Intraestromal Corneal Ring in Mild Keratoconus

Intrastromal Corneal Ring Was Effective for the Treatment of Mild Keratoconus

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03127163

Enrollment

Registered

2017-04-25

Start date

2015-01-10

Completion date

2017-01-10

Last updated

2017-04-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cornea, Eye Diseases, Keratoconus, Ophthalmological Disorder

Brief summary

To determine whether the implantation of an intrastromal corneal ring is an effective treatment for a homogeneous group of mild keratoconus patients.

Detailed description

A group of 65 patients with mild keratoconus were implanted with a Ferrara ring in a single eye. Six months after surgery, the aberrations were measured and the visual function was determined using clinical indices. The aberrations, especially comatic aberration (coma), were measured independently.

Interventions

DEVICEIntraestromal corneal ring

The patients underwent surgery to implant the intrastromal corneal ring (Ferrara Ophthalmics, Belo Horizonte, Brazil) using a manual technique. The procedures were performed by a single surgeon with extensive training in corneal surgery. All patients received the same ring, and the number (1 or 2 segments), thickness, and arc size were calculated using the nomogram provided by the manufacturer.

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

NONE

Intervention model description

Intraestromal corneal ring

Eligibility

Sex/Gender

ALL

Age

17 Years to 47 Years

Healthy volunteers

Inclusion criteria

* Investigators used the Amsler-Krumeich classification and included only patients classified as grade I or II.

Exclusion criteria

* Investigators excluded patients with central corneal scarring, with other eye disorders, or with previous ocular surgery. We also excluded patients with a history of herpes infection, keratitis, corneal dystrophies, diagnoses of autoimmune diseases, systemic connective tissue disorders, or acute keratoconus.

Design outcomes

Primary

Measure	Time frame	Description
Aberrations were measured and the visual function was determined using clinical indices.	3 months after surgery	Wave front data

Secondary

Measure	Time frame	Description
UCVA	3 months after surgery	Uncorrected visual acuity
BCVA	3 months after surgery	Best corrected visual acuity

Countries

Brazil

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026