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Biomedical subjects

C J MacEwen

Publications and source records attributed to C J MacEwen.

At least 19 recordsLinked to original sources
PubMed2002

Factors influencing visual outcome in anisometropic amblyopes.

AIM: To identify which factors influence the final visual acuity in children with anisometropic amblyopia. METHODS: A retrospective analysis of 112 children with anisometropic amblyopia, identified from examining all case notes of children who had failed preschool or school screening. RESULTS: The age at presentation had no effect on the final visual outcome (p=0.804). Both the degree of refractive error and the degree of anisometropia at presentation correlated with final visual acuity (p<0.001 and p=0.001). Those with strabismus had a poorer final outcome. CONCLUSIONS: The age at presentation of a child with anisometropic amblyopia appears to have no significant effect on the final visual acuity. The amount of refractive error and degree of anisometropia at presentation do correlate strongly with final visual acuity. This would suggest, firstly, that children with poorer visual acuity at presentation and higher degrees of anisometropia should be treated more aggressively and that, secondly, children with anisometropic amblyopia should be treated regardless of age.

Age Factors↗
PubMed2002

Rapid mutation detection by the transgenomic wave analyser DHPLC identifies MYOC mutations in patients with ocular hypertension and/or open angle glaucoma.

AIMS: To rapidly screen Scottish patients with a family history of open angle glaucoma (OAG) or ocular hypertension (OHT) for mutations in the myocilin gene (MYOC) and develop a new rapid screening method for MYOC mutation detection. METHODS: All three exons of the MYOC gene were amplified by PCR from genomic DNA and subjected to direct DNA sequencing. Mutation detection methodology was also developed based on denaturing high performance liquid chromatography (DHPLC). A recurrent mutation was investigated by analysis of microsatellite haplotypes at the MYOC gene locus. RESULTS: Mutations were identified by DNA sequencing in four families. MYOC mutation Q368X was found in three kindreds and the fourth family carried the mutation G367R. The Q368X mutation was found to be associated with the same haplotype for markers closely flanking the MYOC gene. The mutations were identified by direct sequencing and were also readily detected by DHPLC analysis of PCR fragments, demonstrating that this is a robust method for MYOC analysis in future. CONCLUSIONS: Mutations in the MYOC gene were identified in patients presenting with highly variable phenotypes from normal through OHT to severe OAG. Haplotype analysis showed that mutation Q368X is likely to be an ancestral mutation in this population. DHPLC analysis is an accurate, rapid and cost effective method for MYOC mutation analysis in large population samples.

Adult↗
PubMed2001

Value of nasal endoscopy and probing in the diagnosis and management of children with congenital epiphora.

BACKGROUND: Congenital nasolacrimal obstruction is usually the result of failure of canalisation of the distal end of the nasolacrimal duct. The most common outcome is spontaneous resolution, but some children do require surgical treatment by probing. Probing is a blind procedure with a recognised failure rate. METHODS: In 52 lacrimal systems of 40 children nasal endoscopy was combined with a "stepwise" systematic probing in an attempt to improve the outcome and reduce the number of repeat procedures. RESULTS: Combined nasal endoscopy and probing improved the understanding of outflow obstruction in young children. The success of the procedure depended upon the level of the obstruction within the outflow system. Formation of a false passage was seen in six cases (15%). The probe was rerouted under direct visualisation in these cases to form a functioning passage. Reasons for failure were identified in those who did not have a successful outcome and only one repeat procedure was required. CONCLUSION: Using nasal endoscopy the area of lacrimal outflow obstruction at the lower end of the nasolacrimal duct can be observed directly and it is possible to guide the progress of probing under direct vision. This gives better information about the nature of the obstruction, minimises the formation of false passages, and allows a wider range of treatment options under a single anaesthetic.

Algorithms↗
PubMed2000

Ocular sports injuries: the current picture.

