The authors considered a group of patients with newly diagnosed primary open-angle glaucoma studying the effects of a 4-week treatment with timolol or dorzolamide on retrobulbar vessels. Ocular hemodynamics were assessed by means of color Doppler imaging of the ophthalmic artery, the temporal short posterior ciliary arteries (SPCAs) and the central retinal artery. For each vessel, systolic and diastolic blood flow velocities were measured, and the resistivity index (RI) was calculated. The only significant result was a reduction of temporal SPCA RI after dorzolamide treatment in comparison with baseline (p = 0.011). In the same group, dorzolamide treatment had a slight and nonsignificant increase in temporal SPCA diastolic velocity. The resistance decrease observed after dorzolamide treatment in the ciliary circulation may be due to the decrease in intraocular pressure or a possible direct vasodilating effect of the drug.

Keywords:
Primary open-angle glaucoma, Ocular hemodynamics, Dorzolamide, Color Doppler imaging
1.
Leighton DA, Phillips CI: Systemic blood pressure in open-angle glaucoma, low tension glaucoma, and the normal eye. Br J Ophthalmol 1972;56:447–453.
2.
Tielsch JM, Katz J, Sommer A, Quigley HA, Javitt JC: Hypertension, perfusion pressure and primary open-angle glaucoma. Arch Ophthalmol 1995;113:216–221.
3.
Kaiser HJ, Flammer J: Systemic hypotension: A risk factor for glaucomatous damage? Ophthalmologica 1991;203:105–108.
4.
Hayreh SS, Zimmermann MB, Podhajsky P, Alward ALM: Nocturnal arterial hypotension and its role in optic nerve head and ocular ischemic disorders. Am J Ophthalmol 1994;117:603–624.
5.
Gasser P, Flammer J, Guthauser U, Mahler F: Do vasospasms provoke ocular diseases? Angiology 1990;41:213–220.
6.
O’Brien C: Vasospasm and glaucoma. Br J Ophthalmol 1998;82:855–857.
7.
Flammer J: To what extent are vascular factors involved in the pathogenesis of glaucoma? in Kaiser HJ, Flammer J, Hendrickson P (eds): Ocular Blood Flow. Basel, Karger, 1996, pp 12–39.
8.
Klaver JH, Greve EL, Goslinga H, Geijssen HC, Heuvelmans JH: Blood and plasma viscosity measurements in patients with glaucoma. Br J Ophthalmol 1985;69:765–770.
9.
Hamard P, Hamard H, Dufaux J, Quesnot S: Optic nerve head blood flow using a laser Doppler velocimeter and haemorheology in primary open angle glaucoma and normal pressure glaucoma. Br J Ophthalmol 1994;78:449–453.
10.
Sugiyama T, Moriya S, Oku H, Azuma I: Association of endothelin-1 with normal tension glaucoma: Clinical and fundamental studies. Surv Ophthalmol 1995;39(suppl 1): S49–S56.
11.
Kaiser HJ, Flammer J, Wenk M, Luscher T: Endothelin-1 plasma levels in normal tension glaucoma: Abnormal response to postural changes. Graefes Arch Clin Exp Ophthalmol 1995;233:484–488.
12.
Williamson TH, Harris A: Ocular blood flow measurement. Br J Ophthalmol 1994;78:939–945.
13.
Harris A, Kagemann L, Cioffi GA: Assessment of human ocular hemodynamics. Surv Ophthalmol 1998;42:509–533.
14.
Trew DR, Smith SE: Postural studies in pulsatile ocular blood flow. II. Chronic open angle glaucoma. Br J Ophthalmol 1991;75:71–75.
15.
James CB, Smith SE: Pulsatile ocular blood flow in patients with low tension glaucoma. Br J Ophthalmol 1991;75:466–470.
16.
Wolf S, Arend O, Sponsel WE, Schulte K, Cantor LB, Reim M: Retinal hemodynamics using the scanning laser ophthalmoscopy and haemorheology in chronic open-angle glaucoma. Ophthalmology 1993;100:1561–1566.
17.
Suzuki R, Sugihara I, Kurimoto S: Retinal circulation in primary open-angle glaucoma tested by videodensitometric image analysis. Ann Ophthalmol 1992;24:273–277.
18.
Galassi F, Nuzzaci G, Sodi A, Casi P, Vielmo A: Color Doppler imaging evaluation of optic nerve blood supply in normal and glaucomatous subjects. Int Ophthalmol 1992;16:273–276.
19.
Yamazaki Y, Miyamoto S, Hayamizu F: Color Doppler velocimetry of the ophthalmic artery in glaucomatous and normal subjects. Jpn J Ophthalmol 1994;38:317–321.
20.
Harris A, Sergott RC, Spaeth GL, Katz JL, Shoemaker JA, Martin BJ: Color Doppler analysis of ocular blood velocity in normal tension glaucoma. Br J Ophthalmol 1995;79:732–734.
21.
Kaiser HJ, Schoetzau A, Stumpfig D, Flammer J: Blood-flow velocities of the extraocular vessels in patients with high-tension and normal-tension primary open angle glaucoma. Am J Ophthalmol 1997;123:320–327.
22.
Galassi F, Sodi A, Rossi MG, Ucci F: Results of color Doppler imaging in various types of glaucoma; in Pillunat LE, Harris A, Anderson DR, Greve EL (eds): Current Concepts on Ocular Blood Flow in Glaucoma. The Hague, Kugler Publications, 1999, pp 119–127.
23.
