sildenafil-citrate and Optic-Neuropathy--Ischemic

Phosphodiesterase type 5 (PDE5) inhibitors are the first line drugs for treatment of erectile dysfunction. Sildenafil (Viagra(R)), tadalafil (Cialis(R)), and vardenafil (Levitra(R)) are from the same class of drugs that inhibit PDE5. Transient visual symptoms such as change in color perception and increased light sensitivity are well-known adverse effects of these drugs and occur in 3-11% of sildenafil users. Vision-threatening (serious) ocular complications, such as nonarteritic ischemic optic neuropathy and cilio-retinal artery occlusion have rarely been reported in PDE5 inhibitor users.. To highlight and analyze the most recently published case literature on serious ocular complications of PDE5 inhibitors.. Search of the peer-reviewed English literature was conducted using Medline. The following databases also were searched: Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, Global Health, and MD Consult. The causality assessment of the reported adverse drug reactions was analyzed by applying both the World Health Organization (WHO) Probability Scale and the criteria utilized by the National Registry of Drug-Induced Ocular Side Effects.. To scientifically and objectively find out if PDE5 inhibitors are associated with vision-threatening ocular complications.. Eight case reports of serious PDE5 inhibitor-associated ocular complications were identified since January 2006 until February 2011. Case reports included cases of anterior and posterior nonarteritic ischemic optic neuropathy, central retinal vein occlusion, cilio-retinal artery occlusion, acute angle closure glaucoma and optic atrophy after sildenafil use.. There is lack of conclusive evidence to indicate a direct cause-effect relationship between PDE5 inhibitor use and vision-threatening ocular events. Men who use PDE5 inhibitors appear to suffer vision-threatening complications at the same frequency as the general population. However, minor visual adverse effects occur in 3-11% of users and they are transient and reversible.

Topics: Adult; Aged; Child; Erectile Dysfunction; Female; Glaucoma, Angle-Closure; Humans; Male; Middle Aged; Optic Atrophy; Optic Neuropathy, Ischemic; Phosphodiesterase 5 Inhibitors; Piperazines; Purines; Retinal Artery Occlusion; Retinal Vein Occlusion; Sildenafil Citrate; Sulfones; Vision Disorders

Sildenafil citrate improves erectile function in men with erectile dysfunction (ED) by selectively inhibiting cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), which is present in all vascular tissue. Sildenafil also has a weaker inhibitory action on PDE6, located in the rod and cone photoreceptors. Modest, transient visual symptoms, typically blue tinge to vision, increased brightness of lights, and blurry vision, have been reported with sildenafil use and occur more frequently at higher doses. Visual function studies in healthy subjects and in patients with eye disease suggest that sildenafil does not affect visual acuity, visual fields, and contrast sensitivity. Transient, mild impairment of color discrimination can occur around the time of peak plasma levels. Spontaneous postmarketing reports of visual adverse events, including nonarteritic anterior ischemic optic neuropathy (NAION), have been reported during the 7 years that sildenafil has been prescribed to more than 27 million men worldwide. However, because men with ED frequently have vascular risk factors that may also put them at increased risk for NAION, a causal relationship is difficult to establish. No consistent pattern has emerged to suggest any long-term effect of sildenafil on the retina or other structures of the eye or on the ocular circulation.

Topics: Color Vision Defects; Controlled Clinical Trials as Topic; Erectile Dysfunction; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vasodilator Agents; Vision Disorders; Visual Acuity; Visual Fields

The recent reports of non-arteritic anterior ischemic optic neuropathy (NAION) occurring shortly after ingestion of erectile dysfunction agents have raised the question of whether these agents have a cause-and-effect relationship to NAION. The nature of optic nerve head blood flow and the various factors that influence it, the systemic vascular effects of these agents, and the clinical features of NAION lead me to believe that these agents are contributory factors. Patients with the appropriate risk factors should, therefore, be warned of this possibility and advised to refrain from using these agents.

