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Fifteen cases of monocular diplopia or polyopia in U.S. Air Force flying personnel appeared due to optical aberrations of physiologic variations within the refracting elements of the eye. In most cases, this symptom was compatible with excellent visual acuity and was not regarded as a detriment to safe and accurate visual performance.
The case report presented here describes a situation in which diplopia resulted as an effect secondary to maxillary infiltration anesthesia. Prior cases and theories regarding the mechanisms involved are reviewed, and a new theory explaining this phenomenon is proposed. The autonomic nervous system is presented as the logical basis for the untoward systems, rather than simple circulation of anesthetic solution in the vascular tree.
A case is presented in which a 49-year-old man has had progressive proptosis and diplopia over a six-week period without pain, loss of vision, or history of other ophthalmic or systemic disorders. The diagnostic work-up leading to a diagnosis of thyroid ophthalmopathy in such cases is discussed. Although the orbitopathy usually has a self-limited course, major complications are corneal exposure and optic neuropathy. The several modes of therapy available to treat these complications (systemic corticosteroids, orbital radiation, and orbital decompression are described.
An accurate clinical evaluation of vertical diplopia is predicated upon meticulous history-taking, observations regarding the presence and pattern of an anomalous head position, and the analysis of several subjective and objective tests of extraocular muscle function. To reach a final diagnosis with minimum risk and expense to the patient the examiner must be familiar with the neuroanatomy of the supranuclear and infranuclear pathways which control the actions of the vertically-acting extraocular muscles, the clinical methods and pitfalls of a number of clinical techniques which are used to identify an underacting extraocular muscle, and the hallmark characteristics of a supranuclear, infranuclear and restrictive ophthalmopathy.
Detection and diplopia thresholds for vertical disparities are found to decrease when the presentation time of the stimulus with disparity is increased between 20 msec and 2 sec. This result supports the following notions previously put forward in literature; (a) the human visual system embodies detection processes which reveal vertical disparities; there is no sensory fusion mechanism in this system that gradually conceals vertical disparities: (b) the detection of vertical disparity in tachistoscopically presented stimuli is not based upon the initial appearance of the stimulus with disparity.
Several studies have reported that the magnitude of chromostereopsis changes as the pupil size changes. Einthoven's theory, that chromostereopsis is determined by interocular differences of monocular transverse chromatic aberration, can not easily explain this change. Therefore, several alternative hypotheses have been introduced, most notably by Vos [(1960) Vision Research, 6, 105-107], who argues that shifts in chromostereopsis with pupil size are due to decentration of the peak of the Stiles-Crawford effect (SCE) with respect to the pupil. We tested this hypothesis by measuring chromostereopsis under both scotopic (no SCE) and photopic conditions with centered and decentered artificial pupils. The results show that the SCE plays an important role in the effect of pupil size on chromostereopsis. Similar changes were also measured in monocular chromatic diplopia which supports the hypothesis that the effect of pupil size on chromostereopsis is due to monocular mechanisms.
A 14-year-old boy had a severe blow to the right orbit, which caused a blow-out fracture of the orbital floor and damage to the inferior rectus with resultant diplopia. After two operations his vision is still not perfect.
We report about a boy with the symptoms of Gradenigo's syndrome (abducens nerve palsy, acute otitis media, unilateral headache). The MR imaging showed a sinus vein thrombosis instead of the expected petroapicitis. After 2 weeks of conservative therapy with antibiotics and anticoagulation, without any clinical effort the boy underwent a mastoidectomy. Headache and otitis media recovered quickly but the diplopia still remained after 25 months.
A 36-year-old female patient developed diplopia and an ipsilateral lateral rectus paresis following local anesthetic administration to remove a left maxillary second molar. Complete resolution occurred within 3 hours. The clinical examination and management plan are reviewed for this uncommon occurrence. The relevant anatomical pathways are discussed and illustrated with photographs.
After having a radial keratotomy, a physician developed binocular diplopia. The differential diagnosis and management of symptoms by appropriate spectacles is described.
Normal binocular vision requires that all involved structures; ocular, muscular, and neuronal; be intact and all of the intricate processes controlling conjugate gaze and cortical fusion be functioning. Diplopia may represent pathology at any point in this complex system. A careful history and physical examination may reveal a relatively benign etiology or may compel rapid diagnostic studies to evaluate the patient for neurological catastrophe.
We present a case of persisting diplopia after bilateral laser in situ keratomileusis in a patient with high anisometropia and amblyopia. Treatment of this complication by ocular-muscle surgery was not possible because of missing fusion. We suggest that, especially in cases with anisometropia, a complete examination of binocularity be performed before refractive surgery.
