{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T08:58:28Z","timestamp":1781254708936,"version":"3.54.1"},"reference-count":35,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T00:00:00Z","timestamp":1781222400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Pediatric keratoconus may progress rapidly, and treatment decisions are often made before prolonged observation is possible. This study evaluated 24-month visual, tomographic, pachymetric, and biomechanical outcomes after conventional epithelium-off corneal collagen cross-linking (CXL) using Pentacam tomography and Corvis ST dynamic Scheimpflug analysis. Materials and Methods: This single-center observational longitudinal cohort included 28 eyes of 23 patients aged 13\u201318 years treated at the OCULENS Clinic, Cluj-Napoca, Romania, between 2019 and 2023. Because the study had no untreated or alternative-treatment control group, postoperative changes were interpreted as associations after CXL rather than as proof of causality. Baseline, 6-, 12-, and 24-month values were analyzed for UCVA, BCVA, Kmax, thinnest pachymetry, SP-A1, deformation amplitude (DA), first and second applanation times (A1T and A2T), highest concavity (HC) radius, and BAD-D. Repeated-measures ANOVA was used after assessment of within-eye difference normality; findings were interpreted cautiously because the analysis was eye-based, the cohort was small, and multiple outcomes were examined. Results: UCVA improved from 0.53 \u00b1 0.16 to 0.44 \u00b1 0.16 logMAR and BCVA from 0.31 \u00b1 0.11 to 0.25 \u00b1 0.11 logMAR (both p &lt; 0.001). Mean Kmax decreased modestly from 54.36 \u00b1 3.11 D to 53.41 \u00b1 2.79 D, while SP-A1 increased from 84.69 \u00b1 4.75 to 97.39 \u00b1 5.11 (both p &lt; 0.001). Thinnest pachymetry showed early postoperative thinning followed by partial recovery by 24 months. DA decreased, A1T increased, A2T decreased, HC radius increased, and BAD-D decreased significantly. Kmax and SP-A1 were inversely correlated at all visits (r = \u22120.714 to \u22120.773; all p &lt; 0.001), but these correlations were considered exploratory. Post-24-month retreatment and keratoplasty-related events were recorded descriptively and were not included in the formal 24-month model. Conclusions: Within the prespecified 24-month analytic window, conventional epithelium-off CXL was associated with stabilization, modest visual and tomographic improvement, and a concordant biomechanical stiffening signal. The results should be interpreted as cautious observational findings rather than definitive evidence of long-term stability, because of the small sample, eye-level analysis, absence of a control group, limited follow-up, and lack of formal repeatability testing.<\/jats:p>","DOI":"10.3390\/medicina62061145","type":"journal-article","created":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T06:53:10Z","timestamp":1781247190000},"page":"1145","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Biomechanical and Tomographic Outcomes in Pediatric Keratoconus Treated with Conventional Epithelium-Off Corneal Collagen Cross-Linking"],"prefix":"10.3390","volume":"62","author":[{"given":"Radu-Nicolae","family":"Pop","sequence":"first","affiliation":[{"name":"OCULENS Ophthalmology Clinic, 400501  Cluj-Napoca, Romania"},{"name":"Faculty of Medicine, \u201cLucian Blaga\u201d University, 550169 Sibiu, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patricia Ariadna","family":"Nicula","sequence":"additional","affiliation":[{"name":"OCULENS Ophthalmology Clinic, 400501  Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina Ariadna","family":"Nicula","sequence":"additional","affiliation":[{"name":"OCULENS Ophthalmology Clinic, 400501  Cluj-Napoca, Romania"},{"name":"Department of Oral and Maxillofacial Surgery and Radiology, Faculty of Dentistry, \u201cIuliu Ha\u021bieganu\u201d University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dorin Vasile","family":"Nicula","sequence":"additional","affiliation":[{"name":"OCULENS Ophthalmology Clinic, 400501  Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bianca","family":"Pop","sequence":"additional","affiliation":[{"name":"Surgical Department, University of Agricultural Sciences and Veterinary Medicine, 400372 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/S0039-6257(97)00119-7","article-title":"Keratoconus","volume":"42","author":"Rabinowitz","year":"1998","journal-title":"Surv. Ophthalmol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1097\/ICO.0000000000000408","article-title":"Global consensus on keratoconus and ectatic diseases","volume":"34","author":"Gomes","year":"2015","journal-title":"Cornea"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.preteyeres.2015.07.001","article-title":"Corneal