Evaluation of choroidal thickness and retinal nerve fiber layer thickness in patients with unilateral amblyopia: a prospective study / Avaliação da espessura da coroide e da camada de fibras nervosas da retina em pacientes com ambliopia unilateral: um estudo prospectivo

ABSTRACT Purpose: to compare the Subfoveal choroidal thickness (SFCT) and Retinal Nerve Fiber Layer Thickness (RNFL) of amblyopic and normal fellow eyes. Design: Prospective, cross-sectional, observational case series. Methods: Forty patients age 12 to 41 years (mean 23.73 ± 6.42) with unilateral amblyopia were studied. Among them, 11(28.2%) patients had amblyopia secondary to strabismus and 29(71.8 %) had anisometropic amblyopia. Optical coherence tomography (OCT) of the peripapillary RNFL thickness of amblyopic and fellow eyes was performed. RNFL thickness measurements were taken from the superior, inferior, nasal and temporal quadrants in the peripapillary region. Also, subfoveal choroidal thickness (SFCT) was measured using spectral domain optical coherence tomography (SD-OCT). Results: Mean global RNFL thickness of the amblyopic and fellow eyes was 104.48 microns and 102.83 microns, respectively. The difference between the two groups was not statistically significant (p>0.05%). The thicknesses of the superior, inferior, nasal and temporal quadrants of the retinal nerve fiber layer between the amblyopic and normal fellow eyes showed no statistically significant difference (p>0.05%). However, the SFCT of amblyopic eye was 11 or more microns thicker than the fellow eye and this was statistically significant different (p<0.05%). Conclusions: This study demonstrated SFCT in amblyopic eyes was significantly thicker than the normal fellow eyes. The amblyopic process may involve the choroid, but not the prepapillary NFL.

RESUMO Objetivo: comparar a espessura da coroide subfoveal (CSF) e da camada de fibra nervosa retinal (CFNR) de olhos amblíopes e normais. Design: série de casos prospectivos, transversais e observacionais. Métodos: Quarenta pacientes com idade entre 12 e 41 anos (média 23,73 ± 6,42) com ambliopia unilateral foram estudados. Entre eles, 11 (28,2%) pacientes apresentavam ambliopia secundária a estrabismo e 29 (71,8%) apresentavam ambliopia anisometrópica. Foi realizada tomografia de coerência óptica (TCO) da espessura da CFNR peripapilar do olho amblíope e do outro olho. As medidas de espessura da CFNR foram realizadas nos quadrantes superior, inferior, nasal e temporal na região peripapilar. Além disso, a espessura da coroide subfoveal (CSF) foi medida através de tomografia de coerência óptica de domínio espectral (TCO-DE). Resultados: A espessura média global da CFNR do olho amblíope e do outro olho foi de 104,48 mícrons e 102,83 mícrons, respectivamente. A diferença entre os dois grupos não foi estatisticamente significativa (p > 0,05%). As espessuras dos quadrantes superior, inferior, nasal e temporal da camada de fibras nervosas da retina entre o olho amblíope e o normal não apresentaram diferença estatisticamente significativa (p > 0,05%). No entanto, a CSF do olho amblíope foi 11 mícrons mais espessa (ou mais) do que a do outro olho - essa diferença foi estatisticamente significativa (p < 0,05%). Conclusões: Este estudo demonstrou que a CSF dos olhos amblíopes foi significativamente mais espessa do que a dos olhos normais. O processo amblíope pode envolver a coroide, mas ele não envolve a CFNR peripapilar.

Posterior keratoconus and iris atrophy: a fortuitous association? / Ceratocone posterior e atrofia de iris: uma associação incidental?

ABSTRACT The authors describe an unusual association between posterior keratoconus and iris atrophy, confirmed by a complete ocular evaluation, scheimpflug imaging and pachymetric curve. A hypothesis for concomitant findings is discussed.

RESUMO Os autores descrevem a rara associação entre ceratocone posterior e atrofia de íris, confirmada por avaliação oftalmológica completa, imagens de scheimpflug e curva paquimétrica. Sugere-se uma hipótese que explique a concomitância de ambas as alterações.

