A practice based study of factors influencing intra-ocular pressure.

Many factors are claimed to influence the pressure measured by the tonometer. This study analyses intra-ocular pressure data collected over 10 years on 500 'normal' individuals using a non-contact tonometer. It attempts to analyse which patient variables are relevant and considers the effects of age, sex, laterality and refractive status on intra-ocular pressure, using various statistical techniques. No significant relationship was found for age, sex or refractive error, but axis of astigmatism and laterality were found to be significant factors.