HEMODYNAMIC AND VISUAL FUNCTION EFFECTS OF ORAL NIFEDIPINE IN PATIENTS WITH NORMAL-TENSION GLAUCOMA

PURPOSE: To investigate ocular hemodynamic and visual function changes in patients with normal-tension glaucoma after treatment with a calci um channel blocker (nifedipine). METHODS: In 21 patients with normal t ension glaucoma, color Doppler imaging of the ophthalmic, central reti nal, and short posterior ciliary arteries was carried out after a 4-we ek washout: of prior drug treatment and again after 6 months of treatm ent with nifedipine (30 mg per day) Visual field sensitivity, spatial contrast sensitivity, and intraocular pressure were also recorded. RES ULTS: Three subjects experienced intolerable side effects from the dru g and were removed from the study, In two other patients, visual funct ion was substantially reduced after 4 months of treatment; nifedipine was discontinued, In the remaining 16 subjects, mean intraocular press ure, retrobulbar hemodynamics, visual field mean sensitivity, and cont rast sensitivity at 3, 12, and 18 cycles per degree (cpd), respectivel y, were unchanged after nifedipine treatment. Contrast sensitivity at 6 cpd, however, improved after drug treatment (P =.004). Individuals w ith the greatest improvements in contrast sensitivity at. 6 cpd showed the largest increases in ophthalmic arterial peak systolic velocity ( r =.57; P =.02) and end-diastolic velocity (r =.65; P =.001). CONCLUSI ON: Nifedipine fails to provide uniform visual function or retrobulbar hemodynamic responses in patients with normal tension glaucoma, Those patients who do show improved visual function also show improved indi ces of retrobulbar perfusion.