structure and transparency","volume":"49","author":"Meek","year":"2015","journal-title":"Prog. Retin. Eye Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1775","DOI":"10.18240\/ijo.2019.11.17","article-title":"The correlation between keratoconus and eye rubbing: A review","volume":"12","author":"Najmi","year":"2019","journal-title":"Int. J. Ophthalmol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2257","DOI":"10.1007\/s10792-017-0699-8","article-title":"Pediatric keratoconus: A review of the literature","volume":"38","author":"Mukhtar","year":"2018","journal-title":"Int. Ophthalmol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"214","DOI":"10.4103\/ijo.IJO_1263_20","article-title":"Pediatric keratoconus\u2014Current perspectives and clinical challenges","volume":"69","author":"Anitha","year":"2021","journal-title":"Indian J. Ophthalmol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"620","DOI":"10.1016\/S0002-9394(02)02220-1","article-title":"Riboflavin\/ultraviolet-A-induced collagen crosslinking for the treatment of keratoconus","volume":"135","author":"Wollensak","year":"2003","journal-title":"Am. J. Ophthalmol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1006\/exer.1997.0410","article-title":"Induction of cross-links in corneal tissue","volume":"66","author":"Spoerl","year":"1998","journal-title":"Exp. Eye Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"796","DOI":"10.1016\/j.jcrs.2007.12.039","article-title":"Collagen crosslinking with riboflavin and ultraviolet-A light in keratoconus: Long-term results","volume":"34","author":"Hoyer","year":"2008","journal-title":"J. Cataract. Refract. Surg."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.jcrs.2010.07.030","article-title":"Corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results","volume":"37","author":"Hersh","year":"2011","journal-title":"J. Cataract. Refract. Surg."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"753","DOI":"10.3928\/1081597X-20121011-01","article-title":"Progression of keratoconus and efficacy of corneal collagen cross-linking in children and adolescents","volume":"28","author":"Chatzis","year":"2012","journal-title":"J. Refract. Surg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"520","DOI":"10.1016\/j.ajo.2012.03.020","article-title":"Two-year corneal cross-linking results in patients younger than 18 years with documented progressive keratoconus","volume":"154","author":"Vinciguerra","year":"2012","journal-title":"Am. J. Ophthalmol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"793","DOI":"10.3928\/1081597X-20121011-08","article-title":"Corneal collagen cross-linking for progressive keratoconus in pediatric patients: A feasibility study","volume":"28","author":"Zotta","year":"2012","journal-title":"J. Refract. Surg."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1097\/ICO.0000000000000702","article-title":"Pediatric corneal collagen cross-linking: Long-term follow-up of visual, refractive, and topographic outcomes","volume":"35","author":"Bayraktutar","year":"2016","journal-title":"Cornea"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1111\/aos.13224","article-title":"Cross-linking in children with keratoconus: A systematic review and meta-analysis","volume":"95","author":"McAnena","year":"2017","journal-title":"Acta Ophthalmol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"211","DOI":"10.2174\/1874364101711010211","article-title":"Collagen cross-linking for paediatric keratoconus","volume":"11","author":"Panos","year":"2017","journal-title":"Open Ophthalmol. J."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1136\/bjophthalmol-2016-310108","article-title":"Corneal collagen cross-linking in paediatric patients affected by keratoconus","volume":"102","author":"Knutsson","year":"2018","journal-title":"Br. J. Ophthalmol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1097\/ICO.0000000000001505","article-title":"Corneal collagen crosslinking with riboflavin and ultraviolet A light for pediatric keratoconus: Ten-year results","volume":"37","author":"Mazzotta","year":"2018","journal-title":"Cornea"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"95","DOI":"10.4103\/meajo.MEAJO_240_18","article-title":"Safety and efficacy of corneal cross-linking in pediatric patients with keratoconus and vernal keratoconjunctivitis","volume":"26","author":"Alrobaian","year":"2019","journal-title":"Middle East. Afr. J. Ophthalmol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Kobashi, H., and Rong, S.S. (2021). Corneal cross-linking for paediatric keratoconus: A systematic review and meta-analysis. J. Clin. Med., 10.","DOI":"10.3390\/jcm10122626"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"874","DOI":"10.1097\/ICO.0000000000002808","article-title":"Progression of pediatric keratoconus after corneal cross-linking: A systematic review and pooled analysis","volume":"41","author":"Achiron","year":"2022","journal-title":"Cornea"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"983","DOI":"10.1007\/s40123-022-00508-9","article-title":"Pediatric crosslinking: Current protocols and approach","volume":"11","author":"Polido","year":"2022","journal-title":"Ophthalmol. Ther."