To the Editor.
—Ophthalmologic risks of inversion devices used for exercise or therapy recently have been discussed.1,2 I have previously reported periorbital petechiae in two middleaged aspirin users and I did a pilot study to expand on earlier work in two ways: (1) Half of the 20 young healthy male subjects (average age, 21 years) were given 325 mg of aspirin three hours prior to inversion, thereby prolonging their bleeding times by 3.4 ± 0.8 minutes. (2) Ocular pneumoplethysmography (OPG)4 was used because of its more objective endpoints compared with ophthalmodynamometry used by other investigators1,2 and its ability to calculate ocular blood flow (OBF).5 Each of the 20 participants was subjected to three successive ten-minute inversions, separated by 15-minute rest periods. Although numerous physiologic variables were monitored and are being published elsewhere,6 herein we report visual acuity, intraocular pressure (IOP), OPG, OBF, petechiae, and retinal
Plocher DW. Ophthalmic Response to Inverted Posture. Arch Ophthalmol. 1985;103(6):762-763. doi:10.1001/archopht.1985.01050060020006