Purpose: To evaluate and compare changes in scanning laser ophthalmoscopy, HRT II, and perimetry in adult primary open angle and chronic angle closure glaucoma over at least five years.
Design: Prospective non-randomized clinical trial.
Methods: 245 eyes of 245 patients, 116 primary open angle glaucoma, POAG eyes and 129 primary angle closure glaucoma, PACG eyes were studied. Standard achromatic perimetry and optic nerve head topography by HRT II were studied serially, at baseline and thereafter every six months.
Results: 14 POAG eyes (11.2%) and 20 PACG eyes (15.5%) showed progression on achromatic perimetry. Kaplan-Meier analysis showed a survival rate of 71% at 148 months for PACG and 86% at 144 months in POAG eyes. Eyes that progressed had frequent records (median 3.08 visits, range 2-10 visits) of a rise of IOP of >4 mm, over the target IOP, during follow-up. In stable eyes, PACG required >50% reduction in IOP to achieve stability on HRT, while POAG eyes showed improvement of optic nerve head parameters even with an IOP reduction of 25%.
Conclusion: Intermittent IOP fluctuations of ≥4 mm Hg over the mean IOP was associated with progression in POAG and CPACG eyes. PACG eyes appeared to progress faster and to a greater extent, and were more resistant to changes in ONH tomography following standard therapy, requiring a larger percentage drop in IOP to manifest improvement in optic nerve head parameters, as compared to POAG eyes.