Analysis of the diurnal intraocular pressure profile pre and post trabeculectomy using 24-hour monitoring of intraocular pressure.

PURPOSE: To compare the diurnal intraocular pressure (IOP) profile pre and post trabeculectomy with a control group of medically controlled patients. We compared the change in mean, peak, and diurnal IOP fluctuation. METHODS: This was an observational study of patients at the Bristol Eye Hospital, United Kingdom. All patients underwent initial and subsequent phasing, with surgery between for cases. The unpaired Student t test compared the changes (initial-subsequent) in mean, peak, and fluctuation between cases and controls. RESULTS: Fifteen eyes underwent trabeculectomy surgery while the control group contained 17 eyes controlled on topical medical treatment. There was a statistically significant reduction in both mean IOP of 3.7 mmHg (p=0.002) and peak IOP of 4.4 mmHg (p=0.025) in the surgical group compared to the medical group. There was no statistically significant change in the IOP fluctuation between the 2 study groups (p=0.296). CONCLUSIONS: There is a significant reduction in mean IOP and peak IOP following trabeculectomy. We showed no statistically significant change in the diurnal fluctuation of IOP following trabeculectomy.