia refratária. .

Amblyopia after unilateral infantile cataract extraction after six weeks of age / Ambliopia no pós-operatório de catarata congênita unilateral operada após seis semanas de vida

PURPOSE: To determine interocular grating acuity difference in children treated for unilateral infantile cataract. METHODS: A group of 27 children previously treated for unilateral infantile cataract, had their monocular visual acuity measured by sweep visual evoked potentials. Interocular grating acuity difference was calculated as the absolute subtraction of monocular acuity scores. Lens status, opacity severity and eye alignment were considered for analysis. RESULTS: Mean interocular grating acuity difference obtained from unilateral cataract patients was 0.58 ± 0.20 logMAR. This result was significantly larger than 0.10 logMAR used as normative data. Children with severe opacities had a more pronounced amblyopia than the moderate ones. No significant correlation between amblyopia and strabismus or aphakia was found. CONCLUSIONS: Interocular acuity difference in this group of unilateral congenital cataract was more pronounced than previous reports, mainly because of delay in diagnosis, surgery and optical correction.

OBJETIVOS: Determinar a diferença interocular da acuidade visual de resolução de grades em crianças operadas de catarata congênita unilateral. MÉTODOS: Um grupo de 27 pacientes operados de catarata congênita unilateral tiveram mensurada sua acuidade visual monocular pelo potencial visual evocado de varredura. A diferença interocular foi calculada pela subtração absoluta das acuidades monoculares. A intensidade da opacificação, implante ou não de lente intraocular e presença de estrabismo foram consideradas para análise. RESULTADOS: A média da diferença interocular foi de 0,58 ± 0,20 logMAR. Esse resultado foi significantemente maior que 0,10 logMAR, valor considerado como média normal nos estudos normativos. Crianças com opacidades intensas tiveram ambliopia mais pronunciada que os casos moderados. Não houve correlação significante entre a intensidade da ambliopia com estrabismo e afacia. CONCLUSÕES: A diferença interocular nesse grupo de crianças operadas de catarata congênita unilateral foi muito mais pronunciada que artigos prévios, provavelmente pelos atrasos no diagnóstico, intervenção cirúrgica e correção óptica.

Evaluation of central, steady, maintained fixation grading for predicting inter-eye visual acuity difference to diagnose and treat amblyopia in strabismic patients.

Background: Diagnosis of amblyopia in preverbal strabismic patients is frequently made by binocular fixation preference (BFP) testing. The reports on reliability of BFP are equivocal. This study evaluated the reliability of BFP testing in patients with horizontal strabismus. Materials and Methods: This prospective observational study included patients with manifest, horizontal, comitant deviation >10 prism diopter (PD). Inter-eye acuity difference (IEAD) was calculated by converting Snellen visual acuity to logMAR and was compared with BFP testing. The fixation behavior of the non-preferred eye was evaluated by a single investigator as central or uncentral, steady or unsteady and maintained or unmaintained. Amblyopia was defined as the IEAD of >0.2 logMAR. Results: Of total 61 patients 36 were females and 36 had convergent squint, mean age 9.8 years. The correlation of BFP testing with IEAD was good for esotropia and exotropia. The sensitivity, specificity, positive and negative predictive value of central, steady, maintained (CSM) grading was 93%, 78%, 79%, and 93% respectively. Sensitivity and negative predictive values were higher in children aged four to nine years and anisometropia >1 diopter. The correlation between IEAD and lower grades of BFP testing was poor. Conclusions: CSM grading for BFP testing is useful for the detection of strabismic amblyopia but not useful to differentiate the depth of the amblyopia.

P-VEP as Predictor of Occlusion Therapy

No abstract available.

P-VEP as Predictor of Occlusion Therapy

No abstract available.

