Research advances of microperimetric biofeedback training for low-vision rehabilitation in macular diseases / 国际眼科杂志(Guoji Yanke Zazhi)

@#In clinical practice, many macular diseases in advanced stages such as age-related macular degeneration(ARMD)and Stargardt disease are manifested reduced visual acuity, unstable and even paracentral fixation resulting from the central scotoma followed by the scarring of neovascular fibres or the impairment of photoreceptors and retinal pigment epithelium, which cause great distress to patients' life, work and psychology. For a long time, there have been limited rehabilitation treatments for such patients. However, recent articles have indicated that biofeedback training by using microperimetry is expected to enhance neurosensory adaptation by achieving cortical plasticity, and makes better use of residual retinal function to help those with low vision associated with central scotoma consolidate or establish stable central or paracentral fixation, thereby improving visual function including visual acuity and reading speed. In order to improve the understanding of this rehabilitation therapy, this article will overview the mechanism and protocol of microperimetric biofeedback training(MBFT), the selection of the preferred retinal locus, the clinical application in macular diseases and its prospects.

Research advances in low-vision rehabilitation by means of microperimeter biofeedback examination in patients with different macular diseases / 眼科新进展

In macular diseases,there is a typical development of a central scotoma which is responsible for the central visual acuity loss,reading speed reduction and changing in fixation stability.The prevention and treatment of degenerative macular disease have not yet received satisfying functional results.Effectiveness of biofeedback treatment in visual rehabilitation has been evidenced in several studies.The microperimeter can improve their visual abilities and lay the basis for new,more manageable visual aids by using cerebral plasticity and neurosensorial adaptation to the central scotoma of patients with macular diseases.The purpose of this review is to summarize key fmdings on characteristics of central scotoma,the plasticity of human visual system and visual rehabilitation via microperimetry.

Change of macular microperimetry in diabetes patients without diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the macular function of patients with diabetes mellitus(DM)who had no diabetic retinopathy(DR). <p>METHODS: Totally 140 eyes of 70 subjects with diabetes who had no vision disorders and fundus abnormalities(DM group)and 160 eyes of 80 normal subjects(control group)were examined. In DM group, from 20 to 30 were 8 patients(16 eyes), from 30 to 40 were 18 patients(36 eyes), from 40 to 50 were 24 patients(48 eyes), over 50 were 20 patients(40 eyes). In control group, there were 20 people in each age stages. Retinal imaging and macular microperimetry were measured by MP-l Microperimeter. The mean retinal light sensitivity(MS)in the central 20°, fixation stability and fixation position in the central 2° and 4° were recorded. <p>RESULTS: With the ages from 20 to 30, the MS of DM group and control group were 15.32±1.82, 19.41±0.32dB; from 30 to 40, the MS were 14.93±2.11, 18.92±0.73dB; from 40 to 50, the MS were 14.55±2.84, 18.21±0.53dB; over 50 years, the MS were 13.21±2.25, 17.14±1.21dB; respectively,the difference was all statistically significant between the two groups with the same age(<i>P</i>>0.05). All subjects were central fixation. Among 160 eyes of control group, fixation was stable in 124 eyes(77.5%), relative unstable in 36 eyes(22.5%); among 140 eyes of DM group, fixation was stable in 109 eyes(77.9%), relative unstable in 31 eyes(22.1%), the difference was statistically significant(<i>χ</i>²=0.00549, <i>P</i>>0.05). <p>CONCLUSION: The macular function and the MS in the central 20° had been damaged before fundus morphological abnormalities were detected in patients with diabetes. However, compared with control group, the fixation position and fixation stability did not changed significantly in patients with diabetes.

Retinal sensitivity in healthy Indians using microperimeter.

Aims: To establish the retinal sensitivity values in healthy Indians using microperimeter. Materials and Methods: In this prospective study, 144 healthy volunteers were included. All the participants underwent a comprehensive ophthalmic examination including contrast sensitivity. Microperimetry was performed in the central 20° of the macula using 76 stimulus points to assess the retinal sensitivity, and the fixation characteristics in the study population were assessed. Results: The mean age of the study sample was 43.08 ± 10.85 years (range: 25‑69). Mean retinal sensitivity was 18.26 ± 0.99 dB. Males had significantly increased retinal sensitivity (18.34 vs. 18.17 dB, P = 0.03). The linear regression analysis revealed a 0.04 dB per year age‑related decline in mean retinal sensitivity. Contrast sensitivity was significantly correlated with the mean retinal sensitivity (r = 0.432, P < 0.001). Fixation stability in the central 2° and 4° were 69% and 89%, respectively. Conclusion: Microperimeter is an ideal tool to assess the retinal sensitivity and the fixation behavior. These normative values could help in drawing a meaningful conclusion in various retinal pathologies.

Application of Microperimeter in the Visual Function Evaluation / 法医学杂志

In condition of direct vision on fundus of eye, microperimeter can quantitatively detect the retinal light sensitivity of macular area, and record real time tracking of the eye, automatically analyze the location and stability of fixation. Microperimeter matches fundus image with micro cyclogram point-to-point, thus it achieves the combination of visual function and structure. The characteristics of microperimeter have good relations with subjective vision, so it can be a new method for the accurate vision evaluation and has application potential to assess the visual function in legal medicine. In this ar-ticle, we summarize the principle, method and parameters of microperimeter. Also, the applications of microperimeter in vision assessment are focused in order to provide a reference for the assessment of visual function in the legal medicine.

