Characterising keratometry in different dog breeds using an automatic handheld keratometer

Abstract

Background Keratometry is clinically important and is routinely performed as part of human ophthalmic examination. In veterinary ophthalmology, little is known about keratometry in dogs, and its practical application has been limited. The present study aimed to describe keratometry in some dog breeds popular in Japan using a handheld keratometer. Methods Client-owned dogs of various signalment were enrolled prospectively in the keratometry examination. Interbreed variations in mean corneal curvatures (R1R2avg) and corneal astigmatism (Δ(R1−R2)) were evaluated statistically with respect to their bodyweight based on the data which fulfilled the predetermined inclusion criteria. P<0.05 was considered statistically significant. Results On examination of 237 dogs from 16 different breeds, R1R2avg (mean±sd) ranged from 7.54±0.30 mm in Pomeranians to 9.28±0.19 mm in golden retrievers. Δ(R1−R2) (mean±sd) ranged from 0.22±0.11 mm in miniature schnauzers to 0.57±0.30 mm in French bulldogs. Conclusion The present study successfully described keratometry in 16 dog breeds. The study revealed considerable interbreed variations in both R1R2avg and Δ(R1−R2), which did not necessarily correlate with bodyweight. These results are useful both clinically in fitting contact lenses in the management of corneal diseases and non-clinically in optometric studies in dogs.

Retention, Bacterial Adhesion, and Biofilm Formation between Anionic and Zwitterionic Bandage Contact Lenses in Healthy Dogs: A Pilot Study

“…The BCL sizes were chosen based on the canine’s weight, according to a previous report [ 10 ]. For individuals weighing less than 12 kg, BCLs with a BC of 8.9 mm were used.…”

“…In addition, there are considerable variations in corneal curvature among canine breeds and weights. Most veterinary ophthalmologists are likely to stock no more than a few BCLs of different types and sizes [ 9 , 10 ]. Thus, BCLs having an appropriate base curve (BC) for the canine corneal curvature may not always be applied.…”

Keratometry in normal cats: a cross-sectional study in Japan using an automated handheld keratometer

“…In humans, corneal curvature measurements show significant variations among different populations and across different sexes of the same nationality and race [6,23,26]. This was also evident when keratometry was performed for dogs of different breeds and breed groups segregated by their body size [9,16]. In cats, these evaluations have not been conducted.…”

“…The degree of corneal astigmatism (|Δ(R1−R2)|) was also calculated as the absolute difference between the radii of the minor and major corneal meridians in diopters. All the measurements were obtained by a single examiner following a previously described technique [16]. At least three consecutive measurements were obtained for each eye, and the averages of these measurements were used for statistical analysis.…”