Corneal Tomographic Changes After Complete Suture Removal In Penetrating Keratoplasty: Comparison Between Keratoconus And Non-Ectatic Corneal Diseases

Published 2026 - 44th Congress of the ESCRS

Reference: FP22.02 | Type: Free paper | DOI: 10.82333/xsyv-hs17

Authors: Dr Damla Balaban ¹ , Dr L.Raşid Alkan ¹ , Prof. Dr Bahri Aydın ¹ , Prof. Dr Mehmet Cüneyt Özmen* ¹ , Prof. Dr R.Fikret Akata ¹

¹Opthalmology,Gazi University Faculty of Medicine,Ankara,Türkiye

Purpose

To evaluate longitudinal corneal tomographic changes before and after complete suture removal following penetrating keratoplasty (PK) and to compare keratometric responses between eyes with keratoconus and non-ectatic corneal diseases. Because intrinsic biomechanical instability persists in ectatic corneas even after transplantation, we aimed to determine whether suture removal induces different postoperative corneal responses between these two disease groups.

Setting

Tertiary referral university hospital, Department of Ophthalmology, Gazi University School of Medicine, Ankara, Türkiye.

Methods

In this retrospective longitudinal comparative study, 482 eyes that underwent penetrating keratoplasty between 2011 and 2021 were screened. Eyes aged ≥18 years with complete suture removal and available corneal tomography at predefined follow-ups were included. Eyes with ocular trauma, postoperative complications, inadequate follow-up, or poor-quality tomography were excluded. Scheimpflug tomography was performed preoperatively and at 3, 6, and 12 months postoperatively, and after complete suture removal. K1, K2, Kmean, Kmax, corneal astigmatism, and zonal Kmin–Kmax values were analyzed. Eyes were classified as keratoconus or non-ectatic disease groups, and comparisons were performed using appropriate statistical tests (p<0.05).

Results

Following screening of 482 eyes, 100 eyes met inclusion criteria (50 keratoconus, 50 non-ectatic). Follow-up duration was comparable (84.4±35.5 vs 84.3±27.5 months respectively, p=0.982). Pre-suture removal K1 (p=0.191), K2 (p=0.163), and Kmean (p=0.453) were similar between groups, whereas Kmax was higher in keratoconus eyes (p=0.021). After complete suture removal, keratometric steepening was greater in keratoconus eyes, with Kmean increasing from 40.15±6.01 D to 46.97±3.39 D versus 39.20±6.27 D to 41.95±4.29 D (p<0.001). In the 5-mm zone Kmax remained higher (51.69±5.59 vs 44.29±4.61 D, p<0.001). Final BCVA was worse in keratoconus eyes (0.65±0.53 vs 0.45±0.18 logMAR, p=0.017), while intraocular pressure showed no difference.

Conclusions

Complete suture removal after penetrating keratoplasty induces greater keratometric and visual changes in keratoconus compared with non-ectatic corneal diseases. Persistent steepening in the mid-peripheral 5–7 mm zone suggests a distinct biomechanical response related to residual host corneal instability. Careful timing of elective suture removal in keratoconus eyes may help reduce postoperative refractive instability and improve visual rehabilitation.