Pattern Visual Evoked Potential as a Predictor of Occlusion Therapy for Amblyopia

PURPOSE: This study was conducted to investigate the role of the pattern visual evoked potential (pVEP) as a predictor of occlusion therapy for patients with strabismic, anisometropic, and isometropic amblyopia. The secondary aim was to compare the characteristics of pVEP between strabismic and anisometropic amblyopia. METHODS: This retrospective comparative case series included 120 patients who had received occlusion therapy or a glasses prescription for correction of strabismic, anisometropic, and isometropic amblyopia (20 patients had strabismic amblyopia, 41 patients had anisometropic amblyopia, and 59 patients had isometropic amblyopia). For each patient, the value of the P100 latency on pVEP at the time of the initial diagnosis of amblyopia was collected. Subsequently, the P100 latency was compared according to types of amblyopia. Fifty of 120 patients (7 patients with strabismic amblyopia, 21 patients with anisometropic amblyopia, and 22 patients with isometropic amblyopia) who were followed-up for longer than 6 months were divided into two groups based on the value of their P100 latency (Group 1, P100 latency 120 msec or less; Group 2, P100 latency longer than 120 msec.) The amount of visual improvement after occlusion therapy or glasses was compared between two study groups. RESULTS: The mean P100 latency was 119.7+/-25.2 msec in eyes with strabismic amblyopia and 111.9+/-17.8 msec in eyes with non-strabismic (anisometropic or isometropic) amblyopia (p=0.213). In Group 1, the mean visual improvement after occlusion therapy or glasses was 3.69+/-2.14 lines on Dr. Hahn's standard test chart; in Group 2, the mean improvement was 2.27+/-2.21 lines (p=0.023). CONCLUSIONS: The P100 latency on pVEP at the time of initial diagnosis was significantly related to the visual improvement after occlusion therapy or glasses in patients with strabismic, anisometropic, and isometropic amblyopia. Therefore, it was presumed that patients with a delayed P100 latency might have less visual improvement after occlusion therapy or glasses. In addition, there was no apparent difference in P100 latency between patients with strabismic and non-strabismic (anisometropic or isometropic) amblyopia.

Outcomes of 6 Hour Part-time Occlusion Treatment Combined with Near Activities for Unilateral Amblyopia

PURPOSE: To evaluate the outcome of the part-time occlusion therapy with near activities in monocular amblyopic patients according to gender, age, severity of amblyopia, and the cause of amblyopia. METHODS: Fifty eight patients who were prescribed part-time occlusion therapy with near activity from July 1998 to October 2004, were included in this retrospective study. All patients were divided into groups by gender, age, severity of amblyopia, and the cause of amblyopia. Main outcome measures were best corrected visual acuity, line improvement, and success rate. RESULTS: At the end of patch therapy, visual acuity improved from baseline by an average of 3.2+/-2.5 lines (0.33+/-0.26 log MAR), and follow-up period was 19.71+/-14.61 months (1.62+/-1.20 years). At the last follow-up, visual acuity improved from baseline by an average of 3.7+/-2.4 lines (0.38+/-0.26 log MAR), and follow-up period was 37.41+/-25.83 months (3.08+/-2.12 years). The success rate was 86% (50 patients) at the end of patch therapy. In 44 patients out of 50 patients (88%), the visual acuity was maintained. While 43 patients out of 47 patients who were less than 7 years old (91%) achieved success, 7 patients out of 11 patients 7 years or older (64%) achieved success (p=0.035). CONCLUSIONS: Six-hour part-time occlusion treatment combined with near activities appears to be favorable in treating 58 children during follow-up of mean 3.08 years. The significant factor was the age at initial treatment.

Outcomes of 6 Hour Part-time Occlusion Treatment Combined with Near Activities for Unilateral Amblyopia

