Evidence map›Paper›PMID 41820582›Full record

Observational studyScientific reports2026

Corneal allogenic intrastromal ring segments improve visual and topographic outcomes in advanced keratoconus : Short Title: CAIRS in Advanced Keratoconus.

Nilufer Yesilirmak, Necip Kara, Bekir Eren Aksoy, Dondu Melek Ulusoy

Abstract readObservational Study
In one paragraph

Observational study in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Nilufer Yesilirmak *Department of Ophthalmology, Ankara Yildirim Beyazit University, Ankara, Turkey. dryesilirmak@gmail.com.
Necip Kara *Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
Bekir Eren AksoyUlucanlar Eye Training and Research Hospital, Ankara, Turkey.
Dondu Melek UlusoyDepartment of Ophthalmology, Ankara Bilkent City Hospital, Ankara, Turkey.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

This study aims to evaluate the efficacy and safety of corneal allogeneic intrastromal ring segments (CAIRS) in patients with advanced keratoconus. This retrospective observational study included 25 eyes of 20 patients with advanced keratoconus (defined as a maximum keratometry (Kmax) of ≥ 58.0 D) who had unsatisfactory vision with spectacles and intolerance to scleral lenses. All patients underwent femtosecond laser-assisted tunnel creation, followed by implantation of allogeneic stromal segments prepared from donor corneal tissue. In cases of suboptimal outcomes, tissue reshaping or double segment implantation was performed. Pre- and postoperative evaluations included uncorrected (UDVA) and corrected distance visual acuity (CDVA), manifest refraction, spherical equivalent (SE), Scheimpflug-based tomography, keratometric parameters, corneal thickness, and higher-order aberrations. Patients were followed for a mean of 11 months. Mean UDVA improved significantly from 1.42 ± 0.33 LogMAR to 0.46 ± 0.27 LogMAR (p < 0.001), and CDVA improved from 1.18 ± 0.44 LogMAR to 0.25 ± 0.16 LogMAR (p < 0.001), with nearly half of the patients gaining 10 Snellen lines. Mean SE decreased from - 9.66 D to - 1.33 D (p < 0.001). Significant reductions in K1, K2, Kmean, and Kmax were observed (all p < 0.05), with coma aberration improving from 1.39 μm to 0.41 μm (p = 0.005). Central corneal thickness remained stable. No adverse events occurred. In conclusion, CAIRS provided substantial visual, refractive, and topographic improvements in advanced keratoconus, including very severe cases. Larger, prospective, long-term studies are warranted to confirm its role in advanced keratoconus management.

Indexed as

Corneal StromaCorneal TopographyCorneal TransplantationKeratoconusAdultFemaleHumansMaleRetrospective StudiesTransplantation, HomologousTreatment OutcomeVisual AcuityYoung Adult

Identifiers

PMID41820582
PMCPMC13102976

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.