ESCRS - FP30.09 - Stage-Specific Response To Corneal Allogenic Intrastromal Ring Segments (Cairs) Treatment In Keratoconus Eyes With And Without Prior Corneal Cross-Linking

Stage-Specific Response To Corneal Allogenic Intrastromal Ring Segments (Cairs) Treatment In Keratoconus Eyes With And Without Prior Corneal Cross-Linking

Published 2026 - 44th Congress of the ESCRS

Reference: FP30.09 | Type: Free paper | DOI: 10.82333/hv0g-yv78

Authors: Dr Matin Suleymanzade* 1 , Dr Sepideh Lotfi Sadigh 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 assess stage-specific visual and keratometric response patterns following Keranatural treatment in keratoconus eyes with and without prior corneal collagen cross-linking (CXL) using a large real-world cohort.

Setting

This study conducted at Swiss Vision Eye Clinic.

Methods

This retrospective study included 260 keratoconus eyes treated with Keranatural, comprising 122 eyes with prior CXL (CXL-positive) and 138 eyes without CXL (CXL-negative). Eyes were classified according to the Amsler–Krumeich system (Grades 1–4). Stage distribution in the CXL-positive group was 38 Grade 1, 42 Grade 2, 16 Grade 3, and 26 Grade 4 eyes; corresponding numbers in the CXL-negative group were 61, 46, 16, and 15, respectively. Pre- and postoperative uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), maximum keratometry (Kmax), and mean keratometry (Kmean) were recorded, and treatment-related gains were compared in a stage-based manner within and between cohorts.

Results

In the CXL+ group: UCVA gain was similar across stages (p>0.05), whereas CDVA gain was stage-dependent, with Grade 1 eyes showing less improvement than Grades 2–4 (p≤0.043). Kmax reduction showed limited stage-related differences, while Kmean reduction was greater in Grades 3–4 vs Grade 1 (p≤0.026) and in Grade 4 vs Grade 2 (p=0.010), indicating a stronger structural response in advanced disease.
CXL− group: Keranatural produced significant visual and keratometric improvement across all stages; early-stage eyes achieved smaller CDVA and Kmean gains than moderate–advanced stages (all p<0.01), likely due to better baseline visual and corneal status.

Conclusions

Keranatural treatment provides meaningful visual and keratometric improvement across all stages of keratoconus, regardless of prior CXL status. Treatment response demonstrates a consistent stage-dependent pattern, with greater functional and corneal flattening gains in moderate-to-advanced disease, while early-stage eyes show smaller improvements due to favorable baseline status. These findings indicate that disease stage is the primary determinant of outcome magnitude, with prior cross-linking acting as a modifier rather than a prerequisite. Keranatural represents a stage-adaptive and broadly applicable optimization strategy in keratoconus management.