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.