Effect of sildenafil on ocular haemodynamics


Purpose To study the effect of sildenafil, which is an effective agent for the treatment of erectile dysfunction, on ocular haemodynamics.

Methods In this prospective study we examined the effect of a single oral dose of 50 mg sildenafil (Viagra) in a group of healthy young male volunteers, by using colour Doppler ultrasound imaging to measure haemodynamic variables in the central retinal artery (CRA), short temporal posterior ciliary artery (STPCA) and ophthalmic artery (OA). The following examinations were performed on both eyes immediately before and 1 h after a single oral dose of 50 mg sildenafil: visual acuity, intraocular pressure (IOP), colour vision, anterior segment, fundus appearance, resting heart rate, blood pressure and colour Doppler measurements.

Results After sildenafil administration, peak systolic velocity, mean velocity and end-diastolic velocity significantly increased in the OA of both eyes. All Dopper indices remained non-significant for the CRA and STPCA of both eyes. Sildenafil did not cause any significant change in IOP, colour vision, visual acuity, systolic blood pressure or diastolic blood pressure. However, heart rate measurements increased significantly after sildenafil administration compared with baseline (p = 0.003).

Conclusion The increased flow velocity in the ophthalmic artery seems to be due to a vasodilator effect of sildenafil.


  1. 1

    Boolel M, Gepi-Attee S, Gingell JC, et al. Sildenafil, a novel effective oral therapy for male erectile dysfunction. Br J Urol 1996;78:257–61.

    Article  Google Scholar 

  2. 2

    Burnett AL . Role of nitric oxide in the physiology of erection. Biol Reprod 1995;52:485–9.

    CAS  Article  Google Scholar 

  3. 3

    Tarrett NK, Bell AS, Brown D, et al. Sildenafil (Viagra), a potent and selective inhibitor of type 5 cGMP phosphodiesterase with utility for the treatment of male erectile dysfunction. Bioorg Med Chem Lett 1996;6:1819–24.

    Article  Google Scholar 

  4. 4

    Goldstein I, Lue TF, Padma-Nathan H, et al. for the Sildenafil Study Group. Oral sildenafil in the treatment of erectile dysfunction. N Engl J Med 1998;338:1397–404.

    CAS  PubMed  Google Scholar 

  5. 5

    Vobig MA, Klotz T, Staak M, et al. Retinal side effects of sildenafil. Lancet 1999;353:375.

    CAS  Article  Google Scholar 

  6. 6

    Marmor MF . Sildenafil (Viagra) and ophthalmology. Arch Ophthalmol 1999;117;518.

    CAS  Article  Google Scholar 

  7. 7

    Erickson SJ, Hendrix LE, Massaro BM, et al. Colour Doppier flow imaging of the normal and abnormal orbit. Radiology 1989;173:511–6.

    CAS  Article  Google Scholar 

  8. 8

    Lieb WE, Cohen SM, Merton DA, et al. Color Doppler imaging of the eye and orbit: technique and normal vascular anatomy. Arch Ophthalmol 1991;109:527–31.

    CAS  Article  Google Scholar 

  9. 9

    Aburn NS, Sergott RC . Orbital color Doppler imaging. Eye 1993;7:639–47.

    Article  Google Scholar 

  10. 10

    Guthoff RF, Berger RW, Winkler P . Doppler ultrasonography of the ophthalmic and central retinal vessels. Arch Ophthalmol 1991;109:532–6.

    CAS  Article  Google Scholar 

  11. 11

    Lieb WE . Color ultrasonography of the eye and orbit. Curr Opin Ophthalmol 1993;4:68–75.

    CAS  Article  Google Scholar 

  12. 12

    Williamson TH, Baxter GM, Dutton GN . Color Doppler velocimetry of the arterial vasculature of the ophthalmic nerve head and orbit. Eye 1993;7:74–9.

    Article  Google Scholar 

  13. 13

    Walker DK, Ackland MJ, James GC, et al. Pharmacokinetics and metabolism of sildenafil in mouse, rat, rabbit, dog and man. Xenobiotica 1999;29:297–310.

    CAS  Article  Google Scholar 

  14. 14

    Ballard SA, Gingell CJ, Tang K, et al. Effects of sildenafil on the relaxation of human corpus cavernosum tissue in vitro and on the activities of cyclic nucleotide phosphodiesterase isozymes. J Urol 1998;159:2164–71.

    CAS  Article  Google Scholar 

  15. 15

    Moreland RB, Goldstein I, Traish A . Sildenafil, a novel inhibitor of phosphodiesterase type 5 human corpus cavernosum smooth muscle cells. Life Sci 1998;62:309–18.

    Article  Google Scholar 

  16. 16

    Boolell M, Allen MJ, Ballard SA, et al. Sildenafil: an orally type 5 cyclic GMP-specific phosphodiesterase inhibitor for the treatment of penile erectile dysfunction. Int J Impot Res 1996;8:47–52.

    CAS  PubMed  Google Scholar 

  17. 17

    Jeremy JY, Ballard SA, Naylor AM, et al. Effects of sildenafil, a type-5 cGMP phosphodiesterase inhibitor, and papaverine on cyclic GMP and cyclic AMP levels in the rabbit corpus cavernosum in vitro. Br J Urol 1997;79:958–63.

    CAS  Article  Google Scholar 

  18. 18

    Waldman SA, Murad F . Cyclic GMP synthesis and function. Pharmacol Rev 1987;39:163–96.

