(201) OPHTHALMOLOGICAL AND PSYCHOPHYSICAL CHANGES IN MALES USING PHOSPHODIESTERASE INHIBITORS TYPE 5
Authors: Souza Paes A , Afonso Teixeira T , Rocha Lopes G , Santos Almeida HK , Prado Dantas HV , Garcia De Azevedo ME , Tenório Da Silva F , Dias Rocha K , Tiyomi Sacata Tongu Nazima M 
Published: December 2024

Abstract

Introduction
Phosphodiesterase Inhibitors (PDI) are involved in numerous physiological processes throughout the body and have been identified in different tissues, including the penis, lungs, and heart. These molecules play significant roles in penile erection physiology, inhibiting PDE type-5 in the smooth muscle of the sinusoids of the corpus cavernosum. Nevertheless, a minority of patients undergoing treatment for erectile dysfunction (ED) with PDE5i have encountered unfavorable visual occurrences, encompassing Arterial Ischemic Optic Neuropathy. This phenomenon arises due to the concurrent inhibition of PDE type 6, exclusively found within the retinal structure.

Objective
We aim to evaluate the ophthalmologic and psychophysical changes in men with a recent diagnosis of ED before and after a dose of tadalafil 20 mg.

Methods
We assess a cohort of men aged 33-59 without previous ophthalmological surgical intervention. We excluded men with diabetes and uncontrolled systemic arterial hypertension. The following parameters were analyzed before and after 12 hours of 20 mg tadalafil administration: visual adverse effects, arterial blood pressure, cardiac frequency, bilateral intraocular pressure (IOP), and visual acuity. We performed the Fansworth-Munsell D15 color discrimination, the Lantony D15 test, and optic coherence tomography (OCT) to evaluate the retinal layer thickness. Data analysis was performed using SPSS 22.0. P was set at 0.05.

Results
The most frequent complaints related to the drug were increased body temperature, headache, eye discomfort, and muscle pain (24.24%, 21.21%, 9.09%, and 9.09%, respectively). Visual adverse effects were reported in 19% of 30 men (mean age 49.4 ± 6.7 years old). There was a reduction in IOP (P = 0.023), and the reduction in diastolic arterial blood pressure after the medication was statistically significant (P = 0.004). OCT data showed significant differences in the left eye’s internal and external upper quadrants (respectively, P = 0.023 and P = 0.038). Four of the six patients experiencing visual symptoms exhibited increased thickness in the macula, especially on the Foveal Minimum (FM), with a 2.48% increase (p = 0.020), and the fovea, with a 1.17% increase (p = 0.017). Concerning the Fansworth-Munsell D15 test data, the Color Confusion Index (CCI), the Confusion-Index (C-Index), and the Selectivity Index of saturated colors (S-Index) decreased after the tadalafil administration. However, the differences were only significant in the right eye-CCI (P = 0.012) and right eye-C-Index (P = 0.027). The Lantony D15 test revealed a statistical difference in the left eye-C-Index (P = 0.048).

Conclusions
Tadalafil 20 mg may cause mild and temporary unwanted symptoms, the most common being increased body temperature and headache. Nonetheless, it did not significantly affect IOP, although there was a slight decrease. The drug caused a notable decline in diastolic pressure in the vascular system, but there were no significant changes in the systolic pressure or heart rate. Regarding the retina structure, the FM and fovea sectors’ thickness increased, while the other sectors’ thickness decreased. The study confirmed that tadalafil has adverse effects, including decreased diastolic pressure and discrete visual changes. However, it is ocularly safe due to its low specificity for PDE-6, which is almost exclusively found in the retina.

Disclosure
No.