Comparison of Central Corneal Thickness Measurements Using Specular Microscope, Optical Biometer and Corneal Topographer

Doi: 10.36351/pjo.v37i3.1236

Abstract

Purpose:  To compare the Central Corneal Thickness (CCT) measurements by three different devices in normal eyes.

Study Design:  Cross sectional observational study.

Place and Duration of Study:  Dow University of Health Sciences and Dr. Ruth K.M. Pfau Civil Hospital, Karachi, from October 2020 to January 2021.

Methods:  80 eyes of healthy subjects aged between 20 to 50 years were included in the study. Patients with corneal pathologies, systemic disease, history of ocular surgery or trauma, high intraocular pressure and high refractive error were excluded. Subjects underwent full ophthalmic examination. Central Corneal Thickness was measured by specular microscope (Shin-Nippon SPM-700; Rexxam Co. Ltd, Takamatsu, Japan), optical biometer (AL-Scan; Nidek, Gamagori, Japan) and corneal topographer (TMS-5; Tomey corporation, Nagoya, Japan). All data entry and analysis was done on SPSS version 23. For correlation among devices, Pearson correlation coefficient was used. Scatter plot was drawn for graphical presentation.

Results:  80 eyes of 80 healthy subjects (50 males, 30 females) were recruited in the study by convenient sampling. The mean age was 37.76 ± 8.35 years. Mean Central Corneal Thickness values were 515.57 ± 31.54 µm, 510.21 ± 30.11 µm, 522.03 ± 29.78 µm with specular microscope, optical biometer and corneal topographer respectively. Measurements by these devices strongly correlate with each other using Pearson correlation coefficient (r = 0.927 to 0.966, p ? 0.001).

Conclusion:  The results of Central Corneal Thickness measurements obtained from these three devices positively correlate with each other so any of these devices can be used for its measurement.

Key Words:  Central Corneal Thickness (CCT), Specular microscope, Optical biometer, Corneal topographer.