Accelerated cross-linking technique using a protective corneal donor flap in the treatment of progressive keratoconus on «thin» corneas

• Main Authors: A. V. Tereshchenko, I. G. Trifanenkova, S. K. Demyanchenko, Yu. Yu. Golubeva, E. N. Vishnyakova, N. A. Kondrateva
• Format: Article
• Language: Russian
• Published: Publishing house "Ophthalmology" 2021-07-01
• Series: Офтальмохирургия
• Subjects: progressive keratoconus; thin cornea; ultraviolet crosslinking; protective donor corneal flap
• Online Access: https://www.ophthalmosurgery.ru/jour/article/view/758
• ISSN: 0235-4160; 2312-4970

Purpose. To develop a method of accelerated ultraviolet crosslinking with an initial corneal thickness equal to or less than 400 microns using a protective donor corneal flap. Definition of safety and effectiveness of this method in the treatment of progressive keratoconus.Material and methods. 20 patients (20 eyes) with a diagnosis of progressive keratoconus 2–3 stages were included in the study. The accelerated crosslinking was carried out with an IROC-VX-2000 device (Switzerland). A protective donor corneal flap was cut out by using a Femto LDV Z8 femtosecond laser («Ziemer», Switzerland). The thickness of the protective flap of the donor cornea was determined as the difference between 450 μm and the obtained value of the patient’s pachymetry in 30 minutes of saturation with Dextralink in μm.Results. Indicators of uncorrected visual acuity and corrected visual acuity returned to the level of preoperative values and did not tend to decrease until the end of the observation period for 6 months. The average keratometry indices gradually decreased: after 3 months – 50.3±1.5 μm, after 6 months – 48.9±1.8 μm, by 12 months – 46.7±2.1 μm. A decrease in elevation indicators of the anterior and posterior surfaces was marked on elevation maps throughout the observation period.Conclusion. The proposed ultraviolet crosslinking technique using a protective donor corneal flap in patients with corneal thickness 400 μm or less is reproducible. This technique proves its effectiveness and safety and allows to stabilize the condition in patients with progressive keratoconus with adequate visual function. This makes this technique necessary, taking into account the lack of adequate cross-linking technology with a thin cornea.