1/14. Improvement of visual function in an adult amblyope.PURPOSE: In this case report, the efficacy of occlusion therapy was investigated in a strabismic amblyope above the currently accepted age for treatment. Success was assessed not simply by a change in visual acuity, but by examining a number of parameters which relate to both sensory and motor aspects of visual function. methods: As well as routine orthoptic and optometric evaluation, additional tests were administered as follows: high and low contrast LogMAR Crowded Acuity, repeat letter acuity, and hyperacuity measurements. RESULTS: A functional loss in each of the tests used was demonstrated, and occlusion therapy appeared to improve all aspects of the amblyopia, with a significant difference in pre- and post-therapy results. CONCLUSIONS: The results of this study suggest that: (1) occlusion therapy can produce substantial improvements in visual function in adult amblyopia; (2) many aspects of visual function can improve beyond the traditional critical periods for development in amblyopia; and (3) with good patient compliance and cooperation, age should not be the critical factor in the initiation of treatment for amblyopia.- - - - - - - - - - ranking = 1keywords = contrast (Clic here for more details about this article) |
2/14. Hemifacial infantile hemangioma with intracranial extension: a rare entity.Intracranial hemangiomas are uncommon, especially in the absence of diffuse hemangiomatosis or the syndrome consisting of posterior fossa malformations, hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, eye abnormalities, sternal clefting, and/or supra-umbilical raphe (PHACES). We saw an 8-month-old ex-premature girl with a large left-sided ocular and facial hemangioma that had been growing since early infancy. Examination revealed a 7 x 13 cm violaceous tumor involving the left periocular region and face. Ophthalmologic examination revealed deprivation amblyopia, anisometropia with myopia and astigmatism. magnetic resonance imaging demonstrated a vascular tumor mass involving the scalp, face, and calvarium with extension into the orbit, infratemporal fossa, nasopharynx, lateral medullary cistern, internal auditory canal, and fourth ventricle. Marked enhancement was seen with contrast, and no posterior fossa malformations were noted. She was treated with prednisolone, which was tapered over 12 months. Follow-up magnetic resonance imaging examination at 25 months showed a marked decrease in the size of all lesions, with residual hemangioma in the periorbital soft tissues and small foci in the orbit and intracranial sites. The brain and ventricular system were normal. Intracranial hemangioma may occur in the setting of a large facial hemangioma (especially segmental) in the absence of the PHACES syndrome or diffuse hemangiomatosis. Radiological imaging should be considered to assess for intracranial hemangioma as well as posterior fossa or arterial anomalies.- - - - - - - - - - ranking = 1keywords = contrast (Clic here for more details about this article) |
3/14. Training the adult amblyopic eye with "perceptual learning" after vision loss in the non-amblyopic eye.We recently reported acuity development in the amblyopic eye of a 60-year-old patient after loss of vision in her non-amblyopic eye. Here, we focus on the training that we implemented, based on new insights from psychophysical procedures aiming at functional visual improvement of adults ("perceptual learning"). We alternately used the following procedures: grating acuity (Teller-Cards); contrast sensitivity (Vistech-charts); two spatial localization tests (vertical alignment, pointing); and labyrinth patterns for a eye-hand coordination exercise. One month without intervention was followed by six months of training and two blocks of pleoptic treatment. Clinical parameters were assessed monthly. Besides acuity gain, we observed enhanced grating resolution and contrast sensitivity, decreased alignment distortions, pointing shifts, mainly after pleoptics, and more efficient labyrinth tracing. A questionnaire reflected the patient's perception of the changes. These data confirm the plasticity of the adult amblyopic system, be it spontaneous due to the loss of the non-amblyopic eye or caused by the intervention or both. Further experience is necessary to isolate the role of the intervention. Our results also underline the limitation of adult plasticity, emphasizing the importance of early diagnosis and treatment of amblyopia.- - - - - - - - - - ranking = 210900.60863466keywords = contrast sensitivity, sensitivity, contrast (Clic here for more details about this article) |
4/14. Form vision deprivation amblyopia: further observations.Nine cases of esotropia occurring in deprivation amblyopia, where exotropia rather than esotropia is usually found, showed a refractive error of hypermetropia. This fact suggested that an accommodative factor is largely responsible for the development of esotropia. A- or V-pattern strabismus was encountered in a higher incidence in deprivation amblyopia than in ordinary strabismus. Pattern-reversal VEP showed more prominent abnormality than flash VEP did. Studies of the sensitive period of the visual system revealed that the sensitivity is likely to be low for a month or two after birth and increases with a peak around the 18th month of age, decreasing thereafter with a waning slope to the end of the 8th year of life.- - - - - - - - - - ranking = 26.903313017566keywords = sensitivity (Clic here for more details about this article) |
5/14. Two year electrophysiology follow-up in quinine amblyopia. A case report.A 19-year-old girl presenting with quinine amblyopia had serial electrophysiology studies over a 2 year period. Visually evoked responses and the electro-oculogram were abolished early. By 2 months the VER and visual acuity had returned to normal. The electroretinogram, initially mildly subnormal, became virtually abolished by 2 months. No recovery in cone function took place. Of the rods 50% regained function with normal latency by 1 year, but receptor sensitivity did not return to normal until 2 years after ingestion. The electro-oculogram also recovered slowly over a 2 year period. This pattern suggest that quinine exerts a direct toxic effect on the cells of the outer retina and pigment epithelium, as well as on the ganglion cells.- - - - - - - - - - ranking = 26.903313017566keywords = sensitivity (Clic here for more details about this article) |
