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C J MacEwen

Publications and source records attributed to C J MacEwen.

At least 19 recordsLinked to original sources
PubMed2006

The variable expression of keratoconus within monozygotic twins: dundee University Scottish Keratoconus Study (DUSKS).

INTRODUCTION: As part of a longitudinal observational prospective study (Dundee University Scottish Keratoconus Study, DUSKS) a caucasian female subject was identified with keratoconus affecting both corneas. Of interest was that the subject's mother was a monozygotic twin, however, the mother was reportedly unaffected by keratoconus, although her sister (the subject's aunt) had been diagnosed with keratoconus. METHOD: Computer video-keratoscopy (CVK) was undertaken was on this family to clarify this apparent discordance. RESULTS: CVK demonstrated the variable expression of the keratoconic phenotype, by identifying evidence of subclinical keratoconus in the 'unaffected' twin. CONCLUSION: So far only one set of monozygotic twins with keratoconus have been reported within the UK, this paper reports a second. Since CVK has been available the majority agree on concordance of keratoconus expression but not all, including this study. If monozygotic twin studies demonstrate heterogeneity of keratoconus this may at least explain the contradictory data that exists within the literature and why the inheritance pattern of keratoconus is still unclear in 2005.

Corneal Topography↗
PubMed2006

Quantitative analysis of corneal microstructure in keratoconus utilising in vivo confocal microscopy.

PURPOSE: To establish and quantify the in vivo confocal microscopic features of moderate to advanced keratoconus. METHODS: Nineteen keratoconus subjects were catergorised using Orbscan-derived corneal apex power and pachymetry as exhibiting moderate (n=7) and advanced (n=12) keratoconus. Control subjects included 23 noncontact lens wearers (Group A) and 15 contact lens wearers (Group B). All subjects underwent Confoscan slit scanning in vivo confocal microscopy. RESULTS: Compared with Group A (4912+/-434 cells/mm(2)), basal epithelial density was significantly lower in both moderate (4592+/-414 cells/mm(2), P<0.05) and advanced keratoconus (4530+/-596 cells/mm(2), P=0.01). In comparison to Group A (761+/-118 cells/mm(2)), anterior stroma keratocyte density was significantly greater in both moderate keratoconus (883+/-111 cells/mm(2), P=0.001) and advanced keratoconus (952+/-122 cells/mm(2), P<0.001). Compared to Group A (504+/-80 cells/mm(2)) posterior stroma keratocyte density was also significantly greater in advanced keratoconus (599+/-97 cells/mm(2), P<0.001) and posterior stromal keratocyte density appeared to increase with increasing severity of keratoconus (P<0.05). However, comparing control Groups A and B, contact lens wear per se, was associated with significantly reduced (P=0.000) keratocyte density in the anterior stroma (609+/-66 cells/mm(2)) and demonstrated a trend (P=0.056) in the posterior stroma (470+/-63 cells/mm(2)). Keratoconic corneas (429+/-72 microm) were significantly thinner than control Groups A (508+/-77 mm) and B (495+/-80 microm). The presence of keratoconus did not affect the endothelial cell density (P=0.54). CONCLUSION: In vivo confocal microscopy can provide insight into the microstructural changes that occur in keratoconus.

Adult↗
PubMed2006

Flexible trainees in Scotland.

INTRODUCTION: Demand for flexible training is increasing. The contribution of such trainees to the trained medical workforce is not clear. METHODS: All full time and flexible trainees in Scotland were 'tracked' at the completion of training. RESULTS: 80% of flexible trainees took up a consultant post of which 93% were in Scotland. 82% of full time trainees took up a consultant post of which 80% were in Scotland. DISCUSSION: Flexible trainees become consultants at the same rate as their full time counterparts. They are commonly geographically tied and are therefore more likely to remain in Scotland and contribute to retention of doctors in this country.

Attitude of Health Personnel↗
PubMed2005

Atypical unilateral superior keratoconus in young males.

Generally in keratoconus the corneal apex displacement is inferior in position and bilateral in expression. Two young male keratoconic subjects enrolled in the Dundee University Scottish Keratoconus Study (DUSKS) demonstrated with corneal topography the presence of unilateral superior keratoconus. Successful visual rehabilitation of a superior cone with contact lens fitting represents a particular challenge to the contact lens practitioner. This report discusses the management of two such cases.

