No effects of long-term sildenafil treatment on ocular functions

Purpose: Sildenafil is a new and effective oral medication for the treatment of erectile dysfunction. The purpose of this study was to assess the long-term effects of sildenafil on visual acuity, color vision, intraocular pressure (IOP), electroretinography (ERG), blue-on-yellow and white-on-white Humphrey visual field (HVF), and tear functions. Methods: Ten impotent patients ingested 50 mg of sildenafil one or more times a week for a minimum of 3 months. Ten age-matched subjects without any ophthalmological disorders other than refractive problems served as controls. Visual acuity (Snellen), color discrimination (Ishihara), and a slit-lamp examination were performed on the patients. Cotton thread and Schirmer I tests and tear break-up time were applied to random eyes of all subjects. IOP was measured in both eyes of the patients by Goldmann applanation tonometry. Both eyes of each subject were tested with white-on-white (fastpac 30-2, size 3 stimulus) followed by blue-on-yellow (fastpac 30-2, size 5 stimulus) HVF analyzer. ERG in scotopic (dark-adapted) condition was performed with unipolar corneal electrodes and rod response was recorded. Results: In comparison with control, no clinically or statistically significant differences were detected in the patients ingesting sildenafil with regard to the visual acuity, color discrimination, IOP, mean deviation, cotton thread and Schirmer I tests, tear break-up time, amplitude, and implicit time of b-wave. Conclusion: Long-term treatment with sildenafil did not produce any significant abnormality on ocular functions. Repeated exposures of ocular tissues to therapeutic doses of sildenafil are unlikely to impair their functions.