Effects of Sildenafil on Choroidal Thickness in AMD
Status:
Terminated
Trial end date:
2014-05-01
Target enrollment:
Participant gender:
Summary
Choroidal thinning has been hypothesized to partake in the pathogenesis of age-related
macular degeneration (AMD), but it is not known if increasing choroidal thickness may
potentially alter the disease course. Past studies have shown that a single dose of the
phosphodiesterase type-5 inhibitor sildenafil citrate can increase choroidal thickness in
young healthy patients. The investigators hypothesize that sildenafil may also increase
choroidal thickness in eyes with AMD and perhaps potentially reduce AMD progression.
Alternatively, if sildenafil has minimal effect on choroidal thickness in eyes in patients
with AMD, such results may suggest that choroidal vascular compliance or stiffness is reduced
in this condition. Patients seen at the Duke Eye Center with a diagnosis of AMD or
age-matched control subjects with no macular pathology will be administered a single 100mg
oral dose of sildenafil citrate (Viagra®; Pfizer), and undergo EDI-OCT imaging before and
after treatment. Images obtained will be used to measure choroidal thickness, as well as
central macular thickness (CMT) and macular volume (MV). Choroidal thickness changes after a
single-dose sildenafil treatment in AMD patients will be compared with age-matched control
subjects using standard statistical methods. By also correlating choroidal thickness changes
with functional (visual acuity) and anatomical (CMT & MV) changes, the investigators hope to
further their understanding of the choroid's role in aging and AMD pathogenesis. The safety
of a single dose of sildenafil citrate will be addressed by excluding any patients with risk
factors or using medications that are contraindicated for sildenafil as determined by careful
informed consent and a study questionnaire.