Related Experiment Video
Updated: Apr 24, 2026
A Modified Mirror Test as a Visual Guide for the Self-awareness Trait in Wild Antarctica Penguins, Pygoscelis adeliae
Published on: July 8, 2025
Central corneal thickness and intraocular pressure in captive black-footed penguins (Spheniscus dermersus)
Elisa M Gonzalez-Alonso-Alegre1, Eva Martinez-Nevado, Alicia Caro-Vadillo
1Departamento de Medicina y Cirugia Animal, Facultad de Veterinaria de la Universidad Complutense de Madrid, Hospital Clínico Veterinario Complutense, Avda. Puerta de Hierro s/n, 28040, Madrid, Spain.
Objective:
To determine the central corneal thickness (CCT) by ultrasonic pachymetry and the effect of these values on the measurements of intraocular pressures (IOP) with rebound tonometry (TonoVet(®) ) in a captive flock of black-footed penguins (Spheniscus dermersus). Variations in CCT by age and weight, and variations in IOP by age were compared.
Animal Studied:
Both eyes of 18 clinically normal black-footed penguins (Spheniscus dermersus) were used.
Procedure:
The IOP was measured by the TonoVet(®) in both eyes of all the penguins. CTT measurements were performed 5 min later in all eyes using an ultrasound pachymeter.
Results:
The mean IOP values ± SD were 31.77 ± 3.3 mm Hg (range of mean value: 24-38). The mean CCT values were 384.08 ± 30.9 μm (range of mean value: 319-454). There was no correlation between IOP and CCT values (P = 0.125). There was no difference in CCT measurements by age (P = 0.122) or weight (P = 0.779). A correlation was observed (P = 0.032) between IOP values and age. The coefficient of correlation was negative (ρ = -0.207).
Conclusions:
Ultrasound pachymetry has shown to be a reliable and easy technique to measure CCT in penguins. No correlation was observed between IOP and CCT values in this study. IOP showed a significant but weak decrease as age increased in the black-footed penguin.
