Hypobaric hypoxia: effects on contrast sensitivity in high altitude environments.

Background: Effects of hypobarism and hypoxia on visual performance and mainly on contrast sensitivity (CS) are well known. The purpose of this study was to compare the adjustments of corneal thickness in hypobaric hypoxia conditions with changes in contrast sensitivity.

Methods: There were 12 healthy, emmetropic subjects assigned to the 14(th) Wing Aircrew based in Pratica di Mare AFB (Rome, Italy) who were evaluated for changes occurring in central corneal thickness (CCT), measured by portable ultrasonic pachymeter, and CS, assessed after reading the standard Pelli-Robson charts, during modification of atmospheric pressure and, therefore, of oxygen partial pressure.

Age-related visual signal changes induced by hypoxemic hypoxia: a study on aircraft pilots of different ages.

Purpose: Exposure to high altitude leads to a series of alterations of higher nervous functions because of hypobaric hypoxia. Sensory systems, mainly the visual one, seem to be particularly involved. This study aimed to assess the effects of hypoxemic hypoxia on the transmission of the visual stimulus simulating a condition of breathing at an altitude of 18,000 feet (5,486 m) through the administration of an air mixture with 10% O2.

Hypobaric hypoxia: effects on intraocular pressure and corneal thickness.

Objective: The purpose of this study focused on understanding the mechanisms underlying ocular hydrodynamics and the changes which occur in the eyes of subjects exposed to hypobaric hypoxia (HH) to permit the achievement of more detailed knowledge in glaucomatous disease.

Methods: Twenty male subjects, aged 32±5 years, attending the Italian Air Force, were enrolled for this study. The research derived from hypobaric chamber, using helmet and mask supplied to jet pilotes connected to oxygen cylinder and equipped with a preset automatic mixer.

Fixed topical combinations in glaucomatous patients and ocular discomfort.

Objective: The purpose of this study was to verify the ocular comfort of a fixed topical combination of brinzolamide 1% plus timolol 0.5% suspension vs. dorzolamide 2% plus timolol 0.