Corneal-Wavefront guided transepithelial photorefractive keratectomy after corneal collagen cross linking in keratoconus

Abstract

PurposeTo evaluate the efficacy and safety of Corneal-Wavefront guided transepithelial photorefractive keratectomy (TransPRK) after corneal collagen cross linking (CXL) in keratoconic patients.MethodsIn this retrospective, non-comparative, consecutive case series, 39 keratoconic eyes underwent Corneal-Wavefront guided TransPRK for the correction of aberrations at least 4 months after conventional CXL at SEKAL Rovigo Microsurgery Centre, Rovigo, Italy. Two eyes (5%) underwent a secondary laser retreatment for the improvement of post-operative visual acuity and were not included in this retrospective analysis. The mean age of the patients was 35 ± 12 years (19–64 years) at the time of the surgery. Keratron-Scout (Optikon) topographer was used for diagnostic tests and a flying-spot laser (AMARIS; SCHWIND eye-tech-solutions) was used for the refractive surgery. Complete ophthalmic examinations were performed before and after the surgery (4–36 months postoperatively with a mean follow up time of 10 ± 8 months).ResultsPreoperatively, eyes showed irregular astigmatism up to 8D. At last postoperative follow-up, 21 eyes (57%) had UDVA better than 20/40, and six eyes (16%) had UDVA of 20/20. Twenty-three eyes (62%) were within 1.50D of attempted correction in spherical equivalent (mean deviation from target was +1.09 ± 2.36D, range −2.50 to +7.38D). No eye lost 2 Snellen lines of CDVA, and 15 eyes (41%) had an increase of more than 2 lines.ConclusionsCorneal-Wavefront guided transepithelial PRK ablation profiles after conventional CXL yields to good visual, optical, and refractive results. These treatments are safe and efficacious for the correction of refracto-therapeutic problems in keratoconic patients.

Simultaneous Transepithelial Topography-Guided Photorefractive Keratectomy and Accelerated Cross-Linking in Keratoconus: 2-Year Follow-Up

“…Additionally, the Amaris platform and Optimized Refractive Keratectomy-Custom Ablation Manager (ORC-CAM) software were used in only a few studies with a limited number of patients and short follow-up periods. Camellin et al [ 14 ] evaluated 37 eyes, but 31 of the eyes had follow-up periods that ranged from 4 months to 1 year. Müller and Lange [ 15 ] evaluated only nine eyes and the patients had follow-ups at 18 months.…”

Keratoconus Management With Customized Photorefractive Keratectomy by Artificial Intelligence Ray-Tracing Optimization Combined With Higher Fluence Corneal Crosslinking: The Ray-Tracing Athens Protocol

“…9 In addition, wavefront-guided photorefractive keratectomy (PRK) normalization has been also reported as a combination treatment along with CXL for keratoconus. [10][11][12] Ray tracing has been described as a means of customization for routine myopic excimer treatments, using bimodal calculation of light incidence through the human eye, studied with the aid of wavefront, anterior segment tomography, and interferometry axial length data. We present in this study a modification of the Athens protocol for progressive keratoconus, using artificial intelligence-generated ray-tracing calculation of the excimer laser-customized ablation aiming to normalize the distorted optics by the ectasia.…”

Ray-Tracing Transepithelial Excimer Laser Central Corneal Remodeling Plus Pachymetry-Guided Accelerated Corneal Crosslinking for Keratoconus

“…[13][14][15][16][17][18] Other studies have demonstrated that excimer laser CCR can also be performed at least 6 to 12 months after CXL treatment. 15 Retrospective, noncomparative consecutive case series in patients who underwent corneal wavefront-guided trans-PRK for the correction of aberrations at least 4 to 6 months after CXL reported that corneal wavefront-guided transepithelial PRK ablation profiles after conventional CXL also yield good visual, optical, and refractive results. 16,17 Although these combined treatments have been performed and are widespread for over a decade, the literature shows inhomogeneous protocols 5,6,[10][11][12][13][14][15][16][17][18]22 and different settings both in excimer laser planning and crosslinking application, which can be considered a limitation.…”

“…8 The long-term follow-up studies have demonstrated the efficacy and safety of these procedures in improving the UCVA and BSCVA of patients with KC performed simultaneously (on a same-day basis) or sequentially (6 months at least after CXL). [9][10][11][12][13][14][15][16][17][18] CXL has paved the way for these treatments by strengthening the corneal stroma and stabilizing the progression of KC. [19][20][21] The all-surface laser ablation in patients with KC is planned by using topography-guided algorithms, optimizing the optical zones and reducing the HOAs while minimizing the consumption of stromal tissue, and beyond improving patient's UDVA and BSCVA, another purpose of this therapeutic option consists in giving another chance of contact lens fitting on a more regular reshaped corneal surface.…”