CASE PRESENTATION:Corneal Dystrophy
Dr. Nilay Nitin Patel
Dr. Nita Shanbhag
D Y Patil University, School of Medicine
Nerul, Navi Mumbai
Case History• A 45 year old woman came with complaints of Gradual
Progressive Diminision of Vision in both eyes since 10 years of
age
• Patient was apparently alright before that with good visual acuity
• No H/o Photophobia, Coloured halos, Watering and Pain
• No H/o Trauma, Viral infection
• No relevant family history
• No H/o of any systemic illness
• No known drug allergy
Ocular ExaminationRIGHT EYE LEFT EYE
V/A 6/36 6/60
Pin hole Vn 6/36 NI 6/60 NI
Retinoscopy +1.25 / +1.25 +1.0 / +1.0
IOP Digitally normal Digitally normal
Lids / lashes Normal Normal
Sclera / Conjunctiva
Not congested Not congested
Cornea Multiple white dots about 0.5mm in diameter eroding out of the epithelium, studding the stroma not involving the endothelium, spread over 8mm area, with interdigitating network of filaments
Anterior chamber Normal in depth. No KPs, flares and cells.
Iris / Pupil CPN / CCRTL CPN / CCRTL
Lens Clear Clear
EOM Free and full Free and full
Dil. Fundus Examination
Media: ClearDisc:0.3 cup with normal NRRVessels: WNL; Macula: Normal FR: +
Media: ClearDisc:0.3 cup with normal NRRVessels: WNL; Macula: Normal FR: +
Gonioscopy Open angles Open angles
RE LE
Characteristics Lattice Granular Macular
Genetics Autosomal Dominant Autosomal Dominant Autosomal Recessive
Onset 1st decade of life Early Adolescence 1st decade
VisionEarly reduction with
obvious cloudingGood until middle age
Reduced by 30-40 years, FC by 50 years
SymptomsSevere recurrent
erosionsMinimal inflammation
and irritationMild recurrent erosions
Opacites
Grayish ‘ pipe cleaner’ linear, branching, threads; dots and
flakes; distinct borders
Grayish opaque granules; bread
crumbs; sharp borders
Grayish opaque spots; indisctinct borders
Intervening Stroma Relatively clear Clear Diffusely clear
Distribution of Opacities
Entire cornea with dots; linear opacities central;periphery usually clear;
Progress to central disciform by middle age
Axial only; periphery clear
Entire cornea; but most dense centrally
Histopathology
Large hyaline lesions with scattered fibrillar
material; also subepithelial
Discrete, hyaline, granulated
Diffuse, granular, nonhyaline,
Asso with keratocytes
DefectStructural protein:
primary amyloidosis of cornea
Structural proteins: hyaline degeneration of
collagen
Metabolic: defective acid
mucopolysaccharide metabolism
Corneal Stromal Dystrophy
Types of Lattice Corneal dystrophy
CharacteristicsType I ( Biber-Haab-Dimme)
Type II ( Meretoja Syndrome )
Type III
Usual age of onset <10 years >20 years >40 years
Visual acuity Impaired by age 40-60 Good until age 65 Impaired after 60
Systemic amyloidosis No Yes No
Faces Normal
Masklike facial expression, blepharochalasis, floppy ears, protruding lips
Normal
Nervous system NormalCranial and peripheral nerve palsies
Normal
Skin NormalDry, itchy, and lax with amyloid deposits
Normal
Cornea
Delicate interdigitating network of filaments; no lines present at early stages
Thick and radially oriented linesExtending to periphery
Thick lines
Episodic corneal erosions
Yes Yes No
Granular Dystrophy Type 2 (Avellino /Granular- Lattice Dystrophy)
• Gen: Autosomal Dominant related to the TGFBI gene, locus 5q31
• Recurrent erosions are more common
• Biomicroscopically, granular deposits are more superficial; as the disease progresses, a snowflake appearance deeper in the stroma can be noted.
• The linear refractile deposits tend to be deeper than the granular deposits, but with progression these lines coalesce with the round opacities.
• Pathology: mixed deposits of hyaline and amyloid; hyaline stains with Masson Trichrome and amyloid stains with Congo Red
Stains Lattice Granular Macular Avellino
PAS (Periodic acid schiff) + + +
Trichrome Masson + + +
Congo red (Under polarization) + +
Alcian blue +
Stains used for Histopathological diagnosis of the Stromal Corneal Dystrophy
InvestigationsOcular
• IOP
• Sac syringing
• Corneal Topography
• Anterior Segment OCT
• UBM
• Pachymetry
• Posterior segment I/O to r/o
any retinal Pathology
Systemic
• Diabetes
• Hypertension
• Systemic Amyloidosis
• Peripheral and cranial
nerve involvement
Initial medical management
• Lubricating drops, or autologous serum
therapy
• Punctal plugs
• Bandage Contact Lenses +/- antibiotics for
recurrent
erosions
DiscussionIf Epithelium & Stroma involved
• Common
• DALK
– Manual
– Excimer donor lenticule giving better approximation with lesser astigmatism
– Femto donor Lenticule with more optimal results
If Endothelium involved
• Very Rarely
• PKP is the only Mx option
– With good visual prognosis
– Recurrences of primary
dystrophy are known in
the graft
In this case PKP is preferred over DALK because dissection of the stroma would be difficult as the stromal involvement is extensive.
Differential Diagnosis
• Lattice Corneal Dystrophy - Type I, III, IIIa, IV: these dystrophies typically present with central anterior stromal corneal lattice lines at variable stages in life, recurrent corneal erosions, and no systemic features
• Granular Corneal Dystrophy – Avellino, Reis Bückler
• Macular Corneal Dystrophy – Type I, Type Ia, Type II
• Schnyder Corneal Crystalline Dystrophy (SCCD)IMPRESSION: Avellino Corneal Dystrophy
THANK YOU
Dystrophy vs Degeneration
Dystrophies:
• Genetic (usually Aut Dom) with
onset in childhood/early
adulthood
• Not associated with systemic
disease
• Bilateral
• Centrally located within the
cornea
• Typically involve only one layer of
the cornea
Degenerations: • Progressive (onset typically after
age 40)
• Usually unrelated to family history
or genetic predisposition
• Commonly associated with
systemic disease (rheumatologic,
infectious)
• Usually unilateral, asymmetric if
bilateral, and peripherally located
on the cornea
• Can involve one or multiple layers
of the cornea
• Often associated with
neovascularization
TGFβ1 and Corneal Dystrophies
• Transforming Growth Factor Beta Induced Protein (gene product of TGFβ1) is very abundant in cornea
- >30 mutations in TGFβ1 gene that result in corneal dystrophies - 68 kDa protein known as keratoepithelin
• It is secreted by corneal epithelial cells and is found in normal stroma bound to type VI collagen
- Mutations in theTGFβ1 gene protein aggregation in the cornea 2/2 protein misfolding
• TGFβ1 induced protein accumulates as insoluble products in various forms. The severity, clinicopathologic variations , age of onset, and location of deposits all depend in the type of amino acid alterations in the protein
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