distichia
Enable an agent to explain human distichiasis, record its anatomical features and ocular effects, and support evidence-based clinical review and follow-up.
Bundle → Layer → Finding → Questions Filled
5 bundles · 9 layers · 13 findings · 21 questions
Lash identity and boundaries Resolve what the registered term denotes and what anatomical evidence supports its use.
Term and unit
Preserve the distinction between an abnormal lash and a patient-level condition.
Distichia referent
Veterinary usage describes distichia as abnormal eyelashes; this supports a provisional lash-level interpretation rather than an abstract-concept model. [Madison Veterinary Specialists](https://www.mvsvets.com/wp-content/uploads/2015/08/Distichia.pdf)
- Does the registry's originating record denote an individual lash, multiple lashes or the condition distichiasis? definition
- Which originating identifier and terminology source support that interpretation? provenance
Anatomical discrimination
Identify the observed lash exit site independently of its direction.
Exit-site evidence
Human clinical descriptions locate distichiasis lashes at meibomian gland openings; examination evidence should establish the relevant anatomy for the host. [University of Iowa atlas](https://webeye.ophth.uiowa.edu/eyeforum/atlas/pages/distichiasis/)
- Where does the shaft emerge relative to the meibomian openings and normal lash-bearing region? measurement
- What observed anatomy supports distichia rather than trichiasis, ectopic cilia or entropion? boundary
Lash map and development Describe the distribution of abnormal lashes and the evidence for their history.
Lid distribution
Locate visible shafts within an explicit examination area.
Mapped lash burden
Record counts and annotated positions per eyelid, including examination limitations and any multiple shafts seen at one opening.
- How many abnormal shafts are visible on each examined eyelid, and where are they? measurement
- Which magnification, images and examiner observations support the count and site map? provenance
Onset and context
Separate first detection from supported developmental or acquired origin.
Origin confidence
Human distichiasis is described as congenital or acquired; an agent should preserve the evidence behind any origin assignment rather than infer it from the current appearance. [University of Iowa atlas](https://webeye.ophth.uiowa.edu/eyeforum/atlas/pages/distichiasis/)
- What earlier examinations or histories establish when the abnormal lashes were first present? provenance
- Does the available evidence justify a congenital or acquired designation, or only an unknown onset? boundary
Ocular contact and effects Connect lash mechanics to observed ocular findings without assuming causation.
Contact mechanics
Observe how the shaft interacts with the eye.
Shaft-surface interaction
Document shaft direction, apparent stiffness and contact during the observed examination conditions.
- Does the lash touch the cornea or conjunctiva, and does contact vary with blinking or eyelid position? measurement
- Which lash characteristics and examination conditions support the contact assessment? provenance
Clinical attribution
Evaluate symptoms and surface injury alongside alternative explanations.
Lash-related effects
Veterinary guidance reports both asymptomatic cases and cases with irritation or corneal injury; record observed effects separately from attribution to the lash. [Madison Veterinary Specialists](https://www.mvsvets.com/wp-content/uploads/2015/08/Distichia.pdf)
- What discomfort, discharge, redness or ocular surface damage was reported or demonstrated? measurement
- What evidence links those findings to the mapped lash, and what competing causes remain? boundary
Management and reassessment Support clinician-directed decisions and evaluate outcomes at identified lash sites.
Management basis
Make the evidence behind observation or intervention reviewable.
Clinician-selected response
Record the clinician's decision, target lashes and expected outcome in the applicable human or veterinary context.
- What examination findings support observation, symptom management or lash-directed intervention? action
- Which clinician selected the approach, and which mapped sites and clinical effects does it address? provenance
Site-specific follow-up
Compare subsequent lash and ocular findings with baseline observations.
Persistence and outcome
Veterinary guidance notes possible regrowth after cryotherapy; follow-up should distinguish reappearance at a treated site, newly detected lashes and persistent symptoms. [Madison Veterinary Specialists](https://www.mvsvets.com/wp-content/uploads/2015/08/Distichia.pdf)
- At reassessment, which previously mapped sites contain visible lashes, and how have ocular findings changed? measurement
- Do persistent symptoms, new injury or lash reappearance require further clinician review under the recorded care plan? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these check these first hold for the sense of distichia this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these kinds and varieties hold for the sense of distichia this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these real-world use hold for the sense of distichia this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these failure modes and hazards hold for the sense of distichia this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of distichia this model covers, and on what evidence? provenance
Classifiers Filled
- Family
- Thing Registry
- Category
- Cross-cutting context
- Entry kind
- thing
- Plane
- XCT
- Domain
- XCT.STA
- Other names and narrower kinds
- Tristichiasis
What it is Filled
Distichiasis is a human eyelid condition characterised by accessory eyelashes emerging from or near the openings of the meibomian glands along the posterior eyelid margin; these lashes may contact the ocular surface and cause irritation or damage, although the condition can be asymptomatic.
