Moderate to severe keratoconus. Keratoconus
Conditions
Interventions
Control group:Participants in this group undergo intracorneal ring implantation as the standard treatment for keratoconus. The surgical procedure is performed by an experienced surgeon according to a
Sponsors
Tehran University of Medical Sciences
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Inclusion criteria
Inclusion criteria: Age between 18 and 40 years Diagnosis of moderate to severe keratoconus (stage 2 or 3 based on the Amsler–Krumeich classification) Evidence of progressive keratoconus during the past 2 years Increase of more than 1.0 diopter in steep keratometry during the past 2 years Increase of more than 1.0 diopter in manifest refractive cylinder during the past 2 years Change of more than 0.5 diopter in manifest spherical equivalent during the past 2 years Intolerance to rigid gas permeable (RGP) contact lenses Reduced corrected distance visual acuity with spectacles or contact lenses Mean keratometry value = 55 diopters Thinnest corneal thickness greater than 400 micrometers Clear central cornea without scarring Clinical indication for intracorneal ring implantation Willingness to participate in the study and ability to provide written informed consent Ability to attend postoperative follow-up visits
Exclusion criteria
Exclusion criteria: History of any prior ocular surgery Presence of any corneal pathology other than keratoconus Presence of central corneal scarring History of herpetic eye disease Severe dry eye disease Presence of systemic autoimmune disease Diabetes mellitus Collagen vascular disease Use of systemic immunosuppressive medications Pregnancy or breastfeeding Uncontrolled glaucoma Pre-existing retinal disease Neuro-ophthalmic disease affecting visual function History of ocular trauma Presence of active ocular infection Inability to comply with postoperative follow-up visits
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in corrected distance visual acuity (CDVA) measured using LogMAR chart. Timepoint: Primary outcomes are assessed at baseline (before intervention) and at 1, 3, 6, and 12 months after the intervention. Method of measurement: Corrected distance visual acuity is measured using the Logarithm of the Minimum Angle of Resolution visual acuity chart.;Change in refractive spherical equivalent measured in diopters. Timepoint: Primary outcomes are assessed at baseline (before intervention) and at 1, 3, 6, and 12 months after the intervention. Method of measurement: Refractive error is measured by performing complete ocular refraction including objective and subjective refraction.;Change in maximum corneal keratometry (Kmax) measured in diopters. Timepoint: Primary outcomes are assessed at baseline (before intervention) and at 1, 3, 6, and 12 months after the intervention. Method of measurement: Maximum corneal keratometry is measured using corneal tomography imaging system.;Change in corneal tomographic parameters assessed using corneal tomography. Timepoint: Primary outcomes are assessed at baseline (before intervention) and at 1, 3, 6, and 12 months after the intervention. Method of measurement: Corneal tomographic parameters are assessed using corneal tomography imaging. | — |
Countries
Iran (Islamic Republic of)
Contacts
Public ContactDr. Hesam Hashemian
Tehran University of Medical Sciences
Outcome results
None listed