KERATOPLASTY
| A | Progressive corneal ulcer | |
| B |
Keratoconus |
|
| C |
Anterior staphyloma |
|
| D |
High myopia |
An indication for therapeutic keratoplasty is:
| A |
Progressive corneal ulcer |
|
| B |
Keratoconus |
|
| C |
Anterior staphyloma |
|
| D |
High myopia |
|
In keratoplasty the diseased corneal disc is replaced by a corresponding sized graft from a human cadaver eye. |
|
|
Penetrating (full thickness) keratoplasty |
Lamellar (partial thickness) keratoplasty |
Keratoconus
|
|
Complications of keratoplasty
|
|
A corneal graft which be obtained within 4 hours of death carries good prognosis.
Percentage of endothelial cell loss during Descent’s membrane stripping in automated penetrating keratoplasty
| A | 0-5% | |
| B |
10-15% |
|
| C |
30-40% |
|
| D |
50-60% |
C i.e. 30-40%
The incidence of endothelial cell loss in donor tissue of Descemet stripping endothelial keratolplasty is nearly 36%, mainly in the central area of graft. Compared with penetrating keratoplasty, EK involves more donor-tissue manipulation including lamellar dissection and folding, which could potentially damage donor endothelium. On the other hand EK grafts are usually larger (8-9 mm diameter compared with typical PK diameter of 7 – 8mm) and provide a larger reservoir of healthy donor endothelium. However, several recent reports suggest that endothelial cell loss in first few years after EK is similar to that experienced after PK.
Deep anterior lamellar keratoplasty is indicated in:
| A |
Disease of deeper cornea e.g. endothelial damage |
|
| B |
Full thickness corneal opacities |
|
| C |
Bullous keratopathy |
|
| D |
Superficial corneal opacities |
Ans. Superficial corneal opacities