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Wajnsztajn, D., Shmueli, O., Tarnovsky, Y., Frucht-Pery, J., and Solomon, A. (2023). Outcome indicators for cross linking in pediatric keratoconus. Front. Med., 10.","DOI":"10.3389\/fmed.2023.1149641"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.ajo.2023.01.012","article-title":"Long-term safety and efficacy of corneal collagen crosslinking in a pediatric group with progressive keratoconus: A 7-year follow-up","volume":"250","author":"Polido","year":"2023","journal-title":"Am. J. Ophthalmol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1016\/j.ajo.2023.07.017","article-title":"Corneal collagen cross-linking for progressive keratoconus in pediatric patients: Up to 14 years of follow-up","volume":"255","author":"Vinciguerra","year":"2023","journal-title":"Am. J. Ophthalmol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1016\/j.ajo.2015.02.005","article-title":"Transepithelial versus epithelium-off corneal cross-linking for progressive keratoconus: A randomized controlled trial","volume":"159","author":"Soeters","year":"2015","journal-title":"Am. J. Ophthalmol."},{"key":"ref_27","first-page":"CD013512","article-title":"Transepithelial versus epithelium-off corneal crosslinking for progressive keratoconus","volume":"3","author":"Ng","year":"2021","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_28","first-page":"579190","article-title":"Corneal biomechanical changes after crosslinking for progressive keratoconus with the corneal visualization Scheimpflug technology","volume":"2014","author":"Steinberg","year":"2014","journal-title":"J. Ophthalmol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"34","DOI":"10.3928\/1081597X-20151207-09","article-title":"New Scheimpflug dynamic in vivo curve analyses to characterize biomechanical changes of the cornea after cross-linking for progressive keratoconus","volume":"32","author":"Steinberg","year":"2016","journal-title":"J. Refract. Surg."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"803","DOI":"10.3928\/1081597X-20160629-01","article-title":"Detection of keratoconus with a new biomechanical index","volume":"32","author":"Vinciguerra","year":"2016","journal-title":"J. Refract. Surg."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Jian, W., Shen, Y., Tian, M., and Zhou, X. (2021). One-year follow-up of corneal biomechanical changes after accelerated transepithelial corneal cross-linking in pediatric patients with progressive keratoconus. Front. Med., 8.","DOI":"10.3389\/fmed.2021.663494"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1577","DOI":"10.1177\/1120672120944798","article-title":"Corneal biomechanical outcome of collagen cross-linking in keratoconic patients evaluated by Corvis ST","volume":"31","author":"Jabbarvand","year":"2021","journal-title":"Eur. J. Ophthalmol."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Borderie, V., Beauruel, J., Cuyaub\u00e8re, R., Georgeon, C., Memmi, B., and Sandali, O. (2023). Comprehensive assessment of Corvis ST biomechanical indices in normal and keratoconus corneas with reference to corneal enantiomorphism. J. Clin. Med., 12.","DOI":"10.3390\/jcm12020690"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"3635","DOI":"10.1007\/s00417-024-06549-z","article-title":"Biomechanical changes following corneal crosslinking in keratoconus patients","volume":"262","author":"Felter","year":"2024","journal-title":"Graefes Arch. Clin. Exp. Ophthalmol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"951","DOI":"10.18240\/ijo.2024.05.21","article-title":"Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions: Theoretical basis","volume":"17","author":"Caruso","year":"2024","journal-title":"Int. J. Ophthalmol."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/6\/1145\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T08:35:11Z","timestamp":1781253311000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/6\/1145"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,12]]},"references-count":35,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,6]]}},"alternative-id":["medicina62061145"],"URL":"https:\/\/doi.org\/10.3390\/medicina62061145","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,12]]}}}