The Relationship between Higher-order Aberrations and Amblyopia Treatment in Hyperopic Anisometropic Amblyopia

PURPOSE: To investigate the relationship between higher-order aberrations (HOAs) and amblyopia treatment in children with hyperopic anisometropic amblyopia. METHODS: The medical records of hyperopic amblyopia patients with both spherical anisometropia of 1.00 diopter (D) or more and astigmatic anisometropia of less than 1.00 D were reviewed retrospectively. Based on the results of the amblyopia treatment, patients were divided into two groups: treatment successes and failures. Using the degree of spherical anisometropia, subjects were categorized into mild, moderate, or severe groups. Ocular, corneal, and internal HOAs were measured using a KR-1W aberrometer at the initial visit, and at 3-month, 6-month, and 12-month follow-ups. RESULTS: The results of the 45 (21 males and 24 females) hyperopic anisometropic amblyopia patients who completed the 12-month follow-up examinations were analyzed. The mean patient age at the initial visit was 70.3 months. In total, 28 patients (62.2%) had successful amblyopia treatments and 17 patients (37.8%) failed treatment after 12 months. Among the patient population, 24 (53.3%) had mild hyperopic anisometropia and 21 (46.7%) had moderate hyperopic anisometropia. When comparing the two groups (i.e., the success and failure groups), ocular spherical aberrations and internal spherical aberrations in the amblyopic eyes were significantly higher in the failure group at every follow-up point. There were no significant differences in any of the HOAs between mild and moderate cases of hyperopic anisometropia at any follow-up. When the amblyopic and fellow eyes were compared between the groups there were no significant differences in any of the HOAs. CONCLUSIONS: HOAs, particularly ocular spherical aberrations and internal spherical aberrations, should be considered as reasons for failed amblyopia treatment.

The Relationship between Higher-order Aberrations and Amblyopia Treatment in Hyperopic Anisometropic Amblyopia

PURPOSE: To investigate the relationship between higher-order aberrations (HOAs) and amblyopia treatment in children with hyperopic anisometropic amblyopia. METHODS: The medical records of hyperopic amblyopia patients with both spherical anisometropia of 1.00 diopter (D) or more and astigmatic anisometropia of less than 1.00 D were reviewed retrospectively. Based on the results of the amblyopia treatment, patients were divided into two groups: treatment successes and failures. Using the degree of spherical anisometropia, subjects were categorized into mild, moderate, or severe groups. Ocular, corneal, and internal HOAs were measured using a KR-1W aberrometer at the initial visit, and at 3-month, 6-month, and 12-month follow-ups. RESULTS: The results of the 45 (21 males and 24 females) hyperopic anisometropic amblyopia patients who completed the 12-month follow-up examinations were analyzed. The mean patient age at the initial visit was 70.3 months. In total, 28 patients (62.2%) had successful amblyopia treatments and 17 patients (37.8%) failed treatment after 12 months. Among the patient population, 24 (53.3%) had mild hyperopic anisometropia and 21 (46.7%) had moderate hyperopic anisometropia. When comparing the two groups (i.e., the success and failure groups), ocular spherical aberrations and internal spherical aberrations in the amblyopic eyes were significantly higher in the failure group at every follow-up point. There were no significant differences in any of the HOAs between mild and moderate cases of hyperopic anisometropia at any follow-up. When the amblyopic and fellow eyes were compared between the groups there were no significant differences in any of the HOAs. CONCLUSIONS: HOAs, particularly ocular spherical aberrations and internal spherical aberrations, should be considered as reasons for failed amblyopia treatment.

Factors Associated with the Direction of Ocular Deviation in Sensory Horizontal Strabismus and Unilateral Organic Ocular Problems

PURPOSE: To evaluate factors associated with the direction of horizontal deviation in the sensory strabismus of patients with unilateral organic amblyopia. METHODS: The medical charts of 53 patients who had been diagnosed with sensory strabismus between 2000 and 2009 were reviewed retrospectively. The underlying ocular disease, time of onset and the duration of vision impairment, refractive error and axial length of the fixing eye, and the direction and angle of deviation were analyzed to determine the distribution of underlying diseases and any factors relevant to determining the direction of the horizontal deviation. RESULTS: Congenital cataracts were the most common underlying disease, found in 33 patients, followed by acquired cataracts, optic nerve disorders, retinal detachment, glaucoma and lens subluxation. Among the 50 patients with horizontal strabismus, 11 had esotropia and 39 had exotropia. The incidence of esotropia was significantly higher when the fixing eye had hyperopia or emmetropia, than when the eye was myopic. Age of onset of vision deterioration and at diagnosis of sensory strabismus, and the axial length of the fixing eye had no relationship to the direction of horizontal deviation. In addition, the duration of visual impairment had no significant relationship with the direction or extent of horizontal deviation. CONCLUSIONS: The most common cause of sensory strabismus was congenital cataracts and the most frequent type of strabismus was exotropia. With respect to the direction of horizontal strabismus, esotropia occurred significantly more often when the refractive error of the fixing eye was hyperopia or emmetropia than when the fixing eye was myopic.