OBJECTIVES: To determine the recent incidence of eye injury due to sport in Scotland, identify any trend, and establish which sports are responsible for most injury? The type of injury and final visual outcome is also evaluated. METHODS: A prospective observational study of ocular injuries sustained during sport was performed over a one year period. Only patients requiring hospital admission were included. Data were collected on a standardised proforma and entered into a central database. Patients were followed up for at least three months. RESULTS: Of 416 patients admitted because of ocular injury, 52 (12.5%) resulted from playing a sport. Although all racquet sports together accounted for 47.5% of these injuries, football was the single most common sport associated with ocular trauma, being responsible for 32.5% of cases. The most common clinical finding was macroscopic hyphaema occurring in 87.5% of patients. Overall the final visual acuity was 6/6 in 92.5% of patients. CONCLUSIONS: The incidence of eye injury due to sport at 12.5% is lower than previously reported, suggesting a change in the pattern of ocular trauma. Football is the single most common cause of ocular injury from sport in Scotland, but the wearing of protective headgear would be difficult to instigate. The incidence of hyphaema in sport related ocular trauma (87.5%) is almost double that of all ocular injury (47.8%), so the potential for serious visual loss as the result of a sports injury should not be underrated. Ophthalmologists have a role in protecting this young population at risk by actively encouraging the design and use of protective eyewear.

Adolescent↗
PubMed2000

The technique of nasendoscopy in the evaluation of nasolacrimal duct obstruction in children.

Epiphora in infancy is most commonly the result of failure of canalisation of the nasolacrimal duct and most cases resolve spontaneously within 12 months. Lacrimal probing is the standard operative treatment when conservative expectant management fails. While this carries a high success rate, it does not reliably localise the site of obstruction, can create a false passage and may induce traumatic stenosis in the lacrimal passages. Nasendoscopy in conjunction with the lacrimal probing overcomes these problems as the procedure is performed under direct vision. The precise site of opening of the nasolacrimal duct is ascertained, the nature of obstruction established and the risks of false passage creation minimised. We report this technique of endoscopic assessment of lacrimal probing, and the outcome results of twenty such procedures performed on thirteen children.

Child, Preschool↗
PubMed1999

Eye injuries in children: the current picture.

AIMS: To investigate the current causes and outcomes of paediatric ocular trauma. METHODS: A prospective observational study of all children admitted to hospital with ocular trauma in Scotland over a 1 year period. RESULTS: The commonest mechanism of injury was blunt trauma, accounting for 65% of the total. 60% of the patients were admitted with a hyphaema. Injuries necessitating admission occurred most frequently at home (51%). Sporting activities were the commonest cause of injury in the 5-14 age group. There were no injuries caused by road traffic accidents or fireworks. Patients were admitted to hospital for a mean of 4.2 days (range 1-25 days). One (1%) child had an acuity in the "visually impaired" range (6/18-6/60) and one (1%) was "blind" (6/60) in the affected eye. No child was bilaterally blinded by injury and none required blind or partial sight registration. CONCLUSION: This study has shown that the incidence of eye injuries affecting children has fallen. The outcome of ocular trauma has improved significantly, and for the first time paediatric injuries appear to have a better prognosis than injuries affecting adults.

Accidents, Home↗
PubMed1999

Ocular injuries.

Approximately half of all patients who present to an eye casualty department do so because of ocular trauma. In Scotland, the cumulative incidence of ocular trauma requiring admission is 8.14 per 100,000 of the population annually. Over 10% of these people will lose useful vision in the injured eye. This review discusses the mechanisms of ocular trauma, its management and potential outcomes, and the changing trends in the pattern of ocular injuries.

Eye Burns↗
PubMed1998

The natural history of epiphora in childhood.

PURPOSE: To investigate the incidence and aetiology of epiphora in a population of 7-year-old children and determine whether a conservative management policy for congenital nasolacrimal duct obstruction (CNLDO) results in excess lacrimal dysfunction in later childhood. METHODS: A postal questionnaire was sent to the parents of a large cohort of 7-year-old children previously investigated to determine the incidence and natural progression of CNLDO. They were asked about the presence of epiphora, and its relationship to atopic disease and the presence of upper respiratory tract infections (URTI). Information on epiphora had also been gathered from the same cohort at age 3 1/2 years at a routine examination. Data were compared with those for epiphora in infancy in the same cohort. RESULTS: The incidence of epiphora at 3 1/2 years was 5.5%, and 7 years 7.7%. At age 7 years 70% of cases were related to atopic disease or URTI. CNLDO was not significantly related to epiphora in later childhood (p = 0.000032). CONCLUSIONS: A policy of delaying nasolacrimal probing in CNLDO until after the age of 1 year does not result in a detectable excess of lacrimal dysfunction in later childhood, when epiphora is more likely to be related to atopic disease or upper respiratory tract infection.

