Biomedical subjects

K A Oduwaiye

Publications and source records attributed to K A Oduwaiye.

4 recordsLinked to original sources

PubMed2003

The effect of illumination-microscope angle on slit lamp estimate of the anterior chamber depth.

PURPOSE: The anterior chamber depth can be estimated by the slitlamp without additional attachments. The method involves increasing the length of a horizontal slit focused on the cornea until the corneal and iris/lens images appear to just touch. For a slitlamp angle of 60 degrees, multiplying the just-touching slit length (JTSL) by 1.4 gives an estimate of the anterior chamber depth as measured by ultrasonography. The purpose of this study was to determine whether the slitlamp angle affects the accuracy of the procedure. METHODS: The anterior chamber depth of 63 adult male and female subjects aged between 19 and 44 years was measured by A-scan ultrasonography and estimated by the slitlamp technique. The angle between the illumination and microscope systems was varied at 10 degrees intervals from 30 degrees to 70 degrees. RESULTS: The average ultrasonographic anterior chamber depth for all subjects was 3.23 +/- 0.38 mm. The average JTSL was as follows: 30 degrees = 1.5 mm, 40 degrees = 1.7 mm, 50 degrees = 2.1 mm, 60 degrees = 2.3 mm, and 70 degrees = 2.5 mm. The conversion ratio between the ultrasonographic anterior chamber depth and the average JTSL was as follows: 30 degrees = 2.2, 40 degrees = 1.9, 50 degrees = 1.5, 60 degrees = 1.4, and 70 degrees = 1.3. The ultrasonic anterior chamber depth was best estimated at 60 degrees. The 95% limits of agreement between the estimated and measured anterior chamber depth were as follows: 30 degrees = -0.76 to +0.84 mm, 40 degrees = -0.75 to +0.63 mm, 50 degrees = -0.36 to +0.46 mm, 60 degrees = -0.26 to +0.28 mm, and 70 degrees = -0.45 to +0.41 mm. CONCLUSIONS: These results experimentally confirm Smith's suggestion that the optimum slitlamp angle at which to accurately estimate the anterior chamber depth is 60 degrees. At this angle, estimates of the anterior chamber depth are minimally deviated from the gold standard (A-scan ultrasonography). At a slitlamp angle of 60 degrees, the JTSL can be converted to an estimate of the ultrasonic anterior chamber depth by multiplying it by 1.40.

Adult↗

PubMed2000

Intra-observer repeatability and inter-observer agreement of the Smith method of measuring the anterior chamber depth.

The Smith (1979) method provides a means of estimating the anterior chamber depth without additional attachments to the slit lamp [Smith, R. J. H. (1979). A new method of estimating the depth of the anterior chamber. Br. J. Ophthalmol. 63, 215-220]. In this study, the 95% intra-observer limits of repeatability and the 95% inter-observer limits of agreement of this method have been determined. The intra-observer limits of repeatability were determined by plotting the difference vs the mean of the estimated anterior chamber depth obtained in two different sessions by each of two examiners, while the inter-observer limits of agreement are represented by a plot of the difference vs the mean estimated anterior chamber depth between the two examiners. For one examiner, the 95% intra-observer limits of repeatability was -0.36 to 0.58 mm, while for the other examiner the 95% intra-observer limits of repeatability was -0.25 to 0.37 mm. The 95% inter-observer limits of agreement were -0.31 to 0.23 mm and -0.41 to 0.25 mm for the first and second sessions respectively. The intra-observer limits of repeatability are comparable with those reported for A-scan ultrasonographic measures of the anterior chamber depth. These results imply that the Smith method can be used with a high degree of repeatability and agreement to clinically monitor longitudinal changes in anterior chamber depth.

Adult↗

PubMed1992

The Cardiff Test: a new visual acuity test for toddlers and children with intellectual impairment. A preliminary report.

We have developed a new test for acuity measurements specifically designed for the hard to test group of toddlers and children with intellectual impairment. The test uses vanishing optotypes and the preferential looking technique. Comparison studies with established acuity tests, Snellen, Cambridge and Teller cards show that the test provides a realistic acuity measure. It is highly successful for toddlers and children with intellectual impairment and quicker to administer for the toddler age group.

Adolescent↗

PubMed1992

New acuity test for toddlers.

Preferential looking is the technique of choice for measuring visual acuity in infants and young children. Most workers agree that the toddler age group, 1 to 3 years, is the most difficult to test. This is because of their short attention span and restlessness, but mostly because they find the grating target used in the test, frankly boring. The concept of the vanishing optotype chart offers alternative test targets, while utilizing the technique of preferential looking. We have designed a test which comprises a familiar shape (house, car etc.) on the upper or lower part of a neutral grey card. The shape is computer generated, and designed to fade completely when beyond the resolution limit. Acuity is determined by the width of the white lines making up the shape. As with conventional preferential looking, the observer notes the child's eye movements to determine the position of the target shape. Although picture naming is not required, the shapes help to maintain the child's interest in the test. The test is quick, and is successful with the toddler age group and older patients with intellectual impairment.

Child, Preschool↗