Resultados da correção cirúrgica da exotropia permanente em pacientes amblíopes e não-amblíopes / Surgical correction of permanent exotropia outcomes in amblyopic and non-amblyopic patients

A exotropia permanente (XT) acomete cerca de 1 a 2 por cento da população. Seu tratamento é clínico: antiambliogênico e correção dos erros refrativos, e cirúrgico. O objetivo do tratamento cirúrgico é alinhar os olhos na posição primária do olhar, proporcionando melhor resultado estético. Há muito tempo diversos autores estudam os fatores pré, per e pós-operatórios relacionados ao resultado cirúrgico, uma vez que a taxa de sucesso varia de 60 a 80 por cento. Ainda são poucos os estudos que comparam a presença de ambliopia como fator de influência no resultado final. OBJETIVO: Comparar o resultado cirúrgico dos pacientes amblíopes e não-amblíopes submetidos à cirurgia de correção de XT. MÉTODOS: Análise retrospectiva de 37 prontuários de pacientes amblíopes (Grupo A) e não-amblíopes (Grupo B) submetidos à correção cirúrgica de XT por retrocessoressecção monocular, sendo avaliados os registros pós-operatórios imediatos e tardios. Idade: grupo A 24,7 ± 14,2 anos, grupo B 22,6 ±18,6 anos; Desvio pré-operatório: grupo A 29,1± 7,2Δ, grupo B 28,4 ± 6,8Δ. RESULTADOS: A taxa de sucesso foi de 60 por cento e 100 por cento (p<0,05), no pós-operatório imediato e 50 por cento e 82,3 por cento (p=0,082), no pós-operatório final, nos grupos A e B, respectivamente. Não houve diferença significante quanto aos desvios pós-operatórios imediatos, tardios e variação do desvio. CONCLUSÃO: Pode-se concluir que o grupo B mostrou melhor resultado no pós-operatório imediato; porém não houve diferença no resultado cirúrgico de correção de exotropia permanente entre pacientes amblíopes e não-amblíopes no período pós-operatório de seis meses.

Permanent exotropia (XT) occurs in 1 to 2 percent of the pediatric population. Its management involves careful assessment of patient, treatment of amblyopia, refractive errors and surgery. The aim of the surgery is to straighten the eyes in the primary gaze position, giving a better cosmetic outcome. The factors reported to affect surgical outcome after exotropia surgery vary widely in reports and success rates for strabismus surgery have been reported to range from 60 percent to 80 percent. There are few reports to determine the relation between amblyopia and surgical outcome in exotropic patients. PURPOSE: To compare the surgical outcome of permanent exotropia surgery in amblyopic and non-amblyopic patients. METHODS: This is a retrospective study of 37 clinical records from amblyopic patients (Group A) and non-amblyopic patients (Group B) who underwent recess-resect in one eye for XT. Postoperative deviation was analyzed in one month (immediate) and insixmonths (final) in both groups and in between. Age: group A 24.7 ± 14.2 years, group B 22.6 ± 18.6 years; Preoperative deviation: group A 29.1 ± 7.2Δ, group B 28.4 ± 6.8Δ. RESULTS: The success rate in the imediate postoperative period was 60 percent (Group A) and 100 percent (Group B) (p<0.05); 50 percent (Group A) and 82.3 percent (Group B) (p=0.082) in the final postoperative period. There was a statistical difference in the imediate postoperative deviation, but the final deviation and the variation of the deviation were similar in both groups. CONCLUSION: There is a better outcome in patients of group B and no diference in the surgical outcome between these amblyopic and non-amblyopic patients in the final postoperative period.

