Pix2pix Networks for Scheimpflug Corneal Tomography Image Generation

Assiut University

Status: Completed

Conditions: Eye Diseases

Treatments: Diagnostic Test: Scheimpflug Camera Corneal Tomography

Study type: Observational

Funder types: Other

Identifiers

NCT04582253

17300483

Details and patient eligibility

About

Computer-aided medical image analysis has advantages, but requires large amounts of training data, which are scarce and costly to obtain, are subject to privacy concerns, and are often highly imbalanced, with over-representation of common conditions and poor representation of rare conditions. Consequently, some methods have been proposed to generate artificial medical images using generative adversarial networks (GANs). Computer aided diagnosis of keratoconus is an emerging research field that may benefit greatly from medical image synthesis, which can affordably provide an arbitrary number of sufficiently diverse synthetic images that mimic real Pentacam images. A new conditional GAN, the pix2pix cGAN, has not been used in this context to date. Here, investigators will assess the efficacy of a cGAN implementing pix2pix image translation for image synthesis of color-coded Pentacam 4-map refractive displays of clinical and subclinical keratoconus as well as normal corneas.

Enrollment: 923 patients

Sex: All

Ages: 18 to 50 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Keratoconus group:

  • Presence of a central protrusion of the cornea with Fleischer ring, Vogt striae, or both by slitlamp examination.
  • irregular cornea determined by distorted keratometry mires and distortion of retinoscopic red reflex or both in addition to the following topographic findings as summarized by Pińero and colleagues :
  • focal steepening located in a zone of protrusion surrounded by concentrically decreasing power zones
  • focal areas with dioptric (D) values >47.0D
  • inferior- superior(I-S) asymmetry measured to be > 1.4 D
  • Angling of the hemimeridians in an asymmetric or broken bowtie pattern with skewing of the steepest radial axis(SRAX) .

Suspicious group:

• Defined as subtle corneal tomographic changes as the aforementioned keratoconus abnormalities in the absence of slit- lamp or visual acuity changes typical of keratoconus (forme fruste keratoconus).

Normal group:

• Refractive surgery candidates
• Refractive error of less than 8.0 D sphere
• Less than 3.0 D of astigmatism
• without clinical, topographic or tomographic signs of keratoconus or suspect keratoconus.

Exclusion criteria

• • Systemic disease

  • Other corneal disease such as pellucid marginal degeneration
  • History of trauma
  • Corneal surgery such as corneal cross- linking for progressive keratoconus.

Trial design

923 participants in 3 patient groups

Keratoconus

Description:

Those with a clinical diagnosis of keratoconus such as: a) the presence of a central protrusion of the cornea with Fleischer ring, Vogt striae, or both by slitlamp examination.(b) an irregular cornea determined by distorted keratometry mires and distortion of retinoscopic red reflex or both in addition to the following topographic findings as summarized by Pińero and colleagues: focal steepening located in a zone of protrusion surrounded by concentrically decreasing power zones, focal areas with dioptric (D) values \>47.0D, inferior- superior(I-S) asymmetry measured to be \> 1.4 D or angling of the hemimeridians in an asymmetric or broken bowtie pattern with skewing of the steepest radial axis (SRAX) 2.

Treatment:

Diagnostic Test: Scheimpflug Camera Corneal Tomography

Subclinical keratoconus

Description:

Defined as subtle corneal tomographic changes as the aforementioned keratoconus abnormalities in the absence of slit- lamp or visual acuity changes typical of keratoconus (subclinical keratoconus).

Treatment:

Diagnostic Test: Scheimpflug Camera Corneal Tomography

Normal

Description:

This group comprised refractive surgery candidates and subjects applying for a contact lens fitting with a refractive error of less than 8.0 D sphere with less than 3.0 D of astigmatism and without clinical, topographic or tomographic signs of keratoconus nor suspected keratoconus.

Treatment:

Diagnostic Test: Scheimpflug Camera Corneal Tomography