J.ophthalmol.(Ukraine).2021;4:72-78.

http://doi.org/10.31288/oftalmolzh202147278

Received: 05 March 2021; Published on-line: 16 August 2021


Ultrastructural changes in the chorioretinal complex of the rat after inducing form-deprivation axial myopia only, diabetic retinopathy only and diabetic retinopathy in the presence of myopia

I. M. Mykheitseva,  N. I. Molchaniuk, Abdulhadi Muhammad, S. G. Kolomiichuk, O. O. Suprun

SI "The Filatov Institute of Eye Diseases and Tissue Therapy of the NAMS of Ukraine"; Odesa (Ukraine)

TO CITE THIS ARTICLE:Mykheitseva I.M.,  Molchaniuk N.I., Muhammad Abdulhadi, Kolomiichuk S.G., Suprun O.O.  Ultrastructural changes in the chorioretinal complex of the rat after inducing form-deprivation axial myopia only, diabetic retinopathy only and diabetic retinopathy in the presence of myopia  http://doi.org/10.31288/oftalmolzh202147278


Purpose: To determine the features of the microstructure of choreoretinal complex in rats with diabetes induced by streptozotocin in the presence of axial myopia.

Material and Methods: Fifty-five Wistar rats (110 eyes; age, 2 weeks to 14 weeks) were used in experiments. Four groups were formed: group 1 (axial myopia only); group 2 (diabetes only); group 3 (both myopia and diabetes); and group 4 (controls; intact animals). High form-deprivation myopia was produced in two-week animals by surgically fusing the eyelids of both eyes and these animals were maintained under conditions of reduced illumination for two weeks to induce a more intense myopization of the globe. Eyelid sutures were removed on completion of these two weeks. Two weeks thereafter, type 2 diabetes mellitus was induced in rats with induced axial myopia and intact rats. A 50 mg/kg intraperitoneal streptozotocin injection for 5 days was used for this purpose. Elongated axial length and increased anterior chamber depth as measured by in vivo ultrasound were an objective criterion of the development of myopia in experimental animals. A glucose level of ≥ 4.5 mmol/L was a criterion of the development of diabetes. Two months after inducing diabetes, 14-week rats were sacrificed, and their eye tissue samples were processed by a routine method and assessed by electron microscopy. Ultrastructure of the choroid, RPE, and retinal photoreceptor cells were examined. Ultra-thin sections were cut, stained with lead citrate according to the procedure described by Reynolds, and observed with a PEM-100-01 Transmission Electron Microscope.

Results: Our ultrastructural study found that myopization of the rat globe with elongation of the axial length somewhat reduced the severity of some ultrastructural changes in the choreoretinal complex in induced type 2 diabetes due to reduced choroidal swelling and dominance of compensatory processes with increased energy producing, protein synthesis and other functions in the endothelial vessels and choriocapillaries  as well as RPE cells. Out findings seem to corroborate the concept that myopized eyes have capacity to somewhat buffer the development of severe diabetic retinopathy, likely due to some compensatory-and-restorative processes.

Keywords: streptozotocin-induced diabetes, form-deprivation myopia, rats, electron microscopy, choroidal ultrastructure, retinal pigment epithelium, compensatory processes

 

References

1.Maltsev EV, Zborovska OV, Dorokhova AE. [Fundamental aspects of the development and treatment of diabetic retinopathy]. Ode-sa: Astroprint; 2018. Russian.

2.Zhdankina AA. [Morphological patterns of retinal changes in retinopathy of various origin and their correction with antioxidants: an experimental study]. Abstract of dissertation for the degree of Dr Sc (Med). Tomsk; 2013. Russian.

3.Avetisov ES. [Myopia]. Moscow: Meditsina; 2002. Russian.

4.Barteselli G, Chhablani J, El-Emam S, et al. Choroidal volume variations with age, axial length, and sex in healthy subjects: a three-dimensional analysis. Ophthalmology. 2012;119:2572–8. doi:10.1016/j.ophtha.2012.06.065. 

Crossref  PubMed

5.Astakhov YuS, Belekhova SG. [Choroidal thickness in various grades of myopia]. Oftalmologicheskiie vedomosti. 2013;6(4):35-8. Russian. 

