Correlation Between Q-value Changes and Progression of Pediatric Keratoconus.

Benha University

Status: Completed

Conditions: Keratoconus; Corneal Disease; Collagen Diseases

Treatments: Procedure: Transepithelial Corneal Collagen Cross-linking; Diagnostic Test: Scheimpflug camera

Study type: Observational

Funder types: Other

Identifiers

NCT05114928

RC-10-7-01

Details and patient eligibility

About

Keratoconus is a progressive corneal disease characterized by asymmetric corneal thinning and structural changes in corneal collagen which leads to decrease in visual acuity due to myopic shift, irregular astigmatism or corneal scarring. Early detection of the disease in children aids in halting the progression and improve their quality of life. There is no consensus regarding the progression criteria of the disease, we aimed to assess the changes in corneal asphericity in children after corneal collagen crosslinking and investigate any possible correlation with progression criteria widely used.

Full description

The Keratoconus progression is defined as increasing by 1.0 diopter (D) or more in the maximum keratometry (Kmax), progressive deterioration in Minimal Corneal Thickness is also associated with KC progression, other methods have been investigated to confirm KC progression such as changes in manifest refraction, unaided visual acuity (UAVA), BCVA, posterior keratometric data and higher order aberrations (HOA) which are altered in KC and can aid to confirm disease progression. Q-value (a coefficient of corneal asphericity) reflects the shape of the cornea, its refractive power, and spherical aberration. The mean Q-value in normal cornea is -0.26 ± 0.18, the severity of KC and the Q-value are inversely related.

Mean Q-value in KC at 8mm zone is -0.84 and -1.10 for anterior and posterior corneal surfaces, respectively. Until now, no precise criteria of KC progression especially in cases had undergone previous trans-epithelial corneal collagen cross-linking (TE-CXL) to halt the progression of the disease. In the present study we aimed to analyze the correlation between the changes in Q-value and progression of the KC in children had undergone bilateral TE-CXL.

Enrollment: 9 patients

Sex: All

Ages: 6 to 16 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

Children that were diagnosed as bilateral progressive KC (stage I-III, according to amsler classification, Kmax change >1D between 2 scanning with at least 2 months apart), and their age were less than 16 years old at time of TE-CXL, topographic parameters were Kmax 47-60D and MCT more than 400μm.

Exclusion criteria

Eyes with central corneal scarring, amblyopic eyes, and other corneal pathologies that may alter Pentacam scanning.

Trial design

9 participants in 2 patient groups

Progression Group (P-group)

Description:

Eyes that showed progression of the disease after trans-epithelial corneal collagen cross-linking during the 5 years of follow-up, (number of eyes = 7 eyes).

Treatment:

Diagnostic Test: Scheimpflug camera

Procedure: Transepithelial Corneal Collagen Cross-linking

No Progression Group (NP-group)

Description:

Eyes that showed no progression of the disease after trans-epithelial corneal collagen cross-linking during the 5 years of follow-up, (number of eyes = 11 eyes).

Treatment:

Diagnostic Test: Scheimpflug camera

Procedure: Transepithelial Corneal Collagen Cross-linking