A 50-year-old man with bullous keratopathy secondary to Fuchs' dystrophy undergoes Descemet's membrane endothelial keratoplasty (DMEK). What is the key advantage of DMEK over penetrating keratoplasty (PK) and over DSAEK?
- A DMEK does not require a donor cornea
- B DMEK replaces only the diseased Descemet's membrane and endothelium; it preserves all host stroma and achieves faster, better visual recovery with lower rejection rates ✓
- C DMEK is technically simpler and faster than DSAEK, reducing operating time
- D DMEK eliminates the need for postoperative immunosuppressive therapy
Explanation
DMEK transplants only the donor's Descemet's membrane plus endothelium (~10–15 µm), replacing only the diseased layer without adding donor stroma. Compared to DSAEK (which includes a stromal disc of 100–200 µm), DMEK achieves superior visual outcomes (often 6/6 or better) because the donor-host interface is at the level of Descemet's membrane with negligible stromal contribution. DMEK also has significantly lower rates of immune-mediated graft rejection because minimal antigenic stromal tissue is introduced. PK replaces the full corneal thickness (all layers) and carries higher rejection rates and refractive instability.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.