Abstract
Background: Because calcium channel blockers reduce vascularresistance, they may have a clinical application in the treatment ofnormal-tension glaucoma (NTG). This study investigates changes inboth the optic disc blood flow and the hemodynamics of retrobulbarvessels in NTG patients after the systemic administration of a calcium channel blocker. Methods: Twelve eyes of 12 NTG patients (meanage 57 6 ± 15.3 years) were examined before and after a 4-weektreatment with 2 mg b.i.d. oral nilvadipine, an L-typc calcium channel blocker. By scanning laser-Doppler flowmetry (SLDF), we obtained the velocity, flow, and volume from within a 10 × 10 pixel windowplaced on the temporal rim region of the optic disc perfusion map. Byultrasound color Doppler imaging (CDI), we measured the peak systolicvelocity (PSV) and the end diastolic velocity (EDV) of the ophthalmicartery (OA), central retinal artery (CRA), nasal posterior ciliary artery (NPCA), and temporal posterior ciliary artery (TPCA). We then calculated a resistance index (RI) for each vessel. Results: After treatment, the flow and velocity of the optic disc blood flow significantly increased (P < 0.05).Nilvadipine also significantly reduced RIs of the CRA, NPCA, and TPCA(P <0 .05), and increased both the PSV of the NPCA and the EDVs of the CRA, NPCA, and TPCA. The percent change in velocity correlated significantly with the percent changes of the CRA RI and NPCA RI. Conclusions: Oral nilvadipine appears to reduce orbital vascular resistance, which consequentlyincreases the optic disc blood flow.
Abbreviations.BP – blood pressure;CRA – central retinal artery;CDI – ultrasound color Doppler imaging;EDV – end diastolic velocity;NPCA – short posterior ciliary arteries located nasal to optic nerve;NTG – normal-tension glaucoma;OA – ophthalmic artery;PP – perfusion pressure;PSV – peak systolic velocity;RI – resistance index;SLDF scanning laser-Doppler flowmetry;TPCA – short posterior ciliary arteries locatedtemporal to optic nerve.
Similar content being viewed by others
References
Carter CJ, Brooks DE, Doyle DL, Drance SM. Investigations into a vascular aetiology for low tension glaucoma. Ophthalmology 1990; 97: 49–55.
Cartwright MJ, Grajewski AL, Friedberg, Anderson DR, Richards DW. Immune- related disease and normal- tension glaucoma. A case- control study. Arch Ophthalmol 1992; 110: 500–502.
Gasser P, Flammer J. Blood cell velocity in the nailfold capillaries of patients with normal tension and high tension glaucoma. Am J Ophthalmol 1991; 11: 585–588.
Phelps CD, Corbett JJ. Migraine and low tension glaucoma. Invest Ophthalmol Vis Sci 1985; 26: 1105–1108.
Schulzer M, Drance SM. Biostatistical evidence for two distinct chronic open angle glaucoma populations. Br J Ophthalmol 1990; 74: 196–200.
Braunwald E. Mechanism of action of calcium channelblocking agents. N Engl J Med 1982; 307: 1618–1627.
Flammer J, Guthauser, U, Mahler F. Do ocular vasospasms help cause low tension glaucoma? Doc Ophthalmol Proc Series 1987; 49: 397–399.
Netland PA, Chaturvedi N, Dreyer EB. Calcium channel blockers in the management of low- tension and open- angle glaucoma. Am J Ophthalmol 1993; 15: 608–613.
Kitazawa Y, Shirai H, Go FJ. The effect of Ca2C- antagonist on visual field in low- tension glaucoma. Graefes Arch Clin Exp Ophthalmol 1989; 227: 408–412.
Sawada A, Kitazawa, Yamamoto T, Okabe I, Ichien K. Prevention of visual field defect progression with brovincamine in eyes with normal- tension glaucoma. Ophthalmology 1996; 103: 283–288.
Chauhan BC, Smith FM. Confocal scanning laser Doppler flowmetry: Experiments in a model flow system. J Glaucoma 1997; 6: 237–245.
Groh MJM, Michelson G, Langhans M, Harazny J. Influence of age on retinal and optic nerve head blood circulation. Ophthalmology 1996; 103: 529–534.
Michelson G, Schmauss B. Two dimensional mapping of the perfusion of the retina and optic nerve head. Br J Ophthalmol 1995; 79: 1126–1132.
Michelson G, Schmauss B, Langhans MJ, Harazny J, Groh MJM. Principle, validity and reliability of scanning laser Doppler flowmetry. J Glaucoma 1996; 5: 99–105.
Rosenthal J. Nilvadipine: profile of a new calcium antagonist. An overview. J Cardiovasc Pharmacol 1994; 44 (suppl 2): S92–S107.
Kawakami H, Tomita G, Liou S- Y, Shinohara H, Kitazawa Y. Variations of optic disc blood flow by scanning laser Doppler flowmetry. Rinsho Ganka (Jpn J Clin Ophthalmol) 1997; 51: 995–998.
Niwa Y, Yamamoto T, Kawakami H Kitazawa Y. Reproducibility of color Doppler imaging for orbital arteries in Japanese patients with normal- tension glaucoma. Jpn J Ophthalmol 1998; 2: 389–392.
Ohtsuka M, Yokota M. Komada I, Yamada K, Shibata S. New generation dihydropyridine calcium entry blockers: in search of greater selectivity for one tissue subtype. Gen Pharmac 1989; 20: 539–556.
Shimarnoto Y, Shimamoto Y. Nilvadipine increases cerebral blood flow in elderly hypertensives: comparison with nifedipine. J Human Hypertens 1995; 9: 271–279.
Onda E, Cioffi GA, Bacon DR, Van Buskirk EM. Microvasculature of the human optic nerve. Am J Ophthalmol 1995; 20: 92–102.
Orgü S, Cioffi GA. Embryology, anatomy, and histology of the optic nerve vasculature. J Glaucoma 1996; 5: 285–294.
Rizzo JR, Feke GT, Goger DG, Ogasawara H, Weiter J. Optic nerve head blood speed as a function of age in normal human subjects. Invest Ophthalmol Vis Sci 1991; 2: 3263–3272.
Anderson DR, Braverman S. Reevaluation of the optic disc vasculature. Ophthalmol 1976; 82: 165–174.
Goder G. The capillaries of the optic nerve. Am J Ophthalmol 1974; 7:684–689.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Tomita, G., Niwa, Y., Shinohara, H. et al. Changes in optic nerve head blood flow and retrobular hemodynamics following calcium-channel blocker treatment of normal-tension glaucoma. Int Ophthalmol 23, 3–10 (1999). https://doi.org/10.1023/A:1006423919238
Issue Date:
DOI: https://doi.org/10.1023/A:1006423919238