Age Factors↗
PubMed1996

Congenital nasolacrimal duct obstruction in the second year of life: a multicentre trial of management.

We studied spontaneous resolution of congenital nasolacrimal duct obstruction in the second year of life and compared this with the cure rate after probings undertaken between the ages of 11 and 15 months. Of the 111 eyes of 95 patients studied, 26 eyes were included in a randomised prospective comparison of probing with spontaneous resolution. A further 63 eyes followed a similar management plan to the randomised group and are reported as an observational study. Thirty of the 50 eyes followed up without treatment resolved spontaneously before the age of 2 years, of which 24 resolved before 18 months. The overall cure rate for probing was 74% compared with 60% for spontaneous resolution. At 15 months of age the randomised study confirmed that probing at 12-14 months is an effective intervention compared with spontaneous resolution (p = 0.04). At 24 months of age probing was superior in both randomised and non-randomised studies, but with increased numbers in the spontaneous resolution groups the difference was no longer statistically significant. Up to 18 months of age the frequency of spontaneous resolution makes delay in probing a viable management option to be discussed with the parents. It will also lead to an overestimate of the cure rate in any study of interventional treatment unless controls are included.

Adolescent↗
PubMed1996

Acquired palsy of the oculomotor, trochlear and abducens nerves.

There have been few studies primarily concerned with the relative frequencies, aetiologies and prognoses of ocular motor palsies. Those published have emanated largely from neurological tertiary referral centres rather than primary ophthalmology departments. We have performed a retrospective study of all patients with acquired III, IV or VI cranial nerve palsy who were seen in the orthoptic department at Ninewells Hospital, Dundee, over the 9 year period from 1984 to 1992. A total of 165 cases were identified. VI nerve palsies accounted for the majority of patients (57%), with IV nerve palsies (21%) occurring more frequently than III nerve palsies (17%) and multiple palsies (5%). Thirty-five per cent of cases were of unknown aetiology and 32% of vascular aetiology. The incidence of sinister pathology-neoplasia (2%) and aneurysm (1%)-was surprisingly low. Fifty-seven per cent of all patients made a total recovery (in a median time of 3 months) and 80% made at least a partial recovery. The results are contrasted with those of previous studies and the value of associated symptoms and of further investigation in the assessment of these patients is discussed.

Abducens Nerve↗
PubMed1996

Incidence of cases of ocular trauma admitted to hospital and incidence of blinding outcome.

AIMS: To provide epidemiological data on the current burden of serious eye injuries utilising the hospital eye service, to inform the planning and provision of eye health care, and health and safety strategies for the prevention of ocular injuries. METHODS: A prospective observational study was carried out of all patients with ocular trauma admitted to hospitals in Scotland, under the care of a consultant ophthalmologist, during a 1 year period. The population of Scotland represented the population at risk of injury. Visual outcome (Snellen visual acuity in the injured eye) was measured at the time of final discharge from ophthalmic care and at follow up. RESULTS: All ophthalmic departments in Scotland participated and a total of 415 residents of Scotland were admitted. The 1 year cumulative incidence of ocular trauma necessitating admission to hospital is estimated to be 8.14 per 100 000 population (95% CI 7.38 to 8.97). Some 13.2% (n = 26/197) of patients discharged from follow up had a poor visual outcome with a visual acuity less than 6/12 in the injured eye. Some 10.7% (21/197) patients at this time had a blinding outcome in the injured eye (visual acuity less than 6/60). No patient was registered blind or partially sighted during the study period. The home was the single most frequent place for blinding injuries to occur (52%, n = 11/21), followed by the workplace 24% (n = 5/21). The 1 year cumulative incidence of blinding outcome from serious ocular trauma is estimated to be 0.41 per 100 000 population per year (95% CI 0.26 to 0.64). CONCLUSION: The current burden of serious ocular trauma presenting to the hospital eye service has been quantified from this population based study, and for the first time, a direct estimate of the incidence of the subsequent blinding outcome from these injuries has been provided. Ocular trauma remains an important cause of avoidable and, predominantly, monocular visual morbidity (visual impairment and blindness), with over half of the blinding injuries now occurring in the home. Health education and safety strategies should now consider targeting the home for the prevention of the serious eye injuries in addition to the traditional work, sports, and leisure environments and their related activities.

