Advertisement

Inward and outward permeability of the blood-retinal barrier in experimental myopia

  • Akitoshi Yoshida
  • Satoshi Ishiko
  • Mitsuru Kojima
Pathophysiology

Abstract

• Background: To investigate the pathophysiology of the retina in myopia, vitreous fluorophotometry was used to evaluate the permeability of the blood-retinal barrier (BRB) in experimentally induced myopia in cynomolgus monkeys. • Methods: Five animals underwent unilateral eyelid suturing. The suture was removed temporarily at 3, 10, 16, 28 and 36 months, and the dioptric power and axial length were measured in both eyes. Vitreous fluorophotometry was performed before and 60 min after intravenous injection of fluorescein-Na. BRB inward permeability (Pin) was determined by a computer simulation method. At 36 months, fluorescein-Na was injected into the vitreous cavity, and the intraocular fluorescence was measured. BRB outward permeability (Pout) was determined by the computer simulation method. • Results: Significant myopia developed by 10 months after suturing and progressed thereafter. Starting at 10 months, the Pin of sutured eyes increased significantly compared with control fellow eyes, and the increase continued throughout the observation period. At 36 months, the BRB Pout was significantly lower (P<0.05) in the myopic than in the emmetropic fellow eyes, suggesting decreased active transport mechanisms at the BRB in myopia. • Conclusion: Our study demonstrated, for the first time, abnormal permeability of the BRB in myopic monkey eyes. Such abnormal permeability may play an important role in the development in human myopes of retinal and vitreous changes such as retinal detachment. Thus, simply correcting refractive errors surgically may not represent a cure for myopia. Patients who have had refractive surgery to correct myopia should also be closely followed up by vitreoretinal specialists to manage vitreoretinal disorders in originally myopic eyes.

Keywords

Retinal Detachment Myopia Refractive Error Active Transport Mechanism Dioptric Power 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Cunha-Vaz JG, Maurice DM (1967) The active transport of fluorescein by the retinal vessels and the retina. J Physiol (Lond) 191:467–486Google Scholar
  2. 2.
    Iuvone PM, Tigges M, Fernandes A, Tigges J (1989) Dopamine synthesis and metabolism in rhesus monkey retina: development, aging, and the effects of monocular visual deprivation. Visual Neurosci 2:465–471Google Scholar
  3. 3.
    Iuvone PM, Tigges M, Stone RA, Lambert S, Laties AM (1991) Effects of apomorphine, a dopamine receptor agonist, on ocular refraction and axial elongation in a primate model of myopia. Invest Ophthalmol Vis Sci 32:1674–1677PubMedGoogle Scholar
  4. 4.
    Kitano S, Nagataki S (1986) Transport of fluorescein monoglucuronide out of thé vitreous. Invest Ophthalmol Vis Sci 27:998–1001PubMedGoogle Scholar
  5. 5.
    Mader TH, White LJ (1995) Refractive changes at extreme altitude after radial keratotomy. Am J Ophthalmol 119:733–737PubMedGoogle Scholar
  6. 6.
    Rodriguez A, Camacho H (1992) Retinal detachment after refractive surgery of myopia. Retina 12:S46-S50PubMedGoogle Scholar
  7. 7.
    Seto C, Araie M, Takase M (1986) Study of fluorescein glucuronide. II. A comparative ocular kinetic study of fluorescein and fluorescein glucuronide. Graefe's Arch Clin Exp Ophthalmol 224:113–117CrossRefGoogle Scholar
  8. 8.
    Simon G, Parel J-M, Lee W, Kervick GN (1991) Gel injection adjustable keratoplasty. Graefe's Arch Clin Exp Ophthalmol 229:418–424CrossRefGoogle Scholar
  9. 9.
    Talley AR, Hardten DR, Sher NA, Kim MS, Doughman DJ, Carpel E, Ostrov CS, Lane SS, Parker P, Lindstrom RL (1994) Results one year after using the 193-nm excimer laser for photorefractive keratectomy in mild to moderate myopia. Am J Ophthalmol 118:304–311PubMedGoogle Scholar
  10. 10.
    Wiesel TN, Raviola E (1977) Myopia and eye enlargement after neonatal lid fusion in monkeys. Nature 266:66–68CrossRefPubMedGoogle Scholar
  11. 11.
    Yoshida A, Hosaka A (1984) A new vitreous fluorophotometer. Jpn J Clin Ophthalmol 38:1195–1199Google Scholar
  12. 12.
    Yoshida A, Hosaka A (1986) A study on blood-retinal barrier in myopia: analysis employing vitreous fluorophotometry and computer simulation. Acta Soc Ophthalmol Jpn 90:527–533Google Scholar
  13. 13.
    Yoshida A, Kojima M (1984) A simplified method for normalization of vitreous fluorophotometric readings by using protein-unbound fluorescein concentration in the plasma. I. Normalization of 60 min vitreous readings. Jpn J Clin Ophthalmol 38:1287–1291Google Scholar
  14. 14.
    Yoshida A, Murakami K, Kojima M (1986) Investigation of the vitreoretino-ciliary barrier by vitreous fluorophotometry. 5. Alteration of the inward permeability of the blood-retinal barrier and the diffusion coefficient of fluorescein in the vitreous with aging in normal subjects. Acta Soc Ophthalmol Jpn 90:589–594Google Scholar
  15. 15.
    Yoshida A, Ishiko S, Kojima M (1992) Outward permeability of the blood-retinal barrier. Graefe's Arch Clin Exp Ophthalmol 230:78–83CrossRefGoogle Scholar
  16. 16.
    Yoshida A, Ishiko S, Kojima M, Lipsky SN (1992) Blood-ocular barrier permeability in monkeys. Br J Ophthalmol 76:84–87PubMedGoogle Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • Akitoshi Yoshida
    • 1
  • Satoshi Ishiko
    • 1
  • Mitsuru Kojima
    • 1
  1. 1.Department of OphthalmologyAsahikawa Medical CollegeAsahikawaJapan

Personalised recommendations