Efficacy and Safety of Corneal Collagen Crosslinking in Treatment of Progressive Keratoconus with Consideration to the Long-Term Results
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.
May 06, 2021; Published: may 28, 2021
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 2nd 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 1st group and 255 ± 10,0 µm in the 2nd. 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 2nd 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.
- 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.
- 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
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