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Carbolines; Erectile Dysfunction; Humans; Imidazoles; Male; Optic Disk; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Sildenafil Citrate; Sulfones; Tadalafil; Triazines; Vardenafil Dihydrochloride

Topics: Aged; Arteritis; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase 5 Inhibitors; Risk Factors; Sildenafil Citrate; Vision Disorders; Visual Fields

Topics: Humans; Optic Nerve Diseases; Optic Neuritis; Optic Neuropathy, Ischemic; Sildenafil Citrate

Topics: Adult; Female; Humans; Hypertension, Pulmonary; Nerve Fibers; Optic Neuropathy, Ischemic; Phosphodiesterase 5 Inhibitors; Retinal Ganglion Cells; Scotoma; Sildenafil Citrate; Tomography, Optical Coherence; Visual Acuity; Visual Field Tests; Visual Fields

Topics: Humans; Hypertension, Pulmonary; Optic Neuropathy, Ischemic; Risk Factors; Sildenafil Citrate

We report a case of posterior non-arteritic ischaemic optic neuropathy (NAION) causing bilateral visual loss in a 7-month-old female infant, after a therapeutic course with sildenafil, a phosphodiesterase type 5 inhibitors (PDE5i). The patient was affected by a complex cyanotic congenital heart defect and had undergone cavopulmonary anastomosis (Glenn operation) 3 months ago. After 2 months of recurring chylothorax, a course of oral sildenafil was administered, with the hypothesis that pulmonary vascular resistances were increased. Approximately 4 weeks later the acute onset of visual worsening and poor pupillary light reflex prompted the diagnosis of posterior NAION. Despite a rapid cessation of PDE5i and systemic treatment with corticosteroids, no visual recovery was noticed at 2-year follow-up. NAION has been associated with PDE5i therapy in adults, but to the best of our knowledge it is almost unheard of in children. We suggest close monitoring of visual function in children undergoing treatment with sildenafil.

Topics: Acute Disease; Blindness; Diagnosis, Differential; Female; Follow-Up Studies; Heart Defects, Congenital; Humans; Infant; Magnetic Resonance Imaging; Optic Neuropathy, Ischemic; Phosphodiesterase 5 Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Tomography, X-Ray Computed; Visual Acuity

Erectile dysfunction medications such as sildenafil citrate (Viagra) or tadalafil (Cialis) are commonly prescribed worldwide. They are selective phosphodiesterase-5 inhibitor and partial phosphodiesterase-6 inhibitors causing smooth muscle relaxation in the corpus cavernosum, allowing penile vasodilatation and erection in response to sexual stimuli. Over the years, there have been an increasing number of case reports concerning patients who developed ischemic optic neuropathy soon after the ingestion of these drugs. Although a cause and effect relationship between usage of the drugs and the development of ischemic optic neuropathy is difficult to prove, it is common nowadays to advise patients, especially those suffering from diabetes, hypertension, and ischemic heart disease, regarding the potential risk of visual loss due to ischemic optic neuropathy and treatment with erectile dysfunction drugs. Patients who were diagnosed with ischemic optic neuropathy soon after the ingestion of these erectile dysfunction drugs should be warned about a similar event in their fellow eye and should be advised regarding drug discontinuation.

Topics: Aged; Carbolines; Erectile Dysfunction; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase 5 Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Tadalafil

The diagnosis of optic neuritis and particularly retrobulbar optic neuritis when atypical and not responsive to corticosteroid treatment may need to be revised. This is now especially so in male patients who should be questioned regarding their taking a phosphodiasterase-5 inhibitor in particular Viagra. The case history of such a patient is presented who sustained posterior ischaemic optic neuropathy mistaken for retrobulbar neuritis resulting in bilateral severe visual loss.

Topics: Diagnostic Errors; Humans; Male; Middle Aged; Optic Neuritis; Optic Neuropathy, Ischemic; Phosphodiesterase 5 Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Sildenafil citrate is a selective phosphodiesterase 5 (PDE-5) inhibitor and partial phosphodiesterase 6 inhibitor prescribed for erectile dysfunction. Post-marketing case reports of nonarteritic anterior ischaemic optic neuropathy (NAION) over the past few years suggest a potential link with PDE-5 inhibitors. We report a case of a 48-year-old male patient who had acute vision loss 36 h after the intake of 50 mg sildenafil citrate. NAION occurred at a period of minimal blood level of sildenafil citrate. So, erectile dysfunction drugs must be strongly considered with NAION even though their users may have neither predisposing nor precipitating factors for NAION and even if occurring at a time of minimal blood level of these drugs.

