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Effects of hyper‐ and hypocapnea on choroidal and retinal blood flows and the visual acuity
Author(s) -
Hayashi Naoyuki,
Someya Nami,
Ikemura Tsukasa
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.625.17
Subject(s) - visual acuity , retinal , ophthalmology , medicine , choroid , blood flow , hypocapnia , retina , anesthesia , cardiology , hypercapnia , psychology , acidosis , neuroscience
We investigated whether hyper‐ and hypocapnea change the blood flows in the choroid and retina, and are related to static visual acuity. Eleven healthy subjects performed three trials. In the control trial (CON), minute ventilation (V E ) was not controlled. In the hypocapnea trial (HYPO), the subjects controlled their V E to a target of 20 L/min for 6 min. In the hypercapnea trial (HYPER), the subjects inspired high‐fraction CO 2 gas (F I CO 2 =4%) for 6 min. We measured choroidal and retinal blood flows by laser speckle flowmetry, and static visual acuity by using the Landolt C chart. End tidal partial pressure of CO 2 differed significantly among CON, HYPO, and HYPER (42±1, 21±1, and 48±1 mmHg, respectively; mean±SE). The choroidal and retinal flows decreased significantly from baseline in HYPO (−17±4%), while they did not change significantly in CON and HYPER. The static visual acuity was significantly lower in HYPO than in HYPER (0.14±0.07 vs. 0.18±0.08, p<0.05). These results indicate that hypocapnia reduces choroidal and retinal blood flows, and suggest that the ocular blood flow influences the visual acuity. (Grant from the Yamaha Motor Foundation for Sports to NH)