M.Phil. / Keratometric readings on three subjects were taken both during pregnancy and postpartum. One subject was visually non-compensated and did not require refractive correction, one was a contact lens wearer and one had undergone radial keratotomy. Twenty readings were taken by means of an automatic keratometer on each eye, morning and afternoon, every fortnight. The recent matrix method of optometric statistical analysis was employed and the results graphically compared and analysed. Findings indicate diurnal variations including variation in corneal curvature and variance through the course of normal pregnancy. Most evident was an increase in keratometric variation in all three subjects at the time of birth and a substantial decrease in corneal refractive power in the subject who had before undergone radial keratotomy. This result may have far-reaching implications on the long term prognosis of refractive surgery especially for females of child bearing age. Outliers representing transient increases in curvature were most common in the vertical meridian (indicating possible lid interaction), while the presence of bimodal distributions suggests a sensitivity of the automatic keratometer to changes in head posture.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:3234 |
| Date | 27 August 2012 |
| Creators | Klaassen, Donald Gregory Istvan |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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