Kitaya N, Yoshiba A, Ishiko S, Mori F, Abiko T, Ogasawara H, Kato Y, Nagaoka T: Effect of timolol and UF-021 (a prostaglandin-related compound) on pulsatile ocular blood flow in normal volunteers. Ophthalmic Res 1997;29:139–144.
24.
Grunwald JE: Effect of topical timolol on human retinal circulation. Invest Ophthalmol Vis Sci 1986;27:1713–1719.
25.
Grunwald JE: Effect of timolol maleate on the retinal circulation in human eyes with ocular hypertension. Invest Ophthalmol Vis Sci 1990;31:521–526.
26.
Arend O, Harris A, Arend S, Remky A, Martin BJ: The acute effect of topical beta-adrenoreceptor blocking agents on retinal and optic nerve head circulation. Acta Ophthalmol Scand 1998;76:43–49.
27.
Baxter GM, Williamson TH, McKillop G, Durron GN: Color Doppler ultrasound of orbital and optic nerve blood flow: Effects of posture and timolol 0.5%. Invest Ophthalmol Vis Sci 1992;33:604–610.
28.
Nicolela MT, Buckley AR, Walman BE, Drance SM: A comparative study of the effects of timolol and latanoprost on blood flow velocity of the retrobulbar vessels. Am J Ophthalmol 1996;122:784–789.
29.
Harris A, Spaeth GL, Sergott RC, Katz LJ, Cantor LB, Martin BJ: Retrobulbar arterial hemodynamic effects of betaxolol and timolol in normal-tension glaucoma. Am J Ophthalmol 1995;120:168–175.
30.
Evans DW, Harris H, Chung HS, Cantor LB, Garzozi HJ: Effects of long-term hypotensive therapy with nonselective beta-blockers on ocular hemodynamics in primary open-angle glaucoma. J Glaucoma 1999;8:12–17.
31.
Hauge A, Nicolaysen G, Thoresen M: Acute effects of acetazolamide on cerebral blood flow in man. Acta Physiol Scand 1983;117:233–239.
32.
Sullivan HG, Kingsbury TB, Morgan ME, Jeffcoat RD, Allison JD, Goode JJ, McDonnel DE: The rCBF response to Diamox in normal subjects and cerebrovascular disease patients. J Neurosurg 1987;67:525–534.
33.
Kazumata K, Tanaka N, Ishikawa T, Kuroda S, Houkin K, Mitsumori K: Dissociation of vasoreactivity to acetazolamide and hypercapnia: Comparative study in patients with chronic occlusive major cerebral artery disease. Stroke 1996;27:2052–2058.
34.
Harris A, Tippke S, Sievers C, Picht G, Lieb W, Martin B: Acetazolamide and CO2: Acute effects on cerebral and retrobulbar hemodynamics. J Glaucoma 1996;5:39–45.
35.
Dallinger S, Bobr B, Findl O, Eicher HG, Schmetterer L: Effects of acetazolamide on choroidal blood flow. Stroke 1998;29:997–1001.
36.
Kiss B, Dallinger S, Findl O, Rainer G, Eichler HG, Schmetterer L: Acetazolamide-induced cerebral and ocular vasodilation in humans is independent of nitric oxide. Am J Physiol 1999;276(6, pt 2):R1661–1667.
37.
Harris A, Arend O, Arend S, Martin B: Effects of topical dorzolamide on retinal and retrobulbar hemodynamics. Acta Ophthalmol Scand 1996;74:569–572.
38.
Schmidt KG, Von Ruckmann A, Pillunat LE: Topical carbonic anhydrase inhibition increases ocular pulse amplitude in high tension primary open angle glaucoma. Br J Ophthalmol 1998;82:758–762.
39.
Martinez A, Gonzalez F, Capeans C, Perez R, Sanchez-Salorio M: Dorzolamide effect on ocular blood flow. Invest Ophthalmol Vis Sci 1999;40:1270–1275.
40.
Harris A, Arend O, Kagemann L, Garrett M, Chung HS, Martin B: Dorzolamide, visual function and ocular hemodynamics in normal-tension glaucoma. J Ocul Pharmacol Ther 1999;15:189–197.
41.
Jonas JB, Gusek GC, Naumann GOH: Optic disc morphometry in chronic primary open-angle glaucoma. I. Morphometric intrapapillary characteristics. Graefe’s Arch Clin Exp Ophthalmol 1988;226:522–530.
42.
Jonas JB, Gusek GC, Naumann GOH: Optic disc morphometry in chronic primary open-angle glaucoma. II. Correlation of the intrapapillary morphometric data to visual field data. Graefe’s Arch Clin Exp Ophthalmol 1988;226:531–538.
43.
Greve EL, Langerhorst CT, van den Berg TTJP: Perimetry and other visual function tests in glaucoma; in Cairns JE (ed): Glaucoma I. London, Grune & Stratton, 1986, pp 37–77.
44.
Chylack LT Jr, Wolf JK, Singer DM, Leske MC, Bullimore MA, Bailey IL, Friend J, McCarthy D, Wu S-Y: The lens opacities classification system III. Arch Ophthalmol 1993;111:831–836.
45.
Harris A, Joos K, Kay M, Evans D, Shetty R, Martin B: Acute IOP elevation with scleral suction: Effects on retrobulbar haemodynamics. Br J Ophthalmol 1996;80:1–5.
46.
Trible JR, Sergott RC, Spaeth GL, Wilson RP, Katz J, Moster MR, Schmidt CM: Trabeculectomy is associated with retrobulbar hemodynamic changes: A color Doppler analysis. Ophthalmology 1994;101:340–351.
© 2002 S. Karger AG, Basel
2002
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.