Avaliação da espessura da camada de fibras nervosas da retina e mácula em pacientes com ambliopia / Thickness of the retinal nerve fiber layer, macular thickness, in patients with amblyopia

OBJETIVO: Avaliar a espessura da camada de fibras nervosas da retina em olhos amblíopes e comparar com olhos normais e certificar se há correlação com a redução da acuidade visual. Além disso, este estudo se propõe avaliar a eficácia e eficiência em uma série de casos do protótipo de um equipamento nacional de magnificação para leitura. MÉTODOS: Participaram deste estudo 30 pacientes na faixa etária entre 9 e 80 anos (17 do sexo masculino). Foi desenvolvido um aparelho portátil, patenteado pela Unifesp (PI#020050145260), com um sistema de captura de imagens acoplado a um monitor de 5,6 polegadas proporcionando um aumento de 15 x. Foram analisadas a eficácia da acuidade visual e a eficiência de leitura após a utilização do protótipo proposto. RESULTADOS: Seis pacientes (20 por cento) apresentaram AV 8M, 12 pacientes (40 por cento) apresentaram AV 6M, 7 pacientes (23,3 por cento) apresentaram 5 M, 5 pacientes (16,7 por cento) apresentaram 4M. A média de acuidade visual antes da utilização do SLP medida pela tabela LHNV-1 logMAR foi de 5,75M e após a utilização 100 por cento dos pacientes atingiram a eficácia de AV J1. CONCLUSÃO: O protótipo do SLP mostrou-se um recurso alternativo no processo de inclusão social das pessoas com baixa visão com diferentes níveis de resíduo visual. Também pode proporcionar incentivo psicológico, permitir conforto, mobilidade e independência àqueles que necessitam de uma leitura mais prolongada e maior distância de trabalho.

OBJECTIVE: To compare the thickness of the retinal nerve fiber layer (RNFL)and the macular thickness of the amblyopic eye with those of the non-amblyopic eye in patients with unilateral amblyopia using optical coherence tomography (OCT). METHODS: OCT was performed for13 patients with unilateral amblyopia who had no neurologic disease. Nine male andfour female patients, whose ages ranged from 23 to 63 years, were enrolled in the study. The RNFL thickness average analysis program was used to evaluate mean superior, inferior, temporal, and nasal thickness. The data for all clock quadrants (12 values averaged) were identified as the overall RNFL. The retinal thickness analysis program was used to evaluate macular scans. Data were compared using the Man n-Whitney U test. The mean age ( standard deviation) was 35,43years. RESULTS: There were 13 eyes with amblyopia; this group had visual acuity 0,1 logMAR or better in the best eye. OCT parameters including the RNFL thickness in all quadrants, overall RNFL thickness and macular thickness showed no significant differences between the two groups (p >0,5). CONCLUSION: Assessment of RNFL thickness and macular thickness with OCT revealed no difference between the two eyes of patients with unilateral amblyopia.

Disfuncionalidad neuronal y psicomotora como resultado del retraso del tratamiento de la ambliopía / Neuronal and psychomotor malfunction secondary to delayed amblyopia treatment

BACKGROUND: A review of neuronal and psychomotor alterations related to delay of amblyopia treatment was carried out. METHODS: We reviewed various studies to explain the anomalies of visual cortex because of the prevalence of anomalous stimulus in patients with amblyopia. RESULTS: Visual pathways are developed embryologically. The newborn has ocular dominance columns ready to be stimulated, but visual alterations present at this time will generate neuronal changes in visual cortex. CONCLUSIONS: Delay of amblyopia treatment with anomalous visual stimulus will provoke organic changes in visual cortex, inducing alterations of brain functions depending on binocularity. Memory and learning have also been related to this condition.

Efficiency of occlusion therapy for management of amblyopia in older children.

