Demarcation line depth after contact lens–assisted corneal crosslinking for progressive keratoconus: Comparison of dextran-based and hydroxypropyl methylcellulose–based riboflavin solutions

Abstract

During contact lens-assisted CXL, HPMC-based riboflavin seemed to be associated with a deeper demarcation line than dextran-based riboflavin, although both solutions were safe for the endothelium at 6 months.

Superior outcome of corneal collagen cross‐linking using riboflavin with methylcellulose than riboflavin with dextran as the main supplement

“…To our knowledge, only one study has compared intrastromal changes after CXL using either methylcellulose-riboflavin or dextran-riboflavin. However, a contact lens-assisted CXL protocol was used, and only the optical coherence tomography (OCT) demarcation line was evaluated in this study (Malhotra et al 2017). In the present study, we have used conventional UVA irradiation and 0.1% riboflavin with either dextran or methylcellulose as the main supplement during the CXL procedure.…”

Transepithelial Collagen Cross-linking versus Contact Lens-assisted Collagen Cross-linking for Progressive Keratoconus with Borderline Corneal Thickness: A Prospective Comparative Study

“…We have also previously documented a mean DL depth of 235.3 ± 64.9 µm in patients undergoing CACXL with dextran containing riboflavin. 16 In the present study where a HPMC containing, dextran free riboflavin formulation was used, the mean demarcation line depth measured on ASOCT in CACXL patients was approximately 60-70 µm deeper, i.e., 308.2 ± 84.2 µm. Interestingly the TECXL group also had a mean demarcation line depth of 294.4 ± 57.1 µm which was comparable to that of the CACXL group (p = 0.66) and that of standard 'epithelium-off' CXL.…”

“…We have partially reported data of the nine patients belonging to the CACXL group in a previous study retrospectively comparing outcomes of CACXL performed using either a dextranbased or HPMC based riboflavin formulation. 16 In the present study mean age was comparable being 19.9 ± 4.7 years (range 13-29 years) and 18.4 ± 4.3 years (range 13-24 years) for the TECXL and CACXL groups respectively (p = 0.48) The mean follow-up duration of 282.2 ± 56.5 days (range 184-374 days) in the TECXL group and 240.2 ± 54.9 days (range 189-308 days) in CACXL group was also comparable (p = 0.11). As shown in Table 1, the groups were similar with respect to baseline visual, refractive, keratometric and biomechanical parameters, as well as the mean ECD.…”

“…Various studies have compared TECXL with standard epithelium off CXL in patients suitable for conventional cross-linking with mixed results. 8,[17][18][19][20] Outcomes of TECXL in patients with thin corneas have however been reported only by a few authors, 9,10 and published data about outcomes of CACXL is also limited 11,16 as this technique is relatively recent. In the present study, a greater number of keratometric parameters (K m , steep K, flat K) improved significantly in the CACXL group (p = 0.001, 0.003 and 0.004, respectively) while in the TECXL group only flat K showed significant improvement (p = 0.009) other parameters remaining stable.…”

“…13 ASOCT was repeated 1 month after CXL to note the appearance and depth of the demarcation line as described previously. 16 Briefly, the depth of the demarcation line (visible as a hyperreflective line in the corneal stroma) was measured at five points including the centre and 1.5 mm and 3 mm nasal and temporal to the centrally measured location ( Fig. 1).…”