Diseases
Fuchs endothelial dystrophy
Fuchs endothelial dystrophy (Fuchs) is a bilateral, non-inflammatory disorder characterized by the formation of Hassall-Henle warts in between the corneal endothelial cells on Descemet membrane. Since the cells balance the hydration state of the cornea, a compromised endothelial cell pump mechanism results in an overhydration of the cornea, that is referred to as ‘corneal decompensation’. Until recently, Fuchs was managed by penetrating keratoplasty. Advanced treatment modalities suchs as (advanced) Descemet membrane endothelial keratoplasty (DMEK), developed by NIIOS, enable earlier intervention and improved the prognosis and rate of visual rehabilitation.
Etiology
Unknown. Although inheritance as an autosomal dominant trait and higher prevalence in women has been reported in the literature, these statistics have not been substantiated in our own patient series. Fuchs most often presents itself in the fifth or sixth decade of life, but may also be seen in younger patients.
Symptoms
Reduced visual acuity due to edema or optical interference by Hassall-Henle warts formation. Sometimes foreign body sensation, irritation, tearing and sensitivity to light. In late phases, subepithelial blister formation may induce pain.
Signs
- Hassall-Henle warts or guttata; seen as ‘black holes’ in the endothelial mosaic with specular microscopy;
- Endothelial cell density may be decreased;
- Increased stromal thickness due to edema with loss of corneal transparency;
- Formation of subepithelial bullae in advanced cases;
- Subepithelial and stromal scarring may occur in long-standing cases.
Management
In patients with pain due to local corneal decompensation associated with relatively good visual acuity, anterior stromal micropuncture, excimer laser surface ablation (PTK) or amniotic membrane transplantation may be performed.
Patients with markedly reduced visual acuity are eligible for posterior lamellar keratoplasty, and in particular Descemet stripping endothelial keratoplasty (DSEK) or Descemet membrane endothelial keratoplasty (DMEK), both techniques developed by NIIOS.
Although widely prescribed, hyperosmotic sodium chloride 5% drops and ointment may only have a limited placebo effect. There may be no proven rationale for intraocular pressure lowering medications. Soft contact lens fitting to control pain may be considered a short-term solution. Penetrating keratoplasty may be considered obsolete.
With advanced treatment modalities, such as Descemet membrane endothelial keratoplasty (DMEK), complete visual rehabilitation may be achieved with an excellent long-term prognosis. Read more about our (advanced) DMEK treatment or our clinical results.
Keratoconus
Keratoconus is a non-inflammatory, corneal ectasia (point-shaped deformation). Until recently, keratoconus was managed by fitting a rigid gas-permeable contact lens, and penetrating keratoplasty when contact lens intolerance developed. Advanced treatment modalities such as Bowman layer transplantation, developed by NIIOS, enable earlier intervention and improved the prognosis and visual rehabilitation.
Etiology
Unknown. May be associated with ocular and systemic diseases such as habitual eye rubbing, atopic dermatitis, Down’s syndrome, Marfan’s syndrome, osteogenesis imperfecta or Ehlers-Danlos syndrome. Onset in puberty or early adulthood.
Symptoms
Decreased visual acuity due to irregular astigmatism and/or corneal scarring. An acute corneal hydrops may induce pain.
Signs
- Bilateral, progressive thinning of the corneal stroma, most often paracentral temporal inferior;
- Distortion of the corneal contour with keratometry and computerized corneal topography, retinoscopy, and keratoscopy;
- Vertical Vogt’s striae may be evident in Descemet membrane at the apex of the cone;
- Munson’s sign: indentation of the lower lid by the conic cornea in downgaze;
- Rizutti’s sign: conical reflection on the nasal cornea if the cone is illuminated from the temporal side;
- Fleischer’s ring: ring shaped iron deposition at the level of the epithelial basement membrane;
- Descemet membrane rupture may result in acute hydrops with stromal edema and subepithelial central scarring.
Management
- Fitting of rigid gas-permeable contact lens;
- UV-crosslinking;
- Bowman layer transplantation (developed by NIIOS);
- Deep anterior lamellar keratoplasty (DALK) (developed by NIIOS).
Intrastromal corneal ring implants may give variable results. Selective cases may be eligible for surface ablation, lasik, ALTK or epikeratoplasty. Penetrating keratoplasty may be considered obsolete. With advanced treatment modalities, such as Bowman layer transplantion, further deformation of the cornea may be prevented with an excellent long-term prognosis. Please read more about our treatment options for keratoconus.
Bullous keratopathy
Bullous keratopathy is an overhydration of the cornea due to endothelial dysfunction. Commonly, the endothelial cell density is reduced, and because the cells balance the hydration state of the cornea, a compromised endothelial cell pump mechanism is referred to as ‘corneal decompensation’. Until recently, bullous keratopathy was managed by penetrating keratoplasty. Advanced treatment modalities such as (advanced) Descemet membrane endothelial keratoplasty (DMEK), developed by NIIOS, enable earlier intervention, and improved the prognosis and the rate of visual rehabilitation.
Etiology
Most often following complicated cataract extraction or other surgical trauma. Chronic endothelial cell damage may result from anterior chamber intraocular lenses or chronic inflammation. Idiopathic and congenital endothelial dystrophies occur in sporadic cases.
Symptoms
Reduced visual acuity with tearing and sensitivity to light are common. Subepithelial blister formation may induce intense pain.
Signs
- Epithelial edema with microcysts and formation of subepithelial bullae;
- Increased stromal thickness due to edema with loss of corneal transparency;
- Subepithelial and stromal scarring may occur in long-standing cases.
Management
In patients with pain due to local corneal decompensation associated with relatively good visual acuity, anterior stromal micropuncture, excimer laser surface ablation (PTK) or amniotic membrane transplantation may be performed.Patients with markedly reduced visual acuity are eligible for posterior lamellar keratoplasty, and in particular Descemet stripping endothelial keratoplasty (DSEK) or Descemet membrane endothelial keratoplasty (DMEK), both techniques developed by NIIOS.
Although widely prescribed, hyperosmotic sodium chloride 5% drops and ointment may only have a limited placebo effect. There may be no proven rationale for intraocular pressure lowering medications. Soft contact lens fitting to control pain may be considered a short-term solution for bulous keratopathy. Penetrating keratoplasty may be considered obsolete.
With advanced treatment modalities, such as Descemet membrane endothelial keratoplasty (DMEK), complete visual rehabilitation may be achieved with an excellent long-term prognosis. However, both the overall ocular condition as well as the duration of the disorder itself may affect the final visual outcome. Read more about our (advanced) DMEK treatment or our clinical results.