Adolescent↗
PubMed1996

Epidemiology and implications of ocular trauma admitted to hospital in Scotland.

OBJECTIVES: To describe the current epidemiology of serious ocular trauma which necessitates admission to hospital so that health and safety strategies for the prevention of ocular injuries and their role within the national health strategy, The Health of the Nation, can be better informed. DESIGN: A prospective observational study of all patients with ocular trauma admitted to hospital under the care of a consultant ophthalmologist between 1 November 1991 and 31 October 1992. SETTING: All ophthalmic department in Scotland. SUBJECTS: All patients with ocular trauma admitted to hospital in Scotland. The population of Scotland represented the population at risk of injury. MEASURES AND MAIN RESULTS: Measures included the type and cause of injury, the place where it occurred, and awareness of risk and safety. All ophthalmic departments in Scotland participated and 428 admissions were reported. The home was the most common place for a serious injury to occur (30.2%), followed by the workplace (19.6%) and a sports or leisure facility (15.8%). The home was the single most frequent place of injury for the 0-15 year and 65 year and over age groups. Tools or machinery, either at home (13.9%) or at work (10.3%), were collectively (24.2%) the most frequent cause of injury, followed by assault (21.8%) and sports-related activities (12.5%). The most frequent type of injury was a blunt injury (54.4%). Six per cent (n = 25) of all injuries were bilateral. Only 13.2% of patients were aware of any risk of injury, with 5.6% aware of any risk at home. When applicable, protective eye wear was only available to 48.6% of patients and only 19.4% of these used it. CONCLUSION: Serious ocular trauma frequently occurs at home and the young and the elderly are particularly at risk. This represents a significant change in the epidemiology of serious ocular trauma and has important implications for prevention. Health and safety strategies specifically aimed at preventing eye injury should now include the home as a high risk environment in addition to the work-place and sports/leisure facilities. The target groups for accident prevention in The Health of the Nation strategy include those at risk of serious ocular trauma with potentially sight threatening sequelae. Those involved in implementing the national accident prevention strategy should be aware of this, for in this process it is possible that some serious eye injuries may also be prevented.

Accidents, Home↗
PubMed1994

Long-term results after probing for congenital nasolacrimal duct obstruction.

The long term results of probing for congenital nasolacrimal duct obstruction were reviewed using a parental questionnaire issued to both treated and age-matched control groups. On follow up 4-13 years after probing in childhood 30% of patients still had symptoms of epiphora or discharge. Surprisingly, a similar high symptom rate was found in the controls, such that there was no statistically significant difference in the rate of symptoms between the two groups. Probing had therefore apparently reduced the symptom rate to a level close to normal for the age group concerned. All studies on the incidence of congenital nasolacrimal duct obstruction must be interpreted with reference to the known high rate of spontaneous resolution as a clear trend has been demonstrated towards a lower incidence of symptoms the longer the follow up after probing. This finding would support a policy of delay before further intervention in patients with mild residual symptoms after a technically successful probing.

Child↗
PubMed1994

The value of skull radiography in ophthalmology.

Skull radiographs and special views are still requested in ophthalmology despite the increasing availability of other radiological investigations such as CT, MR imaging and ultrasound. In order to assess the value of skull radiography in ophthalmology we retrospectively studied the use of skull radiographs and CT images in our department. In only one instance was patient management based purely on skull radiograph findings. Over 50% of CT examinations had been preceded by skull films which made no contribution towards management. In some cases the skull films had been misleading by not showing significant pathology and had consequently created considerable delay before diagnosis was reached. It is therefore unjustifiable to use skull films as a method of screening for orbital or intracranial disease and there is little indication for skull radiography in ophthalmology, except in detection of intraocular foreign bodies, facial and orbital fractures and simple sinusitis.

Brain Neoplasms↗