Transepithelial accelerated corneal collagen crosslinking in patients with progressive keratoconus: long term follow up results

• Autor(a) principal: Miguel Pereira Correia Natal
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/10216/134509
• topic: Medicina clínica; Clinical medicine

Purpose: to systematically evaluate the long-term efficacy of transepithelial accelerated corneal collagen crosslinking (TE-ACXL) in the treatment of eyes with progressive keratoconus by reporting its visual and morphological outcomes throughout a 4-year follow-up. Methods: eyes of patients who underwent TE-ACXL (6mW/cm2 for 15 minutes) for progressive keratoconus were included in this retrospective cohort study. Best-corrected visual acuity (BCVA), keratometry measurements, thinnest corneal thickness (PachyMin), and topographic indexes were analyzed preoperatively and every 6 months after TE-ACXL, up to a maximum of 48 months. Disease progression was defined as an increase ≥ 1.00 D in corneal astigmatism, an increase ≥ 1.00 D in maximum keratometry (Kmax), a decrease ≥ 2% in PachyMin, or an increase ≥ 0.42 units in D-index. Results: the study enrolled 39 eyes from 30 patients. No significant differences were observed in BCVA, corneal astigmatism, Kmax, index of surface variance (ISV), index of height decentration (IHD), and keratoconus index (KI) between baseline and subsequent follow-up evaluations (p>0.05). There was a significant increase at 12-, 24- and 36-months follow-up in mean keratometry (Km) (0.66 ± 1.07 D, p=0.001; 0.94 ± 1,42 D, p=0.001; 1.48 ± 1.19 D, p=0.002) and D-index (0.50 ± 1.05 units, p=0.011; 0.53 ± 1.19 units, p=0.024; 1.29 ± 1.11 units, p=0.003). There were significant decreases in PachyMin at 36 months (-10.45 ± 15.20 µm, p=0.046) and in index of vertical asymmetry (IVA) at 24 months (-0.07 ± 0.16 units, p=0.024). 28 (71.8%) eyes maintained progression by at least one criterion. 2 (5.1%) eyes fulfilled all 4 progression criteria. Surgery and follow-up were uneventful in all subjects. Conclusion: TE-ACXL seems to be a safe and effective treatment for progressive keratoconus. Definition of new specific and significant progression criteria and further prospective studies with larger cohorts are recommended.