A 2-d-old Warmblood colt was submitted for autopsy with a spectrum of bilateral ocular abnormalities. At postmortem examination, a constellation of lesions within the anterior segment included retention of ectodermal elements, compatible with choristoma. Ocular choristomas can be localized to different intraocular structures and are rare in equids. The morphologic features in our case were suggestive of abnormal corneal differentiation.
AppleDJNaumannGOH. Malformations and anomalies of the eye. In: NaumannGOHAppleDJ, eds. Pathology of the Eye. Springer, 1986:63–98.
2.
BallandO, et al. Canine bilateral conjunctivo-palpebral dermoid: description of two clinical cases and discussion of the relevance of the terminology. Case Rep Vet Med2015:876141.
3.
BarkyoumbSDLeipoldHW.Nature and cause of bilateral ocular dermoids in Hereford cattle. Vet Pathol1984;21:316–324.
4.
BarsottiG, et al. Ocular abnormalities in healthy Standardbred foals. Vet Ophthalmol2013;16:245–250.
5.
BaumgartnerWA, et al. Bilateral intraocular glandular choristomas in a Thoroughbred foal. Vet Ophthalmol2009;12:106–114.
6.
BerkowskiW, et al. Microphthalmia, corneal dermoids, and congenital anomalies resembling Goldenhar syndrome in a cat. J Am Vet Med Assoc2018;252:324–329.
7.
BrudenallDK, et al. Bilateral corneoconjunctival dermoids and nasal choristomas in a calf. Vet Ophthalmol2008;11:202–206.
8.
CathelinA, et al. Ocular dermoids in 13 cats: a multicentre retrospective study. J Feline Med Surg2022;24:745–753.
9.
ChoPW, et al. Microphthalmia with multiple ocular abnormalities in a foal. Vet Ophthalmol2024. doi:10.1111/vop.13254.
10.
ChograniM, et al. Molecular analysis of the PAX6 gene for aniridia and congenital cataracts in Tunisian families. Hum Genome Var2014;1:14008.
11.
ClarkeLL, et al. Congenital ocular abnormalities in free-ranging white-tailed deer. Vet Pathol2018;55:584–590.
12.
EvansHESackWO.Prenatal development of domestic and laboratory mammals: growth curves, external features and selected references. Zentralbl Veterinarmed1973;2C:11–45.
13.
GornikKR, et al. Unilateral choristoma of the nictitating membrane in a horse. J Am Vet Med Assoc2015;246:231–235.
14.
KaushikS, et al. Anterior segment dysgenesis: insights into genetics and pathogenesis. Indian J Ophthalmol2022;70:2293–2303.
15.
LabelleAL, et al. Ophthalmic lesions in neonatal foals evaluated for nonophthalmic disease at referral hospitals. J Am Vet Med Assoc2011;239:486–492.
16.
MakraZJakabC.Bilateral corneal dermoids and eyelid malformation in a colt—a case report. Acta Vet Brno2018;87:73–76.
17.
MannI. Developmental Abnormalities of the Eye. 2nd ed.British Med Assoc, 1957:357–364.
18.
MannI.A rare congenital abnormality of the eye. Br J Ophthalmol1930;14:321–330.
19.
MansourAM, et al. Ocular choristomas. Surv Ophthalmol1989;33:339–358.
20.
MartinsBGaleraP. Embryology and anatomy of the equine eye. In: WongDMWilkinsPA, eds. Equine Neonatal Medicine. Vol. 2. Wiley-Blackwell, 2024:1178–1184.
21.
MoonJH, et al. Bilateral ocular osseous choristomas. Pediatr Radiol2005;35:1145–1146.
22.
NajmiH, et al. Congenital solitary osseous choristoma of the left lateral canthus: a case report. BMC Ophthalmol2024;24:140.
23.
RobertsSM.Congenital ocular anomalies. Vet Clin North Am Equine Pract1992;8:459–478.
24.
TamimiY, et al. FGF19 is a target for FOXC1 regulation in ciliary body-derived cells. Hum Mol Genet2006;15:3229–3240.
25.
TobaigyMF, et al. An incidental finding of intraocular choristoma in an enucleated microphthalmic globe: a histopathologic case report. Int J Surg Case Rep2021;79:70–72.
26.
TurnerAG.Ocular conditions of neonatal foals. Vet Clin North Am Equine Pract2004;20:429–440.
27.
ValentiniS, et al. Assessment of intraocular measurements in neonatal foals and association with gender, laterality, and body weight: a clinical study. PLoS One2014;9:e109491.
