Transepithelial Enhanced Fluence Pulsed Light M Accelerated Crosslinking for Early Progressive Keratoconus with Chemically Enhanced Riboflavin Solutions and Air Room Oxygen

Abstract

Purpose: To assess the 3-year clinical results of the 18 mW 7 J/cm2 transepithelial enhanced fluence pulsed light M accelerated crosslinking in the treatment of progressive keratoconus (KC) with chemically enhanced hyper-concentrated riboflavin solutions without iontophoresis and with air-room oxygenation. Setting: Siena Crosslinking Center, Siena, Italy. Methods: Prospective pilot, open non-randomized interventional study including 40 eyes of 30 young adult patients over 21 years old (10 simultaneous bilateral) with early (Stage I and II) progressive KC undergoing TE-EFPL 18 mW/7 J/cm2 ACXL (EFPL M TECXL). The 12 min and 58 s pulsed light (1 s on/1 s off) UV-A exposure treatments were performed with a biphasic corneal soaking using Paracel I 0.25% for 4 min and Paracel II 0.22% for 6 min riboflavin solutions and New KXL I UV-A emitter (Glaukos-Avedro, Waltham, USA) at an air room of 21% oxygenation. All patients completed the 3-year follow-up. Results: CDVA showed a statistically significant improvement in the third postoperative month (Δ + 0.17 d. e.) with a final gain of +0.22 d. eq. AK showed a statistically significant decrease in the sixth postoperative month (Δ − 1.15 diopters). K itmax showed a statistically significant decrease at 1-year follow-up (Δ − 1.3 diopters). The coma value improved significantly by the sixth month (Δ − 0.54 µm). MCT remained stable during the entire follow-up. No adverse events were recorded. Corneal OCT revealed a mean demarcation line depth at 282.6 ± 23.6 μm. Conclusions: Transepithelial enhanced fluence pulsed light M accelerated crosslinking with chemically enhanced riboflavin solution halted KC progression in young adult patients without iontophoresis and no intraoperative oxygen supplementation addressing the importance of increased fluence.

Progressive high-fluence epithelium-on accelerated corneal crosslinking: a novel corneal photodynamic therapy for early progressive keratoconus

“…The progressively higher fluence protocols enhance Epi-Off and Epi-On efficacy, as demonstrated in past and recent literature ( 9 – 12 , 15 ). The increased fluence variance may be the key to optimizing the photodynamic process of Epi-On crosslinking, paving the way to the final switch ( 9 ). We present the preliminary data of the new pachymetry-based progressively higher fluence Epi-On nomogram as a new paradigm of corneal photodynamic therapy for early progressive KC ( 22 – 24 ).…”

“…What is even more relevant is the absence of risks and adverse events, which place this method amongst the prophylactic therapies of primary and iatrogenic corneal ectasia as it can be applied purely preventively, even in cases of ectasia that have not yet evolved, to safeguard patients' vision with excellent compliance. The approach also allows for the possibility of simultaneous outpatient interventions, causing minimal postoperative discomfort and avoiding microstructural damage to the ocular surface so that patients may return to their normal activities the day after ( 9 ). The high fluence era began in 2016, with studies on customized CXL by Seiler (the first study with 10 J/cm 2 ) ( 11 ) and Mazzotta (the first study with PiXL at 10 and 15 J/cm 2 ) ( 12 ).…”

“…Many parameters have been adapted to optimize the effectiveness of Epi-On accelerated crosslinking. The most important was represented by the increased fluence that passed from the original 5.4 to 7 J/cm 2 , which ensured greater penetration, visibility of deeper demarcation lines, and higher efficacy of the new Epi-On procedures without intraoperative supplemental oxygen ( 9 ).…”

Early findings in a prospective randomised study on three cross-linking treatment protocols: interruption of the iontophoresis treatment protocol

“…We, therefore, concluded that this protocol is not suitable for halting keratoconus disease progression. Possible means of improving the efficacy of the iontophoresis-assisted protocol include a longer irradiation time, the addition of oxygen during treatment, or pulsed UV-A irradiation 48. We also concluded that the way in which progressive keratoconus is diagnosed, and the way in which treatment efficacy is evaluated, significantly affect the interpretation of the outcome.…”

“…Possible means of improving the efficacy of the iontophoresis-assisted protocol include a longer irradiation time, the addition of oxygen during treatment, or pulsed UV-A irradiation. 48 We also concluded that the way in which progressive keratoconus is diagnosed, and the way in which treatment efficacy is evaluated, significantly affect the interpretation of the outcome. These aspects should be considered in future clinical investigations of CXL.…”