PURPOSE: To evaluate the outcome of the part-time occlusion therapy with near activities in monocular amblyopic patients according to gender, age, severity of amblyopia, and the cause of amblyopia. METHODS: Fifty eight patients who were prescribed part-time occlusion therapy with near activity from July 1998 to October 2004, were included in this retrospective study. All patients were divided into groups by gender, age, severity of amblyopia, and the cause of amblyopia. Main outcome measures were best corrected visual acuity, line improvement, and success rate. RESULTS: At the end of patch therapy, visual acuity improved from baseline by an average of 3.2+/-2.5 lines (0.33+/-0.26 log MAR), and follow-up period was 19.71+/-14.61 months (1.62+/-1.20 years). At the last follow-up, visual acuity improved from baseline by an average of 3.7+/-2.4 lines (0.38+/-0.26 log MAR), and follow-up period was 37.41+/-25.83 months (3.08+/-2.12 years). The success rate was 86% (50 patients) at the end of patch therapy. In 44 patients out of 50 patients (88%), the visual acuity was maintained. While 43 patients out of 47 patients who were less than 7 years old (91%) achieved success, 7 patients out of 11 patients 7 years or older (64%) achieved success (p=0.035). CONCLUSIONS: Six-hour part-time occlusion treatment combined with near activities appears to be favorable in treating 58 children during follow-up of mean 3.08 years. The significant factor was the age at initial treatment.

Is age relevant for the success of treatment of anisometropic amblyopia?

A prospective cohort study of 200 anisometropic amblyopes was conducted. The patients were classified into two groups. Group A: Patients less than 12 years of age. This consisted of 144 (72%) patients, the average age being 7.77 years (+/-2.34, range 1 to 12). Group B: Patients more than 12 years of age. This comprised 56 (28%) patients, the average age being 19.8 years (+/-5.47, range 12 to 30). Criterion for success was defined as best corrected visual acuity of 20/40 (0.5 logMAR equivalent) or better. The Chi-square test was used to compare baseline characteristics and success rates. There were no significant differences in the baseline characteristics between the two groups ( P =0.07). The treatment was successful in 108 (75%) in Group A and in 34 (60.7%) in Group B ( P = 0.07). There was no statistically significant change in the success rate of treatment of anisometropic amblyopia, even beyond 12 years of age.

Evaluation of relationship of ocular parameters and depth of anisometropic amblyopia with the degree of anisometropia.

PURPOSE: (1) To find out the relationship of the depth of amblyopia with the degree of anisometropia, in untreated cases of anisometropic amblyopia without strabismus, for both myopic and hypermetropic individuals. (2) To find out the relationship between various ocular parameters, such as axial length and corneal curvature, with the degree of anisometropia between the two eyes. MATERIALS AND METHODS: This prospective study was conducted between January 2001 and March 2003, in 85 cases of untreated anisometropic amblyopia, who attended the author's out patient department. All these patients were subjected to a meticulous ocular examination, with special emphasis on (1) refraction under cycloplegia (2) best corrected visual acuity (3) measurement of axial length by A Scan (4) keratometry . The depth of amblyopia was calculated in two ways: (1) By finding out decimal visual acuity for each eye and subsequently calculating their difference. (2) By converting the Snellen acuity into Log MAR units, which was calculated by finding the Logarithm of the reciprocal of the decimal visual acuity for the two eyes, followed by calculating the difference between the two. The difference in refraction between the two eyes as a measure of anisometropia, was determined by the difference in spherical equivalent between the refraction for each eye. RESULTS: On comparing hypermetropic and myopic cases, a significant correlation was found between depth of amblyopia and the degree of anisometropia, in both myopic and hypermetropic patients. The correlation coefficients were however, found to be greater for hypermetropic than myopic individuals. It was observed that the difference between the axial length of the two eyes contributed to a major part of anisometropia, more so in myopic cases. CONCLUSIONS: The depth of amblyopia correlates with the degree of anisometropia in previously untreated anisometropic amblyopia patients.

Part-Time Occlusion Therapy for Anisometropic Amblyopia Detected in Children Eight Years of Age and Older

