ArticleBMC veterinary research2017
The refractive state of the eye in Icelandic horses with the Silver mutation.
Article in BMC veterinary research, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 4 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
4 citing papers in PubMed, 18 citations in OpenAlex.
- Advances in Equine Genomics: Decoding the Genetic Architecture of Morphology, Performance, Behavior, and Adaptation.Molecular biotechnology · 2026Review
- Horse vision through two lenses: Tinbergen's Four Questions and the Five Domains.Frontiers in veterinary science · 2025Review
- Inconsistencies in horse coat color registration: A case study.Journal of equine science · 2020Article
- Erratum to: The refractive state of the eye in Icelandic horses with the Silver mutation.BMC veterinary research · 2017Article
Corrections and comments
- Erratum issued
Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe syndrome Multiple Congenital Ocular Anomalies (MCOA) is a congenital eye disorder in horses. Both the MCOA syndrome and the Silver coat colour in horses are caused by the same missense mutation in the premelanosome protein (PMEL) gene. Horses homozygous for the Silver mutation (TT) are affected by multiple ocular defects causing visual impairment or blindness. Horses heterozygous for the Silver mutation (CT) have less severe clinical signs, usually cysts arising from the ciliary body iris or retina temporally. It is still unknown if the vision is impaired in horses heterozygous for the Silver mutation. A recent study reported that Comtois horses carrying the Silver mutation had significantly deeper anterior chambers of the eye compared to wild-type horses. This could potentially cause refractive errors. The purpose of the present study was to investigate if Icelandic horses with the Silver mutation have refractive errors compared to wild-type horses. One hundred and fifty-two Icelandic horses were included in the study, 71 CT horses and five TT horses. All horses were genotyped for the missense mutation in PMEL. Each CT and TT horse was matched by a wild-type (CC) horse of the same age ± 1 year. Skiascopy and a brief ophthalmic examination were performed in all horses. Association between refraction and age, eye, genotype and sex was tested by linear mixed-effect model analysis. TT horses with controls were not included in the statistical analyses as they were too few.
resultsThe interaction between age and genotype had a significant impact on the refractive state (P = 0.0001). CT horses older than 16 years were on average more myopic than wild-type horses of the same age. No difference in the refractive state could be observed between genotypes (CT and CC) in horses younger than 16 years. TT horses were myopic (-2 D or more) in one or both eyes regardless of age.
conclusionOur results indicate that an elderly Icelandic horse (older than 16 years) carrying the Silver mutation is more likely to be myopic than a wild-type horse of the same age.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.