Safe size of corneal graft with less chances of failure is ?
**Core Concept**
The size of the corneal graft is a critical factor in the success of corneal transplantation. A graft that is too small may not cover the entire area of the damaged cornea, leading to recurrent corneal erosion and graft failure. Conversely, a graft that is too large may cause complications such as astigmatism, irregular astigmatism, and increased risk of wound dehiscence.
**Why the Correct Answer is Right**
The ideal size of a corneal graft is typically 8-9 mm in diameter, as this provides a good balance between covering the entire area of the damaged cornea and minimizing the risk of complications. A graft of this size allows for adequate wound closure, reduces the risk of astigmatism, and promotes optimal healing. The size of the graft is determined by the size of the donor cornea, the size of the recipient's cornea, and the location of the graft.
**Why Each Wrong Option is Incorrect**
**Option A:** A graft size of 7 mm is too small and may not provide adequate coverage of the damaged cornea, leading to recurrent corneal erosion and graft failure.
**Option B:** A graft size of 10 mm is too large and may cause complications such as astigmatism, irregular astigmatism, and increased risk of wound dehiscence.
**Option C:** A graft size of 6 mm is even smaller than option A and would likely result in inadequate coverage of the damaged cornea.
**Clinical Pearl / High-Yield Fact**
The size of the corneal graft should be carefully matched to the size of the recipient's cornea to minimize the risk of complications and promote optimal healing.
**Correct Answer:** C. 6 mm