Maculopatía tóxica por cloroquina y rehabilitación visual mediante microperímetro MP1 / Phacoemulsification in the treament of iridocorneal endothelial syndrome

La cloroquina es un fármaco que puede producir disfunciones visuales, baja visión e incluso ceguera según la dosis. Una dosis acumulativa menor a 100 g de cloroquina, o una duración de tratamiento de menos de un año raramente se asocia con lesión retiniana. El riesgo de toxicidad aumenta cuando la dosis acumulativa excede los 300 g (250mg/día durante 3 años). Este medicamento es utilizado en el tratamiento de enfermedades autoinmunes. Se presenta una paciente de 44 años de edad, con antecedentes de artritis reumatoide hace 14 años para lo cual se indicó tratamiento con cloroquina (1 tableta 250 mg/diaria) desde el diagnóstico inicial, y presenta un diagnóstico de maculopatía por cloroquina hace 5 años, a consulta por presentar baja visión y solicitando una posibilidad de rehabilitación visual. Se realizó examen oftalmológico, estudios complementarios y se rehabilitó mediante el microperímetro MP1. Se concluye que la maculopatía por cloroquina es una de las causas de discapacidad visual y que la rehabilitación visual con microperimetría proporciona mejoría en varios parámetros visuales, mejorando la calidad visual del paciente

Chloroquine-induced toxic maculopathy and visual rehabilitation through the use of microperimeter MP1.Chrloroquine is a drug that may cause visual dysfunctions, low vision and even blindness depending on dose. An accumulative dose lower than 100 g of chloroquine or a length of treatment less than one year is rarely associated to retinal injure. The toxicity risk increases when the accumulative dose exceeds 300 g (250mg/day for 3 years). This drug is used in treating autoimmune diseases. Here is the case of a 44 years-old patient, with history of rheumatoid arthritis for 14 years. Chloroquine treatment was indicated (one 250 mg tablet daily) at the time of initial diagnosis. Five years ago, he was diagnosed with chloroquine-induced maculopathy when he went to the doctor's because of low vision and asked for possible visual rehabilitation. An ophthalmologic exam, some supplementary studies and rehabilitation through the microperimeter MP1 were all performed. It was concluded that chloroquine-maculopathy with microperimetry provides improvement of several visual parameters and better visual quality for the patient

Morphological and Functional Correlates in Goldmann-Favre Syndrome: A Case Series

The purpose of this study is to describe the correlation of findings between results from spectral domain optical coherence tomography (SD-OCT) and microperimetry in a case series regarding patients with Goldmann-Favre syndrome. Goldmann-Favre syndrome is a rare autosomal recessive hereditary vitreo-retinal degeneration that impacts the functionality of vision in subjects. Three men with this condition were assessed and subjected to microperimetry and SD-OCT. Two of the men were brothers. This study finds that the retinoschisis and macular cystoid changes noted in the SD-OCT matched the scotomas revealed by the microperimetry. The findings of each of the individual cases are reported herein.

Rehabilitación visual mediante el microperímetro MP1 en pacientes con agujero macular y baja visión / Visual rehabilitation by means of MPI microperimeter in patients with macular hole and low vision

Objetivo: Evaluar los beneficios de la estimulación visual usando el microperímetro MP1 en pacientes con baja visión por agujero macular atendidos en consulta de baja visión en el Instituto Cubano de Oftalmología “Ramón Pando Ferrer” en el año 2010. Métodos: Se realizó un estudio experimental, tipo serie de casos. Fueron estudiadas, antes y después de la rehabilitación, las siguientes variables: agudeza visual mejor corregida de cerca con cartilla Zeiss y agudeza visual mejor corregida de lejos usando cartilla Feinbloom, estabilidad de la fijación y sensibilidad retiniana por medio del microperímetro MP1 y velocidad de lectura. Se realizaron 10 sesiones de estimulación de 10 minutos cada una con una frecuencia semanal, empleando el módulo de “biofeedback” del microperímetro MP1. Se realizó análisis estadístico por medio del test de student para muestras pareadas. Valores de p= 0,05 se consideraron como estadísticamente significativos. Resultados: La agudeza visual para lejos y cerca mejoró de 0,18 a 0,23, y de 0,21 a 0,51 respectivamente, la sensibilidad retiniana aumentó de 2,69 a 7,86 dB, la estabilidad de la fijación antes de la estimulación: inestable (80,77 %), relativamente inestable (15,38 %) y estable (3,85 %) y después de la misma: no inestable, relativamente inestable (30,77 %) y estable (69,23 %). La velocidad de lectura mejoró de 35 a 104 palabras por minuto. Conclusión: La estimulación visual empleando el microperímetro MP1 mejoró el rendimiento visual de los pacientes con agujero macular y baja visión.

Objective: To evaluate the benefits of visual stimulation by using the MP1 microperimeter in patients with low vision due to macular hole, who were seen at low vision service of “Ramón Pando Ferrer" Cuban Institute of Ophthalmology during 2010. Methods: An experimental, case series type study was carried out. The following variables were studied before and after the rehabilitation: best near spectacle-corrected visual acuity with Zeiss chart and best distance spectacle-corrected visual acuity with Feinbloom chart, fixation stability and retinal sensitivity by means of the MP1 microperimeter and reading speed. Ten 10-minute sessions of stimulation weekly using the MP1 microperimeter biofeedback module were given. Statistical analysis was performed with paired Student’s t-test. P values less than 0,05 were considered statistically significant. Results: Distance and near visual acuity improved from 0,18 to 0,23, and from 0,21 at 0,51; retinal sensitivity increased from 2,69 to 7,86 dB, fixation stability was unstable (80.77 %), relatively unstable (15.38 %) and stable (3,85 %) before stimulation and after the sessions: not unstable, relatively unstable (30,77 %) and stable (69,23 %). The reading speed improved from 35 to 104 words per minute. Conclusion: Visual stimulation by using the MP1 microperimeter improved the visual performance of patients with macular hole and low vision.