Posters

Effect of phenylephrine hydrochloride in the accommodative system of the human eye

Poster Details

First Author: J.Esteve-Taboada SPAIN

Co Author(s):    R. Montes-Mico   P. Bernal   A. del Aguila-Carrasco   T. Ferrer-Blasco           

Abstract Details

Purpose:

The effect of phenylephrine hydrochloride (PHCl) in the accommodative system of the human eye is not yet clearly known. This work summarizes the main conclusions that have been outlined in previous reports.

Setting:

University of Valencia, Spain

Methods:

PHCl is a sympathomimetic mydriatic agent that is used to dilate the iris before eye surgery or eye clinical examinations. PHCl has been used in multiple accommodation studies without a clear understanding of its effect on the ciliary muscle that controls the accommodative state. In the majority of the reported studies, few details are provided regarding important parameters such as the subject age, the ocular pigmentation, or the actual amplitude of accommodation before instillation of PHCl eyedrops. All these parameters could influence the efficacy of PHCl on the ciliary muscle of the human eye

Results:

The measurement method used to assess the accommodative state of the eye is of greater importance. The push-up test is commonly applied to subjectively measure the accommodative amplitude, but it does not unequivocally determine the accommodative state of the eye. Many factors could influence the results provided by this test, such as pupil size variation, that affects the depth of field of the eye, and ocular aberrations. The use of devices that provide objective measurements of the accommodative state, like the Hartinger Coincidence Refractometer reported in previous studies, allows for explaining the effect of PHCl in the maximum accommodative amplitude of the eye.

Conclusions:

Differences in the effect induced by PHCl over the accommodation system of the human eye are obtained depending on the subjective or objective method that is used to measure the accommodative amplitudes. Objective measurement devices do generally not confirm the decrease in accommodative amplitude measured with subjective methods. Changes measured in the accommodative system are likely due to optical changes in the eye following mydriasis rather than sympathetic inhibition of the ciliary muscle

Financial Disclosure:

NONE