Topics: Egypt; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vasodilator Agents

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Databases, Factual; Drug Prescriptions; Erectile Dysfunction; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase 5 Inhibitors; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Sildenafil Citrate; Sulfones; United States; United States Department of Veterans Affairs; Veterans

Topics: Adrenergic beta-Antagonists; Aged; Antihypertensive Agents; Atenolol; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Diltiazem; Dose-Response Relationship, Drug; Drug Interactions; Drugs, Chinese Herbal; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Hypotension; Male; Optic Nerve; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Retinal Artery; Risk Factors; Sildenafil Citrate; Simvastatin; Sulfones; Vision, Low

Topics: Amlodipine; Antihypertensive Agents; Disease Progression; Dose-Response Relationship, Drug; Drug Interactions; Erectile Dysfunction; Humans; Hypertension; Male; Middle Aged; Optic Nerve; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Prostatectomy; Prostatic Neoplasms; Purines; Retinal Artery; Risk Factors; Sildenafil Citrate; Sulfones; Time; Vision, Low

Topics: Adult; Humans; Kidney Failure, Chronic; Male; Optic Neuropathy, Ischemic; Piperazines; Purines; Retinal Artery Occlusion; Retinal Vein Occlusion; Sildenafil Citrate; Sulfones; Vasodilator Agents

Since the launch in 1998 of the anti-impotence drug sildenafil (viagra), the American food and drug administration has identified 50 cases of drug-related blindness, the so-called nonarteritic anterior ischemic optic neuropathy. This, very serious, side effect frequently leads to sudden, mostly irreversible loss of vision, and there is no proven effective treatment to cure patients or to prevent recurrence. The mechanism of ischemic optic neuropathy is not clear, but it could be related to the fact that the ophthalmic and central retinal arteries have an autoregulation of their own blood flow without any autonomic nerve supply; vasoreactivity could be lower albeit efficient, and therefore more vulnerable to systemic modifications of the circulation. But decreased visual acuity and loss of visual ability also are, although uncommon, anesthesiological and surgical complications. These data are consistent with the hypothesis that sildenafil, surgery and anesthesia, taken together, could be a potentially dangerous cocktail of risk factors for sudden irreversible loss of vision. To reduce the risk, sildenafil use should be avoided at least one week before surgical operations, since the reported cases of blindness developed 36h after drug ingestion.

Topics: Anesthesia; Blindness; Carbon Dioxide; Humans; Hypertension; Ischemia; Male; Optic Nerve; Optic Nerve Diseases; Optic Neuropathy, Ischemic; Piperazines; Postoperative Complications; Purines; Risk; Risk Factors; Sildenafil Citrate; Sulfones; Vasodilator Agents

Topics: Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Retinal Artery Occlusion; Retinal Vein Occlusion; Sildenafil Citrate; Sulfones; Vasodilator Agents

To determine the feasibility of a case-control study of phosphodiesterase (PDE)-5 inhibitors and nonarteritic ischemic optic neuropathy (NION).. Retrospective cohort study using the National Veterans Health Administration's pharmacy and clinical databases.. setting: National database. patient population: Male veterans 50 years of age and older with newly diagnosed NION or "possible" NION. interventional procedure: Dispensed prescription for a PDE-5 inhibitor. outcome measure: Incidence of NION and "possible" NION based on exposure to PDE-5 inhibitors.. The relative risk of NION among men prescribed a PDE-5 inhibitor was 1.02 (95% confidence interval [CI]: 0.92 to 1.12). The relative risk of possible NION among men prescribed a PDE-5 inhibitor was 1.34 (95% CI: 1.17 to 1.55).. The collective risk of NION and possible NION was marginally significant (relative risk [RR] 1.10 95% CI: 1.02 to 1.20). A case-control study, in which the dependent variable is NION and the effect size of the PDE-5 inhibitor is assumed small, is feasible.

