Aetiology

The most common posterior corneal dystrophy, characterised by a slowly progressive dysfunction of the corneal endothelium that eventually results in corneal oedema and reduced vision; resultant stromal and epithelial oedema leads to epithelial bullae

Studies of familial FECD cases show that the disease has an autosomal dominant inheritance pattern. However, the majority of patients with FECD have sporadic disease, without a familial history

The ICD3 classification categorises FECD patients as those with: 1) early-onset FECD, 2) identified genetic loci, and 3) disease without known inheritance

Predisposing factors

Most cases begin in the fourth decade or later
Female:male predominance = 2.5:1 to 3:1
A rare early-onset variant begins in the first decade of life
Smoking

Symptoms of corneal dystrophy

None in the early stages
Symptoms rare under age 50
Glare and blurred vision especially on waking (symptoms accentuated by overnight corneal oedema)
Diurnal changes in refraction (relatively myopic on waking)
Sharp pain (when epithelial bullae rupture)

Signs of corneal dystrophy

Bilateral (may be asymmetrical)
Central cornea affected (may extend to periphery in time)

• excrescences on posterior surface (guttata) produce ‘beaten metal’ appearance and interrupt specular image of endothelium
• thickened Descemet’s membrane
• fine pigment dusting on endothelium
• cystic epithelial oedema, ground glass appearance (bullous keratopathy)
• stromal oedema and thickening (endothelial decompensation)
  • increase in CCT with increasing severity plus enhanced overnight swelling
  • further increase in stromal oedema may result in folds in Descemet’s membrane
  • NB increased CCT may be present without observable signs of oedema
• posterior stromal scarring

Loss of contrast sensitivity
Reduced corneal sensitivity
The stages of Fuchs Dystrophy have been graded by a number of authorities,
but none have gained universal acceptance

Differential diagnosis

Pseudophakic or aphakic bullous keratopathy
Posterior polymorphous dystrophy
Cornea guttata (often listed as a dystrophy, but not necessarily progressive)
Corneal hydrops (in keratoconus)
Keratic Precipitates (KP) in Anterior Uveitis
Pigment Dispersion Syndrome
Herpetic Stromal Keratitis
Contact lens overwear

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

Photography and imaging, including specular microscopy (if available)
Measurement of central corneal thickness (CCT) for monitoring progression of disease
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Where there is pain, a therapeutic contact lens may protect exposed corneal nerves and reduce friction between lid margins and bullae on blinking                                                                              (GRADE*: Level of evidence=low, Strength of recommendation=weak)

Ocular lubricants for symptomatic relief (drops for use during the day, unmedicated ointment for use at bedtime)
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Oc. sodium chloride 5% or gutt. sodium chloride 5% (in severe cases with persistent oedema) applied in the mornings and as necessary. The dosage will need to be varied as usefulness or otherwise in controlling the patient’s symptoms becomes apparent
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Management category

B1: initial management, possible routine referral (modified statement)

Possible management by ophthalmologist

Confirmation of diagnosis
Photography and imaging, including specular microscopy
Measurement of CCT for monitoring progression of disease
Repeat assessment to establish progression
When condition no longer responsive to management of symptoms, may offer
surgery:

• posterior lamellar transplantation (currently the preferred treatment for irreversible corneal endothelial decompensation);
• techniques include:
  • Descemet’s Stripping Automated Endothelial Keratoplasty, DSAEK
  • Descemet’s Stripping Endothelial Keratoplasty, DSEK
  • Descemet’s Membrane Endothelial Keratoplasty, DMEK
• penetrating keratoplasty
• either of the above procedures may be combined with cataract surgery if this is clinically indicated

Endothelial keratoplasty procedures have largely superseded PK for FECD. Low certainty evidence supports the conclusion that DMEK has faster visual recovery and a better visual outcome than DSEK. Prospective national registry data from Australia and the UK shows higher transplant Prospective national registry data from Australia and the UK shows higher transplant failure rates for endothelial keratoplasty than are seen following PK. These higher failure rates of EK compared with PK may be acceptable given the established benefits of the procedure, including lower refractive error, structural globe integrity, and faster visual recovery

