Large Diurnal Variation of Intraocular Pressure Despite Maximal Medical Treatment in Juvenile Open Angle Glaucoma

Abstract

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). 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. 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. 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.