Keraring Implantation Based on Alfonso Nomogram

NCT07540208 | Active Not Recruiting

• 1 other identifier: OKIPKGASN
• Study Type: interventional
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

Keratoconus (KC) is a bilateral asymmetric progressive corneal degenerative disease associated with corneal thinning and protrusion. The management of moderate progressive keratoconus involves halting its progression through corneal cross-linking as well as flattening of the ectatic steep cornea through the implantation of intrastromal corneal rings (ICR). Different nomograms were used to guide ophthalmic surgeons for the proper choice of ICR implantation to achieve the best results. The aim of the current study is to assess the visual, refractive and tomographic outcomes of Keraring implantation based on the Alfonso nomogram, in patients with keratoconus.

Conditions

Keratoconic Subjects

Keywords

Keratoconus; Intrastromal corneal rings; Alfonso nomogram

Outcome Measures

Primary Outcomes (3)

• Corrected distance visual acuity

  Corrected distance visual acuity is measured with Snellen's acuity chart and converted to logarithm of the minimum angle of resolution (logMAR) notation.

  6 months

• Spherical equivalent refraction

  Spherical equivalent in diopters is measured with Topcon autorefractometer.

  6 months

• Maximum keratometry

  The maximum keratometry in diopters is measured using pentacam.

  6 months

Study Arms (1)

Keraring implantation based on Alfonso nomogram

ACTIVE COMPARATOR

Patients with moderate progressive keratoconus, underwent Keraring implantation based on Alfonso morphological surgical nomogram.

Procedure: Intrastromal corneal ring segment implantation (ICRS)

Interventions

Intrastromal corneal ring segment implantation (ICRS) PROCEDURE

Patients with moderate progressive keratoconus underwent femtosecond laser-assisted intrastromal corneal ring (Keraring) implantation based on the Alfonso morphological surgical nomogram.

Keraring implantation based on Alfonso nomogram

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Patients aged between 18-35 years.
• Patients diagnosed with progressive keratoconus.
• Mean keratometry (Km) between 48-60 D.
• Clear cornea

You may not qualify if:

• Mild or advanced keratoconus
• Corneal scarring.
• Other corneal or ocular diseases.
• Systemic diseases such as diabetes mellitus and autoimmune diseases.

Sponsors & Collaborators

• Assiut University: lead

Study Sites (1)

TIBA Eye Center

Asyut, Asyut Governorate, 71515, Egypt

Location

Related Publications (1)

• Sakellaris D, Balidis M, Gorou O, Szentmary N, Alexoudis A, Grieshaber MC, Sagri D, Scholl H, Gatzioufas Z. Intracorneal Ring Segment Implantation in the Management of Keratoconus: An Evidence-Based Approach. Ophthalmol Ther. 2019 Oct;8(Suppl 1):5-14. doi: 10.1007/s40123-019-00211-2. Epub 2019 Oct 11.

  PMID: 31605316 BACKGROUND

MeSH Terms

Conditions

Keratoconus

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: April 13, 2026
• First Posted: April 20, 2026
• Study Start: March 1, 2025
• Primary Completion: March 1, 2026
• Study Completion (Estimated): September 1, 2026
• Last Updated: April 20, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)