Purpose: To investigate the effects of the phosphodiesterase-5 inhibitor, sildenafil citrate, on choroidal thickness using eye-tracked enhanced depth imaging spectral-domain optical coherence tomography.
Methods: In a prospective interventional study, 8 healthy subjects (4 men and 4 women) with no ocular history underwent enhanced depth imaging spectral-domain optical coherence tomography at baseline, 1 hour, and 3 hours after the ingestion of 100 mg of sildenafil citrate. Choroidal thickness measurements for both eyes using enhanced depth imaging spectral-domain optical coherence tomography were taken by 2 masked readers at baseline, 1-hour, and 3-hour time points. Statistical analysis was performed to compare the measurements of choroidal thickness at each of the three intervals.
Results: The mean age of the subjects was 35.9 years (range 30-46 years). Mean choroidal thickness at baseline was 334 μm (± 57 μm). Mean choroidal thickness increased by 12.3% to 375 μm (± 68 μm) at 1 hour after ingestion (P < 0.001). At 3 hours after ingestion, the mean choroidal thickness remained elevated at 372 μm (± 61 μm), 11.6% thicker than baseline (P < 0.001). There was no significant difference in choroidal thickness between the 1-hour and the 3-hour intervals (P = 0.719).
Conclusion: Sildenafil citrate appears to increase choroidal thickness as measured by eye-tracked enhanced depth imaging spectral-domain optical coherence tomography measurements in healthy subjects 1 hour and 3 hours after ingestion. These findings may be of relevance given that increased choroidal thickness appears to be a risk factor for central serous chorioretinopathy and that several reports have suggested an association between phosphodiesterase-5 inhibitors and this disorder.