Related Experiment Video
Updated: Aug 31, 2025

In vivo Structural Assessments of Ocular Disease in Rodent Models using Optical Coherence Tomography
Published on: July 24, 2020
Normative Values for Corneal Tomography and Comparison of Both Eyes in Young Saudi Males with 20/20 Vision Using
Omar Alshehri1, Ahmed M Abdelaal2, Ghufran Abudawood1
1Ophthalmology Department, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia.
Purpose:
Anterior segment evaluation using Scheimpflug imaging with the Pentacam scanner allows the acquisition of a plethora of information. It aids in screening and diagnosing corneal pathologies and determining suitability for keratorefractive procedures. This research has significant benefits in terms of establishing normative tomographic values, which is crucial in countries where Keratoconus (KC) is more prevalent, especially among young age group, along with aiding future research in the field of refractive surgery by providing relevant normative data.
Methods:
A retrospective review of digital corneal tomography images for a group of medically and ophthalmologically free males aged between 18 and 21 years with 20/20 unaided distant visual acuity was performed.
Results:
A total of 1272 subjects (2544 eyes) were included. Findings revealed a mean maximal corneal curvature (Kmax) of 42.91 ± 1.40D (range 36.90-47.80D). The mean flat keratometry (K1) was 41.87 ± 1.31D (range 36.00-46.40D). The mean steep keratometry (K2) was 42.66 ± 1.35D (range 36.70-47.60D). The mean corneal astigmatism (CA) was 0.79 ± 0.37D (range 0.00D-2.30D). The mean central corneal thickness (CCT) was 558.53 ± 33.84 μm (range 421-677 μm). The mean thinnest corneal location thickness (TCLT) was 551.64 ± 34.08 μm (range 417-669μm). The mean corneal diameter (CD) and anterior chamber depth (ACD) were 12.13 ± 0.39 mm (range 10.50-13.60 mm) and 3.12 ± 0.29 mm (range 2.08-4.08 mm), respectively. The median differences between both eyes of the same subject were as follows: kmax difference of 0.20D (IQR 0.1-0.4); K1, K2 and CA difference of 0.20D (IQR 0.1-0.3) for all 3 parameters; CCT and TCLT difference of 5.00 μm (IQR 3.0-9.0) and 6.00 μm (IQR 3.0-10.0), respectively; CD difference of 0.10 mm (IQR 0.0-0.1); and ACD difference of 0.04 (IQR 0.02-0.06).
Conclusion:
We believe our data can aid in establishing normative tomographic values and acceptable differences between both eyes. Our data may also help detect subtle corneal pathology and be useful for researchers and innovators in the field of ophthalmology.
Related Concept Videos
Imaging Studies III: Computed Tomography
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Angle Closure Glaucoma: Treatment
Glaucoma: Overview

