Issue 10/2026
Grupcheva1, Н., D. Grupchev2, D.
1 University Hospital „Medica“ – Ruse
2 University Hospital „St. Sofia“, MC „Grupchevi+“ – Varna
Keratoconus is a bilateral, asymmetric, non-inflammatory corneal ectasia, affecting more often males and with high clinical significance in Bulgaria. The pathophysiology includes enzymatic deficiency of lysyl oxidase, leading to disruption of collagen cross-linking, reduced corneal hysteresis and progressive thinning of the stromal layer with cone-shaped deformation. The disease manifests itself at puberty, with risk factors being heredity, the allergic triad and eye rubbing, as well as systemic diseases (e.g. Down syndrome). Modern diagnostics relies on corneal tomography and optical coherence tomography (OCT), which have replaced the classical Placido topography, allowing the identification of subclinical and frusto forms. Management is complex and individualized: optical correction with spectacles, rigid gas permeable (RGP) contact lenses or scleral lenses is adapted to the stage of the disease, while surgical options include intrastromal corneal segments (ICRS), corneal allogeneic intrastromal rings (CAIRS), intrastromal lamellar implants and deep anterior lamellar keratoplasty (DALK). Crosslinking remains a key procedure to halt progression. Today, the most precise is theranostic crosslinking, which provides real-time measurement of riboflavin saturation and delivered UV energy, improving standardization and efficacy. Our institutional experience with theranostic crosslinking in 30 long-term follow-up patients showed a reduction in maximum keratometry of ≥1 diopter in 27 patients at 6 months, with full rehabilitation within 24 hours. Algorithmic integration of precise tomographic diagnostics, timely crosslinking and individualized optical and surgical correction is a guarantee for optimal results. Pharmacological and genetic are the potential for future therapies.
Key words: keratoconus, corneal ectasia, corneal crosslinking, theranostic crosslinking, corneal tomography, rigid contact lenses, deep anterior lamellar keratoplasty, CAIRS, keratoplasty
Adress for correspondence:
Prof. Dr. H. Grupcheva, MD
MC „Grupchevi+“
1А, „Seliolu“ str.
9002, Varna
e-mail: cgrupchevа@gmail.com