Determination of loss in visual functions with personal protective equipment in emergency medical services.

Abstract

PURPOSE: To investigate de effect of personal protective equipment (PPE) used by emergency medical services (EMS) on visual functions. METHODS: This was a cross-sectional study of 36 subjects from the "Servicio de Asistencia Municipal de Urgencia y Rescate" (SAMUR, Madrid, Spain). The mean age was 30.83 years. All of them were free of any ocular disease or pathology. Several aspects of visual tasks commonly encountered in daily driving were studied, distance visual acuity with high (VA) and lower contrast (VA 5%), contrast sensitivty (CS), colour vision (Ishiara), visual field (VF) and depth perception (Stereopsis). Each subject performed test without devices, under habitual binocular conditions to produce the baseline visual score (BVS). The test were then repeated while wearing four PPE, having three different degrees of protection. These were: type I only with mask (M1); type II orange (O2); and type II, blue (B3) and green-yellow (G3), combined with a mask. All tests were performed under two lighting conditions: photopic (100-85 cd/m2) and mesopic (2cd/m2)