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Case-Control Studies; Cyclic Nucleotide Phosphodiesterases, Type 5; Databases, Factual; Drug Prescriptions; Erectile Dysfunction; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Retrospective Studies; Risk Factors; Sildenafil Citrate; Sulfones; United States; United States Department of Veterans Affairs; Veterans

Topics: Carbolines; Erectile Dysfunction; Humans; Imidazoles; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Tadalafil; Triazines; Vardenafil Dihydrochloride; Vasodilator Agents

To determine the association between Viagra (sildenafil) and Cialis (tadalafil) and non-arteritic anterior ischaemic optic neuropathy (NAION).. A retrospective matched case-control study was conducted. 38 cases of NAION in males were identified from an academic ophthalmology practice in Birmingham, Alabama, and matched (on age) to 38 controls without a history of NAION. Self reported information regarding past and current use of Viagra and/or Cialis was obtained via a telephone questionnaire from interviewers who were not blind to case status.. Overall, males with NAION were no more likely to report a history of Viagra or Cialis use compared to similarly aged controls (odd ratio (OR) 1.75, 95% confidence interval (CI) 0.48 to 6.30 and OR 1.82, 95% CI 0.21 to 15.39). However, for those with a history of myocardial infarction, a statistically significant association was observed (OR 10.7, 95% CI 1.3 to 95.8). A similar association was observed for those with a history of hypertension though it lacked statistical significance (OR 6.9, 95% CI 0.8 to 63.6).. For men with a history of myocardial infarction or hypertension the use of Viagra or Cialis may increase the risk of NAION. Physicians prescribing these medications to patients with these conditions should warn them about the potential risk of NAION.

Topics: Carbolines; Case-Control Studies; Erectile Dysfunction; Humans; Hypertension; Male; Middle Aged; Myocardial Infarction; Odds Ratio; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Retrospective Studies; Sildenafil Citrate; Sulfones; Tadalafil; Vasodilator Agents

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Adverse Drug Reaction Reporting Systems; Carbolines; Erectile Dysfunction; Humans; Imidazoles; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Tadalafil; Triazines; Vardenafil Dihydrochloride; Vision Disorders

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Amiodarone; Erectile Dysfunction; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Sildenafil Citrate; Sulfones

Nonarteritic anterior ischemic optic neuropathy (NAION) has been reported rarely in men after taking sildenafil or other phosphodiesterase 5 inhibitors for erectile dysfunction (ED). The incidence of NAION in men receiving sildenafil treatment for ED was estimated using pooled safety data from global clinical trials and European observational studies. Based on clinical trial data in more than 13,000 men and on more than 35,000 patient-years of observation in epidemiologic studies, we estimated an incidence of 2.8 cases of NAION per 100,000 patient-years of sildenafil exposure. This is similar to estimates reported in general US population samples (2.52 and 11.8 cases per 100,000 men aged >or=50 years). The data cited herein do not suggest an increased incidence of NAION in men who took sildenafil for ED.

Topics: Aged; Erectile Dysfunction; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Sildenafil Citrate; Sulfones

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Blindness; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Topics: Carbolines; Case-Control Studies; Data Interpretation, Statistical; Erectile Dysfunction; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Tadalafil

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Atherosclerosis; Carbolines; Erectile Dysfunction; Humans; Imidazoles; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Sildenafil Citrate; Sulfones; Tadalafil; Triazines; Vardenafil Dihydrochloride; Vision Disorders

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Aged; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vision Disorders; Visual Acuity; Visual Fields

Seven patients, aged between 50 and 69 years, had typical features of nonarteritic anterior ischemic optic neuropathy (NAION) within 36 hours after ingestion of sildenafil citrate (Viagra) for erectile dysfunction. Six patients had vision loss within 24 hours after use of the agent. Final visual acuity in the affected eye ranged from 20/20 to light perception. Both eyes were affected in one individual. All affected individuals had pre-existing hypertension, diabetes, elevated cholesterol, or hyperlipidemia. Seven similar cases have been previously reported. Sildenafil may provoke NAION in individuals with an arteriosclerotic risk profile.

