Corneal Disorders Flashcards
Reis Bucklers
=RBCD
AD - TGFbeta1 - keratoepithelin Presents in 1st or 2nd decade Central cornea Hyaline Bowman’s layer dystrophy Recurrent erosion Stromal scar
Thiel-Behnke
=TBCD
TGFbeta1
Bowman’s layer
Curly fibers on EM
Less recurrent erosion/stromal scar
Epithelial and subepithelial dystrophies
EBMD Meesman (MECD) Gelatinous drop-like (GDCD) Subepithelial mucinous (SMCD) Lisch (LECD) Epithelial recurrent erosion (ERED)
TGB1 dystrophies
= epithelial-stromal
RBED
TBED
Granular (GCD1, GCD2)
Lattice (LCD1, variants: III, IIIa, I/IIIa, IV)
Stromal dystrophies
Macular (MCD) Granular Lattice Schnyder (SCD) Congenital stromal (CSCD) Fleck (FCD) Posterior amorphous (PACD) Pre-Descemet (PDCD)
Endothelial Dystrophies
Fuchs Posterior polymorphous (PPCD) Congenital hereditary (CHED)
DLK Grades
I-IV
I - peripheral granular cells; topical steroids, Q2-3D f/u
II - Central granular cells; topical steroids +/- interface irrigation, Q1-2D f/u
III - “Threshold” w central clumped WBC, POD 2-3; interface irrigation, topical +/- oral steroid, QD f/u
IV - scarring, stromal melt, hyperopic shift, mud cracks; all above, too. Poor prognosis.
How does INTACS act locally
- Flattens in the 3 clock hours where it is placed
- Thicker rings cause increased flattening
What are the available corneal inlays, and how do they work?
Presbyopia correction:
- AcuFocus Kamra: for post-LASIK patients, to non-dominant eye. Opaque ring matches to pupil size — dilation with distance vision focuses light from around inlay. Construction with near vision focuses only light within inlay.
- Revision Optics’ Raindrop: corneal flap formed and inlay placed. Centered to pupil, remodeling overlying epithelium for more prolate shape, enhancing near vision. Without altering distance. (Reaction can cause opacification/scarring, tx with steroid v explantation)
Thickness required for cross linking
400uM (UVA penetrates 300 uM) — can use hypotonic riboflavin
UVA can damage corneal endothelium
Riboflavin acts as a barrier to UVA penetration. Must visualize riboflavin in the AC prior to UVA tx
Effects of CCL
Free radicals from UVA action upon riboflavin cause collagen cross linking
Cornea flattening (avg 1-2D)
Cornea thinning
Stiffening
What is the Dresden Protocol?
Epi-off CCL
- Remove epithelium
- Treat with riboflavin q2min x30min (confirm penetration at slit lamp by visualizing riboflavin in AC; hypotonic or preservative-containing riboflavin can assist penetration)
- Treat with UVA 3mW/cm2 x 30 min OR 6mW/cm2 x15min
Contraindications to CCL
- Thickness <400uM
- Prior herpetic infection (possible réactivation, poor healing)
- Poor epithelial healing
- Central corneal scarring
- Severe dry eye
- Autoimmune disease
How does the Athens Protocol augment the Dresden Protocol?
By adding PRK or topo-guided PRK
Intraocular contact lens
= ICL = posterior chamber phakic IOL
e.g. STAAR Visian ICL
Complications: ACC (typically peripheral), lens decentration
Less common complications: persistent IOP elevation, RD, endophthalmitis
