Acute effects of coffee consumption on the microcirculation of macula and optic nerve head.

Purpose: This study aimed to evaluate the acute changes in retinal vasculature following coffee consumption. Methods: This is an interventional case series. The subjects were 22 healthy young adults. They were asked to rest in a silent room for 15 min; then, their heart rate, blood pressure, and arterial oxygen saturation pressure were measured with a single patient monitoring system. Optical coherence tomography (OCT) and OCT angiography (OCT-A) imaging of the disc and macula were performed for both eyes of the subjects. These measurements were repeated 45 min after drinking a cup of 450 ml of coffee containing a standard dose of 130 mg of caffeine. Macular and optic nerve head neurovasculature changes were assessed. Results: The results of our study did not show a significant change in peripapillary retinal nerve fiber layer thickness and neural structural and vascular parameters of the optic nerve head. Although assessments of macular vasculature showed a significant decrement in superficial (p = 0.01) and deep vessel density (p = 0.05) at parafovea, vessel densities (VDs) at the fovea, and deep capillary plexus at perifovea showed no significant change. Conclusion: Consuming one cup of coffee (150 mg caffeine) statistically changes central foveal thickness and parafoveal blood flow but likely does not have a clinical impact in healthy young adults.

Effect of oral photochemotherapy (8-methoxypsoralen + UVA) on the electrophysiologic function of retina.

CONTEXT: Since we had observed electroretinographic (ERG) abnormalities in some patients undergoing photochemotherapy with normal eye examination, we decided to investigate the effects of this therapy on retinal function. OBJECTIVE: To investigate the effects of oral photochemotherapy (8-methoxypsoralen + Ultraviolet-A) on electrophysiologic function of retina. MATERIALS AND METHODS: Patients with vitiligo, psoriasis or eczema were enrolled. Patients with any abnormal eye exam or a positive drug or family history for retinal disease were excluded. Baseline standard ERG was provided with the RETIport32 device. The second ERG was performed 6 months after the first and at least 1 week after the last photochemotherapy session (mean number of sessions: 45 ± 11). The outcome measures were changes in rod response, standard combined response, single-flash cone response, 30-Hz flicker (N1-P1) and oscillatory potentials amplitudes. RESULTS: Forty patients were enrolled; 20 of them (mean age: 31.1 ± 12 years) completed the study. The mean rod response b-wave amplitude decreased from 88.9 ± 47.5 to 86.4 ± 36.6 and standard combined response b-wave amplitude decreased from 266.52 to 261.85 µV (p = 0.422 and p = 0.968, respectively) and the standard combined response a-wave amplitude increased from 155.4 ± 40.0 at baseline to 165.1 ± 48.4 in the follow-up ERG (p = 0.092). The mean single-flash cone response a-wave amplitude decreased insignificantly in the follow-up ERG trace (34.5 ± 13.7 and 29 ± 15.4, respectively, p = 0.242). The mean single-flash cone response b-wave amplitude showed an insignificant increase (p = 0.087). The amplitudes of 30-Hz flicker wave and oscillatory potentials did not change significantly in the follow-up ERG (p = 0.551 and p = 0.739, respectively). CONCLUSION: Since no significant change in ERG traces was observed, oral photochemotherapy seems safe for retinal electrophysiologic function.