1/31. The Lancaster red-green test before and after occlusion in the evaluation of incomitant strabismus.BACKGROUND: patients with incomitant strabismus can often fuse in a limited area of gaze. Prolongation of neurologically learned fusional vergence tone ("vergence adaptation") in and near this area can result in misleading measurements with standard clinical measures of strabismus. Monocular occlusion for at least 30 minutes eliminates most of the effect of vergence adaptation. The Lancaster red-green test provides an elegant and convenient map of incomitant strabismus. We investigated the efficacy of the Lancaster red-green test before and after monocular occlusion for the investigation of incomitant strabismus. methods: We retrospectively studied the results of the Lancaster red-green test in 6 patients with incomitant vertical strabismus in whom we suspected that vergence adaptation might be distorting the pattern of deviation. The test was performed before and after monocular occlusion for 30 to 60 minutes, and the preocclusion and postocclusion results were compared. RESULTS: In the 6 cases studied, the Lancaster red-green test showed at least a 5-PD increase in the hyperdeviation, after monocular occlusion. The increases were mostly in primary gaze and downgaze, which tended to regularize the pattern of deviation. CONCLUSIONS: The combination of monocular occlusion and the Lancaster red-green test is useful for uncovering the effect of vergence adaptation. Such results may often simplify the planning of surgical correction because the incomitance usually decreases after monocular occlusion, making it less likely that surgery will worsen the alignment in the area previously fused. We recommend that monocular occlusion should be considered when planning surgery or even prism correction for incomitant deviations, especially when the initial Lancaster red-green test shows an unexpected incomitant pattern where there is fusion in 1 direction of gaze but not in others.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
2/31. The role of restricted motility in determining outcomes for vertical strabismus surgery in Graves' ophthalmology.OBJECTIVE: To identify factors predictive of operative success or failure for vertical muscle surgery performed in patients with Graves' ophthalmopathy. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Thirty-one consecutive patients with Graves' ophthalmopathy who demonstrated vertical ocular motor imbalance, with or without simultaneous horizontal muscle imbalance. INTERVENTION: Vertical extraocular muscle surgery performed either in isolation or in association with horizontal muscle surgery. MAIN OUTCOME MEASUREMENTS: Vertical limitations of extraocular muscles were correlated with preoperative hypertropia. Stepwise linear regression was used to determine the significant predictors of postoperative hypertropia in primary gaze. Logistic analysis was used to estimate the probability of surgical failure (>5 diopters) on the basis of preoperative parameters. RESULTS: The amount of preoperative hypertropia was negatively correlated with total restriction of vertical ductions (r = -0.52, P < 0.01). Preoperative hypertropia was positively correlated with asymmetry in muscle restriction between the two eyes (r = 0.67, P < 0.0001). The best predictor of preoperative hypertropia was the difference between restriction of the contralateral opposing recti, namely the right superior rectus, and the left inferior rectus, as well as the right inferior rectus and the left superior rectus (r = 0.74, P < 0.0001). Restriction of the contralateral opposing recti was also the most significant predictor of surgical success (postoperative hypertropia < 5 prism diopters). CONCLUSIONS: Surgery tailored to address restriction of ductions, specifically the difference between contralateral opposing recti, is likely to improve the success of initial surgery beyond that based primarily on the magnitude of the vertical deviation.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
3/31. 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.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
4/31. Surgical management of strabismus after rupture of the inferior rectus muscle.BACKGROUND: rupture of an inferior rectus muscle is an uncommon problem. The resulting absence of infraduction and large hypertropia that result when the muscle cannot be repaired are challenging to manage surgically. methods: We treated 2 patients who had traumatic rupture of the inferior rectus muscle. Both patients underwent an inferior transposition of the inferior halves of the medial and lateral rectus muscles without disinsertion (modified Jensen transposition procedure). RESULTS: Both patients had a persistent small overcorrection in the primary gaze position. One patient was treated with a second strabismus surgery consisting of a recession of the contralateral superior rectus muscle; the other was treated with prism glasses. Both achieved restoration of depression to approximately 40 degrees and single binocular vision in the primary position at distance, near, and in the reading position. CONCLUSION: This modified Jensen transposition procedure of the horizontal rectus muscles appears to be highly effective in the treatment of the hypertropia and infraduction deficit produced by rupture of the inferior rectus muscle. It also appears to be suitable for use in situations when other rectus muscles are absent or unavailable for surgical manipulation.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
