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Central corneal thickness in koi fish: effects of age, sex, body length, and corneal diameter
Author(s) -
Lynch Gwendolyn L.,
Hoffman Allison,
Blocker Tiffany
Publication year - 2007
Publication title -
veterinary ophthalmology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.594
H-Index - 50
eISSN - 1463-5224
pISSN - 1463-5216
DOI - 10.1111/j.1463-5224.2007.00538.x
Subject(s) - ophthalmology , fish <actinopterygii> , intraocular pressure , anatomy , cornea , medicine , corneal pachymetry , corneal topography , biology , fishery
Objective To establish the central corneal thickness (CCT) of normal koi fish by ultrasonic pachymetry, and its relationship to age, sex, body length and corneal diameter. Methods Age, sex and body length of 33 koi fish (17 male and 16 female fish) were recorded. Horizontal and vertical corneal diameters of each eye were obtained using Jameson calipers. Central corneal thickness of all eyes was measured by ultrasonic pachymetry. Intraocular pressure (IOP) by rebound tonometry was obtained for a subgroup of nine koi (18 eyes). Results Mean central corneal thickness was 325.9 µm. Central corneal thickness of female koi was greater than CCT of male fish ( P < 0.01). Central corneal thickness increased with increasing age overall and within both sexes ( P < 0.01). Central corneal thickness increased with increasing body length ( P < 0.001). For male and female fish, CCT increased with increasing horizontal and vertical corneal diameters ( P < 0.01). Mean horizontal corneal diameter (HCD) was 8.05 mm, mean vertical corneal diameter (VCD) was 7.38 mm, and HCD was consistently greater than VCD. Mean IOP of a subgroup of these koi was 4.9 mmHg by rebound tonometry. Conclusions Koi CCT increases with increasing age, body length and corneal diameter.