Electrophysiological Changes in Cases of Different Stages of Keratoconus

NCT07461129 | Active Not Recruiting DMC

• 1 other identifier: VEP,ERG in keratoconus
• Study Type: observational
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity.A typical patient with keratoconus presents in the teens or early twenties with complaints of blurring or distortion in vision and having to change glasses frequently due to changes in refractive error. Corneal thinning frequently precedes ectasia. In moderate and advance cases, a hemosiderin arc or circle line, known as Fleischer's ring, is frequently seen around the cone base. Vogt's striaes, which are fine vertical lines produced by Descemet's membrane compression, is another characteristic sign. Most patients eventually develop corneal scarring. Munson's sign, a V-shape deformation of the lower eyelid in downward position; Rizzuti's sign, a bright reflection from the nasal area of the limbus when light is directed to the limbus temporal area; and breakages in Descemet's membrane causing acute stromal oedema, known as hydrops, are observed in advanced stages. Corneal blindness is one of the major causes of reversible blindness, which can be managed with transplantation of a healthy donor cornea. It is the most successful organ transplantation in the human body as cornea is devoid of vasculature, minimizing the risk of graft rejection. Preoperative clinical evaluation of visual potential after corneal transplantation in the patient with dense corneal opacity remains difficult using only history and biomicroscopic examination. Some studies found that electrophysiologic tests were good predictors of visual prognosis prior to corneal transplantation. Electrophysiology is an objective functional test of the visual pathway and allows the location of visual dysfunctions to be detected. Full-field electroretinography (ERG) is an established clinical technique used to evoke and record mass responses of the retina to flashes of light. The ISCEV Standard full-field ERGs assess generalized retinal function under dark-adapted (DA) and light-adapted (LA) conditions.The visual evoked potential (VEP) is a cortical response and serves as a functional test of the entire visual pathway from the eye to the visual system of the brain.

Conditions

Keratoconus

Keywords

VEP; ERG; Keratoconus

Outcome Measures

Primary Outcomes (8)

• Measuring the amplitude of P100 wave in pattern visual evoked potential

  Measuring the amplitude of P100 wave of pattern visual evoked potential in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

• Measuring the Latency of P100 wave of pattern evoked potential

  Measuring the latency of P100 wave of pattern visual evoked potential in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

• Measuring the Amplitude of P2 of Flash visual evoked potential

  Measuring the amplitude of P2 wave of Flash visual evoked potential in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

• measuring the latency of P2 wave of Flash visual evoked potential

  Measuring the latency of P2 wave of Flash visual evoked potential in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

• Measuring the Amplitude of a wave of Full Field Flash Electroretinography

  Measuring the amplitude of a wave of full field flash ERG in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

• measuring the implicit time of a wave of Full Field Flash Electroretinography

  Measuring the Implicit time of a wave of full field flash ERG in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

• Measuring the amplitude of b wave of Full Field Flash Electroretinography

  Measuring the amplitude of b wave of full field flash ERG in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

• Measuring the implicit time of b wave of Full Field Flash Electroretinography

  Measuring the implicit time of b wave of full field flash ERG in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)

  6 months

Study Arms (2)

Keratoconus group

Patients with different stages of keratoconus

Normal

patients whose pentacam doesn't show any keratoconus findings or any other abnormalities

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

Study Population

Study participants will be : from 18 to 40 years old: 50 eyes of control patients 50 eyes of patients who had KC

You may qualify if:

• Patients aged from 18 to 40 years with keratoconus of different stages

You may not qualify if:

• Keratoconus Patients with any prior history of ocular procedures.
• Patients with dense cataract.
• Patients with retinal , vitreous problems or uveiitis .
• Patients with optic nerve pathology
• History of ocular medications e.g antiglaucoma
• History of previous ocular surgery

Sponsors & Collaborators

• Minia University: lead

Study Sites (1)

Minia university eye hospital

Minya, Minya Governorate, 61512, Egypt

Location

Related Publications (1)

• google scholar

  BACKGROUND

MeSH Terms

Conditions

Keratoconus

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Study Officials

• Hossameldin Mohamed Mohamed Moharram, ph.D

  Minia university eye hospital

  STUDY CHAIR

• Mohamed Abdelhamid Mahmoud, Ph.D

  Minia university eye hospital

  STUDY DIRECTOR

• Amr Ahmed Mohamed, Ph.D

  Minia university eye hospital

  STUDY DIRECTOR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Study Record Dates

• First Submitted: January 21, 2026
• First Posted: March 10, 2026
• Study Start: August 20, 2025
• Primary Completion (Estimated): June 20, 2026
• Study Completion (Estimated): August 20, 2026
• Last Updated: March 11, 2026

Record last verified: 2026-03

Locations

EG (1)