ORPHA:137672
Pellucid marginal degeneration
Publications
810
90.3th percentile
Trials
3
Interventional, condition-specific
Researchers
841
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare disorder of the anterior segment of the eye characterized by slowly , bilateral, non-ulcerative, non-inflammatory, clear thinning of the inferior portion of the peripheral cornea (extending from the 4 o'clock to the 8 o'clock position), with an area of corneal protrusion above the point of maximal thinning, resulting in against-the-rule astigmatism with decreased visual acuity. The central cornea is of normal thickness.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0015298
- UMLS:C0339288
Research stages
Trial readiness signals
Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”
2/6 stages with a signal
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
810 matched papers (513 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- Interventional trialPresent
3 matched on ClinicalTrials.gov (1 recruiting in sample)
Biology
Genes and phenotypes
Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.
Do we know what causes it?
Not yet — the cause hasn't been pinned down in GenCC.
No strong gene–disease assertion joined for this Orphanet entity.
Phenotypes (Monarch / HPO)
Not enriched in this build — Monarch phenotype joins were not run for this record.
Animal models (Monarch / Alliance)
Not enriched in this build.
Literature
Is anyone studying this?
810
810 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.
810 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).
513 in the last 10 years · high confidence · 90.3th percentile (publications denominator)
Phrase hits: 810 · MeSH hits: 0
Who's working on it?
841
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.
- 01Seitz B4 papers · 2024
Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany.
Papers in Europe PMC - 02Sharma N4 papers · 2025
Ophthalmology, All India Institute of Medical Sciences, New Delhi, IND.
Papers in Europe PMC - 03Ambrósio R Jr3 papers · 2026
Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil; Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil; Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil; Department of Ophthalmology, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo, Brazil; Department of Ophthalmology, Federal University the State of Rio de Janeiro (UNIRIO), USA. Electronic address: dr.renatoambrosio@gmail.com.
Papers in Europe PMC - 04Chaurasia S3 papers · 2025
Department of Ophthalmology, L. V. Prasad Eye Institute, Telangana, India.
Papers in Europe PMC - 05Dandapani R3 papers · 2023
Refractive Services, The Eye Foundation, Coimbatore, Tamil Nadu, India.
Papers in Europe PMC - 06Flockerzi E3 papers · 2024
Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany.
Papers in Europe PMC - 07Jhanji V3 papers · 2025
Cornea, Cataract, and External Disease Services, University of Pittsburgh School of Medicine, Pittsburgh, USA.
Papers in Europe PMC - 08Li X3 papers · 2025
Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Department of Ophthalmology, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
Papers in Europe PMC - 09Mounir A3 papers · 2026
Ophthalmology Department, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt.
Papers in Europe PMC - 10Nanavaty MA3 papers · 2025
Sussex Eye Hospital, University Hospitals Sussex NHS Foundation Trust, Brighton BN2 5BF, UK.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
3
interventional trials for this specific condition
3 interventional trials matched this specific condition name; 1 currently recruiting in our sample.
Data as of 27 July 2026
3 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 85.1th percentile).
high confidence · 85.1th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
3 interventional trials matched after quoted-phrase search and title/condition post-filter.
- NCT07135167·RECRUITING·Compassionate Use Study of Epi-ON Corneal Collagen Crosslinking Performed Using UVA Exposure on Eyes With Ectatic Corneal Diseases for Subjects With Down Syndrome
Conditions: Down Syndrome (DS) · Keratoconus · Pellucid Marginal Degeneration · Forme Fruste Keratoconus (FFK)·Matched via name phrase
Where to find support
We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:
India — NPRD
Last verified 2026-07-26This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.
Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.
How we counted this
Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.
"Pellucid marginal degeneration"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Pellucid marginal degeneration"
Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).
Study-type breakdown: 3 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-27T07:27:27.018Z