Solodkova EG, Fokin VP, Balalin SV* and Melikhova IA

S. Fyodorov Eye Microsurgery Federal State Institution, Volgograd Branch, Russia

*Corresponding Author: Balalin SV, S. Fyodorov Eye Microsurgery Federal State Institution, Volgograd Branch, Russia.

Received: May 06, 2021; Published: may 28, 2021

Abstract

Purpose: To evaluate the efficacy and safety of a modified technique of corneal collagen crosslinking (CXL) versus standard protocol basing on changes of clinical and morphological characteristics of the cornea in the early and late postoperative period.

Materials and Methods: Two groups of patients were examined: group I (25 persons/25 eyes) consisted of patients treated for progressive keratoconus in accordance with a standard protocol of corneal collagen crosslinking, group II comprised those, who underwent crosslinking, performed in a modified technique - 36 persons (36 eyes). Prior to and after the procedure (1, 3, 6 and 12 months postoperatively), all patients had an extensive eye examination, including optical coherence tomography (OCT) of the cornea (OCT RS-3000, Nidek, Japan), confocal microscopy (Confoscan4, Nidek, Japan).

Results: Faster re-epithelialization of the cornea occurred in the 2^nd group. In both groups there was observed a significant increase of UCVA (from 0,15 ± 0,12 to 0,35 ± 0,14 in the first group and from 0,13 ± 0,11 to 0,33 ± 0,14 in the second) and BCVA (from 0,3 ± 0,18 to 0,05 ± 0,12 in the first group and from 0,4 ± 0,16 to 0,6 ± 0,18 in the second group) at 6 and 12 months follow-ups. One month postoperatively a well-defined rear stromal haze or "demarcation line" was confirmed by OCT and microscopy in all the treated eyes. By that time the depth of "demarcation line" location averaged 262 ± 15,0 µm in the 1^st group and 255 ± 10,0 µm in the 2^nd. The confocal microscopy revealed that histomorphologic changes were more pronounced in the first group within the whole follow-up period. Starting from the third month of observation a statistically significant downtrend in the rating of all the studied symptoms, with persistence of that tendency in the time that followed - at 6 and 12 months check-ups, was registered in the 2^nd group of patients, which pointed at milder and faster corneal recovery after CXL performed in accordance with the modified technique. Endothelial cell density (ECD) remained unchanged in all the cases in both groups within the whole follow-up period.

Conclusion:

1. Positive dynamics in postoperative UCVA and BCVA values, inalterability of ECD in all the cases allowed considering both options of corneal collagen crosslinking safe, with comparable clinical efficacy.
2. However, in view of more evident increase of BCVA in the second group, milder recovery in the early postoperative period and achievement of adequate and safe level of histomorphologic corneal changes after CXL, the modified technique of progressive keratoconus treatment seemed to be more advantageous.

