Large diurnal variation of intraocular pressure despite maximal medical treatment in juvenile open angle glaucoma

PURPOSE: To report the clinical significance of large fluctuations in intraocular pressure (IOP) and the effect of trabeculectomy on diurnal IOP variations in 2 cases of maximally medically treated juvenile open angle glaucoma (JOAG). PATIENTS AND METHODS: A 24-hour IOP monitoring was performed before and after trabeculectomy on both eyes of 2 JOAG patients-one with transiently blurred vision early in the morning, the other with progression of visual field defect despite apparently well-controlled IOP. The patients' optic discs were scanned with Heidelberg retina tomograph (HRT) during peak and trough IOPs before trabeculectomy. RESULTS: Preoperatively, diurnal IOP varied widely up to 20/19 (OD/OS) mm Hg in case 1 and up to 16/22 (OD/OS) mm Hg in case 2, even though both patients were using 4 different types of antiglaucoma eye drops. Peak IOP was associated with temporary blurring of vision and mild corneal edema in 1 patient (case 1). Heidelberg retina tomograph revealed a deepening of the optic cup and a resultant narrowing of the neuroretinal rim at peak IOP in this patient; this was not detected in the second patient who had tilted optic discs. After trabeculectomy, diurnal IOP fluctuations were reduced to 4-6/2-4 (OD/OS) mm Hg in case 1 and to 6-7/3-7 (OD/OS) mm Hg in case 2, with a decrease in peak IOPs as well. CONCLUSIONS: Wide diurnal variation should be suspected in JOAG patients, even when receiving maximal medical treatment; this is especially important in cases with temporary blurred vision and/or progression of visual field defect despite apparently well-controlled IOP. Trabeculectomy was more effective in reducing diurnal IOP variation than medical treatment.