Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Spearman's Rank Correlation Test

Spearman's Rank Correlation Test

Spearman's rank correlation test, also known as Spearman's rho, is a nonparametric method for assessing the strength and direction of association between two variables. This test is particularly valuable when the data distribution is unknown or when the assumption of normality does not hold. Named after the English psychologist and statistician Dr. Charles Edward Spearman, it serves as the nonparametric counterpart to Pearson's correlation coefficient.
Spearman's test calculates correlation by...

Assessment of the Abdomen III: Palpation

Assessment of the Abdomen III: Palpation

Palpation is a crucial tactile examination method for assessing abdominal organs and detecting conditions like tenderness, distention, masses, or fluid. It involves both light and deep palpation techniques, each serving specific diagnostic purposes. Light palpation helps identify tenderness and other surface-level indicators, while deep palpation locates and assess abdominal masses and organ boundaries. A skilled professional can gather valuable insights through palpation, including evaluating...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Normative Values for Anterior Segment Parameters Associated with Glaucoma in "At-Risk" Ghanaian Clinical Population.

Clinical ophthalmology (Auckland, N.Z.)·2026

Same author

Parenthood and Mental Health Among University Populations in Sub-Saharan Africa: A Cross-Sectional study.

Health science reports·2026

Same author

Emerging Technologies for the Management and Mitigation of Myopia Progression: A Scoping Review.

Health science reports·2026

Same author

Risk Factors of Keratoconus in High School Students in Trinidad and Tobago: A Cross-Sectional Study.

Health science reports·2026

Same author

Human resources, infrastructure, and supply systems for refractive error care in Bhutan: A WHO RESAT analysis.

BMC health services research·2026

Same author

A Pilot Study of Retinal Vessel Calibre and Its Potential Link to Cardiovascular Risk in HIV.

Clinical optometry·2026

Search research articles

Related Experiment Video

Updated: Jun 25, 2026

Full-Field Optical Coherence Microscopy for Histology-Like Analysis of Stromal Features in Corneal Grafts

Full-Field Optical Coherence Microscopy for Histology-Like Analysis of Stromal Features in Corneal Grafts

Published on: October 21, 2022

Validity of keratoconus screening tests.

Zahra A Rashid¹, Khathutshelo P Mashige¹, Vanessa R Moodley¹

¹Discipline of Optometry, University of KwaZulu-Natal, Durban, South Africa.

Clinical & Experimental Optometry

|July 22, 2025

Summary

This summary is machine-generated.

This study found that combining visual acuity, retinoscopy, and refraction with corneal topography improves keratoconus screening in students. A specific combined criterion offers the most effective early detection of this eye condition.

Keywords:

Astigmatism keratoconus keratometry retinoscopy screening

More Related Videos

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Published on: May 25, 2020

Author Spotlight: Establishing a Practical and Cost-Effective Protocol for Corneal Sensitivity Testing in Clinical Settings

Author Spotlight: Establishing a Practical and Cost-Effective Protocol for Corneal Sensitivity Testing in Clinical Settings

Published on: August 2, 2024

Related Experiment Videos

Last Updated: Jun 25, 2026

Full-Field Optical Coherence Microscopy for Histology-Like Analysis of Stromal Features in Corneal Grafts

Full-Field Optical Coherence Microscopy for Histology-Like Analysis of Stromal Features in Corneal Grafts

Published on: October 21, 2022

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Published on: May 25, 2020

Author Spotlight: Establishing a Practical and Cost-Effective Protocol for Corneal Sensitivity Testing in Clinical Settings

Author Spotlight: Establishing a Practical and Cost-Effective Protocol for Corneal Sensitivity Testing in Clinical Settings

Published on: August 2, 2024

Area of Science:

Ophthalmology
Public Health
Optometry

Background:

Keratoconus screening in adolescents is crucial for early detection and intervention.
Reliable cut-off values for screening tests are needed to facilitate early disease identification.
This study evaluated the validity of clinical tests for keratoconus screening in high school students.

Purpose of the Study:

To compare the effectiveness of various clinical tests in screening for keratoconus among high school students.
To identify optimal referral criteria for keratoconus detection in an adolescent population.
To establish reliable cut-off values for keratoconus screening.

Main Methods:

A population-based, prospective, cross-sectional study involving multistage cluster sampling of 3051 students (mean age 17.4 years).
Participants underwent visual acuity assessment, auto-refraction, retinoscopy, and corneal topography.
Students were categorized into non-keratoconus, keratoconus suspect, and keratoconus groups.

Main Results:

Of 3051 students, 51 (1.7%) were diagnosed with keratoconus.
Keratoconus patients showed worse visual acuity, more myopia, and higher astigmatism compared to controls (p < 0.05).
A combined referral criterion (scissors reflex on retinoscopy OR max anterior corneal curvature >46.5 D OR astigmatism >2.50 D) demonstrated the highest Youden Index (0.46).

Conclusions:

Monocular visual acuity, retinoscopy, keratometry, and refraction, alongside corneal topography, should be integrated into keratoconus screening protocols.
A recommended combined referral criterion includes a scissors reflex on retinoscopy, maximum anterior corneal curvature >46.5 D, or astigmatism >2.50 D.
This approach enhances the effectiveness of early keratoconus detection in student populations.