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Biomedical subjects

John L Crompton

Publications and source records attributed to John L Crompton.

9 recordsLinked to original sources

Practical clinical approaches to functional visual loss.

Functional visual loss (FVL) refers to subnormal vision or altered visual fields where no underlying pathology of the visual system can be found. It may be seen in a continuum from frank malingering to hysteria. FVL may first present to the general practitioner or physician and the financial burden of evaluation and potential disability-related claims may be substantial. Diagnosis relies on a high index of suspicion and demonstration with a few simple tests that the patient has better vision than alleged. The aim of this review is to provide a practical approach to examination of patients with suspected functional visual loss. An accurate and early diagnosis of FVL starts with a high index of suspicion. Only a few of the tests need to be learned well, performed smoothly and confidently. These clinical tests obviate the need to perform expensive imaging such as magnetic resonance imaging and if used in the correct setting have the potential to reduce further the cost of diagnosis. Management requires an understanding approach and confrontation is seldom helpful. It is important to stress to the patient that FVL has a good prognosis, thereby providing "a way out" and giving the patient the opportunity to recover.

Blindness↗

Polymyalgia rheumatica and giant cell arteritis--An ophthalmic emergency.

BACKGROUND: The occurrence of giant cell arteritis (GCA) in the setting of polymyalgia rheumatica (PMR) is not uncommon. It is imperative to recognise the symptoms and signs of GCA in this setting as the treatment of PMR with low dose corticosteroids will not protect the patient against the blinding consequences of GCA. OBJECTIVE: This article reports the case of a woman with PMR who developed sudden and irreversible vision loss due to GCA. DISCUSSION: It is important to recognise GCA in patients with PMR before the onset of permanent visual disability. A rising erythrocyte sedimentation rate in such patients may herald the onset of GCA. Other risk factors for GCA include age over 50 years, female gender, symptoms of ischaemia, and temporal artery abnormalities on examination. The latter two features warrant urgent ophthalmic or rheumatological review.

Aged↗

Optic nerve calcification after trauma.

Two patients with remote histories of severe optic nerve trauma displayed profound intraorbital optic nerve calcification on imaging studies. The presumed mechanism is optic nerve hemorrhage. Although calcification is known to occur long after brain hemorrhage, no comparable cases have been previously reported.

Adult↗

Craniopharyngioma: a review of long-term visual outcome.

PURPOSE: To assess the clinical presentation and long-term visual outcome in a series of patients with craniopharyn-gioma. METHODS: Retrospective case review. RESULTS: Thirty-six patients were reviewed, comprising 19 female patients and 17 male patients. The age range was 2-77 years with a bimodal distribution of 17 children (mean age 10 years) and 19 adults (mean age 47 years). Blurred vision was the most common visual complaint (23 cases, 64%) and headache the most frequent systemic complaint (19 cases, 53%). The average duration of systemic symptoms was 45 weeks compared to 10 weeks for visual symptoms. Deficits in visual acuity occurred in 13 patients (36%) and showed no significant change from initial presentation to final review. Sixteen patients (44%) had bitemporal hemianopia on presentation and pleomorphism (change from one type of visual field defect to another) occurred in 11 patients. Recurrence of tumour occurred in 15 patients (42%) and was more likely in children (59%) than adults (26%). The mean time period to recurrence was 7 years. The average follow-up period for all cases was 10 years. CONCLUSION: Patients with craniopharyngioma generally present late, and the visual symptoms are often preceded by a long history of systemic symptoms. Children are more likely to present with systemic symptoms than adults. Visual field pleomorphism is a feature of craniopharyngioma and occurred in one-third of the patients. Local recurrence is common. Although magnetic resonance imaging is the recommended means of follow up, regular neuro-ophthalmic review is useful in the early detection of anterior visual pathway compression by recurrent tumour.

Adolescent↗

Self-inflicted blindness and Brown-Séquard syndrome.

A 30-year-old paranoid schizophrenic man suffered a psychotic episode while flying on an airplane, locked himself in the bathroom, detached the temples of his sunglasses, and stabbed them deeply into both medial orbits. He then secured one temple into the door hinge and rammed the back of his neck repeatedly against it. The injuries caused no light perception from optic nerve trauma and a Brown-Séquard hemitransection of the spinal cord.

Adult↗

Traumatic chiasmal syndrome: a series of 19 patients.

PURPOSE: To present a clinical series of 19 patients with traumatic chiasmal syndrome. METHODS: A retrospective study was performed. This included all patients with traumatic chiasmal syndrome seen in the neuro-ophthalmology clinic at the Royal Adelaide Hospital between January 1970 and January 2000. RESULTS: Of the 19 study patients, most were young males involved in motor accidents. Two-thirds had skull fractures. Three-quarters of patients had a final visual acuity of 6/12 or better in at least one eye. Ten patients had a complete optic nerve palsy. The incidence of diabetes insipidus in this study was 37%. The incidence of cranial nerve lesions, hypopituitarism, carotid cavernous fistula, and other deficits were documented. Magnetic resonance imaging and surgical findings were consistent with known mechanisms of chiasmal injury. CONCLUSIONS: Trauma is a rare cause of chiasmal syndrome. Patients with bitemporal field defects should be questioned about prior head injury. In the acute setting, magnetic resonance imaging is the most useful investigation. The treating practitioner should anticipate and treat associated endocrine, ocular motility, and other disorders. Mechanisms of damage to the optic chiasm after trauma include direct tearing, contusion haemorrhage and contusion necrosis. These mechanisms should not be considered mutually exclusive. Unilateral temporal hemianopia with a fellow blind eye is not necessarily the result of chiasmal disruption.

Adolescent↗