Effect of Five-day “Dry” Immersion on Eye Hydrodynamics


The study of eye hydrodynamics following five-day “dry” immersion (DI) was aimed at evaluating the influence of compensatory body hypohydration on the intraocular hydrodynamic balance. For the first time the data of electronic eye tonography before and after modeled microgravity were compared. The study involved ten male volunteers 24 to 40 years of age without ophthalmologic pathologies. Electronic eye tonography results and hypohydration dynamics were assessed by fluid balance. Electronic tonography was performed before DI and on post-DI days 1 and 7 to measure the true intraocular pressure and to calculate the intraocular fluid production rate (F), coefficient of aqueous humor outflow ease, Bekker coefficient, and trophic coefficient (TC). On post-DI day 1, F reduction was observed in eight volunteers (60% of cases, 12 eyes). Level of the F reduction varied from 40% of the baseline value (5 eyes) to abnormally low 54% (7 eyes) underlying trophic changes. TC went down in 60% of cases (12 eyes); in 50% of cases (6 eyes) TC reduction was clinically significant. By the seventh day after DI, intraocular hydrodynamics was comparable with the baseline. It is hypothesized that the reflectory hypohydration during DI (the Gauer–Henry reflex) is responsible for changes in the intraocular hydrodynamics; the depth of these changes is determined by the degree of compensatory hypothalamic influence upon the antidiuretic hormone-angiotensin II system.

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  1. 1

    Marshall-Bowman, K., Barratt M.R., and Gibson C.R., Ophthalmic changes and increased intracranial pressure associated with long duration spaceflight: an emerging understanding, Acta Astronaut., 2013, vol. 87, no. 4, pp. 77–87.

    CAS  Article  Google Scholar 

  2. 2

    Makarov, I.A., Voronkov, Yu.I., and Aslanjan, M.G., Ophthalmic changes associated with long-term exposure to microgravity, Hum. Physiol., 2017, vol. 43, no. 1, pp. 105–113.

    Article  Google Scholar 

  3. 3

    Nesterov, A.P., Glaukoma (Glaucoma), Moscow, 2008.

    Google Scholar 

  4. 4

    Serenko, A.F. and Ermakova, V.V., Sotsial’naya gigiena i organizatsiya zdravookhraneniya (Social Hygiene and Organization of Health Care Service), Moscow, 1984, 2nd ed.

    Google Scholar 

  5. 5

    Nesterov, A.P., Bunin, A.Ya., and Katsnel’son, L.A., Vnutriglaznoe davlenie. Fiziologiya i patologiya (Intraocular Pressure: Physiology and Pathology), Moscow, 1974.

  6. 6

    Pantileeva, V.M., Neuroendocrine regulation factors of intraocular pressure: experimental and clinical studies, Extended Abstract of Doctoral (Med.) Dissertation, Moscow, 1973.

  7. 7

    Markevich, T.V., The functional parameters of ophthalmotonus and hydrodynamic indicators of the eye during hypofunction of the thyroid gland under euthyroid compensation, Extended Abstract of Cand. Sci. (Med.) Dissertation, Tyumen, 2005.

  8. 8

    Amirova, L.E., Neuromuscular and cardiovascular disorders in orthostatic and postural instability caused by microgravity, Cand. Sci. (Biol.) Dissertation, Moscow, 2018.

  9. 9

    Modak, S., Studies of left ventricular functions by systolic time intervals on exposure to dry immersion, Indian J. Aerospace Med., 2004, vol. 48, p. 48.

    Google Scholar 

  10. 10

    Nelson, E.S., Mulugeta, L., and Myers, J.S., Microgravity-induced fluid shift and ophthalmic changes, Life, 2014, vol. 4, no. 4, p. 621.

    Article  PubMed  PubMed Central  Google Scholar 

  11. 11

    Krupina, T.N., Tizul, A.Ya., and Kuz’min, M.P., Clinical and physiological changes in the human body during prolonged antiorthostatic hypokinesia, Aviakosm. Ekol. Med., 1982, vol. 16, no. 2, pp. 29–34.

