Posterior polymorphous corneal dystrophy

What it is

From: Orphanet

A rare mild subtype of posterior corneal dystrophy characterized by small aggregates of apparent vesicles bordered by a gray haze at the level of Descemet membrane, generally with no effect on vision.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal Descemet membrane morphology · Very frequent (99-80%)

Abnormality of Descemet's membrane, which is the basement membrane of the corneal endothelium.

Reduced number of corneal endothelial cells · Very frequent (99-80%)

A reduction in the number of corneal endothelial cells.

Amblyopia · Occasional (29-5%)

Reduced visual acuity that is uncorrectable by lenses in the absence of detectable anatomic defects in the eye or visual pathways.

Anterior synechiae of the anterior chamber · Occasional (29-5%)

Adhesions between the iris and the cornea.

Astigmatism · Occasional (29-5%)

A type of refraction error associated with abnormal curvatures on the anterior and/or posterior surface of the cornea.

Corneal stromal edema · Occasional (29-5%)

Abnormal accumulation of fluid and swelling of the stroma of cornea.

Increased corneal curvature · Occasional (29-5%)

An increase in the degree of curvature of the cornea compared to normal.

Uveal ectropion · Occasional (29-5%)

Presence of iris pigment epithelium on the anterior surface of the iris.

Very low visual acuity · Occasional (29-5%)

A reduction in visual acuity with best corrected visual acuity between 1.40 (20/500) and 1.89 logMAR (up to roughly 20/1590).

Reduced visual acuity · Occasional (29-5%)

Blurred vision · Very rare (<4-1%)

Lack of sharpness of vision resulting in the inability to see fine detail.

Corneal opacity · Very rare (<4-1%)

A reduction of corneal clarity.

Ectopia pupillae · Very rare (<4-1%)

A malposition of the pupil owing to a developmental defect of the iris.

Esotropia · Very rare (<4-1%)

A form of strabismus with one or both eyes turned inward ('crossed') to a relatively severe degree, usually defined as 10 diopters or more.

Other findings in the same source

From: Orphanet

Additional reported features include Glaucoma (Very rare (<4-1%)); Lacrimation abnormality (Very rare (<4-1%)); Ocular hypertension (Very rare (<4-1%)); Ocular pain (Very rare (<4-1%)); Photophobia (Very rare (<4-1%)); Chorioretinal degeneration (Very rare (<4-1%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Childhood

Inheritance in the source

From: Orphanet

Autosomal dominant

Frequency and the population described

From: Orphanet

Point prevalence: 1-9 / 100 000; Czech Republic; Value and class.

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal dominant pattern means that one altered copy of a relevant gene can be sufficient for the condition. Some affected people inherit the change; others have a new change without an affected parent. The precise finding, family history and condition determine what this means for relatives.

Which doctor should you see?

The suggested department for discussing Posterior polymorphous corneal dystrophy is Ophthalmology, with a ophthalmologist as the relevant type of clinician. Ophthalmologist; paediatric services for children as appropriate.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which part of the eye or visual pathway is affected?
• What change in vision requires immediate contact with the eye service?
• What are the aims and alternatives of any proposed eye treatment?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Posterior polymorphous corneal dystrophy. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.