PURPOSE: To determine the outcome of part-time occlusion therapy in children with anisometropic amblyopia detected after they were 8 years of age. METHODS: We analyzed 29 eyes with anisometropic amblyopia in children 8 years of age and older. The mean age was 8.79+/-0.98 (range 8~12) years old. The subjects whose best-corrected visual acuity (BCVA) did not improve by two lines or better within 2 weeks of wearing glasses full-time were prescribed occlusion therapy for 6 hours a day outside of school hours, along with the instruction to wear glasses full-time. Subjects who complied with occlusion for more than 3 hours a day were considered to comply well. RESULTS: The major component of the anisometropia was hyperopia in 51.7% of the subjects, and hyperopia plus astigmatism was found in 24.1%. The mean pretreatment BCVA score was 0.51+/-0.23 (LogMAR). Compliance was 89.66%. The mean posttreatment BCVA was 0.03+/-0.01 (LogMAR), and the success rate, based on a posttreatment BCVA of 0.1 (LogMAR) and better, was 96.43%. It took an average of 4.79+/-3.35 months to reach the desired posttreatment BCVA. The mean posttreatment stereopsis was 79.78+/-37.61 seconds of arc. The recurrence rate was 8%. The visual improvement was related to the degree of compliance (p=0.000). The time taken to reach the posttreatment BCVA was shorter in subjects with a better pretreatment BCVA (p=0.019), but it did not relate to the compliance (p=0.366). CONCLUSIONS: The most common component of anisometropia detected after 8 years of age was hyperopia. The part-time occlusion therapy, which had been carried out after school hours, was successful in most cases.

Factors influencing visual rehabilitation after occlusion therapy in unilateral amblyopia in children.

BACKGROUND & OBJECTIVE: Amblyopia is one of the most common causes of visual impairment in adults and children, and visual loss may be permanent if not treated in time. Though many studies have been done on occlusion therapy which is the mainstay in the treatment of unilateral amblyopia, discrepancies exist in literature about quantification of treatment and follow up measures. The present study was undertaken to evaluate the factors responsible for the successful outcome of treatment and the optimum time required for the same in children with unilateral amblyopia. METHODS: Baseline characteristics of 63 verbal patients with unilateral amblyopia (strabismic, anisometropic, mixed) referred to the Strabismus and Amblyopia Clinic at the Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi between September 2001 to December 2002 who improved to the desired level of visual acuity after treatment for amblyopia in the mentioned time period, were analyzed to assess for factors that directly or indirectly influenced the optimum visual rehabilitation and the average duration of therapy required for the same. The evaluation included assessment of the baseline best-corrected visual acuity (BCVA) and refractive status in both eyes, the age at presentation, the type of amblyopia present, fixation pattern in the amblyopic eye, inter-eye visual acuity difference, and evaluation of compliance through a parental diary system. RESULTS: Baseline BCVA in the amblyopic eye was similar in all the three groups. Patients with anisometropic amblyopia showed a quicker response to therapy. Compliance to treatment was the major factor affecting the overall time required for a successful outcome in most cases. The overall time required for the treatment to be successful (including the period of maintenance) was about 1,089 h. INTERPRETATION & CONCLUSION: This hospital-based study showed that the average duration of occlusion therapy to achieve stable isoacuity was 7.2 months with an average occlusion of 6-7 h/day. Compliance to therapy was the most important factor affecting the duration of therapy. With increasing emphasis on paediatric eye diseases, amblyopia is at last getting its due importance as a cause of treatable correctable paediatric visual impairment which can have lifelong repercussions, both in terms of individual disability and financial burden to the society if not treated in time. As the therapy is simple and effective if started early, mass awareness, visual screening, and counselling would go a long way in treating the patients, thus decreasing the prevalence of amblyopia in the country.

Deterioration of Accommodative Esotropia during Part-time Occlusion Therapy

The authors report two cases of suddenly deteriorated accommodative esotropia with amblyopia during part-time occlusion therapy. A 7-year-old girl with right accommodative esotropia, which was well controlled, showed marked increase in esodeviation after part-time occlusion and regained orthophoria without occlusion. This phenomenon was repeated. Recession of both medial recti was performed and orthophoria was well maintained at both distant and near targets. Accommodative esotropia of a 9-year-old boy with glasses also showed a striking increase in esodeviation after part-time occlusion. The authors recommended wearing only glasses without occlusion or surgery and he recovered fusion. Three months later, orthophoria was maintained at distant target, with 8PD esophoria at near target with glasses. Although this complication should be considered before occlusion therapy, it must be taken continuously if needed, because an increase of the deviation size with occlusion may simply reflect a true deviation and may not be a poor prognostic sign.