Keywords: Keratoconus; Crosslinking; Modified Technique

References

1. Solodkova EG and Remesnikov IA. “Analysis of long-term results of corneal collagen crosslinking in the treatment of progressive keratoconus”. The Journal of Practical Medicine 1 (2021): 118-120.
2. Solodkova EG., et al. “Comparative analysis of methods for keratoconus treatment. Abstracts of The VI Annual All-Russian Scientific Practical Conference of Young Scientists “Current Problems of Ophthalmology” within the Scientific Practical Conference “Fyodorov Memorial Lectures-2011”. Moscow (2011): 229-231.
3. Pashtaev NP and Zotov VV. “A new method of corneal collagen crosslinking in the treatment of patients with keratoconus. Preliminary results”. Abstracts The Scientific Practical Conference “Fyodorov Memorial Lectures” (2011): 84.
4. Feinbaum C. “Current Aspects of Keratoconus Etiopathogenesis and Treatment”. Ophthalmosurgery 3 (2011): 80-83.
5. Anwar M and Teichmann KD. “Deep lamellar keratoplasty: Surgical techniques for anterior lamellar keratoplasty with and without baring of Descemet's membrane”. Cornea 21 (2002): 374-383.
6. Bahar I., et al. “Comparison of three different techniques of corneal transplantation for keratoconus”. International Ophthalmology 28 (2008): 141-146.
7. Colin J., et al. “Correcting keratoconus with intracorneal rings”. The Journal of Cataract and Refractive Surgery 26 (2000): 1117-1122.
8. Efron N and Hollingsworth J. “New perspectives on keratoconus as revealed by corneal confocal microscopy”. Clinical and Experimental Optometry1 (2008): 34-35.
9. Ferrara de A and Cunha P. “Tecnica cirurgica para correcao de myopia Аnel Corneano Intra-Estromal”. Revista Brasileira de Oftalmologia 54 (1995): 577-588.
10. Kaya V., et al. “Efficacy of Corneal Collagen Cross-linking Using a Custom Epithelial Debridement Technique in Thin Corneas: A confocal Microscopy Study”. Journal of Refractive Surgery6 (2011): 444-450.
11. Li Y., et al. “Keratoconus diagnosis with optical coherence tomography pachymetry mapping”. Ophthalmology 12 (2008): 2159-2166.
12. Maeda N., et al. “Automated keratoconus screening with corneal topography analysis”. Investigative Ophthalmology and Visual Science 35 (1994): 2749-2757.
13. Mazzotta C., et al. “Stromal haze after combined riboflavin-UVA corneal collagen cross-linking in keratoconus: in vivo confocal microscopic evaluation”. Clinical and Experimental Ophthalmology 35 (2007): 580-582.
14. Pinelli R. “C3-R treatment opens new frontiers for keratoconus and corneal ectasia”. Eyeworld 34 (2007): 36-39.
15. Price FW and Price MO. “Adult keratoplasty: has the prognosis improved in the last 25 years?” International Ophthalmology3 (2008): 41-146.
16. Rabinowitz YS. “Keratoconus”. Survey of Ophthalmology 42 (1998): 297-319.
17. Raiskup F., et al. “Permanent corneal haze after riboflavin-UVA-induced cross-linking in keratoconus”. Journal of Refractive Surgery 25 (2009): 824-828.
18. Roe RH., et al. “The value-based medicine comparative effectiveness and cost-effectiveness of penetrating keratoplasty for keratoconus”. Cornea9 (2008): 1001-1007.
19. Smolek MK and Klyce SD. “Neural network classification of corneal topography”. Investigative Ophthalmology and Visual Science 38 (1997): 2290-2299.
20. Spoerl E., et al. “Crosslinking Effects in the cornea of Rabbits”. Ophthalmology 97 (2000): 203-206.
21. Spoerl E., et al. “Thermomechanical Behavior of Collagen-Crosslinked Porcine Cornea”. Ophthalmologica 218 (2004): 136-140.
22. Spoerl E., et al. “Increased Resistance of Crosslinked Cornea against Enzymatic Digestion”. Current Eye Research1 (2004): 35-40.
23. Wollensak G., et al. “Riboflavin/Ultraviolet-A Induced Collagen- Crosslinking for the Treatment of Keratoconus”. American Journal of Ophthalmology 135 (2003): 620-627.
24. Wollensak G., et al. “Collagen Fiber Diameter in the Rabbit Cornea after Collagen-Crosslinking by Riboflavin/UVA”. Journal Cornea 23 (2004): 503-507.
25. Wollensak G., et al. “Collagen Fiber Diameter in the Rabbit Cornea after Collagen- Crosslinking by Riboflavin/UVA”. Journal Cornea5 (2004): 503-507.

Citation

Citation: Balalin SV., et al. “Efficacy and Safety of Corneal Collagen Crosslinking in Treatment of Progressive Keratoconus with Consideration to the Long-Term Results".Acta Scientific Ophthalmology 4.6 (2021): 92-100.

Copyright

Copyright: © 2021 Balalin SV., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.