In a university ophthalmology department, a cluster of postoperative diplopia and ptosis cases occurred in the initial 3 months after hyaluronidase (Wydase) became unavailable for use with injection anesthesia. These cases suggest that hyaluronidase, when used with injection anesthesia, may protect extraocular muscles and nerves from the toxic effects of local anesthetic agents. The spreading action of hyaluronidase facilitates uniform diffusion of anesthetic agents. This prevents elevated extracellular tissue pressure, a cause of ischemic damage to extraocular muscles or nerves. Hyaluronidase may also prevent focal accumulations and concentrations of local anesthetic agents, which at high enough levels may cause myotoxic or neurotoxic damage, fibrosis, and contracture of extraocular muscles or nerves.
BACKGROUND: Abnormal pressure from the upper eye lid can cause a kink in the corneal vault along the lid margin. Depending on whether the lower or upper part of the lid exerts the higher pressure, the upper segment of the cornea acquires a prismatic effect which is base up or down, respectively. This causes a ghost image below or above the main image. In patients whose upper eye lid occasionally reaches down such that the kink traverses the pupillary area, the ghost image appears whenever they raise their lid above its usual position. The purpose of the present paper is to describe a retinoscopic phenomenon that allows an easy diagnosis of this condition. PATIENTS AND METHODS: About 20 patients with a ghost image below or above the main image were examined with a Placido disc, with a photokeratometer, and with a streak retinoscope. RESULTS: Photokeratometry revealed a slight deformation of the ring reflexes along a horizontal line at the border of the upper third of the cornea. This deformation was obvious only in a minority of the patients. The retinoscopic findings were more characteristic. With the streak horizontal, two or three light bands separated by dark intervals were seen in a "with movement", suggesting the impression of a Venetian blind being lowered or raised behind the pupil. Because of this impression, the author suggests the term ""Venetian blind phenomenon." DISCUSSION AND CONCLUSION: Monocular diplopia caused by abnormal lid pressure can be easily diagnosed by the "Venetian blind phenomenon". The optics can be explained as follows. Both the beams entering into, and emerging out of the patient's eye are being split by the prismatic effect of the upper cornea. Principally, this should result in four images; since, however, two of them overlay each other, only three separate images remain. In cases where the upper cornea is deflected backwards, resulting in a prismatic effect base down, the examiner can see all three images. In cases where the upper cornea is deflected forwards, resulting in a prismatic effect base up, the beams emerging from the patient's eye diverge, and the uppermost beam falls upon the examiner above his pupil, so that he can see only two of the three images.
Neurofibromatosis type II (NF II) is rare and most commonly presents with hearing loss, tinnitus and/or vestibular disturbance in the third decade of life. The authors describe a rare case presenting with NF II with vertical diplopia due to IV(th) nerve palsy. The patient was otherwise asymptomatic despite multiple extensive lesions on MRI.
We report the cases of five patients who have experienced postoperative diplopia after cataract surgery under peribulbar anaesthesia and in whom orbital Magnetic Resonance Imaging was performed immediately after the diagnosis. In four patients, the imaging study showed a T2 hyper-intensity signal and swelling of one extraocular muscle that was interpreted as oedema. Therefore, these cases were most probably a result of an accidental i.m. injection of local anaesthetics. In the other patient, the imaging study revealed no abnormality.
Patients with intermittent exotropia (strabismus) can either fixate normally or allow one eye to deviate outward by as much as 60 degrees. Two such patients (D.N. and K.C.) were studied and it was found that during eye deviation, binocular correspondence is maintained by completely 'remapping' egocentric space for the deviating eye alone using extraretinal signals from that eye. Also, by using foveal afterimages we showed that binocular rivalry occurs at a site earlier than this egocentric remapping, probably in area 17 itself. And finally, consistent with the neural remapping hypothesis, patient K.C. also experienced monocular diplopia; objects appeared double when viewed with the deviating eye.
Over the past 5 years, Vicryl mesh (polyglactin-910) implants were used successfully to reconstruct the orbital floor in 28 patients with significant preoperative diplopia due to orbital floor fractures. The layered mesh is available in 26.5 x 24 cm sheets, each of which is folded onto itself into 24 layers and packaged; 24 layers are approximately 4 mm thick. Appropriately sized implants varying in thickness from 6 to 56 layers were used to cover and fill the orbital floor defect. Absorbable Vicryl mesh is well-tolerated by orbital tissues; since it is soft and pliable, it is unlikely to compress orbital structures such as the optic nerve, lacrimal sac, or extraocular muscles. A second surgical site necessary for autogenous implants is avoided. The Vicryl mesh implant is technically easy to insert and does not require fixation in the orbit. Because Vicryl mesh is absorbable, the risks associated with permanent alloplastic implants are reduced. Similarly, there is no potential spread of communicable disease with homologous tissue implants. Follow-up ranged from 1 month to 2 years (median, 13 months). None of the patients had late complications. The only complication was transient, low-grade eyelid inflammation in four patients.