Biomedical subjects

C F Steele

Publications and source records attributed to C F Steele.

4 recordsLinked to original sources

PubMed2006

Error classification in community optometric practice - a pilot project.

OBJECTIVE: A pilot study was conducted to undertake a baseline assessment of errors reported in community optometric practice. The feasibility and acceptability of a method for recording staff-reported errors in optometric community practice was investigated. DESIGN: An anonymous self-reporting system was introduced in order to collect information regarding errors/untoward events in community optometric practice. SETTING: UK community optometric practice. MAIN OUTCOME MEASURES: Classification of errors according to a previously published study pertaining to general medical practice in the same geographical area. RESULTS: Thirty-six notebooks were distributed to 10 participating community optometric practices. At the end of the 1 month study period the note books were returned and the 439 entries made were classified into seven categories: optical prescriptions (18.2%), communication (35.5%), administrative (15%), appointments (2.3%), equipment (11.9%), clinical (10.3%) and other (6.9%). CONCLUSION: A previously developed classification of errors in general medical practice was found to be equally applicable to community optometric practice. This study forms the basis of providing an acceptable and practical methodology, which can be applied by Primary Care Trusts (PCTs) when developing their risk management strategy to include optometry.

Appointments and Schedules↗

PubMed1996

Deep corneal stromal opacities associated with long term contact lens wear.

BACKGROUND: One male and three female long term contact lens wearers (mean age 30.3 years; range 26-33) demonstrated unusual deep corneal stromal opacities which were predominantly just anterior to Descemet's membrane. None had any history of corneal dystrophy. These opacities were more common centrally, but were also identified in the corneal periphery. METHODS: All patients underwent routine ophthalmic examinations and, where appropriate, slit-lamp photography and specular microscopy. RESULTS: Mean lens wear in years and hours per day was 14.3 (range 10-17) and 14.3 (range 12-16) respectively. Specular microscopy disclosed cell densities within normal limits (mean 3041.5 cells per mm2) and coefficient of variation of mean cell area; COV = 0.31. Refractive errors ranged from -12.25 D to +6.25 best vision sphere and all four subjects attained at least 6/9 Snellen visual acuity. The subjects' contact lens wearing history included low water content hydroxymethylmethacrylate (HEMA) contact lenses and high water content HEMA contact lenses. Stromal opacity density was observed to diminish over a period of months on cessation of contact lens wear in two cases. CONCLUSION: The possible causes of these rarely reported opacities are discussed.

Adult↗

PubMed1992

Repeatability, reproducibility and intersession variability of the Allergan Humphrey ultrasonic biometer.

We evaluated repeatability and reproducibility of the Allergan Humphrey model 820 ultrasonic biometer. Sixty eyes (30 subjects) free from ophthalmological abnormality were examined on two separate occasions by two experimenters, one experienced and one inexperienced. The 95% confidence limits for repeatability lie between +0.12/-0.13 mm and reproducibility between +0.15/-0.14 mm for AC depth, between +0.11/-0.13 mm and +0.12/-0.16 mm for lens thickness, between +0.17/-0.19 mm and +0.19/-0.18 mm for right axial length and between +0.26/-0.40 mm and +0.22/-0.25 mm for left axial length. The 40% gain used to measure left axial lengths produced poor retinal echospikes, which may account for reduced accuracy compared to the right eyes using 60% gain. Ten subjects (20 eyes) returned for 3 further visits and the variability over 5 sessions was examined using a two-factor ANOVA with repeated measures on one factor. There were no significant experimenter or session effects and no interaction effect. This biometer gives clinically repeatable and reproducible results and is convenient to use.

Anterior Chamber↗

PubMed1992

Effects of different ocular fixation conditions on A-scan ultrasound biometry measurements.

A-scan readings must be taken along the visual axis for accurate axial length measurement. Various fixation targets, which ideally should not induce accommodation, are used to limit eye movements. In this study results using the Humphrey biometer under different fixation conditions were compared to establish the most suitable target. We also investigated corneal applanation effects by comparing optical and ultrasonic measurements of anterior chamber depth. We examined 12 randomly selected normal eyes of 12 young subjects. Three A-scans were recorded for each of five fixation conditions: spotlight at 6 m; Snellen letter at 6 m; solid probe's built-in green fixation target; Snellen letter at 6 m viewed through a -4.00 DS lens; spotlight at 6 m under cycloplegia (the comparison condition). Variability 'within' each fixation condition, estimated by the standard deviation for each subject, was equal throughout the 12 subjects for each fixation condition. Also variation was independent of size of the ocular dimension. The good agreement between the comparison condition and optical anterior chamber depth measurements indicated that the solid probe produced little applanation. Differences 'between' fixation conditions were investigated. It was concluded that a spotlight or letter at 6 m provides a suitable fixation target for biometry. Built-in fixation targets can produce significant errors.

Adult↗