Topics: Aged; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Visual Acuity; Visual Fields

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Carbolines; Humans; Imidazoles; Male; Optic Neuropathy, Ischemic; Piperazines; Purines; Sildenafil Citrate; Sulfones; Tadalafil; Triazines; Vardenafil Dihydrochloride; Vasodilator Agents

Topics: Erectile Dysfunction; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vision Disorders

We report on a case of combined nonarteritic anterior ischemic optic neuropathy (NAAION) and cilioretinal artery occlusion resulting from misuse of sildenafil citrate (Viagra Pfizer Pharmaceuticals, New York, NY).. This is an observational case report.. A 54-year-old white man developed blindness in his left eye after an overdose of Viagra. He was examined and fully evaluated.. Ocular examinations revealed a left relative afferent pupillary defect and a left combined NAAION and obstruction of the ipsilateral cilioretinal artery.. Although ocular side-effects of Viagra are rare, they are potentially blinding. Patients should be warned about the side-effects and against misuse of this agent.

Topics: Blindness; Drug Overdose; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Piperazines; Purines; Retinal Artery Occlusion; Sildenafil Citrate; Sulfones

Topics: Erectile Dysfunction; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vasodilator Agents; Vision Disorders

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Erectile Dysfunction; Humans; Male; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Sildenafil Citrate; Sulfones

Sildenafil is a phosphodiesterase-type-5 inhibitor indicated for the treatment of erectile dysfunction in men. We report a case of NAION identified from a cohort of 8,893 patients (from a Prescription-Event Monitoring study) prescribed sildenafil by their primary care physician in England between April and June 1999. This 61-year-old patient had risk factors for NAION independent of drug therapy. It was not possible to be confident about a causal association between sildenafil and NAION, though the possibility could not be ruled out. Epidemiological data suggest that one case of NAION might be expected in a cohort of 8,893 subjects. Thus it remains important for clinicians to consider the range of risk factors for NAION; while equally, the processes of pharmacovigilance need to continue as for any recently launched drug preparation.

Topics: Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Piperazines; Product Surveillance, Postmarketing; Purines; Sildenafil Citrate; Sulfones

To describe the clinical features of five patients who developed nonarteritic anterior ischemic optic neuropathy (NAION) after ingestion of sildenafil citrate (Viagra; Pfizer Pharmaceuticals, New York, NY).. Retrospective observational case series.. Five patients with NAION who reported the use of sildenafil citrate before the onset of ocular symptoms.. The symptoms presented, history, ophthalmic examination, and visual field examination of each patient.. Nonarteritic anterior ischemic optic neuropathy developed in one eye within minutes to hours after ingestion of sildenafil. Four of the five patients had no vascular risk factors for ischemic optic neuropathy. The patients all developed unilateral blurry vision, altitudinal visual field defects, and optic disc edema. Each of the patients was noted to have a small cup-to-disc ratio in the unaffected optic nerve.. Sildenafil citrate may be associated with NAION. A small cup-to-disc ratio may be a risk factor for development of NAION in association with the use of sildenafil.

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Adult; Aged; Erectile Dysfunction; Giant Cell Arteritis; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Sildenafil Citrate; Sulfones

Topics: Follow-Up Studies; Humans; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Time Factors; Vasodilator Agents

A 42-year-old male presented with acute onset of an inferior visual field defect OD after sildenafil citrate use. Examination revealed a right relative afferent pupillary defect and a swollen disc with a 0.1 cup-to-disc ratio and a prominent disc hemorrhage. Anterior ischemic optic neuropathy (AION) is associated with acute episodes of hypotension in patients with structurally crowded discs. Sildenafil citrate may cause episodes of hypotension and was temporally related to the onset of symptoms in this patient. Because patients are often reluctant to volunteer their history of sildenafil citrate use, the physician may need to ask specifically about use of this medication. Physicians should counsel patients with crowded optic discs and a history of nonarteritic anterior ischemic optic neuropathy in one eye that use of sildenafil citrate might increase their risk of ischemic optic neuropathy in the fellow eye.

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Adult; Humans; Male; Optic Neuropathy, Ischemic; Papilledema; Phosphodiesterase Inhibitors; Piperazines; Purines; Retinal Hemorrhage; Sildenafil Citrate; Sulfones; Vision Disorders; Visual Fields

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Humans; Impotence, Vasculogenic; Male; Middle Aged; Optic Neuropathy, Ischemic; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones; Visual Fields