5/31. Spontaneous reversal of nystagmus in the dark.AIM: To report five children with horizontal jerk nystagmus in whom eye movement recordings in the dark revealed a spontaneous reversal in the direction of the nystagmus beat. Three patients were blind in one eye and were diagnosed as having a manifest latent nystagmus (MLN), and two patients had strabismus and congenital nystagmus (CN). methods: eye movements were recorded using DC electro-oculography with simultaneous video recording, including infrared recording in total darkness. RESULTS: Four patients had decelerating velocity slow phase jerk nystagmus when recorded under natural lighting conditions; the fifth case had accelerating velocity and linear slow phase jerk nystagmus. Under absolute darkness, nystagmus reversed in direction of beat with a mixture of linear and decelerating velocity slow phase waveforms. One child with unilateral anophthalmos could wilfully reverse the beat direction of his nystagmus by trying to look with his blind eye in the light and dark. CONCLUSIONS: These observations support the theory that LN/MLN beat direction is determined by the "presumed" viewing eye and may be consciously controlled. The spontaneous reversal of beat direction in the dark suggests eye dominance is predetermined. Eye movement recordings identified mixed nystagmus waveforms indicating that CN (accelerating velocity slow phases) and LN/MLN (linear/decelerating velocity slow phases) coexist in these subjects.- - - - - - - - - - ranking = 3keywords = near (Clic here for more details about this article) |
6/31. Ocular neuromyotonia: a case report.Ocular neuromyotonia is a rare motility disorder occurring after tumor irradiation near the skull base or as a consequence of vascular abnormalities. Ocular myasthenia, convergence spasm and a cyclic third nerve palsy must be considered as differential diagnoses. The case of a 32-year-old woman suffering from intermittent diplopia six months after radiation therapy of a recurrent pituary gland adenoma is presented.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
7/31. presbyopia complicating pre-existing strabismus.BACKGROUND: presbyopia may affect pre-existing sensory adaptations or aggravate previously asymptomatic heterophoria. We describe the presentation, underlying problem and management of 11 patients with pre-existing strabismus or heterophoria who presented with new symptoms of double vision attributable to presbyopic change, an association not previously reported. methods: patients with new strabismic symptoms attributable to presbyopia were recruited prospectively over a 1-year period. RESULTS: The 11 patients had had a recent decrease of accommodative amplitude that resulted in blurred vision at near with a breakdown of pre-existing heterophoria (2 patients), alteration of fixation pattern (6 patients), symptomatic alternating fixation (2 patients) or intolerance to correction owing to restrictive strabismus (1 patient). INTERPRETATION: At the onset of presbyopia, symptoms may be varied and subtle. Ophthalmologists and orthoptists should carefully determine the exact nature of the symptoms. Any pre-existing fixation pattern should then be established from the history, old photographs or suppression characteristics. Refractive or surgical management should be aimed at returning the patient to his or her long-standing sensory adaptation. Other important issues, such as incomplete correction of hypermetropia by refractive surgery and problems using bifocals with vertical restrictive strabismus, should be noted.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
8/31. 'V' esotropia and excyclotropia after surgery for bilateral fourth nerve palsy.Six patients had residual diplopia at near in the downgaze position after surgery for bilateral fourth nerve palsy. They all showed a large excyclotropia in the downgaze position that was associated with a "V"-pattern esotropia and could not fuse in the reading position because of the size of the excyclotropia. They were treated with bilateral recessions of the inferior recti, which resulted in an expansion of the single binocular field of vision in downgaze, with an elimination of diplopia in the reading position. None experienced a deterioration in their alignment in the primary position.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
9/31. arnold-chiari malformation.arnold-chiari malformation is a congenital malformation of the skull near the foramen magnum in which the cerebellum and the medulla are caudally displaced. This herniation of the brainstem causes down-beat nystagmus and oscillopsia, the most commonly presenting sign and symptom, respectively. Differential diagnoses for the arnold-chiari malformation include, but are not limited to, demyelinating disease, tumor, and vascular disorders. Symptoms will generally worsen with time and may even be brought on during exercise or valsalva maneuvers. A correct diagnosis can lead to timely surgical intervention which can improve the quality of eye movements. Treatment generally involves the surgical decompression of the surrounding spinal tissue.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
10/31. An unusual case of congenital convergent convergent strabismus fixus.BACKGROUND: Convergent strabismus fixus is classified into congenital and acquired types; however, there are only a few detailed case reports of congenital convergent strabismus fixus. Here, we report a rare case of this condition in which the eyeball was shown by imaging diagnosis to be fixed with a hard cord-like material in the orbit. To our knowledge, there have been no previous reports of congenital convergent strabismus fixus caused by an abnormal cord-like material that was clearly identifiable by imaging. CASE REPORT: The patient was a 16 year old female who visited our department for consultation regarding restoration of normal appearance of her strabismus. She had undergone strabismus surgery at the age of 3 years, but a forced duction test was strongly positive in all directions, and the eyeball was not mobile at the time. The initial surgery performed was a tenotomy of the medial rectus muscle and inferior rectus muscle and resection of the lateral rectus muscle of the right eye. The eye position and eye movement remained unchanged after surgery. At this time, MRI of the orbital region was performed, and an abnormal cord-like material connecting the posterior eyeball to the orbital wall was detected in the orbit. The cord-like material was pulling strongly on the posterior eyeball, congenitally fixing the eye position internally. CONCLUSION: We experienced a rare case in which a hard cord-like material in the orbit congenitally fixed the position of the eyeball. On MRI, the intensity of the cord-like material was clearly different from those of the muscle and nerve tissues. Considering the linearity of the cord-like material and the results of a forced duction test, the cord-like material probably consisted of fairly hard tissue, similar to bone.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
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