Comparison of transepithelial corneal crosslinking with epithelium-off crosslinking (epithelium-off CXL) in adult Pakistani population with progressive keratoconus

Abstract

PURPOSE:The purpose of this study is to compare the safety and efficacy of transepithelial corneal crosslinking (CXL) with epithelium-off crosslinking (epithelium-off CXL) in the treatment of progressive keratoconus in adult Pakistani population.MATERIALS AND METHODS:Sixty-four eyes of 64 consecutive patients of progressive keratoconus were included in this quasi-experimental study. Thirty-two eyes received transepithelial CXL with Peschke TE (0.25% riboflavin (Vitamin B2), 1.2% hydroxypropyl methylcellulose (HPMC), 0.01% benzalkonium chloride) and 32 eyes received epithelium-off CXL with Peschke M (0.1% riboflavin (Vitamin B2) 0.1%, HPMC 1.1%.) The cornea was then exposed to ultraviolet A light at an irradiance of 3 mW/cm2 for 30 min. The primary outcome measure, clinical stabilization of keratoconus was defined as an increase of no more than 1D in Kmax at 1 year. Other parameters evaluated at baseline and 3, 6, 12, and 18 months postoperatively were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), astigmatism (Ast), simulated keratometry, steep keratmetry (steep K), and corneal thickness at thinnest point (pachy thin).RESULTS:Both epithelium-off CXL and transepithelial CXL groups showed a significant reduction in Kmax, steep K, simulated K, corneal pachymetry at all test points (P < 0.05) with significantly greater reductions achieved in epithelium-off CXL group at 18 months follow-up. The mean UDVA, CDVA, SE, Ast significantly improved in both groups (P < 0.05). The mean postoperative UDVA and CDVA between the groups were not significant at 12 months (P = 0.650, 0.018, respectively). Clinical stabilization was achieved in 94% of eyes in epithelium-off CXL and 75% of eyes in transepithelial CXL. In epithelium-off CXL, three eyes exhibited stromal haze resolved by corticosteroid treatment. No complication was documented in transepithelial CXL group.CONCLUSION:Transepithelial CXL is not recommended to be replaced completely by standard epithelium-off CXL due to continued ectatic progression in 25% of cases. However, thin corneas, unfit for standard epithelium-off CXL, can benefit from transepithelial CXL.

Comparison of High Intensity Accelerated Corneal Cross Linking Protocols in Treatment of Progressive Keratoconus;

“…Significant decrease in thinnest pachymetry was also reported for AXL 9 mWatt/cm 2 in comparison against conventional CXL in literature. 12,16,17 We lack the evidence of AXL induced structural change in anterior corneal stroma as anterior segment optical coherence tomography was not done in our study to assess the depth of demarcation line. In addition to this, the major limitation of this study was a relatively small sample size.…”

Evaluation of Changes in Visual Acuity and Contrast Sensitivity in Patients With Keratoconus After Corneal Collagen Cross-Linking

“…Akbar et al, 15 compared transepithelial CXL to epithelium-off CXL in the treatment of progressive KC in adult Pakistani population with regards to safety and efficacy of treatment. The study reports significant improvement in postoperative UCVA as well as CDVA at 12 months with the difference between the two groups being statistically insignificant (p=0.650 and 0.367 respectively).…”

Fibrosis subepitelial de grado IV como complicación de un entrecruzamiento acelerado pulsado de fibras de colágeno corneal transepitelial en un paciente pediátrico: reporte de caso y revisión de los factores asociados

“…El entrecruzamiento de fibras de colágeno corneales o crosslinking, una técnica desarrollada en la universidad de Dresden y aplicada clínicamente por primera vez en 2003 por Wollensak, Spoerl y Seiler, quienes lograron una estabilización de la progresión del queratocono en el 70% de los casos a 5 años 1,2 , es hasta el momento el único tratamiento capaz de retrasar la progresión del queratocono 3 . Existen numerosas publicaciones sobre su eficacia combinada con otros procedimientos [4][5][6][7][8] y sus pocas complicaciones, explicadas en su gran mayoría por variantes específicas en el tratamiento, así como por características del queratocono y de cicatrización del paciente 9 .…”