Clifford R. Weir

Are Orthoptic Exercises an Effective Treatment for Convergence and Fusion Deficiencies

Purpose: To investigate whether orthoptic exercises are an effective way to influence the near point of convergence, fusion range and asthenopic symptoms. Methods: Seventy-eight patients met the inclusion criteria of visual acuity 6/9 or better, no history of orthoptic treatment, squint surgery or Meares Irlen syndrome/dyslexia. Information was collected from case records related to diagnosis, near point of convergence, fusion range, prism and cover test measurements and symptoms. Type, duration and frequency of exercises were also recorded. Non-parametric statistics were applied. Results: Patients ranged in age from 5 to 73 years (mean 11.9). Females outnumbered males (46:32). The diagnoses were: decompensating heterophoria (n = 50) or convergence insufficiency (n = 28: primary 27; secondary 1). Exophoria was more common (n = 65), than esophoria (n = 11) or orthophoria (n = 1). Treatments were aimed at improving near point of convergence and/or reduced fusional reserves. The mean treatment period was 8.2months. Reduced near point of convergence normalized following treatment in 47/55 cases, and mean near point of convergence improved from 16.6 to 8.4 cm (p = 0.0001). Fusional reserves normalized in 29/50. Fusional convergence improved significantly for those with exodeviation (p > 0.0006). Asthenopic symptoms improved in 65 patients. A reduction in deviation of 5 pd or more occurred in 20 patients. Conclusions: Orthoptic exercises are an effective means of reducing symptoms in patients with convergence insufficiency and decompensating exophoria, and appear to target the proximal and fusional components of convergence. Their role in esophoria is unclear and needs further study.

Spatial localisation: does extraocular muscle proprioception play a role?

Abstract Our ability to determine the position of targets in surrounding visual space (spatial localisation) is an important aspect of visual function and requires the integration of both visual (ie retinal) and non-visual (ie extraretinal) information. Afferent signals derived from extraocular muscle proprioceptors are though to contribute to this extraretinal information. However, this has proved to be a contentious issue. This article considers the role of extraocular muscle proprioception in spatial localisation in greater detail by discussing the evidence supporting this viewpoint. This is obtained from two main sources: firstly observations in patients in whom the proprioceptive input has been disrupted either pathologically or surgically, and secondly experimental studies in normal subjects in whom the proprioceptive input has been manipulated. The review concludes by emphasising that whilst proprioception is not the predominant source of extraretinal information that helps us determine visual direction, it is still likely to be a contributory factor.

Proprioception in extraocular muscles.

Human extraocular muscles are richly endowed with sensory receptors. The precise role of afferent signals derived from these proprioceptors in ocular motor control and spatial localization has been the subject of considerable debate for more than a century. Laboratory-based and clinical studies have increasingly suggested that proprioceptive signals from extraocular muscles influence visuomotor behavior.

Dorsal Midbrain Syndrome with Loss of Motor Fusion: a Rare Association

Introduction: Dorsal midbrain syndrome (DMS) is characterized by upgaze paralysis, convergence-retraction nystagmus, and eyelid retraction. Impaired downgaze and pupillary light-near dissociation may co-exist, while less common features including exotropia and convergence paralysis have also been described. However, loss of motor fusion is not a well recognised finding in DMS. Purpose: To describe DMS associated with loss of motor fusion. Methods: Retrospective case series. Results: Five patients (age 21-80 years) presented with features of DMS due to severe head injury (n=1), brainstem stroke (n=3) and pinealoma (n=1). All five complained of constant diplopia with horizontal and vertical separation and had an exotropia (range 20Δ to 70Δ), absent convergence and motor fusion. Two underwent strabismus surgery and subsequently had a variable improvement in their motor fusion. The remaining three patients were managed with occlusion. Conclusion: This case series illustrates the complexity of ocular motility findings associated with DMS and highlights the potential difficulties in the management of patients with loss of motor fusion.

Progressive Esotropia and Restricted Extraocular Movements Associated with Low Myopia

We report the case of a 20-year-old female who developed progressive esotropia, which was associated with low myopia and restricted extracular movements.

Olfactory neuroblastoma--an unusual presentation.

