Question 1. Lattice corneal dystrophy occurs at which layer of cornea:
A) Epithelium
B) Stroma
C) Endothelium
D) Epithelial-Stromal
Answer: D) Epithelial-stromal
Lattice corneal dystrophy is classified as an epithelial stromal dystrophy. Other epithelial stromal dystrophies include Reis Buckler’s dystrophy, Thiel-Behnke dystrophy and Granular dystrophy.
Ref.
Weiss JS, Møller HU, Aldave AJ, Seitz B, Bredrup C, Kivelä T, Munier FL, Rapuano CJ, Nischal KK, Kim EK, Sutphin J, Busin M, Labbé A, Kenyon KR, Kinoshita S, Lisch W. IC3D classification of corneal dystrophies–edition 2. Cornea. 2015 Feb;34(2):117-59. https://core.ac.uk/reader/154266722?utm_source=linkout
Question 2. Which is correct regarding order of recurrence in corneal graft for corneal dystrophies:
A) Reis Buckler > Lattice > Granular > Macular
B) Lattice > Reis Buckler > Granular > Macular
C) Reis Buckler > Granular > Lattice > Macular
D) Macular > Reis Buckler > Lattice > Granular
Answer: C) Reis Buckler > Granular > Lattice > Macular
5 year follow up has shown that corneal dystrophy of Bowman membrane (Which includes Reis Buckler dystrophy) shows highest rate of recurrence (88.2 %) followed by granular (40%) followed by lattice dystrophy (17.8%). Recurrence was found to be infrequent in macular corneal dystrophy.
Ref.
Marcon AS, Cohen EJ, Rapuano CJ, Laibson PR. Recurrence of corneal stromal dystrophies after penetrating keratoplasty. Cornea. 2003 Jan 1;22(1):19-21. https://journals.lww.com/corneajrnl/Abstract/2003/01000/Recurrence_of_Corneal_Stromal_Dystrophies_After.5.aspx
Question 3. Which stain is used to identify LCD:
A) Alcian blue
B) Congo red
C) Masson Trichrome
D) None of the above
Answer: B) Congo red
Congo red stains amyloid which forms the lattices in LCD. Alcian blue stains glycosaminoglycans found in Macular corneal dystrophy. Masson trichrome stains hyaline found in Granular corneal dystrophy.
Ref.
Moshirfar M, West W, Ronquillo Y. Lattice Corneal Dystrophy. https://europepmc.org/article/MED/32310559/NBK430685#free-full-text
Question 4. Not a treatment for LCD?
A) Photherapeutic keratectomy
B) Deep anterior lamellar keratoplasty
C) Penetrating keratoplasty
D) Descemet stripping endothelial keratoplasty
Answer: D) Descemet stripping endothelial keratoplasty
Lattice corneal dystrophy can be treated by DALK, PKP or PTK. DSEK is done for endothelial dystrophies eg. Fuchs endothelial dystrophy
Ref.
Moshirfar M, West W, Ronquillo Y. Lattice Corneal Dystrophy. https://europepmc.org/article/MED/32310559/NBK430685#free-full-text
Question 5. Which is not a cause of recurrent corneal erosions?
A) Fuchs endothelial dystrophy
B) Lattice corneal dystrophy
C) Granular dystrophy
D) Reis Buckler dystrophy
Answer: A) Fuchs endothelial dystrophy
Recurrent corneal erosions are seen in Lattice dystrophy, Granular dystrophy, Macular dystrophy, Map dot fingerprint dystrophy & Reis Buckler dystrophy .
Ref.
Lin SR, Aldave AJ, Chodosh J. Recurrent corneal erosion syndrome. British Journal of Ophthalmology. 2019 Sep 1;103(9):1204-8. https://bjo.bmj.com/content/103/9/1204.abstract