In scope
- Anatomical evidence supports assessment of human distichiasis.
- The location, number and distribution of accessory lashes characterise the condition.
- Lash characteristics and contact with the ocular surface inform assessment of its effects.
- Symptoms and examination findings describe the condition's clinical impact.
- Management decisions and subsequent observations concern the condition and its ocular effects.
Out of scope
- General eyelash anatomy and normal lash variation
- Independent models of trichiasis, ectopic cilia and entropion
- Complete diagnosis and treatment of corneal disease
- Systemic syndromes and genetic disorders associated with distichiasis
- Detailed surgical techniques, medication dosing and anaesthesia protocols
Why it exists Filled
Enable an agent to explain human distichiasis, record its anatomical features and ocular effects, and support evidence-based clinical review and follow-up.
Distinguishing features Filled
- Accessory lashes emerge from or near meibomian gland openings along the posterior eyelid margin, and direction toward the eye alone does not establish distichiasis.
- Abnormal lash origin distinguishes distichiasis from trichiasis involving misdirected lashes arising at normal sites.
- Lashes emerging through the palpebral conjunctiva require distinction from the marginal accessory lashes of distichiasis.
- Inward eyelid rotation is distinct from the abnormal lash origin characteristic of distichiasis.
- Human distichiasis can involve a partial additional row of lashes and can occur without ocular symptoms.
What robots and AI may and may not do Filled
Must not
- Recommend removing eyelashes at home.
- Diagnose a person's eye condition or prescribe treatment.
- Delay care for eye pain or vision changes.
- Share medical information without consent.
Only with a human decision
- Any treatment, such as electrolysis or surgery.
May
- Explain distichia and distichiasis in general terms.
- Encourage a person or animal keeper to see an eye specialist.
Moral aspects Filled
- The condition can damage the cornea and threaten vision.
- It occurs in dogs too, so animal welfare matters.
Who is affected
- Patients
- Pet owners and their animals
Owners Filled
Steward
Each person for their own body; the keeper for an animal.
Links to other meta-models Filled
parent
- Q55789187 - registry parent class
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.distichia
- Wikidata: Q1229478 (https://www.wikidata.org/wiki/Q1229478)
Direct properties not applicable Not applicable
- Host and clinical context: Patient reference, species, age at examination and human or veterinary context
- Lash exit location: Meibomian opening; other eyelid-margin site; palpebral conjunctiva; unresolved
- Eyelid position map: Left or right eye, upper or lower lid, annotated location
- Visible abnormal lash count: Integer lashes per specified lid at a dated examination; uncountable or not assessed
- Lash morphology: Recorded pigmentation, apparent thickness, flexibility and direction; unknown permitted
- Ocular surface contact: Observed; not observed; intermittent; uncertain; not assessed
- Associated ocular findings: No detected effects; discomfort; redness; discharge; epithelial injury; scarring; unresolved
- Post-management lash status: Present; removed; absent on examination; reappeared at mapped site; newly detected elsewhere; uncertain
Plane XCT: no invented physical properties.
Recognition optional Filled
- Extra lashes emerging from the inner rim of the eyelid.
- Lashes pointing toward the eye.
Capabilities and actions required Filled
- Map suspected distichiae to specific eyelids and examination evidence.
- Compare lash origin and eyelid position against neighbouring abnormalities.
- Separate incidental anatomical findings from suspected symptomatic involvement.
- Prepare a clinician-review summary linking lash contact, symptoms and ocular findings.
- Track clinician-selected management and changes at previously mapped lash sites.
Hazards and failure modes required Filled
- Corneal abrasion and ulcer from lashes rubbing the eye.
- Chronic irritation and tearing.
Standards and interfaces required Filled
- The World Health Organization's International Classification of Diseases, Tenth Revision, includes congenital distichiasis under Q10.3, other congenital malformations of the eyelid.
Context of use required Filled
- Distichia are encountered during eyelid examinations when accessory eyelashes arise along the posterior eyelid margin.
- Documenting their position and contact with the eye supports clinical assessment of irritation, tearing and corneal injury.
Sources Filled
- Wikidata item Q1229478: distichia - identity and sense of the item
- Wikipedia: Distichia - general description of the item
Open questions
- Does the originating registry record intend the individual abnormal lash or use distichia as a synonym for distichiasis?
- Why is this entry classified under XCT / XCT.STA, and does its source evidence warrant a different classification?
- Which diagnostic boundaries and terminology conventions should be shared across human and veterinary contexts, and which require species-specific treatment?
- What reproducible examination method best captures fine lashes, intermittent contact and uncertainty in counts?
- Does an existing Vercy world model already cover this concept, requiring a link instead of a separate publication?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q1229478/spec.json