6/14. Changes in the contrast sensitivity of an amblyopic eye after losing the other normal eye.A man aged 17 had an amblyopic left eye with central fixation and lost his normal right eye by an accident. After the accident, spontaneous improvement of the visual acuity of the amblyopic left eye was rapid. Just after the accident, overall contrast sensitivity of the left eye was considerably less than that of a normal adult. Improvement of the contrast sensitivity was recorded first at low spatial frequencies and then at high spatial frequencies. However, the contrast sensitivity at medium spatial frequencies remained less than that of a normal adult. These results suggest that lateral inhibitory processes may be relatively undeveloped or receptive fields do not develop to be as small as those of normal adults.- - - - - - - - - - ranking = 738152.1302213keywords = contrast sensitivity, sensitivity, contrast (Clic here for more details about this article) |
7/14. A quasi-static study of accommodation in amblyopia.A method named quasi-static recording of accommodation is introduced. While accommodative stimulus (AS) is slowly changed over a wide range with a constant velocity (0.2 D s-1), accommodative response (AR) is continuously measured. AS and AR, respectively, are recorded on the abscissa and the ordinate of an x-y recorder to produce a "quasi-static" response/stimulus curve. This method was applied to 28 monocular amblyopic and formerly amblyopic subjects, and the findings were compared with those from their sound eyes. The recordings and subsequent analysis show reduced accommodative amplitude and reduced accommodative accuracy in amblyopic eyes, similar to those reported in previous static measurements of accommodation. In about a half of the amblyopic eyes, the recordings reveal that the fluctuations of accommodation are greater as the target becomes closer. Increased microfluctuation associated with a loss of sensitivity to change of contrast is discussed. This phenomenon suggests that increased microfluctuation is directly associated with reduced performance. In three recovered amblyopes, the accommodative functions were considerably reduced, while the other 10 subjects showed improved functions. It is suggested that, in some cases, the abnormal accommodation is the cause of the amblyopia.- - - - - - - - - - ranking = 27.903313017566keywords = sensitivity, contrast (Clic here for more details about this article) |
8/14. Temporal contrast sensitivity in optic neuritis and amblyopia.Temporal contrast sensitivity was measured in patients with optic neuritis and anisometropic amblyopia. In optic neuritis, attenuated sensitivity was detected at all frequency ranges; however, its degree was more severe than that of retinal diseases even when visual acuity was the same. At the convalescent stage, the low-frequency sensitivity was restored first, and high-frequency loss was observed even when the visual acuity was restored to 1.0. Two amblyopic patients showed attenuated sensitivity at high- and intermediate-frequency ranges, and in one case all frequency sensitivity attenuated. Three other patients showed normal sensitivity. By occlusion of the nonamblyopic eye, recovery of sensitivity was observed in one patient, whose visual acuity improved.- - - - - - - - - - ranking = 527412.94146475keywords = contrast sensitivity, sensitivity, contrast (Clic here for more details about this article) |
9/14. Use of various measures of visual acuity and contrast sensitivity in the evaluation of monocular occlusion and active vision training of three adult amblyopes.Three adult amblyopic patients who underwent vision training involving monocular occlusion of the nonamblyopic eye and stimulation of the amblyopic eye using simple fixation exercises and a spinning grating procedure were evaluated using five different types of acuity testing and two methods of contrast sensitivity. It was found that contrast sensitivity and isolated Landolt C acuity improved sooner and to a greater extent than the more complex visual acuity tasks. One patient who improved only on the simpler tasks complained that the enhanced contrast due to training made vision in that eye less acceptable because it was more confusing. The results show that multiple measures of visual acuity and contrast sensitivity are necessary to adequately monitor the effects of occlusion therapy.- - - - - - - - - - ranking = 738153.1302213keywords = contrast sensitivity, sensitivity, contrast (Clic here for more details about this article) |
10/14. Oculomotor biofeedback therapy for exotropia.Twelve exotropes of various types received oculomotor biofeedback therapy at State College of new york (SUNY) University Optometric Center. feedback of a variable pitch tone which reflected changes in ocular vergence reinforced motor control of eye posture. patients were trained to achieve and sustain alignment in a variety of viewing situations. The six intermittent exotropes in the study who did not have amblyopia or prior history of unsuccessful surgical or orthoptic therapy achieved the highest recovery rating after training. The amblyope and those who had orthoptic training learned to voluntarily correct their eye position, although they did not achieve as acute a sensitivity to loss of alignment as did the others. Therapy restored eye control at near in a young constant exotrope whose condition resulted from severe neurological dysfunction. A constant postsurgical exotrope who had no ability for sensory fusion made little progress. Advantages of oculomotor biofeedback therapy are shorter treatment time, elimination of lengthy home training exercises, and enhanced patient motivation.- - - - - - - - - - ranking = 26.903313017566keywords = sensitivity (Clic here for more details about this article) |
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