    CAS  Google Scholar 

  12. 12

    Tomilovskaya, E.S., An experiment with a 5-day dry immersion: objectives, scope, research structure, and specific methodological approaches, Aviakosm. Ekol. Med., 2011, vol. 45, no. 6, pp. 3–7.

    Google Scholar 

  13. 13

    Metodicheskoe rukovodstvo po klinicheskoi tonometrii i tonografii. Pasport BRID 941222.001PS (Guide for Clinical Tonometry and Tonography, Passport BRID 941222.001PS), Samara: TERA, 1990.

  14. 14

    Nesterov, A.P., Bunin, A.Ya., and Katsnel’son, L.A., Vnutriglaznoe davlenie. Fiziologiya i patologiya (Intraocular Pressure: Physiology and Pathology), Moscow, 1974.

  15. 15

    Skripka, V.K. and Popov, A.D., Kriterii otsenki stabilizatsii protsessa po troficheskomu koeffitsientu pri pervichnoi neoperirovannoi glaukome: Metodicheskie rekomendatsii (Guide on Assessment Criteria of the Stabilization of the Process by the Trophic Coefficient in Primary Non-Operated Glaucoma), Voroshilovgrad, 1979.

  16. 16

    Ignat’eva, S.G., Shilkin, G.A., Yartseva, N.S., et al., Dynamics of intraocular fluid and eye homeostasis, Klin. Oftal’mol., 2010, no. 3, pp. 74–76.

  17. 17

    Krepe, E.M., Respiratory enzyme—coal anhydrase and its role in physiology and pathology, Usp. Sovrem. Biol., 1944, vol. 17, no. 2, pp. 28–35.

    Google Scholar 

  18. 18

    Scrutton, M., Assay of enzymes of carbon dioxide metabolism, in Methods in Microbiology, Norris, J.R., and Ribbons, D.W., Eds., Amsterdam: Elsevier, 1971, vol. 6A, ch. 12, p. 479.

  19. 19

    Tomaselli, C.M., Effect of a central redistribution of fluid volume on response to lower-body negative pressure, Aviat. Space Environ. Med., 1990, vol. 61, no. 1, pp. 38–42.

    CAS  PubMed  Google Scholar 

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The study was conducted as a part of the basic subjects of the Russian Academy of Sciences no. 63.1 “Investigation of the Mechanisms of Sensory and Motor Functioning in Conditions of Altered Gravity and Conceptualization of the Prevention of Microgravity Disturbances in Extralong Space Missions” and no. 63.2 “Investigation of Integrative Processes in the Central Nervous System, Regularities of Human Behavior and Activity in the Noninteracting Conditions and under Extreme Environmental Factors”, and supported by the Russian Foundation of Basic Research, project no. 16-29-083120-OFI-m “Determination of the Optimal Characteristics of Proprioceptive Signals of Various Modality (Supporting, Muscular, and Vestibular) Aimed to Elaborate the Algorithms of their Application in the System of Multimodal Soft Exosceleton with Neurorehabilitative and Space Flight Purposes.”

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Correspondence to O. M. Man’ko.

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Statement of compliance with standards of research involving humans as subjects. The experimental procedure involving humans was approved by the Biomedical Ethics Committee of the Institute of Biomedical Problems of the Russian Academy of Sciences in the level of scientific evidence, sufficiency of medical control, and safety arrangements (protocol no. 471, March 15, 2018). The risk and discomfort experienced during the experiment was accepted as tolerable. Informed consent was obtained from all individual participants involved in the study.

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Translated by E. Sherstyuk

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Man’ko, O.M., Smoleevskii, A.E., Tomilovskaya, E.S. et al. Effect of Five-day “Dry” Immersion on Eye Hydrodynamics. Hum Physiol 46, 792–797 (2020). https://doi.org/10.1134/S0362119720070105

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  • antidiuretic hormone
  • fluid balance
  • intraocular hydrodynamics
  • Gauer–Henry reflex
  • dry immersion
  • electronic eye tonography