The study demonstrates the ability of CXL to slow down KC progression in pediatric patients, improving functional performance. Long-term stability may be correlated with CXL-induced delay in corneal collagen turnover and with spontaneous age-related KC stabilization. A 24% regression rate could be contemplated in the patients who were aged 15 years and younger at the time of inclusion in the treatment protocol.
Purpose:
To evaluate the outcomes of customized corneal crosslinking (CXL) for treatment of progressive keratoconus (KC) using a transepithelial approach with supplemental oxygen.
Setting:
Siena Crosslinking Center, Siena, Italy.
Design:
Prospective interventional case series.
Methods:
Twenty-seven eyes of 24 patients (mean age 29.3 ± 7.3 years) with progressive KC underwent customized corneal CXL using a transepithelial approach with supplemental oxygen. Ultraviolet (UV)-A irradiation of 365 nm wavelength was delivered in an accelerated (30 mW/cm2) pulsed-light UV light exposure in a 2-zone elliptical pattern. A total dose of 10 J/cm2 was delivered at the KC apex, surrounded by a broadbeam spot of 7.2 J/cm2. After 0.25% riboflavin corneal soaking, the UV-A irradiation was initiated in the presence of additional oxygen (≥90% concentration) delivered through special goggles connected to an oxygen delivery system (flow-rate 2.5 liters per minute). Key outcome measures included corrected distance visual acuity (CDVA), keratometry (AK, K1, K2, and K-average), corneal higher-order aberrations, topographic and manifest cylinder, corneal optical coherence tomography (OCT) demarcation line, and endothelial cell count.
Results:
Of the 27 eyes studied, a significant improvement of CDVA was recorded at 6-month follow-up visits, from baseline 0.19 ± 0.06 logarithm of the minimum angle of resolution (logMAR) to 0.11 ± 0.04 logMAR (P < .05). Significant flattening of steep keratometry (K2) was reported with mean change of −1.9 diopters (D) (P < .05), and coma values improved from 0.47 ± 0.28 µm to 0.28 ± 0.16 µm (P < .05). OCT revealed 2 demarcation lines at mean depths of 218.23 ± 43.32 µm and 325.71 ± 39.70 µm.
Conclusions:
In this series, customized CXL using a transepithelial approach with intraoperative supplemental oxygen resulted in clinically meaningful improvements in corneal curvature and CDVA without significant adverse events.
PURPOSE:
To assess 3-year safety and efficacy of enhanced-fluence pulsed-light iontophoresis cross-linking (EF I-CXL) in patients with progressive keratoconus.
METHODS:
This prospective interventional pilot study included 24 eyes of 20 patients, with a mean age of 23.9 years (range: 15 to 36 years). Iontophoresis with riboflavin solution was used for stromal imbibition. The treatment energy was optimized at 30% (7 J/cm
2
) and ultraviolet-A power set at 18 mW/cm
2
× 6.28 minutes of pulsed-light on-off exposure, with a total irradiation time of 12.56 minutes. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal tomography, and corneal optical coherence tomography (OCT) at baseline and 1, 3, 6, 12, 24, and 3 years postoperatively were evaluated.
RESULTS:
At 3 years, average UDVA decreased from 0.50 ± 0.10 to 0.36 ± 0.08 logMAR (
P
< .05), average maximum keratometry decreased from 52.94 ± 1.34 to 51.4 ± 1.49 diopters (D) (Delta: −1.40 ± 0.80 D;
P
< .05), average coma improved from 0.24 ± 0.05 to 0.12 ± 0.02 µm (
P
= .001), and symmetry index decreased from 4.22 ± 1.01 to 3.53 ± 0.90 D. Corneal OCT showed demarcation line detection at 285.8 ± 20.2 µm average depth in more than 80% at 1 month postoperatively.
CONCLUSIONS:
The 3-year results of EF I-CXL showed satisfactory I-CXL functional outcomes, increasing the visibility and the depth of demarcation line closer to epithelium-off standard CXL.
[
J Refract Surg
. 2020;36(5):286–292.]
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