Adolescent↗
PubMed2005

Visual impairment in elderly patients with hip fracture: causes and associations.

AIMS: To evaluate the current visual status and ophthalmic history of a sample of elderly patients with fractured neck of femur and to study the relationship between visual status and demographic factors. METHODS: A four-centre study of all patients admitted to hospital with fractured neck of femur. The setting was two district (Ayr, Dunfermline) and two teaching (Glasgow, Dundee) hospitals in Scotland. The study examined 537 patients aged 65 years and over admitted with acute fractured neck of femur to hospital. RESULTS: Bilateral visual impairment (binocular visual acuity worse than 6/12) was found in 239 of 518 patients (46%). Of this group, the principal causes for visual deficit were untreated cataract (49%), macular degeneration (21%), uncorrected refractive error (17%), and glaucoma (3%). The visually impaired group were more likely to have symptomatic visual complaints (58 vs 26%), however, were less likely to be under optometric care (71 vs 85%). A higher proportion of the group with visual impairment lived in areas of social deprivation (40 vs 26%). CONCLUSIONS: Patients with fractured neck of femur represent a frail elderly group that have poorer vision than that documented in any other elderly population. The visual defect was potentially remediable in the majority of cases but this group of individuals are not generally in touch with the ophthalmic services. Social deprivation appears to be associated with this groups' inability to access ophthalmic care.

Aged↗
PubMed2004

Why is squint surgery in children in decline?

BACKGROUND: /aims: Paediatric squint surgery appears to be declining. This study aims to identify if this is so and, if so, why. METHODS: Retrospective review of (1) episodes of paediatric squint surgery in Scotland and Tayside, 1986-2001, (2) presentations to orthoptists (Tayside) during 1986 and 1996. RESULTS: (1) Overall, a 58% fall in surgery in Scotland and 59% in Tayside. For esotropia, a reduction of 63% (Scotland) and 69% (Tayside). (2) Incidence of esotropia was unchanged; surgery for these esotropes fell (from 55% to 30%) (p = 0.013). More children received maximum hypermetropic correction (p <0.001) and more developed stereopsis (p = 0.003). CONCLUSION: Childhood strabismus surgery, particularly for esotropia, is declining. The maximum hypermetropic correction has improved the functional results.

Adolescent↗
PubMed2004

Effect of mydriasis and different field strategies on digital image screening of diabetic eye disease.

AIMS: To assess the effects of (1) mydriasis and (2) single versus three field photography on screening for diabetic eye disease using digital photography METHOD: Slit lamp examination findings were compared to digital fundal photographs for the detection of any retinopathy and for referable retinopathy in 398 patients (794 eyes). A Topcon TRC-NW6S digital non-mydriatic fundus camera was used. Three photographic strategies were used: undilated single field, dilated single field, and dilated multiple fields. The photographs were presented in random order to one of two retinal screeners. For the single field photographs the screeners were masked to the use of mydriatics. In 13% of fundal photographs, grading was performed by both, rather than just one grader. RESULTS: Mydriasis reduced the proportion of ungradable photographs from 26% to 5% (p<0.001). Neither mydriasis nor three field photography improved the sensitivity or specificity for the detection of any retinopathy or of referable retinopathy when compared with undilated single field photography. The sensitivity and specificity for detecting referable retinopathy using undilated single field photography was 77% (95% CI 71 to 84) and 95 % (95% CI 93 to 97) respectively. Using dilated single field photography the figures were 81% (95% CI 76 to 87) and 92% (95% CI 90 to 94) respectively. Using dilated three field photography the figures were 83% (95% CI 78 to 88) and 93% (95% CI 91 to 96) respectively. Intergrader reliability for the detection of referable retinopathy in gradable photographs was excellent (Kappa values 0.86-1.00). CONCLUSIONS: Mydriasis reduces the technical failure rate. Mydriasis and the three field photography as used in this study do not increase the sensitivity or specificity of detecting diabetic retinopathy.

Adolescent↗
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↗