Visual And Keratometric Optimization With Corneal Allogenic Intrastromal Ring Segments (Cairs)In Previously Cross-Linked Keratoconus: A Stage-Based Analysis
Published 2026 - 44th Congress of the ESCRS
Reference: FP30.08 | Type: Free paper | DOI: 10.82333/tr6z-g184
Authors: Dr Sepideh Lotfi Sadigh* 1 , Dr Matin Suleymanzade 1 , Dr Fatma Feyza Nur Keskin Perk 2 , Dr Dilan Çolak Arici 3 , Dr Ugur Tunc 4 , Burcu Yakut 5 , A/Prof. Aylin Kilic 6
1ophthalmology,Biruni University,Istanbul,Türkiye, 2ophthalmology,Cam ve Sakura City Hospital ,Istanbul,Türkiye, 3ophthalmology,Beyoglu Eye training and research Hospital,Istanbul,Türkiye, 4ophthalmology,Medipol University,Istanbul,Türkiye, 5ophthalmology,Haseki Training and Research Hospital,Istanbul,Türkiye, 6ophthalmology,Swiss Vision Group,Istanbul,Türkiye
Purpose
To evaluate stage-dependent visual and keratometric outcomes of Keranatural treatment in keratoconus eyes previously stabilized with corneal collagen cross-linking (CXL), according to the Amsler–Krumeich classification.
Setting
The study conducted at Swiss Vision Eye Clinic.
Methods
This retrospective study included 122 keratoconus eyes with prior CXL that subsequently underwent Keranatural treatment and had a minimum postoperative follow-up of 6 months. Eyes were classified as Grade 1 (38), Grade 2 (42), Grade 3 (16), or Grade 4 (26) based on the Amsler–Krumeich system. Postoperative gains in uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), maximum keratometry (Kmax), and mean keratometry (Kmean) were compared between disease stages to assess stage-dependent treatment response.
Results
UCVA gain did not differ significantly across disease stages (all p > 0.05). In contrast, CDVA gain showed a significant stage-dependent pattern, with Grade 1 eyes demonstrating lower improvement compared with Grades 2 (p = 0.043), 3 (p = 0.017), and 4 (p = 0.001), while no differences were observed among Grades 2–4. Kmax gain showed limited and inconsistent stage-related differences, reaching significance only between selected stages (Grade 2 vs Grade 3, p = 0.005; Grade 3 vs Grade 4, p = 0.034). Kmean gain demonstrated a clear stage-dependent response, with significantly greater reduction in Grades 3 and 4 compared with Grade 1 (p = 0.026 and p = 0.002, respectively), and greater improvement in Grade 4 compared with Grade 2 (p = 0.010).
Conclusions
In keratoconus eyes previously stabilized with CXL, Keranatural demonstrates a distinct stage-dependent effect. While UCVA improvement is comparable across all stages, CDVA and Kmean gains are greater in moderate-to-advanced keratoconus, indicating increased functional and topographic benefit in later disease stages. These findings support Keranatural as a visual and keratometric optimization strategy following biomechanical stabilization, highlighting the importance of stage-based patient selection.