Authors
Golyakov A.A., Faizrahmanov R.R., Shishkin M.M., Saraeva S.N.
Pirogov National Medical and Surgical Center, Moscow
Abstract
Backgraund: Keratoconus is a disease characterized by thinning of the cornea and weakening of its biomechanical characteristics, which leads to decreased visual acuity and the development of irregular astigmatism. Despite the possibility of long-term stabilization of keratectasia progression with help of crosslinking therapy, there remained dissatisfaction with the refractive outcome of patients and an insufficient improvement in their quality of life. We have proposed a technology for combining ultraviolet corneal crosslinking with personalized photorefractive keratectomy (PRK) using a Microscan Visum laser from a domestic manufacturer.
Aims: To develop a combined technology of corneal UV-crosslinking with personalized (PRK) using the excimer laser Microscan Visum and evaluate its effectiveness and safety based on the results of a two-year follow-up.
Materials and methods: This single-center, prospective, controlled, non-randomized study analyzed the outcomes of patients diagnosed with mild to moderate keratoconus at 12-month follow-up. The first group (control group) – 10 patients (10 eyes) who underwent the standard Dresden protocol for ultraviolet cross-linking; Group 2 (study group) – 10 patients (10 eyes) who underwent simultaneous personalized (PRK) with UV-crosslinking (standard Dresden protocol). Postoperative follow-up was two years. The parameters for evaluation were: uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), spherical equivalent of refraction, keratometry, pachymetry, the presence and depth of the demarcation line according to optical coherent tomographу of the cornea, and TMS-5 keratopography indicators: surface regularity index (SRI), surface asymmetry index (SAI), Klais/Maeda keratoconus index (KCI), the keratoconus severity index (KSI), as well as the Ectasia Suspect Interpreted index (ESI), obtained using a Scheimpflug camera.
Results: 20 people (20 eyes) were included in the study, average age was 30.6±9.5 years. Preoperative: UCVA 0.2±0.1, BCVA 0.4±0.05, mean sphere -4.75±0.25 D, mean cylinder 3.0±0.25 D, mean keratometry 46.59±1.75 D. Optical parameters improved and remind stable by the end of the follow-up period: UCVA 0.59±0.05 (p<0.05), BCVA 0.9±0.05 (p<0.05), mean sphere -2.5±0.25 D (p<0.05), mean cylinder 1.5±0, 25 D (p<0.05), mean keratometry 43.15±0.31 D (p<0.05).
Conclusions: Simultaneous topography-guided personalized PRK with excimer laser Microscan Visum in combination with the standard Dresden protocol for corneal collagen UV-crosslinking showed high efficiency in stabilizing of keratoconus and improving the optical-refractive characteristics of the cornea, and also demonstrated a long-lasting stable result and safety.
Keywords: keratoconus, photorefractive keratectomy, crosslinking, Microscan Visum, ectasia, cornea.
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