Olfactory neuroblastoma, also referred to as esthesioneuroblastoma, is a rare neuroectodermal tumor that originates from the olfactory sensory epithelium in the roof of the nasal fossa (1). The majority of patients present with chronic and progressive symptoms related to the nose or sinuses, such as nasal bleeding and persistent nasal discharge, which may have been present for years before seeking medical advice (2). The most common presenting ocular complaints include chronic periorbital pain, increased lacrimation, and visual disturbance, with diplopia being relatively infrequent at this stage (2). We report a patient with olfactory neuroblastoma who presented atypically with a brief history of diplopia, followed by rapidly progressive proptosis associated with profound uniocular visual loss. CASE REPORT A 23-year-old woman presented to the ophthalmology department with a 3-day history of diplopia. She also reported a 1-month history of nasal stuffiness. She had no past medical or ocular history. Clinical examination revealed visual acuities of 20/20 bilaterally, with no evidence of proptosis. Her pupil reactions were normal, and optic discs were healthy bilaterally. Ocular motility assessment showed a restriction of abduction OS. She was also found to have a nodal mass in the left upper cervical area. A computerized tomography (CT) scan was performed, which showed an extensive lesion affecting the left nasal cavity, both ethmoid sinuses, and sphenoid, left maxillary, and frontal sinuses. There was extension through the skull base into the anterior cranial fossa and laterally into the orbit where there was also evidence of retrobulbar disease. The patient was referred to otolaryngologists for nasal biopsy. Histology showed a malignant round cell tumor infiltrating the respiratory mucosa, with the tumor cells immunoreacting to the neuronal markers neuron-specific enolase (NSE), synaptophysin, and neurofilament. These appearances were believed to be consistent with the diagnosis of olfactory neuroblastoma. During the 2-week period of these investigations, the patient’s vision OS deteriorated rapidly to perception of light only. This deterioration was associated with the development of marked proptosis and further limitation of ocular movements. In addition, she had a left relative afferent pupil defect and bilateral optic disc swelling. In view of this finding, an urgent neurosurgical and neuroophthalmologic opinion was sought. Magnetic resonance imaging (MRI) confirmed a large enhancing soft tissue mass probably originating in the ethmoid and sphenoid sinus regions, extending laterally into the left orbit, and displacing the muscle cone and optic nerve laterally and inferiorly (Fig. 1). The tumor extended into the brain bilaterally, occupying much of the floor of the anterior cranial fossa. There was extensive fluid within the left maxillary antrum thought to be caused by obstruction of the sinus outlet. Chest radiograph, bone marrow aspirate, cerebrospinal fluid (CSF) for cytology, and

Excision of granulation tissue and free conjunctival autograft in the management of necrotizing scleritis.

Purpose: To describe a novel use of conjunctival autograft in the management of surgically induced scleral necrosis that occurred after squint surgery. Methods: Interventional case report. Results: A 22-year-old man underwent bilateral adjustable squint surgery. Two weeks postoperatively, he developed conjunctival retraction and an area of scleral necrosis/melting with 80% thinning. The surrounding conjunctiva was markedly inflamed with raised edges. Screening for autoimmune and vasculitic conditions did not provide any positive results. The conjunctiva surrounding the area of scleral melt was excised and the area covered by a conjunctival autograft resulting in complete healing of the scleral melt within 1 month of surgery. Conclusion: The pathogenesis of surgically induced scleral necrosis not associated with autoimmune conditions may be the result of the products of inflammation and lytic enzymes released by the surrounding conjunctival tissue initiating the scleral melting process. This type of surgically induced scleral necrosis may be successfully managed by excision of the surrounding inflamed conjunctiva, thus removing a potential source of collagenases, and covering the exposed sclera by a conjunctival transplant obviating the need for prolonged high-dose immunosuppression.

Oculomotor nerve paralysis and bilateral facial nerve paralysis as presenting signs of Lyme disease

Lyme disease is a tick-borne illness caused by the spirochete Borrelia burgdorferi . On occasions, patients with Lyme disease present with isolated cranial nerve palsies; multiple palsies have rarely been reported in the literature.We discuss the case of a patient, who presented with a third nerve palsy and bilateral seventh nerve palsies and was subsequently diagnosed as suffering from Lyme disease.To our knowledge, this is the first reported case of Lyme disease presenting with this combination of neurological signs. A 53-year-old male from the Scottish Western Isles presented with a two-day history of double vision. On examination, he was found to have a left third cranial nerve palsy and a left seventh cranial nerve palsy. Five days later, the patient developed a right seventh cranial nerve palsy. Serum and CSF enzymelinked immunosorbent assay (ELISA) and Western blot analysis were both positive for Lyme disease as was CSF polymerase chain reaction (PCR) analysis. Subsequently, the patient gave a history of multiple tick bites over the previous few years. He was commenced on appropriate antibiotic therapy and oral prednisolone. A rapid improvement in his condition was noted. This case demonstrates the importance of considering the diagnosis of Lyme disease in patients with multiple cranial neuropathies, especially those residing in, or with a history of travel to, endemic areas. In addition, it illustrates how early diagnosis, with the institution of appropriate therapy, leads to a prompt improvement in neurological symptoms and signs.

Asymptomatic oculopalatal myoclonus: an unusual case.

Oculopalatal myoclonus is characterised by rhythmic pendular vertical eye movements associated with synchronous contraction of the soft palate.1 It produces intractable oscillopsia,2 and is normally the result of brainstem haemorrhage.2 However, it is does not usually become manifest until several months or even years later, with the longest recorded interval being 49 months.3 We present an unusual case of a patient who sustained a brainstem haemorrhage following trauma. Eight years later he was incidentally noted to …

Botulinum Toxin as a Postoperative Diplopia Test – It Can Also Reduce the Angle of Deviation Prior to Surgery

Abstract Purpose: To investigate how frequently botulinum toxin, when used as a postoperative diplopia test, reduces the angle of deviation prior to subsequent strabismus surgery. Methods: A retrospective study of 39 adult patients with constant concomitant horizontal strabismus who had undergone botulinum toxin injections to assess the risk of postoperative diplopia and then subsequently underwent strabismus surgery. Results: Fourteen out of 39 patients (36%) sustained a reduction of 15 prism diopters or more for near and/or distance when comparing the pre-injection angle of deviation with the preoperative angle of deviation. Conclusion: Approximately one-third of patients receiving botulinum toxin as a postoperative diplopia test maintained a significant reduction in the angle of their deviation prior to undergoing surgery.