1/15. Accommodative and vergence findings in ocular myasthenia: a case analysis. myasthenia gravis (MG) is a neuromuscular disorder that affects skeletal muscles, in particular, the extraocular muscles. Response variability is a hallmark sign. Detailed findings are described in a patient with MG in which the presenting sign was accommodative insufficiency. Objective accommodative findings were recorded 3 years before the onset of myasthenia, soon after the initial diagnosis was made, and then after the treatment commenced with pyridostigmine. In addition, clinical measurements were obtained periodically at different times of the day for various binocular motor functions, including near point of convergence, phoria, fusional and accommodative amplitudes, and relative accommodation. The disease adversely affected all accommodative and vergence findings, with fatigue being the primary disturbance. The therapeutic administration of pyridostigmine improved static measurements of accommodation and vergence and reduced asthenopia. The objective dynamic measurements of accommodation, vergence, and versions were less affected. These findings provide a clear demonstration that both intrinsic and extrinsic ocular muscles may be affected in the prepresbyopic myasthenic patient. ( info) |
2/15. Fatigable ptosis and pseudoretraction caused by myasthenia gravis. The case is presented of a 59-year-old woman with myasthenia gravis. Fatigable ptosis and pseudoretraction caused by the myasthenia gravis are illustrated in a series of clinical photographs. ( info) |
3/15. Orbital imaging demonstrates occult blow out fracture in complex strabismus. BACKGROUND: While strabismologists are familiar with diagnostic evaluation of suspected blow out fractures, unsuspected blow out fractures may further complicate difficult cases of strabismus not clinically supposed to be related to orbital trauma. methods: According to a prospective protocol, we studied five adults presenting with diplopia, and one with convergence-related asthenopia. No patient recalled or had any clinical suspicion of orbital fracture at initial evaluation. Surface coil magnetic resonance imaging of the orbits was performed at 312 microm resolution, slice thickness 2 mm. Quasicoronal images in central gaze were supplemented with eccentric gaze positions, and sagittal and axial images as indicated. RESULTS: Five patients had incomitant hypertropia, and one had abducens paralysis. magnetic resonance imaging disclosed previously unsuspected blow out fractures in all six patients. Three patients had medial wall fracture, one bilaterally. Two patients had inferior wall fractures, and one inferomedial. Although only one patient had an extraocular muscle displaced into a sinus, all had evidence of orbital connective tissue distortion in the region of the rectus extraocular muscle pulleys influencing muscle paths. These effects altered the presentations of more familiar pathologies such as superior oblique palsy. After learning of the MRI findings, most patients then recalled orbital trauma from as early as childhood. CONCLUSION: Unsuspected blow out fractures occur and may confound the usual findings in complex strabismus. High-resolution orbital imaging can detect blow out fractures and clarify the pathophysiology, enabling appropriate surgical management. ( info) |
| We present a hyperopic patient with a decentered line of sight in whom the residual refractive error after toric phakic intraocular lens (TP IOL) implantation was improved by displacement and individualized treatment. A 35-year-old woman presented with asthenopic complaints 2 months after bilateral TP IOL implantation and IOL rotation 4 weeks later. Examination revealed the line of sight to be nasally and inferiorly decentered in relation to the center of the pupil. A more nasal reenclavation of the TP IOL decreased the coma, and the uncorrected visual acuity was 20/20. We conclude that line of sight should be measured before TP IOL implantation, especially in hyperopic eyes. ( info) |
5/15. A tint to reduce eye-strain from fluorescent lighting? Preliminary observations. The rapid modulation of light from fluorescent lamps is responsible for eye-strain and headaches. The modulation is greater at certain wavelengths than at others, and it can therefore be reduced by wearing tinted spectacles. A tint was designed: (1) to minimize the luminous pulsation of light from conventional halophosphate fluorescent lamps; (2) to avoid as much as possible any concomitant increase in the pulsation from triphosphor lamps; (3) to interfere with colour perception as little as possible; and (4) to have a cosmetically acceptable colour appearance. The four design criteria conflict. A compromise design is described, together with case histories of patients who appear to have benefited from the use of the tint. ( info) |
6/15. Duane's retraction syndrome and the relief of secondary torticollis and near point asthenopia with prism. A young woman presented with complaints of reading difficulty. An examination revealed that the patient had Duane's Retraction syndrome--Type III, which affected her right eye. We prescribed yoked prism base left and additional base-in prism for the right eye in a successful attempt to alleviate the patient's symptoms. ( info) |
7/15. review of computerized orthoptics with specific regard to convergence insufficiency. Traditional vision training or orthoptics has used line or contour targets to eliminate suppression and improve vergence performance. Manipulation of these stimuli is slow and arduous. Line stimuli require an experienced doctor/technician to interpret responses. Recently, automated vision training using microprocessor anaglyph stimuli, i.e., random dot stereograms (RDS), has been used in an operant conditioning paradigm. This technique has improved motivation of the patient, improved reliability, and provided standardization of therapy. In addition, the utilization of RDS associated with operant conditioning has been shown to improve vergence performance and to reduce asthenopia in the convergence insufficiency patient. ( info) |
8/15. Accommodation deficiency in healthy young individuals. Ten patients, ages 10 to 19, with accommodation insufficiency are reported. All patients were in good health and asymptomatic, except for asthenopia during near visual activities. Each patient's amplitude of accommodation was measured and found to be considerably below the minimal normal for their respective ages (an average of 6 diopters). Only three patients had associated convergence insufficiency. No etiology for the diminished accommodation was suggested by history or could be identified by careful examination. All patients were successfully managed optically with bifocals or reading glasses, although three required the addition of base-in prisms for the near exodeviation. Near vision testing and determination of the near point of accommodation should be part of the pediatric ophthalmologic examination in all patients with complaints referable to their reading and visual performance at near. ( info) |
9/15. Restricted lees screen fields in patients with asthenopia, with and without psychogenic disorders. Lees screen restrictions of non-specific origin, including apparent restrictions of the SR, IR, and LR muscles, were reported last year by Labow et al. In this complementary study, the authors examined eight apparently healthy subjects who had no history of ocular or psychiatric problems, eight psychiatric patients, and eight who had had a CNS disorder or had suffered cerebral trauma. Comparison of the Lees screen findings, visual fields, and accommodative defects of these patients revealed significant restriction of the Lees screen fields in only those patients who had symptoms of asthenopia (including all in the third group). Thus, such restriction does not depend on emotional state. ( info) |
10/15. Vertical prisms. Why avoid them? Vertical prisms are useful in the permanent or temporary alleviation of asthenopic symptoms arising from a vertical misalignment of the visual axes. A wide variety of both comitant and noncomitant hyperdeviations may be candidates for vertical prism use. Vertical prism strength is seldom difficult to compute and when properly employed, vertical prisms do not lead to unsightly spectacles. ( info) |