    CAS  PubMed  Google Scholar 

  19. 19

    Beova JA . Cyclic nucleotide phosphodiesterases: functional implications of multiple isoforms. Physiol Rev 1995;75:725–48.

    Article  Google Scholar 

  20. 20

    Rendell MS, Rajfer J, Wicker PA, et al. Sildenafil for treatment of erectile dysfunction in men with diabetes. JAMA 1999;281:421–6.

    CAS  Article  Google Scholar 

  21. 21

    Price DE, Boolell M, Gepi-Attee S, et al. Sildenafil: study of a novel oral treatment for erectile dysfunction in diabetic men. Diabet Med 1998;15:821–5.

    CAS  Article  Google Scholar 

  22. 22

    Morales A, Gingell C, Collins M, et al. Clinical safety of oral sildenafil citrate (Viagra) in the treatment of erectile dysfunction. Int J Impot Res 1998;10:69–74.

    CAS  Article  Google Scholar 

  23. 23

    Center for Drug Evaluation and Research. Viagra Tablets (sildenafil citrate): review and evaluation of pharmacology and toxicology data for NDA-20-895. Washington, DC: Division of Cardio-renal Drug Products, Center for Drug Evaluation and Research, Food and Drug Administration, 1998:19–21.

  24. 24

    Center for Drug Evaluation and Research. Animal pharmacology: mechanism of action, section 4.2. In: Viagra (sildenafil): joint clinical review for NDA-20-895. Washington, DC: Center for Drug Evaluation and Research, Food and Drug Administration, 1998.

  25. 25

    Jackson G, Benjamin N, Jackson N, et al. Effects of sildenafil citrate on human hemodynamics. Am J Cardiol 1999;83:C13–20.

    Article  Google Scholar 

  26. 26

    Webb DJ, Boolell M, Muirhead G . Cardiovascular effects of phosphodiesterase type 5 inhibition with concomitant nitrate therapy [abstract]. Circulation 1998;98(Suppl 17):I–637.

    Google Scholar 

  27. 27

    Sipsky ML, Rosen RC, Alexander CJ, et al. Sildenafil effects on sexual and cardiovascular responses in women with spinal cord injury. Urology 2000;55:812–5.

    Article  Google Scholar 

  28. 28

    Shirasaki Y, Su C, Lee TJ, et al. Endothelial modulation of vascular relaxation to nitrovasodilators in aging and hypertension. J Pharmacol Exp Ther 1986;239:861–6.

    CAS  PubMed  Google Scholar 

  29. 29

    Harris A, Williamson TH, Martin B, et al. Test retest reproducibility of color Doppler imaging assessment of blood flow velocity in orbital vessels. J Glaucoma 1995;4:281–6.

    CAS  Google Scholar 

  30. 30

    Hansen N, Stonestreet B, Rosenkrantz T, et al. Validity of Doppler measurements of anterior cerebral artery blood flow velocity: correlation with brain blood flow in piglets. Pediatrics 1983;72:526–31.

    CAS  PubMed  Google Scholar 

  31. 31

    Spencer J, Giussani D, Moore P, et al. In vitro validation of Doppler indices using blood and water. J Ultrasound Med 1991;10:305–8.

    CAS  Article  Google Scholar 

  32. 32

    Rosenberg A, Narayanan V, Jones M . Comparison of anterior cerebral artery blood flow velocity and cerebral blood flow during hypoxia. Pediatr Res 1985;19:67–70.

    CAS  Article  Google Scholar 

  33. 33

    Moncada S, Radomski MW, Palmer RMJ . Endothelium derived relaxing factor: identification as nitric oxide and role in the control of vascular tone and platelet function. Biochem Pharmacol 1988;37:2495–501.

    CAS  Article  Google Scholar 

  34. 34

    Gardiner SM, Compton AM, Bennet T, et al. Control of regional blood flow by endothelium-derived nitric oxide. Hypertension 1990;15:486–92.

    CAS  Article  Google Scholar 

  35. 35

    Kelly PAT, Buckley CH, Ritchie IM, et al. Possible role for nitric oxide releasing nerves in the regulation of ocular blood flow in the rat. Br J Ophthalmol 1998;82:1199–202.

    CAS  Article  Google Scholar 

  36. 36

    Roufail E, Stringer M, Rees S . Nitric oxide synthase immunoreactivity and NADH diaphorase staining are colocalised in neurones closely associated with the vasculature in rat and human retina. Brain Res 1995;684:36–46.

    CAS  Article  Google Scholar 

  37. 37

    Haefliger IO, Flammer J, Luscher TF . Nitric oxide and endothelin-1 are important regulators of human ophthalmic artery. Invest Ophthalmol Vis Sci 1992;33:2340–3.

    CAS  PubMed  Google Scholar 

  38. 38

    Schmetterer L, Findl O, Fasching P, et al. Nitric oxide and ocular blood flow in patients with IDDM. Diabetes 1997;46:653–8.

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Sema Oruç Dündar.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Dündar, S., Dündar, M., Koçak, I. et al. Effect of sildenafil on ocular haemodynamics. Eye 15, 507–510 (2001). https://doi.org/10.1038/eye.2001.163

Download citation


  • Central retinal artery
  • Colour Doppler ultrasound
  • Ophthalmic artery
  • Sildenafil

Further reading