PURPOSE: To analyse results of full time occlusion therapy for amblyopia in children older than 6 years. MATERIALS AND METHODS: This was a retrospective consecutive case series analysis of children treated for amblyopia at a tertiary care center. All children received full time occlusion (FTO) for the dominant eye. RESULTS: Eighty-eight children older than 6 years at the time of initiation of therapy were included. Age at initiation of therapy ranged from 6 to 20 years (9.45 +/- 3.11 years). Forty-two children (47.7%) had strabismic amblyopia, 37 (42.0%) had anisometropic amblyopia and 9 (10.2%) had a combination of strabismic and anisometropic amblyopia. Eighty out of 88 eyes (90.0%) had improvement in visual acuity following FTO. Visual acuity (VA) improved from 0.82 +/- 0.34 at presentation to 0.42 +/- 0.34 (P < 0.001) after FTO. In children with strabismic amblyopia, VA improved from 0.81 +/- 0.42 to 0.42 +/- 0.39 (P <0.001). In children with anisometropic amblyopia, visual acuity of the amblyopic eye improved fron 0.82 +/- 0.24 to 0.36 +/- 0.29 (P< 0.001) following FTO. Out of 13 children older than 12 years, only 6 children (46.1%) had improvement in VA. Mean follow-up after complete stoppage of occlusion was 8.37 +/- 1.78 months. CONCLUSION: Occlusion therapy yields favorable results in strabismic and/or anisometropic amblyopia, even when initiated for the first time after 6 years of age. After 12 years of age, some children may still respond to occlusion of the dominant eye.

Prevalence of amblyopia in ametropias in a clinical set-up.

OBJECTIVE: To find out prevalence of amblyopia in ametropias in a clinical set-up. MATERIALS AND METHODS: In this retrospective clinical study children from 4-5 years age group to the young adults who attended the eye clinic in one year period were included after taking history, VA test by Snellen's Vision Chart, cycloplegic refraction by streak retinoscope in children and wet or dry retinospcopy in young adults; and a thorough anterior and posterior segment eye examinations by slit lamp biomicroscope and ophthalmoscope to exclude structural abnormality of the eye or the posterior visual pathway defects. A total of 970 eye patients having diminution of vision with ametropias were identified and patients having reduction of visual acuity of greater than two lines between the eyes or an absolute reduction in acuity below 6/9 either eye in snellen's vision chart which cannot be corrected by refraction were enrolled to find out prevalence of amblyopia. RESULTS: Out of 970 ametropic eye patients amblyopia was present in 56 patients (5.97%) with anisometropias and high bilateral ametropias. The prevalence of amblyopia according to types of ametropias are: hyperopia 6 (10.71%), myopia 2 (3.57%), myopic astigmatism 31 (55.36%), hyperopic astigmatism 11 (19.64%) and mixed astigmatism 6 (10.71%). Sex distribution of amblyopia is male 32 (57.14%) and female 24 (42.86%). Laterality of amblyopia shows: monocular 40 (71.43%) and binocular 16 (28.57%). CONCLUSION: Out of 970 ametropic eye patients a total of 56 (5.97%) patients have amblyopia. A preschool and school screening program in children in critical period of development of amblyopia must be conducted to find out the ametropias and amblyopia in time; and treat them earlier, by optical correction and amblyopia therapy, effectively and adequately.

Visual Improvement in High Myopic Amblyopic Adult Eyes following Phakic Anterior Chamber Intraocular Lens Implantation

PURPOSE: To evaluate the efficacy and safety of angle-supported phakic anterior chamber intraocular lenses in amblyopic adult eyes with very high myopia. METHODS: We evaluated 12 eyes in nine patients with very high myopic amblyopia who received angle-supported phakic intraocular lenses (Phakic 6H(R)) and followed them for more than six months. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and complications were evaluated. A satisfaction score was rated by patients using a 5-point (1~5) numeric scale. RESULTS: The mean age of patients was 37.3+/-9.4 years, ranging from 29 to 59 years old. The preoperative mean refraction (spherical equivalent, SE) was -20.10+/-5.41 diopters (D). The postoperative mean refraction (SE) was -1.75+/-0.76 D at six months. The postoperative BCVA improved an average 3.92+/-1.24 lines over preoperative values, and mean endothelial cell loss was 8.9% at six months. Development of cataracts, glaucoma, and pupil abnormalities were not demonstrated in any case during the study. The patients were all very satisfied, as the average satisfaction score was 4.3. CONCLUSIONS: This study indicates that angle-supported phakic anterior chamber intraocular lens implantation may be an effective surgical alternative for the correction of amblyopic adult eyes with very high myopia. However, long-term evaluation is necessary to assess possible complications and long-term safety.

