The effect of hyperoxia and hypercapnia on fundus pulsations in the macular and optic disc region in healthy young men

Schmetterer, Leopold; Wolzt, Michael; Lexer, Franz; Alschinger, Christa; Gouya, Ghazaleh; Zanaschka, Gabriele; Fassolt, A; Eichler, Hans‐Georg; Fercher, Adolf Friedrich

doi:10.1016/s0014-4835(05)80019-3

Cited by 39 publications

(26 citation statements)

References 13 publications

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“…However, there is evidence that carbonic anhydrase inhibitors may cause extracellular acidosis. 22 It is worth noting that an increase in arterial PCO 2 , a stimulus that produces extracellular acidosis, also strongly increases choroidal [23][24][25][26][27] and cerebral 1,3,5,18,19,27 blood flow. Moreover, the response to hypercapnia is considerably smaller in the OA.…”

Section: Discussionmentioning

confidence: 99%

Effects of Acetazolamide on Choroidal Blood Flow

Dallinger

Bobr

Findl

et al. 1998

Stroke

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Background and Purpose-The acetazolamide provocation test is commonly used to study cerebrovascular vasomotor reactivity. On the basis of the effect of a carbonic anhydrase inhibitor in the central nervous system, we hypothesized that acetazolamide may also increase blood flow in the human choroid. Methods-In a placebo-controlled, randomized, double-blind, three-way crossover design, acetazolamide (500 mg or 1000 mg IV) or placebo was administered to nine healthy subjects. The effect of acetazolamide was studied at 15-minute intervals for 90 minutes. Pulsatile choroidal blood flow was assessed with laser interferometric measurement of fundus pulsation. In addition, mean blood flow velocity and resistive index in the ophthalmic artery were measured with Doppler sonography. In a second study in six healthy subjects, we assessed the effect of acetazolamide (1000 mg IV) on intraocular pressure. Results-Acetazolamide increased fundus pulsation amplitude in a dose-dependent manner (1000 mg: ϩ33%; 500 mg: ϩ20%; PϽ0.001, ANOVA). The effect of acetazolamide on MFV (1000 mg: ϩ18%; 500 mg: ϩ8%; Pϭ0.003, ANOVA) and RI (1000 mg: Ϫ4%; 500 mg: Ϫ2%; Pϭ0.006, ANOVA) was less pronounced but also significant. Acetazolamide did not induce any changes in systemic hemodynamic parameters but significantly decreased intraocular pressure (1000 mg: Ϫ37%; PϽ0.0001). Conclusions-The present data show for the first time that intravenously administered acetazolamide increases choroidal blood flow in humans. This phenomenon therefore indicates that the acetazolamide provocation test may qualify as a tool to investigate ocular vasomotor reactivity in a variety of ocular diseases. Moreover, the increase in choroidal blood flow after carbonic anhydrase inhibition can be expected to contribute to the therapeutic efficacy of carbonic anhydrase inhibitors in glaucoma. (Stroke. 1998;29:997-1001.)

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Section: Discussionmentioning

confidence: 99%

Effects of Acetazolamide on Choroidal Blood Flow

Dallinger

Bobr

Findl

et al. 1998

Stroke

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“…In healthy subjects the fundus layer from which the main part of the light (at 800 nm) is reflected is most likely Bruchs membrane [5]. Hence the interference fringes, which are used for fundus pulsation measurements, are formed by the reflected waves from the front side of the tear film and Bruchs membrane [21], and FPA is therefore exclusively influenced by the choroidal circulation, with the exception of measurements in the optic disc [18,19,22]. When measurements are performed in AMD patients directly at the neovascularisation, the marked histological changes in the fundus layers must be taken into account [7].…”

Section: Discussionmentioning

confidence: 99%

Topical fundus pulsation measurements in age-related macular degeneration

Schmetterer¹,

Krüger

Findl

et al. 1998

Graefe's Arch Clin Exp Ophthalmol

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“…Hence it is possible that the pulsations were reduced only in the peripheral part of the retina, leading to a reduced global pulsatile blood flow as measured with the Langham system. Fundus pulsation measurements in peripheral parts of the eye fundus or in the optic disc [25,27] could yield additional information concerning regional distribution of ocular blood flow in diabetic retinopathy. Moreover, the Langham technique measures global pulsatile ocular blood flow.…”

Section: Discussionmentioning

confidence: 99%