New possibilities for optimizing the effect of scleroplasty in progressive myopia

Purpose: to experimentally develop a method for preparing an allograft with optimized properties for scleroplasty (SP) in progressive myopia.

Material and methods. The experiment was performed on 40 eyes of 20 Chinchilla rabbits, which were divided into four groups depending on the method of processing the scleral allograft for SP: Group 1 (control) — 5 rabbits (10 eyes) with an intact graft; Group 2 — 5 rabbits (10 eyes) with a graft after ultraviolet (UVA) crosslinking with riboflavin; Group 3 — 5 rabbits (10 eyes) with a graft after UVA crosslinking with riboflavin and with additional treatment with 0.1 % riboflavin solution; Group 4 — 5 rabbits (10 eyes) with a graft after UVA crosslinking with riboflavin with an additional 1.5 % actovegin solution treatment. Comparative evaluation of biomechanical parameters of the graft before and after UVA crosslinking with riboflavin was carried out in vitro using biomechanical testing (AUTOGRAPH device, Japan). Acoustic density of the sclera (ADS) before and after SP was assessed in vivo using an ultrasound diagnostic device VOLUSON 730 (Kretz), and choroidal thickness (CT) using Mirante SLO / OCT (Nidek). One month after SP, a morphological study of the enucleated experimental eyes was performed.

Results. The study of the biomechanical properties of the graft, ADS, CT and the morphological picture of the scleragraft complex showed the advantages of using for SP a graft treated with UVA crosslinking in combination with additional treatment with 0.1 % riboflavin solution (group 3). The elastic modulus as a result of UVA crosslinking increased by 1.2 times. The increase in ADS after SP in the 1st (control) group was on average 14 units, in the 2nd — 17 units, in the 3rd — 23 units, in the 4th — 17 units, i. e. the greatest increase in ADS was noted in group 3. The increase in CT was also the greatest in group 3 — 14.4 ± 0.3 μm, against 6.0 ± 0.3 μm in group 2 and 12.1 ± 0.2 μm in group 4. Morphological study showed better engraftment and ordered structure of the graft in the experimental eyes of group 3.

Conclusion. UVA crosslinking, as the first stage of the graft preparation, allowed increasing its biomechanical stability and preservation of structure during engraftment, and additional treatment with riboflavin contributed to the improvement of blood supply to the choroid. Preparation of alloscleral graftt for scleroplasty in progressive myopia, including two stages — UVA crosslinking and subsequent treatment with 0.1 % riboflavin solution, is the most effective way to optimize its properties.

1. Katargina L.A., Mikhailova L.A. The state of children’s ophthalmological service in the Russian Federation (2012–2013). Russian pediatric ophthalmology. 2015; 10 (1): 5–10 (In Russ.).

2. Grzybowski A, Kanclerz P, Tsubota K, Lanca C, Saw SM. A review on the epidemiology of myopia in school children worldwide. BMC Ophthalmol. 2020 Jan 14; 20 (1):27. doi: 10.1186/s12886-019-1220-0

3. Haarman AEG, Enthoven CA, Tideman JWL, et al. The complications of myopia: A review and meta-analysis. Invest Ophthalmol Vis Sci. 2020 Apr 9; 61 (4): 49. doi: 10.1167/iovs.61.4.49

4. Tarutta E.P. Sclera reinforcement reatment and prevention of complication of progressive myopia. In: Avetisov S.E., Kashchenko T.P., Shamshinova A.M., eds. Visual functions and their correction in children. Moscow: Meditsina; 2005: 191–202 (In Russ.).

5. Iomdina E.N., Tarutta E.P., Markosyan G.A., et al. Biomechanical characteristics of the corneoscleral tunic and the state of the connective tissue system in the children and adolescents presenting with various forms of progressive myopia. Russian pediatric ophthalmology. 2013; 1: 18–23 (In Russ).

6. Tarutta EP, Andreyeva LD. A morphological study of the transplants after scleroplasty in progressive myopia. Exp Eye Res. 1998; 67: 68.

7. Tarutta E.P., Iomdina E.N., Maksimova M.V., Shamkhalova E.Sh., Andreeva L.D. Sclera fortification in children at a high risk of progressive myopia. Vestnik oftal’mologii. 1992; 108 (2): 14–7 (In Russ.).

8. Iomdina E.N., Tarutta E.P., Andreeva L.D., et al. An experimental validation of sclera strengthening treatment of progressive myopia with a biologically active synthetic transplant. Refraktsionnaya khirurgiya i oftal’mologiya. 2005; 4: 19–23 (In Russ.).

9. Tarutta E.P., Iomdina E.N., Markosyan G.A., Andreeva L.D., Lazuk A.V. Reinforced graft for scleroplastic operations. RF Patent No. 2140242, October 27, 1999 (In Russ.).

10. Xue A, Zheng L, Tan G, et al. Genipin-crosslinked donor sclera for posterior scleral contraction/reinforcement to fight progressive myopia. Invest Ophthalmol Vis Sci. 2018 Jul 2; 59 (8): 3564–73. doi: 10.1167/iovs.17-23707

11. Hamdaoui ME, Levy AM, Stuber AB, et al. Scleral crosslinking using genipin can compromise retinal structure and function in tree shrews. Exp Eye Res. 2022 Jun; 219: 109039. doi: 10.1016/j.exer.2022.109039

12. Wollensak G. Corneal collagen crosslinking: new horizons. Expert Review of Ophthalmology. 2010; 5 (2): 201–15. https://doi.org/10.1586/eop.10.7

13. Angelo L, Gokul Boptom A, McGhee C, Ziaei M. Corneal crosslinking: Present and future. Asia Pac J Ophthalmol (Phila). 2022 Sep 1; 11 (5): 441–52. doi: 10.1097/APO.0000000000000557

14. Iomdina Е.N., Tarutta Е.P., Semchishen V.А., et al. Experimental realization of minimally invasive techniques of scleral collagen cross-linking. Vestnik oftal’mologii. 2016; 6: 49–57 (In Russ., In Engl.). doi: 10.17116/engoftalma20161326-4

15. Li Y, Qi Y, Sun M, et al. Clinical feasibility and safety of scleral collagen cross-linking by riboflavin and ultraviolet A in pathological myopia blindness: A Pilot Study. Ophthalmol Ther. 2023 Apr; 12 (2): 853–66. doi: 10.1007/s40123-022-00633-5

16. Kirisenko L.I., Oparina A.E., Puchkina E.V. Comparative evaluation of the use of Korneregel and eye gel “Actovegin” in patients after cataract extraction. Russian medical journal. 2003; 4: 178–9 (In Russ.).

17. Zolotareva R.A., Loginova N.Yu. Riboflavin: general aspects of metabolism. Eurasian Union of Scientists. 2016; 6 (27): 75–7 (In Russ.). https://cyberleninka.ru/article/n/riboflavin-obschie-aspekty-metabolizma