Prevalence of visual deficits among young men in Jordan

To report the pattern of various causes of decreased visual acuity [VA], within the age group of young [18-25 years] healthy adults in Jordan. We carried out this retrospective study on the records of 16550 candidates examined from June 2004 to June 2005 by the Medical Committee of Employment, Royal Medical Services in Amman, Jordan. All candidates received an ophthalmic examination as well as medical and ENT examination. We divided the candidates with visual acuity of less than 6/12 in either eye into 3 groups. The most important cause of decreased VA in the 18-25 years age group was refractive errors followed by amblyopia, which represents the major ophthalmic cause of employment rejection in a wide range of occupations in adult life. This study emphasize the need for early visual screening for refractive errors and anisometropic amblyopia in early primary schools, and every effort must be made to achieve the best possible acuity in young patients with amblyopia

Thicknesses of Macular Retinal Layer and Peripapillary Retinal Nerve Fiber Layer in Patients with Hyperopic Anisometropic Amblyopia

This prospective study was performed to measure the macular and the peripapillary retinal nerve fiber layer (RNFL) thicknesses using optical coherence tomography (OCT) in patients with anisometropic amblyopia. Thirty-one patients with hyperopic anisometropic amblyopia were included. The macular retinal thickness and the peripapillary RNFL thickness were measured using OCT. The mean refractive error was +3.71 diopters (D) and +1.00 D, the mean macular retinal thickness was 252.5 micrometer and 249.7 micrometer, and the mean RNFL thickness was 115.2 micrometer and 109.6 micrometer, in the amblyopic eye and the normal eye, respectively. OCT assessment of RNFL thickness revealed a significantly thicker RNFL in hyperopic anisometropic amblyopia (P=0.019), but no statistically significant difference was found in macular retinal thickness (P> 0.05). In conclusion, the amblyopic process may involve the peripapillary RNFL, but not the macula. However, further evaluation is needed.

Fibras nervosas retinianas mielinizadas: relato de três casos atípicos / Myelinated retinal nerve fibers: report of three atypical cases

Os autores descrevem três casos atípicos de fibras nervosas rtinianas mielinizadas associadas com erros refracionais e ambliopia. Em dois casos o acometimento foi bilateral. Dois pacientes apresentavam miopia e um hipermetropia. Alertam para o diagnóstico precoce destas alteraçöes, considerando que tais fibras mielinizadas podem trazer danos irreversíveis para a funçäo visual dos pacientes

Pérdida del ojo fijador en adultos con ambliopía estrábica / Loss of good eye in adults with strabic amblyopia

Se presentan 8 casos de ambliopía estrábica que perdieron el ojo fijador siendo visualmente adultos. En todos los casos mejoró la gudeza visual de manera importante a partir de los 6 meses siguientes, llegando a su máximo al año y medio. La mejoría de visión no guardó relación con agudeza visual previa, tipo de fijación previo, tratamiento previo, edad en que se perdió el ojo fijador ni profundidad de la pérdida (subtotal o total)

Fibras de mielina, miopia e ambliopia ipsilateral: apresentaçäo de um caso

A associaçäo de fibras de mielina, miopia e ambliopia ipsilateral parece ser uma nova síndrome oftalmológica. A ambliopia nestes casos tem mau prognóstico, talves pela presença de um componente orgânico. A hereditariedade näo esta ainda bem estabelecida

Concidência de blefaroptose com outras alteraçöes oftalmológicas / Coincidence of blepharoptosis with other aphthalmologic changes

Foram analisados 60 pacientes portadores de blefaroptose que passaram pelo Serviço de Motilidade Extrínseca da Santa Casa de Misericórida de Säo Paulo. Observou-se entre eles uma grande incidência de estrabismo (50%), ambliopia (28,3%) e anisometropia (38,3%)

Acromatopsia com ambliopia: a propósito de 3 casos / Achromatopsia with amblyopia: apropos of 3 cases

Apresenta-se, para registro, dois casos comprovados de acromatopsia com ambliopia e reporta-se a um terceiro, de diagnóstico presuntivo e retrospectivo. Esses casos pertencem ao acervo do Instituto Penido Burnier. Trata-se de condiçäo rara, cuja ocorrência é estimada, na populaçäo geral, da ordem de 1 para 300.000. Ao ensejo, caracteriza-se a afecçäo que se define particularmente por: acromatopsia, ambliopia, fotofobia e nistagmo. As coordenadas para o diagnóstico diferencial säo analisadas. Considera-se também a patogenia, os achados histológicos, bem como os procedimentos terapêuticos plausíveis para diminuir o desconforto dos pacientes e permitir-lhes o aprendizado