Crossref 

6.Balashevich LI, Izmailov AS, editors. [Diabetic ophthalmopathy]. St. Petersburg: Chelovek; 2012. Russian.

7.Wang X, Tang L, Gao L, Yang Y, Cao D, Li Y. Myopia and diabetic retinopathy: A systematic review and meta-analysis. Diabetes Res Clin Pract. 2016 Jan;111:1-9. 

Crossref  PubMed

8.Bazzazi N, Akbarzadeh S, Yavarikia SM, et al. High myopia and diabetic retinopathy: A Contralateral Eye Study in Diabetic Pa-tients with High Myopic Anisometropia. Retina. 2017;37(7):1270–6. 

Crossref  PubMed

9.Dujić M, Nikolić Lj, Misailović K, Ignjacev M. Occurrence of changes in the eye in diabetic retinopathy with significant myopia. Srp Arh Celok Lek. Nov-Dec 1998;126(11-12):457-60. Serbian..

10.Beuerman RW, Saw S-M, Tan DTH, Wong T-Y, editors. Myopia: Animal Models to Clinical Trials. 1st ed. Toh Tuck Link (Sin-gapore): World Scientific Publishing Company Pte Ltd; 2010. 

Crossref  

11.Mykheitseva IN, Abdulhadi Muhammad, Putienko AA, et al. [Inducing form-deprivation myopia in animals]. Oftalmol Zh. 2018;2:50-5. Russian.

12.Abdulhadi Muhammad, Mykheitseva IN, Putienko AA, et al. [Relationship of the axial length and anterior chamber depth of the rat globe and development of retinal abnormalities in type 2 diabetes mellitus with myopia]. Oftalmol Zh. 2018;6:44-50. Russian.

13.Reуnolds ES. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol. 1963 Apr;17(1):208-12. doi: 10.1083/jcb.17.1.208.

Crossref  PubMed

14.Lim LS, Lamoureux E, Saw SM.  Are myopic eyes less likely to have diabetic retinopathy? Ophthalmology. 2010 Mar;117(3):524-30. doi: 10.1016/j.ophtha.2009.07.044.

Crossref  PubMed

15.Man RE, Sasongko МВ, Sanmugasundram S, et al. Longer Axial Length Is Protective of Diabetic Retinopathy and Macular Edema. Ophthalmology. 2012 Sep;119(9):1754-9. doi: 10.1016/j.ophtha.2012.03.021.

Crossref  PubMed

16.Fu Y, Geng D, Liu H, Che H. Myopia and/or longer axial length are protective against diabetic retinopathy: a meta-analysis. Acta Ophthalmol. 016 Jun;94(4):346-52. doi: 10.1111/aos.12908.

Crossref  PubMed

17.Dastiridou AI, Ginis Н, Tsilimbaris М. Ocular rigidity, ocular pulse amplitude, and pulsatile ocular blood flow: the effect of axial length. Invest Ophthalmol Vis Sci. 2013 Mar 1;54(3):2087-92. doi: 10.1167/iovs.12-11576.

Crossref  PubMed

18.Shimada N, Ohno-Matsui К, Harino S. Reduction of retinal blood flow in high myopia. Graefes Arch Clin Exp Ophthalmol. 2004;242:284–8. doi: 10.1007/s00417-003-0836-0.

Crossref  PubMed

19.Man RE,  Sasongko MB,  Xie J, et al. Decreased Retinal Capillary Flow Is Not a Mediator of the Protective Myopia–Diabetic Reti-nopathy Relationship. Invest Ophthalmol Vis Sci. 2014 Sep 30;55(10):6901-7. doi: 10.1167/iovs.14-15137.

Crossref  PubMed

20.Man RE,  Sasongko MB,  Wang JJ,  Lamoureux EL. Association between myopia and diabetic retinopathy: a review of observa-tional findings and potential mechanisms. Clin Exp Ophthalmol.  2013 Apr;41(3):293-301. doi: 10.1111/j.1442-9071.2012.02872.x.

Crossref  PubMed

Conflict of Interest Statement:

The authors declare no conflict of interest which could influence their opinions on the subject or the materials presented in the manuscript.