Evidence base

*GRADE: Grading of Recommendations Assessment, Development and Evaluation (see www.gradingworkinggroup.org)

Sources of evidence

Deng SX, Lee WB, Hammersmith KM, Kuo AN, Li JY, Shen JF, Weikert MP, Shtein RM. Descemet Membrane Endothelial Keratoplasty: Safety and Outcomes: A Report by the American Academy of Ophthalmology. Ophthalmology. 2018;125(2):295-310

Greenrod EB, Jones MN, Kaye S, Larkin DF; National Health Service Blood and Transplant Ocular Tissue Advisory Group and Contributing Ophthalmologists (Ocular Tissue Advisory Group Audit Study 16). Center and surgeon effect on outcomes of endothelial keratoplasty versus penetrating keratoplasty in the United Kingdom. Am J Ophthalmol. 2014;158(5):957-66

Knezović I, Dekaris I, Gabrić N, Cerovski J, Barisić A, Bosnar D, Rastegorac P, Parać A. Therapeutic efficacy of 5% NaCl hypertonic solution in patients with bullous keratopathy. Coll Antropol. 2006;30:405-8

Kopplin LJ, Przepyszny K, Schmotzer B et al (for the Fuchs Endothelial Corneal Dystrophy Genetics Multi-Center Study Group). Relationship of Fuchs Endothelial Corneal Dystrophy Severity to Central Corneal Thickness. Arch Ophthalmol. 2012;130:433-9

Nanavaty MA, Wang X, Shortt AJ. Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy. Cochrane Database Syst Rev. 2014;2:CD008420

Nagarsheth M, Singh A, Schmotzer B, Babineau DC, Sugar J, Lee WB, Ivengar SK, Lass JH; Fuchs Genetics Multi-Center Study Group. Relationship Between Fuchs Endothelial Corneal Dystrophy Severity and Glaucoma and/or Ocular Hypertension. Arch Ophthalmol. 2012;130:1384-8

Ong Tone S, Kocaba V, Böhm M, Wylegala A, White TL, Jurkunas UV. Fuchs
endothelial corneal dystrophy: The vicious cycle of Fuchs pathogenesis. Prog Retin
Eye Res. 2020 May 8:100863. doi: 10.1016/j.preteyeres.2020.100863. Online
ahead of print

Rice GD, Wright K, Silverstein SM. A retrospective study of the association between Fuchs’ endothelial dystrophy and glaucoma. Clin Ophthalmol.2014;8:2155-9

Stuart AJ, Romano V, Virgili G, Shortt AJ. Descemet's membrane endothelial keratoplasty (DMEK) versus Descemet's stripping automated endothelial keratoplasty (DSAEK) for corneal endothelial failure. Cochrane Database Syst Rev. 2018;6:CD012097

Williams KA, Keane MC, Coffey NE, Jones VJ, Mills RAD, Coster DJ. The Australian Corneal Graft Registry (2018) Report. South Australian Health and Medical Research Institute 2018

Corneal dystrophies are progressive, usually bilateral, mostly inherited, alterations in corneal transparency that develop without inflammation. In the past, the nomenclature of the many dystrophies has often caused confusion. A newer classification (the IC3D Classification) has been proposed which integrates up-to-date information on phenotypic description, histopathological examination and genetic analysis: https://eyepath.org.uk/2nd-edition-ic3d-classification-of-corneal-dystrophies/

In everyday clinical practice, the most commonly encountered corneal dystrophies are Epithelial Basement Membrane Dystrophy (Map-Dot-Fingerprint Dystrophy, Cogan’s Dystrophy), which affects the epithelium and predisposes to Recurrent Corneal Epithelial Erosion (see the Clinical Management Guideline of that name) and Fuchs Endothelial Corneal Dystrophy, the subject of this Clinical Management Guideline.

Fuchs Endothelial Corneal Dystrophy
Version 14
Date of search 17.11.20
Date of revision 25.02.21
Date of publication 06.08.21
Date for review 16.11.22
© College of Optometrists