Which of the following statements about Fuchs' corneal dystrophy is true?

It is a type of endothelial dystrophy

Glaucoma is not a common association.

It is characterized by bilateral involvement

It primarily occurs in older adults

Statement 1 - A 59-year-old patient presents with flaccid bullae. Histopathology shows a suprabasal acantholytic split. Statement 2 - The row of tombstones appearance is diagnostic of Pemphigus vulgaris.

Statements 1 & 2 are correct, 2 is not explaining 1

Statements 1 and 2 are correct and 2 is the correct explanation for 1

Statements 1 and 2 are incorrect

A 25 -year-old lady with past history of seeing colored haloes was watching a movie in a theater when she started having right eye pain. She started feeling nauseous and had to leave the movie midway due to vomiting. On examination she is found to have ciliary and conjunctival congestion and the pupil is vertically oval. The picture of the eye is given below. All are true about the condition shown except:

Absent reaction to light and accommodation

A patient, three years post-surgery, presents with the condition shown in the image and complains of decreased vision. What is the most likely diagnosis?

Posterior Capsular Opacification

Posterior Subcapsular Cataract (PSC)

Pseudophakic Bullous Keratopathy

Corneal Dystrophies for FMGE: High-Yield Ophthalmology Lessons

Overview & Classification - Corneal Clarity Crisis

Definition: Bilateral, progressive, typically inherited, non-inflammatory conditions causing corneal opacification.
IC3D Classification (International Committee for Classification of Corneal Dystrophies):
- C1: Epithelial & Subepithelial Dystrophies
- C2: Bowman's Layer Dystrophies
- C3: Stromal Dystrophies
- C4: Endothelial Dystrophies
Inheritance Patterns: Primarily Autosomal Dominant (AD).

⭐ Most corneal dystrophies are Autosomal Dominant (AD). Key exceptions include Macular Dystrophy (Autosomal Recessive - AR) and Congenital Hereditary Endothelial Dystrophy (CHED - AR).

Anterior Dystrophies - Superficial Sight Stealers

These dystrophies primarily affect the corneal epithelium, epithelial basement membrane, or Bowman's layer, leading to visual disturbances and recurrent corneal erosions (RCE).

Dystrophy	Gene(s)	Key Clinical Signs	Symptoms (Common: RCE)
EBMD (Cogan's)	Sporadic	Map-like sheets, dots (microcysts), fingerprint swirls; negative fluorescein staining	Often asymptomatic, RCE
Meesmann Dystrophy	KRT3, KRT12	Diffuse, tiny, clear intraepithelial cysts (bubble-like); bilateral, symmetric	Irritation, photophobia, RCE
Reis-Bücklers (CBD I)	TGFBI	Dense, central subepithelial reticular/honeycomb opacities (Bowman's layer)	Painful RCE, ↓vision early
Thiel-Behnke (CBD II)	TGFBI	Subepithelial honeycomb opacities (Bowman's layer, 'curly fibers' on EM); often milder	RCE (less severe), ↓vision later

⭐ EBMD is the most common anterior corneal dystrophy and a frequent cause of recurrent corneal erosions.

Stromal Dystrophies - Mid-Layer Mayhem

Stromal dystrophies involve abnormal material accumulation within the corneal stroma. Key types:

Dystrophy	Inheritance	Gene	Deposit	Staining (Key Finding)	Clinical Notes
Macular	AR	CHST6	GAGs (Mucopolysaccharide)	Alcian Blue	Diffuse stromal haze, ↓ vision early
Granular (Type I)	AD	TGFBI	Hyaline	Masson Trichrome	Discrete "breadcrumb" opacities, clear stroma
Granular (Type II - Avellino)	AD	TGFBI	Hyaline & Amyloid	Masson Trichrome & Congo Red	Combined granular/lattice features
Lattice	AD	TGFBI	Amyloid	Congo Red (apple-green biref.)	Refractile branching lines, recurrent erosions

⭐ Macular Dystrophy is the only autosomal recessive stromal dystrophy among the common ones and causes diffuse stromal haze between opacities.

Macular Corneal Dystrophy Histopathology

Posterior Dystrophies - Deep Decompensation

Endothelial cell dysfunction leads to corneal edema due to pump failure.

Fuchs Endothelial Corneal Dystrophy (FECD)
- Late-onset: TCF4 gene.
- Signs: Corneal guttae (Descemet's excrescences), progressive ↓endothelial cells (risk < 500 cells/mm²), stromal edema (morning blur → persistent haze).
- Patho: Endothelial cell loss & dysfunction → ↓Na+/K+ ATPase pump function → edema.
⭐ Fuchs Endothelial Corneal Dystrophy is characterized by corneal guttae (excrescences of Descemet's membrane) and progressive endothelial cell loss leading to corneal edema.
Posterior Polymorphous Dystrophy (PPMD)
- Signs: Vesicular/band-like lesions on posterior cornea, iridocorneal adhesions. Autosomal Dominant (AD).
Congenital Hereditary Endothelial Dystrophy (CHED)
- Gene: SLC4A11 (Autosomal Recessive, AR).
- Signs: Diffuse bilateral "ground-glass" corneal opacity from birth/infancy; marked corneal thickening, nystagmus.

Specular microscopy of corneal guttae

High‑Yield Points - ⚡ Biggest Takeaways

Macular Dystrophy: Autosomal Recessive, mucopolysaccharide deposits (Alcian blue), most severe visual prognosis.

Granular Dystrophy: Autosomal Dominant, hyaline deposits (Masson trichrome), "bread-crumb" opacities.

Lattice Dystrophy: Autosomal Dominant, amyloid deposits (Congo red), characteristic "lattice lines".

Fuchs Endothelial Dystrophy: Endothelial cell loss with guttae, leads to corneal edema, common in elderly.

Reis-Bücklers Dystrophy: Affects Bowman's layer, causes painful recurrent corneal erosions.

Schnyder Crystalline Dystrophy: Lipid (cholesterol) deposits, often linked to systemic hyperlipidemia.

Congenital Hereditary Endothelial Dystrophy (CHED): Autosomal Recessive, presents with congenital corneal edema.

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